Tales From An Unchecked Mind

A Blog By Daniel Kennett

Xcode Bots: Common Problems and Workarounds

I love Continuous Integration. I’ve never bothered with it for my side projects since it didn’t seem worth the effort, but now it’s built into Xcode I thought “This is Apple! Two clicks and I’m done, right?”


I spent a few hours battling with the Xcode service on my Mac OS X Server, and below I detail workarounds for the problems I encountered getting my projects to build.

Don’t get me wrong — I love Bots, and I’m sure that in a few months these issues will be fixed as they’re getting tripped up by very common situations. Remember to file those Radars!

After a little work, my main side projects are continuously integrated. Hopefully this post will help you do it faster than I did!

Note: All these tips assume you’re using git. If not, well, you’re on your own!

Repositories that require an SSH key to access

If you host your repository on GitHub or similar, you’re likely to use an SSH key to access your code — especially if you have a private repository. GitHub will actually let you check out over https, but where’s the fun in that when you can follow this simple seven-step process?

1) If your SSH key requires a password, you need to make a password-less version of it using ssh-keygen -p (when it asks for a new password, just hit return).

2) In Xcode, choose Product → Create Bot…, name your Bot and untick Integrate Immediately and click Next.

3) In the next pane, choose Guest as your authentication method. This will succeed on your local machine since you have your keys installed. Continue through and create your Bot.

4) Open the Server application and find your new repository and edit it. Change the authentication method to SSH Key and the user name to the correct value (this is git for GitHub).

5) At this point, you’ll notice a new SSH key has been created for you. Either upload the public key to your host, or click Edit… to replace it with your own password-less keys.

6) Save your changes, return to Xcode and click “Integrate Now” in your new Bot.

7) Success!

8) File a Radar asking Apple to add the SSH Key authentication option to Xcode itself. Feel free to duplicate mine: #15184645: Bots: Can’t enter an SSH Key to authenticate a repository in Xcode.

It’s worth noting that you can make this process slightly simpler by manually adding the repository to the Xcode service in the Server app before creating your Bot. This way, you can set up your SSH keys right away. Make sure, however, that you get the URL of the repository to match the URL you have checked out on your local machine, otherwise Xcode won’t pick it up.

Code Signing and Provisioning Profiles

Ahh, Code Signing. It just got easy, and now there’s a new spanner in the works.

Bots run their builds in their own user. This means that even if they build fine when you log into your server, they may fail to build in the Bot. The tricky part here is making your private keys available to the Bot — downloading the certificate from Apple’s Developer Center doesn’t give you back the private key, so you’ll need to import it from a machine with a working build setup using Xcode’s Developer Profile Export/Import.

Once you can log into your server and build your project with signing, a simple way to allow Bots to access your signing certificates is to copy them from your user’s Keychain to the system Keychain.

Make sure you copy the private key by dragging it to the System Keychain. The certificate will be copied as well.

Once you have your certificates in the System Keychain, your Bots will be able to access them.

Adding your Developer Team to the Xcode service in the Server app should automatically deal with Provisioning Profiles. If not, put your profiles in /Library/Server/Xcode/Data/ProvisioningProfiles.


Submodules work fine as long as you don’t have a detached HEAD. If they require SSH keys to access them, after creating your Bot you’ll need to go over to the Server app and manually set up the keys for each submodule.

If you’re not sure if you have a detached HEAD, you can check from the command line or Xcode. On the command line, run git status in each submodule. If you get something like # HEAD detached at 89970d0, you’re in a detached HEAD. From Xcode, try to create a Bot. When it’s time to define authentication for each repository, Xcode will tell you the state of each submodule.

If any of your submodules read “(detached from…)”, they won’t work.

To fix this, you need to get back on a branch. The quickest, hackiest way to do this is to run git checkout -b my-awesome-branch in the submodule to make a new branch. Once that new branch is pushed and available on your remote, your Bot will be able to check it out correctly.

Note: I’ve noticed that Xcode 5.0.1 doesn’t seem to refresh branch information quickly. Try relaunching Xcode if things get weird.

Don’t forget to file a Radar! Again, feel free to duplicate mine: #15184702: Bots: Checkout failure in git projects that have submodules with a detached HEAD.

I made a mistake and now I can’t fix the repository from Xcode!

If you accidentally added a Bot with incorrect authentication details or some other mistake, deleting the Bot may not fix it. You also need to delete the repositories from the Xcode service in the Server app. When you do that, Xcode will offer to reconfigure them when you create a new Bot.

The Future

Despite these niggles, I really love Continuous Integration and Bots. I’ll try to update this post as I find more issues, and hopefully as the Bots feature matures and these issues go away. Follow me on Twitter to get update announcements.


  • October 9th, 2013: Added Radar bug numbers for SSH keys and submodules.

Summer Experiment: Hacking, Agile Style

I’ve been working at Spotify for two and half years now. Previously, I ran my own software company for a number of years. Previously to that, I was in full-time education from the age of… well, whatever age you start going to nursery school.

One big thing I’ve learned since being at Spotify is actually how to make a product. My Computer Science degree taught me how to write programs, and from that I went straight into shipping my own software. Honestly, now I’ve worked at Spotify for a while I realise what a miracle it was that we even shipped anything back then, let alone earn enough money to support multiple employees.

Taking a Break From Programming? Let’s Write a Program!

Like all good programmers I know, I enjoy working on the odd spare-time project now and then. What typically happens in my case is that I sit down, go “Oh, I know!” and start coding. What I normally end up with is a working application that is clearly written by an engineer — it works just fine, but looks like someone fired the AppKit Shotgun at the screen.

The most recent example of this is my new camera. After writing a blog post complaining about how it was stupid for having Facebook and Twitter built-in, I set about sort of reverse-ish engineering the protocol it uses so I could remote control it and download images from the comfort of my chair. The protocol is PTP over IP — PTP is a documented standard, and the “over IP” part is pretty standard too, which is why I hesitate to say I reverse-engineered the protocol. However, the proprietary extensions added by Canon are largely undocumented, which is where I’ve added new knowledge to the area.

After a couple of weekends with Wireshark and Xcode, I had an Objective-C framework with a reasonably complete implementation of the PTP/IP protocol — enough to get and set the various properties of the camera, stream the live view image, perform commands and interact with the filesystem.

A typical side-project: function, but no form.

After a few weeks of doing basically nothing on the project, I went to WWDC and saw Apple’s iOS 7 announcement. After years of being a “Mac and Frameworks” guy, I finally started getting excited about iOS UI programming again, and this camera project seemed like a great way to get back into making iOS apps and learning all the cool new stuff in iOS 7.

