File naming on Canon digital EOS cameras

A couple of months ago, just a few days before leaving for Paris, I finally made the switch to digital photography. I figured I would be much more comfortable than carrying film cartridges all around Paris and swapping them after only 36 frames. And I also got a great deal for a Canon EOS 600D from a local shop, since Canon was about to launch a new model.

Overall I am very happy with the camera. The articulated screen is practical because it helps conserve battery power – I keep it closed most of the time. My habits as a film photographer come in very handy here, because I am used to not reviewing every single shot on a screen – you simply can’t do that with film, so you need to develop a sense of how the picture will turn out simply by looking at the scene and knowing how the camera will capture it. It wasn’t that easy at first, because the new camera tends to over-expose some scenes, for example in dark churches, which can ruin the atmosphere, but in time I learned when to apply some exposure correction.

One thing that bugged me in the first days of using the camera, after I started downloading files to the PC, was the unusual naming convention. I got a mix of files, some named IMG_xxxx, some _MG_xxxx. Since I worked in a Canon support center a couple of years back, I distinctly remembered there was a reason behind this, but just couldn’t recall the specifics. I found the answer pretty quickly online: EOS cameras use the two file name formats to distinguish between photos captured in the sRGB and Adobe RGB color space. But that explanation quickly led to another question: I selected Adobe RGB in the settings and didn’t change it back and forth during the day, so why were the photos named differently?

It turns out that, like many advanced functions, Adobe RGB is only available in the so-called ‘creative’ modes; in the ‘automatic’ modes the camera defaults back to sRGB regardless of the setting – hence the mix. So when the camera is in ‘Landscape’ mode for example it would save a .jpeg file named IMG_xxxx, when I switched back to P mode or to ‘time priority’ it would also go back to naming files _MG_xxxx. Fortunately the file numbers are consecutive regardless of the first three letters. Mystery solved!

There are some small weak point to the camera – or maybe I just didn’t learn to use it properly. Some images show small color aberrations along the lines of strong contrast, but I guess the lens is more to blame for those. I’m not sure why exposure bracketing works the way it does – meaning you define the exposure interval, then you need to press the shutter to capture each picture. It’s even more confusing because the white-balance bracketing works differently and the way I expect it to: after you press the shutter the camera just save three picture, each with slightly different white-balance. I’m pretty sure exposure bracketing worked the same way on older models…

Since I mentioned the vari-angle LCD, I still can’t figure out how Live View is supposed to work – either I’m not getting it or the feature is really crappy. It would be a great way to put the swivel screen to work, capturing difficult scenes from above or below your normal eye level, but my problem with it is that focusing in Live mode is extremely slow; I need to long-press the shutter just to get the camera to focus, and then I have to press it again to actually take the picture! By the time you manage to do that, the scene you wanted to capture is long gone! You can switch to manual focus, where you have to wrestle with the shutter a single time before getting a photo, but that’s not ideal, as the result will likely be out of focus.

OK, it's not a Canon camera, but the technique can be used nevertheless!

The thing I probably miss the most on a dSLR camera is a GPS module to automatically geotag pictures. It would save some time afterwards when organizing files before uploading them to my flickr account. Canon doesn’t offer this feature in semi-professional cameras, the only one with built-in GPS is the upcoming model 6D.