When I decided to get back into SLR photography, I didn’t really give too much consideration to the difference between the different sensor sizes on offer.  After trying a friend’s 40D, I decided it was a good choice for me to go with and indeed it was.  After 8-months of shooting with the 40D, I’ve shot almost 12,000 frames, learned a great deal and produced some images that I’m proud of.

However, having shot with 35mm film in the past, in the back of my mind there was always the desire to get back to shooting with a full frame sensor.  With the recent release of the Canon EOS 5D Mark II, I decided it was a good time to look for used copies of the 5D Mark I.  Given that the 5D is 2-years older than the 40D, it might seem like a bit of a downgrade, but most of the features I use are also on the 5D and then there’s that glorious full frame sensor.

After much consideration, I ordered a used 5D body earlier in the week and received it yesterday.  As yet, I’ve not been able to test my 5D outdoors.  I only got it after darkness had fallen and the weather today has been awful.

Here’s what I’ve found to be the biggest differences between the 5D and 40D (relevant to my style of shooting), so far:

• Full frame sensor. The 5D features a 35.8 x 23.9 mm CMOS sensor as opposed to the 40D’s 22.2 x 14.8 mm CMOS sensor.  That’s approximately 2.6-times the surface area which is quite a significant difference and I’m hoping to see this difference reflected in image quality especially when it comes to shooting landscapes.
• 2.7 million more pixels. More pixels, but spread over a larger area.  Aside from the numbers, I don’t yet know what the real life difference is until I can get out to test it.
• Smaller LCD screen. This makes reviewing images slightly less beneficial as it’s more difficult to see whether or not anything’s blurred.  The 40D screen isn’t ideal for this purpose either, due to it’s relatively low resolution compared to the likes of the 5D MKII, but at least it’s 0.5-inches bigger.  You can still zoom the played back image as per the 40D.
• LCD screen flanked by buttons on left-hand side. This means the LCD screen is further away from the left-hand edge which is a plus point for me as I’m forever getting oil from my nose onto it resulting in constant wiping of the screen.  I’m not as bothered about greasy buttons.
• No built-in flash. Apparently, the larger prism means there’s no room left for a built-in flash.  This isn’t much of an issue for me since I rarely used the 40D’s built-in flash as the results I got from it weren’t great.
• No Auto ISO in AV mode. Aperture priority mode is where I spend most of my time and the 40D provides automatic ISO selection in this mode whereas the 5D only offers automatic ISO selection in fully automatic.  I usually shoot in the lower ISO modes, but do find auto ISO useful on occasion so this is something I’ll miss.
• No fully automatic picture modes i.e. portrait mode, sports mode, night time mode. The 5D’s target audience is more towards the professional end of the market so there are less of the more consumer oriented features.  Again, not really an issue for me since I never really used them.
• No Live View. The 5D pre-dates Live View and this, unfortunately, is one feature that I’ll miss especially when it comes to framing low-level macro shots.
• More prominent Depth of Field preview button. It’s in the same location, but it protudes more from the body making it easier to find.  I always had trouble trying to find the DoF button on the 40D when looking through the viewfinder.  Maybe it was more flush with the body because it was less likely to be used on a more consumer-oriented body?
• Different shutter release sound. The mirror of the 5D still clunks, but the shutter noise is more of a whisper.  It doesn’t make any difference to image quality nor does it have any impact on how I use it.  It’s just a difference I noticed straight away.  I guess it’s similar to noticing the difference between exhaust notes when it comes to cars i.e. a bit nerdy!
• No sensor cleaning. The 40D automatically shakes the sensor upon start-up and shut down.  The 5D has no such feature and any dust collecting on the sensor has to be removed manually.
• Different menu structure. The menus that control the 5D’s behaviour are structured into a single list with the jump button to take you straight to the next section as opposed to the tabbed approach of the 40D.  No great shakes here, but the 5D method might be a littler easier to use.
• Only 10-second self-timer. On the 40D, I used the 2-second self-timer a lot as a means of releasing the shutter without causing any movement of the camera or lens.  10-seconds is too long to wait to take a shot.  Fortunately, I’ve got a cheapo wired remote release which I can use instead.  It’s just not as convenient.
• Different layout of function buttons. For some reason, Canon decided to change the layout of the function buttons that live in front of the right-hand LCD.  That means it’s going to take me a little while before I can change ISO without taking my eye away from the viewfinder.
• Current ISO hidden away. The 40D shows the current ISO value in the viewfinder and in the top-right LCD panel at all times.  The 5D only shows the current ISO when you press the ISO button to change it to a different value.  I think this was a very poor design decision since it’s too easy to be shooting at a completely unsuitable ISO without knowing it.

Full frame means that I can no longer use the APS-C format EF-S lenses, but it does mean that I get much closer to subjects  in order to obtain the same field of view.  This can make a huge difference when it comes to making a subject more prominent against a blurred background and it’s this shallower depth of field that I was really hankering after.  From the indoor test shots I’ve taken, the shallower depth of field is very noticeable.

Hopefully, the weather tomorrow will be improved and I’ll be able to get some naturally-lit shots.