However, wouldn’t it be nice to actually make a product rather than an engineer’s demo project?

Something Something Buzzword Agile

At Spotify, we use Agile. I’m not a die-hard fan of Agile or anything (perhaps it’s just our implementation of it), but I do appreciate how it lets you be organised in how you get work done and how it gives you a picture of what’s left to do.

So, during my July vacation I set aside two weeks with the intention of making a little iPad app to remote control my camera. Rather than immediately creating a new project and jumping into code like I normally do, I decided to employ some techniques — some Agile, some plain common sense — to manage my progress.

Step 1: Mockups

First, I spent a couple of days in Photoshop making mockups of what I wanted to do. The logic behind this was to try and avoid the “blank canvas” feeling you get a few moments after creating a new project in Xcode. With a few mockups under my belt, I would hopefully be able to dive right in without wasting time implementing a UI that I’d have easily seen was unworkable if I’d simply have drawn a picture of it. Indeed, my first idea turned out to be unusable because I’d assumed the camera’s image would fill the iPad’s screen:

Originally, the app’s controls would flank the image vertically, hiding and showing with a tap.

However, when I actually imported an image from my camera it was obvious that layout wouldn’t work. I then spent a little while figuring out how to best deal with an image with a different aspect ratio to the iPad’s screen.

A few mockups refining the main UI. The challenge here is that the aspect ratio of the image coming from the camera isn’t the same as that of the iPad.

Step 2: Insults

When working on anything, having an open feedback loop with your peers is essential. With a project that needs to be done in two weeks, that loop needs to be fast and efficient. Unfortunately, I learned rather quickly at Spotify that in a normal working environment this is completely impossible — apparently, “That idea is fucking stupid and you should be ashamed for thinking otherwise” is not appropriate feedback. Instead, we have to have multi-hour meetings to discuss the merits of everything without being assholes to one another. Coming from the North of England, this came as a huge shock to the system — being assholes to one another is pretty much the only means of communication up there.

For this project, I enlisted the help of Tim (pictured above, enjoying a game of cup-and-ball). Tim and I are great friends, and as such hurl abuse at one another with abandon — exactly the traits required for an efficient feedback loop. Indeed, throughout the project he’d belittle and insult my bad ideas with such ruthless efficiency that I never wasted more than an hour or so on a bad idea.

This is basically the “rubber ducking” theory, except that the duck is a potty-mouthed asshole who isn’t afraid of hurting your feelings.

Step 3: Planning and Monitoring Tasks

This is the typical Agile stuff — I created a note for each task I needed to do in order to have the application I wanted and placed them on a board with Waiting, Doing and Done columns on it. On each note was an estimate on how long I thought that task would take in days, with a margin of error on tasks I wasn’t that sure about — mainly those that involved more protocol reverse-engineering with Wireshark, since I hadn’t figured out the advanced focusing and auto exposure parts in the protocol yet.

Once I’d finished my board, I had between fifteen and twenty-five days worth of work to do in ten days. Obviously that wasn’t going to happen, but it was encouraging that everything that looked like it wouldn’t make the cut was an advanced feature rather than core functionality.

Step 4: Programming!

Finally, after three days of mocking and planning, I pushed “New Project” in Xcode and started coding. This seemed like a lot of honest-to-goodness work for what is supposed to be a fun side-project!

Two Weeks Later…

As a bit of a side note: It’s been a long time since I wrote a “proper” application for iOS (my last complete iOS app ran on the original iPhone), and I did everything the new way: it’s all Auto Layout with roughly half of the constraints done in Interface Builder and the rest in code, and there isn’t a drawRect: in sight. I had a lot of fun learning about the new stuff in iOS 7!

But, the golden question is… was adding three days of overhead to plan out what is ostensibly a throwaway side project worth it? Without it, I’d have had thirteen days to code instead of ten, and as a programmer I enjoy coding a lot more than I do planning and drawing boxes in Photoshop.

The answer, much to my surprise, is an unreserved YES.


I greatly enjoyed the sense of progress moving notes across the board gave, especially when a task took me less time to implement than I’d estimated. It also gave me goals to work towards — having a task I was really looking forward to implementing on the board made working on the boring notes to get there go much faster.

The Board is the Truth

Those little sticky notes really stop you from cutting corners, and cutting corners is what differentiates a hacky side-project from a polished product. For example, one of the most challenging things I encountered in the project was decoding the proprietary autofocus information the camera gives over PTP/IP. There are two main modes, one of which involves the user moving a single box around the screen and having the camera autofocus in that, the other of which user choses from a set of fixed points that correspond to dedicated autofocus sensors in the camera.

The “single box” method was simpler to implement, and I implemented both the protocol work and the UI for it in a day. At this point I was tempted to move on to something else — I mean, you could control focusing now, right? — and without that sticky note on my board I would have done so. After a bit of convincing by Tim, I just couldn’t bring myself to lie to my board and I spent two days implementing the other autofocus method. I’m really glad I did, because I had a ton of fun and ended up with a much more polished product.

Contrast-detect autofocus was fairly simple to implement, as it’s the same on every camera — a single rectangle is defined, which can be moved around the image to define the autofocus area.

Phase-detect autofocus was much harder to implement, mainly due to the focusing point layout — it’s different on every camera. My camera only has nine points, but high-end cameras can have many, many more. This means parsing the autofocus info from the camera properly, as it’ll have different data in it depending on which camera is used.


By the end of the two weeks, my application was in a state in which I could use it to take a photo of the board!

Cheesy action-shot…

…of me taking this photo of the board.

As you can see, I added 1.5 days worth of work during the week and none of the advanced features got implemented, so all I have is a relatively basic remote control. However, this remote control is much, much more polished than it would have been if I hadn’t planned it all out in advance, and I’m much more pleased with what I ended up with vs. an unpolished project with half-working advanced features.

The tasks that got completed are as follows:

TaskEstimated Actual Date Completed
Live View Image 0.5 0.5 23 July 2013
Connect/Disconnect UI2 1.5 23 July 2013
Grid0.5 0.5 23 July 2013
Histogram1 1 24 July 2013
Half/Full Shutter UI1 1 25 July 2013
Property Controls2 1 29 July 2013
Metering2 ± 1 1 30 July 2013
AE Mode Display0.5 0.5 30 July 2013
Exp. Compensation0.5 0.5 30 July 2013
Live View Focusing2 ± 1 2 1 Aug 2013

I did twelve estimated days worth of work in nine actual days, and I either estimated tasks correctly or overestimated how long they’d take. The three tasks I did added up to one and a half days, and they’re highlighted in the table above.


I actually like Agile in this setting a lot more than I do at work. I get to reap the benefits of organising my work without the tedium of the bureaucracy that you encounter in multiple-person teams of people you’re contractually obliged to be nice to. This really shows in my output — the app I’ve made is really going in the direction a real product might, and if I decide I’d like to put this on the App Store I can just pick it up and keep going without having to go back and fill in all the shortcuts I would’ve made in a typical side project.

Most importantly, though: I had a lot of fun doing this — in fact, more than I normally do when working on side projects in a concentrated manner like this. Having mockups to work from and a visualisation of your progress made this project an absolute blast for me.

The Sine of Life

Note: This post is a personal piece and discusses death. If you’re here for programming and monster trucks, you may want to skip this one.

Nearly three months ago I was sitting here in my chair, writing a blog post about some of the lessons I’d learned from my failed software company. It discussed how, despite having a pretty crappy time of it, I’d come out of the process a smarter and better person. “Things are now looking up!”, I wrote, and discussed how my late father’s entrepreneurial spirit had been passed on to me to the point where I was looking forward to maybe starting another business in the future — one that would surely do better than my first! At the very least, I’d be able to avoid the mistakes I’d made before.

I finished the post mid-afternoon and decided to sit on it for a day and re-read it in the morning to make sure it still made sense with a fresh pair of eyes. I was in a pretty reflective mood — this was the first time I’d really written about my Dad, his death in 1998, and his influence on my life even though he’d long passed away. I was happy — my financial troubles from the aftermath of the failed business were all but gone, I was settling down with my fiancée in a new country and we had nothing but an uncomplicated life to look forward to.

That evening, my Mother died.

Once again, I was reminded just how fragile an illusion the “uncomplicated life” really is. Somewhat terrified by the timing of everything, the blog post I wrote never saw the light of day.

Some Time Later…

Twelve weeks later, life is regaining a sort of twisted normality. Everything seems normal enough — I’m getting up, going to work, paying bills. It’s a little bit harder to gain motivation to do anything, and I’m constantly fighting a small, deep-down urge to run back to the UK and hole up in an old friend’s house and feel sorry for myself until he forcibly ejects me from the premises. However, considering that I’m now the root node of my future family, the urge to run back to a known safe place isn’t exactly shocking.

Thankfully, these minor niggles will be temporary. My Father died just when I was old enough to fully understand the magnitude of what happened, so this isn’t the first time I’ve faced my own mortality — something that invariably happens when a loved one passes. As easy it would be to fall into a descending spiral of pity right now, I find myself compelled to go the other way — to embrace that my time in this world will be short and strive for something amazing.

I’m 28 and I’ve already done quite a lot. In the past fifteen years I’ve formed a successful company and enjoyed the spoils of a great wage. I’ve lost that company and endured the defeat of near bankruptcy. I’ve moved countries. I’ve been through the devastation that is a parent dying — twice. I’ve fallen in love. I’ve lived the lonely single life.

What persists through this chaos is not the sorrow of lost parents, the crushing pressure that is £50,000 of debt after having lost your entire income stream, or the pain of a poorly managed company failure severing friendships. What persists are happy memories — the joy of flying to Australia for Christmas with my family and girlfriend and driving down the coast in a rented a convertible car, of celebrating a successful product launch with a friend by driving a pair of Aston Martins around a track all day, and of countless other experiences and memories I wouldn’t have otherwise had.

In life, the highs balance out the lows, much like a sine wave. Sure, some of my lows are my own fault, but that particular trainwreck had an incredible amount of highs to balance it out. I’ve picked myself up, dusted myself off and righted my wrongs — debts have been repaid, friendships repaired.

What I can’t do now is glide along in mediocrity — it’s time to ensure the upwards swing of my sine wave happens by grabbing life by the scruff of the neck and jumping in with both feet. That convertible car I want that’s entirely inappropriate for a country that spends four months a year buried under a metre of snow? Perhaps it’s time to place an order. Those app ideas that’ve been rolling around in the back of my head? Well, it might soon be time to give being my own boss another shot. What could go wrong?

Right now, I’m still feeling the effects of the low swing of the sine — there’s nothing like spending a week buried in paperwork that formalises “Both of my parents are dead, here’s a pile of figures” to the UK government to keep you in a dull mood.

Looking forward, though — looking up — I’m excited as hell.

Canon EOS 6D “Review”

I’ve been in to photography since my Dad (who was a journalist) gave me his Olympus OM-1 SLR when I was a kid, which was released in 1972 and was entirely manual — the battery was optional and only powered the light meter.

Alas, my childhood OM-1 has seen better days.

When I hit 19 or so, I got a part-time job at the now-defunct Jessops camera store, and enjoyed my first income stream and a staff discount, which accelerated my photography interest quite a bit. My next camera was the EOS 3000N, a more modern film SLR. After that, I went digital with the EOS 300D, then an original 5D, then a 7D and after a brief stint with a 60D, I’ve landed with the wonderful EOS 6D.

Now, I’m not actually going to review the camera per se — there are lots of photography review websites far more qualified to do that than me. However, I do absolutely adore this thing — its image quality is superb and it’s beautifully light and easy to carry around. The incredible silent drive mode combined with the amazingly tiny 40mm f/2.8 STM pancake lens allows me to wander around the city and take photos without a bunch of people staring at me — I feel discreet with this setup, which is something I haven’t felt in years.

“I’m not fat, I’m just full-frame!”

However, this camera is the first SLR I’ve purchased that has a built-in shelf life on some of its features, which makes me slightly uncomfortable.

The March of Technology

I have a sort of love-hate relationship with technology, specifically computing technology. I’m a programmer, so obviously computing technology and I are intertwined, but I’m a firm believer that if the user is conscious that their machine has computers in it, the designers failed unless the product is specifically advertised as THIS IS A COMPUTER.

Let me give you an example. I’ve been fortunate enough to own several different cars so far in my life, and by far my favourite is the Mazda RX-8. The RX-8 is designed to be a mechanically brilliant car, and excels in this area — you can hurl it around the track like a madman and it’ll just lap it up and egg you on. When you’re driving, it’s all mechanical — a stubby gearstick sticks up directly from the gearbox, the steering has a very direct connection to the road, and on the dashboard you have a thing that tells you how fast the engine is going, another thing that tells you how fast the car is going, and not much else.

The RX-8’s dashboard.

Underneath this is an incredible amount of computing power trying to make sure I don’t slam face-first into the nearest wall — computers making sure the engine is mixing fuel correctly, computers to make sure the car goes in the direction I tell it to, and so on. However, back in the cockpit all you’re doing is giggling wildly as this glorious heap of metal seems to defy the laws of physics as it propels you around the twisty piece of Tarmac that is whatever racetrack you’re on, and there’s absolutely no indication in the car that there’s all this computing going on behind the scenes unless something goes wrong.

And that’s the way it should be.

Isn’t this supposed to be about a camera?

So, how is this relevant to the EOS 6D? Well, to me, cameras are like cars (and washing machines, toasters, fridges, etc) — they’re appliances designed to do a certain job. Your relationship with them is physical, and all of the control is done through the manipulation of buttons, switches and levers, not touch-screens or keyboards and mice. Sure, they’re computers on the inside, but if I’m conscious of that then something has gone wrong somewhere.

The 6D’s chassis (photo credit: Canon).

This is a physical device which I use to make photographs. Sure, it has a computer inside it, but that’s a detail you don’t care about — the specifications talk about the image quality and how well the camera stands up to rain, not gigahertz and RAM. In ten years, I should still be able to use it to take pictures and as long as I can get them out of the camera and into my computer, I’m set. The computing technology in this thing has one job — to help the user create the best photos they can.

It makes me slightly uncomfortable to switch on my camera to see this:

I’m not actually 100% sure why this feature irks me so much. The WiFi feature of the camera is incredibly useful — I can connect it to my computer or phone and shoot and preview shots wirelessly. However, seeing Facebook and Twitter icons on this thing crosses the line from an appliance to a computer. Before, my camera longevity concerns were all physical — how long will the shutter last? What happens if I get it wet? What if I drop it?

Now, I get to think about stuff other than my camera when thinking about my camera. Twitter are notorious about being strict with their API — what if it changes or goes away? What if Facebook goes the way of every other social network before it? That’s fine on a “big” computer — I’m already conditioned to have to update and change the software set on it, but my camera? It’s a metal box with buttons and switches on it, and I shouldn’t have to deal with “computer crap” like this.


Well, the EOS 6D is a great camera and you should all go buy one. However, seeing features like Facebook and Twitter integration in it make me worry about a future filled with appliances whose feature sets have shelf lives. It’s not just this camera, though — the whole industry is going this way, even cars. The Tesla Model S has Google Maps built right into the dashboard, for example.

My Olympus OM-1 is still exactly as functional as it was when it came out forty years ago. Will I be able to say that about my 6D forty years from now? How about if I bought a Model S? It seems that as technology advances, previously immutable appliances like cameras and cars are getting caught in the net of rapidly obsoleting technology.

Then again, maybe I’m just getting old. My first camera didn’t even require a battery, so obviously my idea of what a camera should be is biased towards a mechanical interface, and memories of mechanical cameras are going the way those of the floppy disk are.

It’s Alive, but Still Very Stupid

Well over a year ago, I blogged about starting a project in which I replace a radio-controlled car’s guts with an Arduino and have it be able to navigate to a given GPS location.

Well, that project is finally underway.


It very quickly became apparent that an Arduino wouldn’t cut it for the kind of computational work I want to do, mainly because of the tiny amount of RAM it has. I ended up with a pairing of a Raspberry Pi and an Arduino Uno. The Arduino’s job is to interface with the various sensors on the car and pass that information back to the Pi, which has a lot more resources for doing computation.

Note: This chapter is a fairly quick overview of how the car is put together. You can find a shopping list with exact components at the end of this post.


The Arduino has a prototype board attached to it, which on the underside has two three-pin connectors for connecting the car’s servos (one for speed, one for steering). The car’s speed controller is connected to the battery and provides the Arduino with power.

The top of the board (which is very messy — I intend to build a much neater one) hosts an accelerometer as well as a few cables for powering the Raspberry Pi, powering the Ultrasonic Sensors and reading data from the Ultrasonic sensors.

Black: Raspberry Pi power, Yellow and white: Ultrasonic sensor power, White four-lane: Ultrasonic sensor data, Raised red board: Accelerometer.

There are four Ultrasonic sensors mounted on the car’s body — three at the front and one at the rear. All the cabling for these sensors end up at a pair of connectors on the inside of the roof, which allows the body to easily be separated from the chassis when needed.

Leaving the body clear so you could see the electronics seemed like a good idea at the time, but instead it all looks messy and is really hard to photograph. Lesson learned!

The Arduino and prototype board are mounted inside an Arduino case that’s attached to the car’s chassis with zip ties. The case has a lid, but I’ve left it out of the photos to illustrate what goes there.

The vertical posts support the body, which rests on the clips. They can be raised to give more room.

Raspberry Pi

The Raspberry Pi is mated with a UI module from BitWizard, which hosts a 2x16 character LCD display, six buttons and a few breakout connectors for various serial busses.

Raspberry Pi with attached UI module. The garbled character to the right of the up arrow should be a down arrow, but there seems to be a bug in my custom character code!

The Raspberry Pi connects to the Arduino twice — once for power from the Arduino and once via USB to communicate with it. When it’s all assembled, it gets rather messy!

Thankfully, with the body on, it’s a lot cleaner. The final part is to find a housing for the Raspberry Pi and a place to mount it on the car itself.

Here’s a diagram of how everything fits together. Clear as mud!



The Arduino is running a very simple loop that polls the attached sensors and writes their values out to the serial port. ACCEL: lines are accelerometer readings in G, and DISTANCE: lines are ultrasonic sensor readings in cm.

ACCEL: 0.06,0.05,0.89
ACCEL: 0.07,0.05,0.90
ACCEL: 0.07,0.05,0.90
ACCEL: 0.06,0.05,0.90
ACCEL: 0.06,0.05,0.88
DISTANCE: 89,111,32,15
ACCEL: 0.07,0.05,0.89
ACCEL: 0.07,0.05,0.90
ACCEL: 0.07,0.04,0.90
ACCEL: 0.07,0.05,0.90
ACCEL: 0.07,0.06,0.90
DISTANCE: 89,111,32,15

Sample Arduino output.

In addition, the Arduino listens for input on the serial port for setting speed and steering values for the servos. This is not unlike the protocol used in my Arduino LED project, with two header bytes, a byte for the steering angle (0 - 180), a byte for the throttle angle (0 - 180) and a checksum byte.

Main Software Stack - Raspberry Pi

Everything so far is just enabling the main software stack of the car to observe and interact with the hardware in the car.

The main software stack is written in C# against the Mono Framework. I chose this setup because it’s pretty much the only nice Object-Oriented language available with a fully featured runtime available on multiple platforms (of course, there’s also Python and Java, but I prefer C# over those two). This setup allows me to write and debug the code on Mac OS X, then copy it over the the Raspberry Pi running Debian Linux for real-life use.

At the moment, the software stack is at the point where it’s a fully functional object model wrapping all of the implementation details of the car:

  • The Sensor class tree provides objects representing the various sensors on the car, providing events for when their readouts change.

  • The Servo class provides getters and setters for adjusting the servos on the car.

  • The SerialCarHardwareInterface class implements the ICarHardwareInterface, which defines various methods for getting the sensors and servos on the car. This is split out into an interface for when I need to implement a mock car for testing AI routines without risking damage to my car or other property (it goes quite fast!).

  • The CarHTTPServer class provides a simple REST API over HTTP to allow other computers on the network to observe the car’s sensors. This is great for writing tools to visualise the car’s status graphically.

RCSensorVisualizer showing the car’s accelerometer (top) and distance (bottom) sensor readouts graphically.

  • The CarEventLoop class runs a dual loop for running AI code. The first loop is a low-latency loop that monitors the car’s sensors, which can have interrupt handlers attached to it — simple classes that decide if execution should be halted, for example if the car turns upside-down. The second loop runs on a different thread and is where the main AI processes will take place. This dual setup allows the car to detect if it’s upside-down and halt operation even an AI process is taking a long time.

  • The I2CUIDevice class provides an interface to the screen mounted to the Raspberry Pi, allowing text to be written to the screen and firing events when buttons are pushed.

  • The MenuController class as friends provide logic for presenting a menu system on the display, allowing menu item selection and navigation, as well as “screens” for presenting information or prompting the user to confirm a chosen action.

Bringing It All Together

Below is a video showing the whole lot working together. I scroll through the menus on the Raspberry Pi and observe sensor readouts as well as adjusting the steering and throttle.

The project is now ready for its next steps, which will be writing AI code to have the car navigate its surroundings. It doesn’t have GPS at the moment so it’ll be limited to “drive forwards and don’t crash into stuff” for now, but it’s a start!

You can find the code for this project over on my GitHub. It includes the Arduino Sketch, the C# software stack for the Raspberry Pi and and Objective-C Mac application for observing the sensors.

Shopping List

The project at the moment uses the following hardware:

Your Runtime and You

There’ve been a few posts* floating around the internets recently discussing some rules about when to use Objective-C or not, mainly focusing on performance but touching on code readability and maintainability too. These posts are all written by intelligent people who make reasonable arguments, I get a rather uneasy feeling reading them.

For a little while I couldn’t place it, but today it came to me — these posts, to me at least, seem to be looking at the problem (or lack thereof) too closely, citing small code snippets and “rules” on how to fix them with the correct choice of language.

* Specifically, point 6 of that post.

Clarifying the Problem

Now, the discussion has become slightly muddled between two issues - one is that Objective-C’s runtime is slower than some other runtimes (like, say, C), and the other is of code efficiency. Since a method call has more overhead in Objective-C, inefficient code is affected more than that same code in C, so people jump to the conclusion that Objective-C is slow and the followup fix is to move to C.

Inefficient code will always be slow. However, since a method invocation has more overhead in Objective-C than C, C++ or most other static runtimes, people who’ve just learned about the Objective-C runtime will often blame the runtime and switch to C.

Unfortunately, I need to be blunt here: If you think your code is slow because Objective-C is slow, you’re wrong. Your code is slow because you wrote slow code.

The Bigger Picture

In day-to-day programming, you may end up in a situation in which you’re looking at objc_msgSend and thinking that Objective-C is too slow. If this is the case, there are only two outcomes.

  1. You wrote inefficient code and need to go fix it. It sucks, but this will be 99.9% of cases.

  2. You screwed up big-style and Objective-C genuinely isn’t the correct tool for the job at hand. This sucks even more, because you misunderstood your problem and now have to scrap all of the Objective-C code you wrote and write it again in something else. This will be very rare.

Thinking about one implementation detail in your runtime (and with Objective-C, that invariably becomes objc_msgSend) is not thinking about the bigger picture and you’ll go down a horrible road of writing little sections of code in C, copying data back and forth between the two runtimes and creating a big horrible mess. You’ll start thinking things like “Accessing this instance variable directly is way faster than using Objective-C properties. This’ll make my app fast!”, and will fall down that horrible trap of pre-optimising stuff that doesn’t actually make a difference.

Instead, you need to be thinking about the behaviour of your runtime and how it affects your problem. Ideally, you should do this before starting to implement your solution to that problem.

Problem 1: I looked at Instruments and objc_msgSend is 10% of my application’s usage!

Is your application actually slow? If not, who cares? If you’re making a lot of method calls, this is to be expected.

This problem has nothing to do with the Objective-C runtime.

Problem 2: I profiled my application when it’s acting slow, and it’s some Objective-C code slowing it down!

Make your code more efficient. Depending on the nature of the problem, one or more of these might help:

  • Stop doing obviously silly things. Loading huge images lazily on the main thread, for instance.

  • Learn about complexity and how to write more efficient code.

  • Learn about perceptive performance. For example, if you do your work on a background thread and keep your UI fluid in the meantime, your application won’t feel slow. It’s better that your application remains fluid and takes ten seconds to do its work than it locking up for five seconds. Five seconds is indeed faster, but it feels a lot slower when an application’s UI is blocked.

This problem also has nothing to do with the Objective-C runtime.

Problem 3: I’ll be working in a realtime thread and I’m worried about the fact that Objective-C is a dynamic runtime!

Aha! Now we’re getting somewhere.

Objective-C isn’t slow. It simply isn’t. However, one thing that it is is dynamic. Objective-C’s dynamic runtime gives it all the wonderful features we adore, but it isn’t appropriate for some uses.

Real-time threads can be one of those uses.

But not because Objective-C is slow.

Because it’s dynamic.

A good example of a realtime thread is a Core Audio render thread. When I get that callback from Core Audio asking me for more audio data to play, I have x milliseconds to return that data before the audio pipelines run out of buffer and an under-run occurs, causing playback stuttering.

Because that number is measured in milliseconds rather than nanoseconds, Objective-C would be perfectly fast enough to perform it. In fact, if I wrote my audio code in Objective-C it’d likely work just fine. However, because I’m under contract to return data in a certain time, I can’t safely use a dynamic runtime like Objective-C to implement it.

C, for instance, has a static runtime and a fixed overhead for method calls. Copy some stuff to the stack, jump to the function’s memory offset, and away you go.

Objective-C, though, is dynamic and you can’t guarantee a thing. Anyone can load a class into the runtime that overrides -methodSignatureForSelector: and redirects your method calls elsewhere, or can use something like method_exchangeImplementations() to swap out method implementations entirely. This means that at runtime, you can’t count on anything being what you thought it was.

So, because I’m under contract to return within a certain time and I personally believe it’s bad form to use a dynamic runtime in such a situation, I choose to implement that problem entirely in C.


The decision to use the C language for problem 3 was entirely a high-level decision based on the behaviour of the Objective-C runtime compared with the problem at hand.

This is really how you should be thinking about your runtime. If you get to the point where you’ve got some slow code and are noticing an implementation detail of the runtime pop up, you need to go back and code better. If you’ve coded the best you possibly can, you need to learn to code better. If you’ve learned to code better and the runtime is still getting in the way, you chose the wrong runtime for the entire problem.

Notice that this entire post is devoid of any code samples. This is intentional — the point of this post is that you choose your language and runtime first based on your problem, not second because of a problem in your code. If you’re switching languages and runtimes halfway through a problem, the issue is your approach to solving the problem, not the language or runtime you’re using to solve it.

My Life in Pictures

In 2005, two things happened: I bought a kickass car, and Aperture 1.0 was released at the rather eye-watering price of £349. At the end of the year, I was playing with Aperture’s photo book tool by putting some pictures of my car in a book and inadvertently started a tradition I simultaneously despise and adore: My Life In Pictures.

Every year, I make a photo book of the interesting stuff that year brought — an interesting outcome is that a book’s thickness is a great way to see how interesting a year was for me. 2009 is an embarrassing 35 pages, whereas 2008 and 2006 are both pushing 100.

I despise them during the construction phase because they take an age to make — over a week of evenings for a long one. By the end I’m so sick and tired of looking at those damn photos I hesitate to buy the book I put together. Thankfully I’ve learned to push through that feeling and order, because every single time a book arrives I adore the result and happily add it to the slowly expanding collection.

Inside 2012 In Pictures.

These things are expensive — 2012 In Pictures is 63 pages and ordered through Blurb, which came to around €55 plus tax and shipping. However, they’re well worth it and I’m already enjoying going back a few years ago and flicking through what I did in the past. They also make great gifts for family members who are into that sort of thing.

Making Future-You Happy: Figuring Out How to Organise and Tag Your Photo Library

My Aperture library is over 15,000 photos strong, which isn’t huge, but it’s enough photos to make proper storage and tagging important.

My Aperture library is organised by Category, then by year (maybe), then by “event”. For example…

  • Events
    • 2010
    • 2011
    • 2012
  • Holidays and Trips
    • 2012
      • WWDC 2012
  • People and Things
    • House

This seemed like a good idea to start with, but it’s actually fairly terrible. For example, I want a photo from WWDC 2012. Is that in Events or Holidays and Trips? I mean, it’s a “trip” for me, but WWDC is actually an event! This wishy-washy organisation isn’t so helpful when you’re trying to find photos from years ago. This, coupled with a complete lack of manual tagging, is a pain to work with.

A Fresh Start

After my previous post discussing Adobe Lightroom, not three weeks ago, basically concluded that I prefer Aperture, well, I’ve decided to slug it out a bit longer with Lightroom and do a long-term test.

On January 1st 2013, after waking up in the afternoon and noting that 2013 was in no was different to 2012, I launched Lightroom and pressed the “New Catalog” button. Starting then, I’d be using Lightroom for all of my photography work instead of Aperture, something I wasn’t sure would be a smart idea considering I didn’t actually like the program all that much. (I’ve since come to like Lightroom much more, but that’s for another post).

New year, New photo library!

With this fresh new start, I’m determined to start and keep up with a photo library that allows me to find my photos reasonably quickly and with as little frustration as possible. My library should meet the following criteria:

  1. I shouldn’t be spending more than a few seconds per photo on import to get the metadata to a state of meeting the rest of these criteria.

  2. A good portion of it should be automatable, if possible.

  3. The metadata should allow me to, in the future, filter down my library to a reasonable number of candidates for the photo I’m actually looking for.

  4. The data input for each photo must conform to a defined schema to keep metadata consistent.

My rationale behind the first entry is that if metadata input takes too long, I won’t bother doing it. The second entry helps the first become more of a reality. The third is a realisation of the first two — if my metadata entry isn’t taking very long, it won’t be that comprehensive, but if I can filter my 15,000 photos down to 150 candidates I’ll be able to find the photo I’m looking for manually in not too much time.

The last entry is to try and combat “tag creep”. I’ve seen this a lot, especially on blogs, where people just type in tags as they pop into their head. For example, in the photo above, well, it’s night. And there are fireworks. Oh, and trees. And clouds! night, fireworks, trees, clouds actually seems like a reasonable set of tags. However, my next fireworks shot is on the next night and there’s only one firework and it’s a starry night. night, firework, trees, starry. The only two tags those photos have in common are night and trees, neither of which are material to the photos! Clearly, we need a well-defined way of tagging photos.

It’s all about the questions!

Earlier this evening, I tweeted asking others how they organised their libraries, and quickly learned that everyone is different, and nobody seems to have a catch-all solution.

So, I started thinking about what I should tag my photos with and didn’t get far. Then, I started thinking about how I try to find photos once they’re in the library. That’s when I started getting somewhere — and I started listing all the questions I ask myself (and my photo library software) when trying to find my photos. Then I remembered that damnit, if I’m putting this effort into cataloging my library, the computer should be asking me the questions!

This brainwave has completely flipped how I think about metadata — it isn’t for finding the photo you want, but for dismissing the photos you don’t want.

The list below isn’t the questions I ask my computer to find photos — it’s the questions I want the computer to be able to ask me to get rid of the photos I’m not interested in:

Where did you put the photo on disk?

I’ll get this out of the way quickly — when trying to find photos, I never think about my computer or any detail of it. Therefore, I don’t care where my photos are on my computer. I let Aperture/Lightroom deal with them as they’d like to, and make sure I have backups. Hard drives, folders and filesystems are things for computers to deal with, not me. Therefore, I don’t use custom folder names or anything crazy like that.

What did you name the photo’s file?

Similar to my previous point, filenames have no hope of being helpful and I never think about them. There’s no way they can contain enough information to be useful, and one day you’ll encounter a USB stick formatted as FAT16 and you won’t be able to put your crazily-named files on it. I’ll let my computer deal with that and not care myself.

When did you take the photo?

Thankfully, assuming you have your camera’s clock set correctly, this is a non-issue. Time and date metadata is already present in my photos. Hooray!

Where did you take the photo?

Location, in my opinion, is one of the most important pieces of metadata a photo can have, even if it’s not that accurate. Hell, especially if it’s not that accurate! For example, I remember seeing an awesome car when I was a kid somewhere in France. That’s enough information (France, 1985 - 1995, Car) to filter out 99% of my library!

I already geolocate my photos in two ways — if I was out and about snapping away I’ll manually geolocate as best as I can when I return. Even if I find a year-old picture on some motorway in Germany, I’ll geolocate it to Germany and be done with it.

If I’m going on a photo walk — that is, a walk or similar with an express intent to take photos along the way - I’ll bring my bike’s GPS with me. It’s a Garmin Montana, and I specifically chose that rather expensive model because the battery lasts up to 16 hours. I can switch it on, throw it in my backpack and when I get home I have a trace of where I’ve been all day. Both Aperture and Lightroom contain tools to link this trace to your photos, automatically and accurately geotagging the day’s photos in an instant.

What is in the photo?

This one is a bit more difficult. Photos always contain lots of things. The photo above contains fireworks, the sky, clouds, trees, people, street lamps, buildings, snow, gravel, probably a mouse hibernating under a bush somewhere (Note: mice probably don’t hibernate in bushes), a bench, etc etc etc.

However, I never care what’s in the photo when looking for it. I care what the photo is of, and that photo is of fireworks. However, as discussed above, telling the computer what the photo is of can quickly get messy.

Instead, I’ve decided to distill this question down further, to a simple yes/no question:

Is the photo of a ______ ?

This way, tags can always be singular. Is the photo of a firework? Is it of a tree?

What environment was the photo taken in?

Sometimes, I want to find some pictures I know were taken at night, or in the snow, or both. Adding a tag for this would be useful!


Sometimes, rather than searching for specific photos, I want to browse through all of the photos I took at, for example, WWDC 2012. In addition, I often keep a photo reference of progress on various projects such as my railway or robotic monster truck.

To allow this, I’ll continue to organise my photos by year, but rather than vague top-level folders I’ll stick with three: Projects, Events & Trips and Photography, the latter reserved for photos where the sole point of taking the photo was to make a beautiful photo.

Additionally, sometimes I want to browse (or share) my favourite photos, either because they’re photos I’m proud of technically or they just remind me of something amazing. For this, I’ll use the star rating system — typically photos in my library are ★★★★★ or nothing.

“Port of San Francisco”, a photo I consider ★★★★★.

The Metadata Schema

Based on these questions and the above criteria, I’ve settled on the following metadata schema on top of the metadata already added to the photo by the camera:

  • Location, as accurately as possible.
  • One tag for the environment (examples: Indoors, Snow, Rain).
  • One tag for the subject matter unless it’s a photo of people, which must be singular (examples: Plane, Car, Landscape).
  • One tag per primary person in the shot (examples: Tim, Chester, Me).
  • If the photo was taken at night, the tag Night.

This metadata schema is quick to enter and will allow me to filter down my library fairly accurately based on the questions I typically ask when searching for photos. It’s also intentionally very restrictive to avoid tag creep — I don’t want to be entering twenty tags per photo in a year’s time as I slowly start adding more things in.

As for whether this will work, well, only time will tell. It can’t be worse than it was before, right?

Your Drives WILL Fail, All at Once: Backing Up for the Apocalypse

So, you’ve decided that it’s time to do proper backups!

If you haven’t decided it’s time to do proper backups, you’re an idiot wrong. All drives, spinning, SSD or otherwise, have a spec called Mean Time Between Failures or MTBF. This is the average time a drive can be expected to work before it fails. Like brake discs on a car, they’re expected to wear out over time. Not fast, but they’re certainly expected to stop working.

Fortunately for you, my dear readers, I have the experience to help! Quoth my friend Tim:

You have, by far, the highest drive failure rate of anyone I know, and I work in a data centre with 1000s of them.

He’s quite right — over the past couple of years I’ve had two spinning disks and one SSD completely die on me. The spinning disks were in an always-on Mac mini and I finally cottoned-on to the fact that laptop drives aren’t designed for continuous running and the head generated therein, and the SSD succumbed to the dreaded 8MB bug that affects cheaper Intel SSDs, which isn’t as “fixed” as they claim.

Still, as a result I’ve gotten my backup regime to the point where the worst part of a drive failure is the effort of buying and replacing the broken drive, and the boredom of watching the progress bar slowly inch forwards as the restoration is done.

If my apartment building catches fire and all of my drives are lost, then the restoration process isn’t so smooth and I don’t have 100% data coverage, but I’ve got the important stuff covered.

I’ve also found a few tricks to ease the pain of restoring, which can be found below. A backup is useless unless it restores properly!

Local Backup

My local backup uses Time Machine to a Drobo connected to a Mac mini that’s at the other end of my apartment. The Drobo can survive a drive failure without breaking a sweat, and there’s a couple of fire walls between the two machines, so if a small fire breaks out with luck one of them will survive.

The Time Machine backup isn’t bootable, so if you’re in a situation where you’d need to carry on using your computer in as little time as possible, consider something like SuperDuper! or Carbon Copy Cloner to keep a live, bootable backup.

Offsite Backup: Online

For offsite backup, I backup my most important stuff (my Documents and Photos folders) online, which totals around 230Gb at the moment. Backing up everything isn’t very economical since it’d take too long, and I could live without most of my other stuff anyway, or get it from somewhere else.

My online backup uses Arq to backup to Amazon Glacier, which I just moved to using instead of Amazon S3. Amazon Glacier is cheaper than S3, but doesn’t have instant access to your data — you may have to wait a few hours between requesting your data and being able to download it. My logic is that if I’m in a situation where I need to recover using my online backup, having to wait a bit will be the least of my worries. Arq supports both S3 and Glacier just fine, so you can use whichever service you prefer.

There are also services that provide online backup solutions, such as CrashPlan, Mozy and many more. However, you have to trust them not to screw up (and going by a friend’s recent experiences, that’s not something you should do lightly). If they go out of business, bye-bye data. However, I trust Amazon not to go out of business any time soon, and Arq backs up using a documented format and there’s even an open-source command-line restoration tool on GitHub, so even if Arq stops being made, I can still get at my data.

Then again, these services do offer some great features such as mailing you a restoration DVD or hard drive if you have a slow internet connection — it’s up to you to weigh up the pros and cons of each method.

Offsite Backup: Offline

If you want everything safely offsite, or online backup isn’t feasible due to a slow internet connection (or both), you’ll want to start physically moving disks around. I don’t do this, but a good solution would be to have two separate backup disks and rotate them. For example:

  • Have Time Machine (or whatever) backup to disk 1. Put disk 2 offsite somewhere, like in a locker at work.
  • One week later, take disk 1 to work and bring disk 2 home with you.
  • Have Time Machine backup to disk 2.
  • One week later, take disk 2 to work and bring disk 1 home with you.
  • Repeat forever!

As of Mountain Lion, Time Machine supports backing up to multiple disks properly, so swapping them out once a week will be seamless. With this setup, if your house catches fire and you lose everything, the worst case scenario is that your backup is a week behind.

Easing Restoration

For local restoration, there’s a few things you can do to make the restoration process a bit easier:

Getting the Operating System Running

If you have a modern Mac, it has a feature called Internet Recovery that allows the machine to download and install Mac OS X onto a completely blank drive.

However, if you don’t have a fast internet connection or if your Mac doesn’t have Internet Recovery (like my iMac), you can do what I did — I set up my Mac mini running Mac OS X Server (which is now a cheap add-on to Mac OS X from the App Store) to act as a NetInstall agent. It’s a really simple process — an assistant will ask you for a Mac OS X installer either from the App Store or an install DVD and convert it to a NetInstall image.

NetInstall images appear as any other startup disk would.

Once this is done, any Mac capable of running the Mac OS X version you’ve made an image of can boot up and install Mac OS X without having to hunt around for installation media. Simply connect your Mac to the same network as the server and hold Command+N as you switch it on.

Note: When installing over NetInstall, don’t be tempted to do it over WiFi. It’ll be slow and painful!

Double Note: NetInstall isn’t the same as NetBoot. NetBoot allows you to boot up a computer normally over the network, which isn’t the same.

Getting Yourself Up And Running

If you’re happy to leave your computer churning away for hours while your backup is being restored, simply have it restore “normally” through Time Machine or your backup software of choice. Your computer will be out of action for the duration of the restore, but it’s simple and your computer will be just like it was before this whole mess started.

However, if you’re like me, you’ll be impatient and will want to start doing stuff with your computer as soon as possible. Please note that this is a very advanced technique, and I’ve purposefully left the instructions vague to dissuade people from doing it. If you don’t know how to do any of the steps I detailed, you should just let your Mac restore fully through your backup software.

  • Using your backup solution, restore as little as possible to get a functioning computer that includes your user account but not the contents of your Documents, Photos, etc folders.
  • Log into your empty user.
  • Start manually copying things from your backup into your home folder.

Using this technique, you can get up and running really quickly while your massive photo library restores in the background. However, it’s critically important that you restore your user from backup, as both the UID and UUID of the user on your computer must match the one in the backup otherwise you’ll get permissions problems.

The last thing to do is to copy the Library folder. This is invisible by default, and replacing your Library folder of the current user is a bad idea. Therefore, you need to:

  • Copy the backed-up Library into your home folder with a new name, like “Library-New”.
  • Reboot your Mac into Recovery Mode by holding Command+R as you reboot.
  • In the Terminal in Recovery Mode, delete your user’s Library folder and move the “Library-New” into its place.

When you reboot normally, your user will be a mirror of what it was in the backup.

Last Words

The problem with backup is that it’s boring and a pain in the ass. What makes it worse is that computers are very good at hiding the fact that drives are, basically, starting to fail the day you buy them — they’re black boxes of electronics that people assume will keep working.

I’ve gone through enough drive failures to feel incredibly uneasy if my important data is in less than three places — my computer, my local backup and my online backup. Unfortunately, I only got this way by suffering data loss when a drive failed years ago and I had no backup.

If you’re reading this and haven’t already started backing up, I’m sure this advice and all other advice about backups will fall on deaf ears. However, once you do suffer data loss, I hope you come back to this article and that it’s useful for next time.

I’ll leave you with this final thought:

Close your eyes and imagine what you’d do if you went to switch on your computer and you found that it’s drives were completely blank. All of those thousands of hours poured into documents, all those photos of your friends and family, all gone. Forever.

If your answer is anything but “I’d buy a new drive and restore from my backup”, you’d better read this post again while buying external hard drives on Amazon.

The Educated Fanboy: Aperture vs. Lightroom

As I’ve grown older (and I’m aware that, at 27, I’m not actually allowed to claim that I’m “old” yet), I seem to have settled into a middle ground between the random person on the street that doesn’t know what a browser is (YouTube Link) and full-out fanboy — something I like to call the educated fanboy.

The Educated Fanboy is someone who, like a normal fanboy, is completely fanatical about the things they choose to use. They research their product(s) to an insane degree, and end up knowing more than is useful (or even healthy) about the companies and products involved. However, unlike a normal fanboy, an educated fanboy is able to answer the question “So, why don’t you use competitor X instead?”


Educated Fanboy answer: I like iOS, but the UI is starting to stagnate a little so I thought I’d hop over and try Android. It’s more interesting, but I miss the seamless integration that iCloud gives you.

Being an Educated Fanboy is why I’m currently using an Android phone after using an iPhone for years, is why I nearly replaced my Canon SLR with a Nikon one despite having a rather large pile of Canon lenses, and is why I have both an iMac and a Windows PC sitting at my desk.

To The Point, Already!

Right! So, I’ve been using Apple’s Aperture as my photography tool since it was at version 1.0 and cost £300. Many years later, I’ve finally decided to sit down and give Adobe’s Lightroom (or, more accurately, Adobe® Photoshop® Lightroom® 4) a go.

Like most fanboy things — Canon vs. Nikon, Xbox vs. Playstation, Corvette vs. Viper, Chrome vs. Safari, Aperture vs. Lightroom, etc — the thing that’ll swing it one way or another for a particular person will be fairly small in the grand scheme of the overall product. All of them are fine products, and nobody can intelligently claim someone is wrong for going one way or the other.

In the Lightroom vs. Aperture fight for my own personal use, the fight came down to three things:

  • Lightroom’s Noise Reduction is absolutely amazing.
  • Aperture’s book templates are way better than Lightroom’s.
  • Lightroom’s workflow MAKES ME WANT TO PUNCH THINGS.

And the workflow is what makes Lightroom fall over for me. When making a book, every time I wanted to make an adjustment to an image I had to hop over to the Develop module, completely removing my book workspace from the screen and breaking my flow. For a while, I just started playing with the Noise Reduction slider to make myself happy again, but considering that I’ve never wanted to de-noise a photo before and that I make books relatively often, there’s no way me and Lightroom can be happy together.

But man, that Noise Reduction…