Introduction

This may seem like a pretty unusual comparison but I thought I’d pull some thoughts together for the benefit of any others out there considering similar dramatic upgrades (maybe from 30D, 50D or 5D classic – not saying those are necessarily the same – but similar era). I’m going to say from the outset that these are my personal views, using LR3 processing the way I like to process, and the review may not tell you a whole lot you can't already guess! I should also point out that whilst I’ve been using a 40D for the past 4 years, I’ve also had the frequent use of a 5DII, so this upgrade was not quite the leap it otherwise may seem…

My reasons for the switch

I came into the digital age late. I shot with an EOS3 for a long time and loved it. It was a highly impressive beast and really was the perfect film camera for me. I then went directly to a 40D and quickly got caught by the digital bug, being very satisfied by the results the 40D pushed out – this lasted for a long time.

Unfortunately times change, my wife got a 5DII and suddenly the high ISO and resolution benefits of FF became apparent in a rather stark way - we took a trip to the national parks in Utah and Arizona last year with a Zeiss 21mm and the 5DII pictures were stunning - so I felt the yearning need to upgrade.

And then came the 5D3, a camera that on paper threatened to be the digital EOS3 – the specs were all there, great AF, decent resolution and great image quality, fantastic built (very important) and most importantly of all (and something the EOS3 was incapable of...) high ISO. In truth, the 5D3 looked like it had everything I wanted from my hit list of features, so I jumped.

Initial impressions – first 30 seconds with the 5D3

It’s a hefty beast! Put a battery and lens on it and it’s actually quite heavy, it certainly feels much more solid than the 40D or the 5D2 for that matter. I’ve mounted it with my 50L and there’s a very pleasing amount of heft to the camera. I can feel the inertia, it feels very well balanced. The grip’s nice too, with a little outpost against which your thumb rests. Gorgeous screen as well, and oh yes, there’s the 100% full frame viewfinder, I can see again! Lovely.

Reach and resolution

There’s no real fun in comparing 100%, max resolution at 100 ISO because the 5DIII squashes the 40D, so I thought I’d address a couple of different scenarios that frequently crop up.

OK, now the maximum reach I have with my current suite of lenses is 200mm using a 70-200mm f4IS. What I want to test here is the relative merits of the 5DIII for shooting a far distance subject. Again, you can say all you like about whether this is a worthwhile test (just buy a longer lens etc), but it’s a fact that crop cameras will always give you more reach that FF for any lens you’re using. So here we go, see that air-conditioning unit over there, let’s see whether the resulting (deliberately unscientific) crop looks better from the 5DIII or the 40D (should be pretty close, 22MP / 1.6 squared = 8.6MP against the 10MP 40D, but of course the sensor on the 5DIII should be much better… ). I’ve processed both raws through lightroom, both shot at 200mm, iso100 and f6.3.

Total image from the 40D

40D 100% crop

5D3 100% crop

Thoughts:

• Cropping to give the same image at 100%, the 40D picture is only marginally bigger than the 5D3 picture as expected (and reflecting the awesome cropability of the 5D3)
• I give sharpness here to the 5D3 which at 100% is extremely impressive. The 40D is just a tiny bit soft which is a bit surprising, and you can see in another test below that this may just be a little bit of camera shack as below the sharpness is completely comparable.
• Colour faithfulness is very good in both which is good to now, though from the variety of shots I've taken to date, the 5D3 shots do tend to be a bit more saturated than both the 40D and the 5D2. Verdict still out as to whether this is a good thing...
• Overall, if I had just one lens and needed the reach, I'd be perfectly happy shooting either camera, so long as the light was good.

Here's another similar test, this time deliberately shooting a subject in shadow. The reason I'm testing this is to see if there's any low ISO noise hanging about and to see the dynamic range in a real life situation. Both of these were shot at iso100, 200mm at f6.3. They are processed in LR3 with noise turned right down to zero and a reasonable and equal amount of sharpening:

Total image from the 40D

40D 100% crop

5D3 100% crop

Thoughts:

• Sharpness perspective, there’s really very little difference although the 40D is picking up more detail here, but both are very sharp crops. Unlike the test above, this is more consistent with my experience with the 40D and the 70-200, it's just an astonishingly sharp lens.
• Colour and contrast, very similar in fact, I set blacks and white balance to be the same but it still seems the 5D3 is slightly more saturated.
• Noise: Something that was always a bit of a puzzle for me was that the 40D had base iso noise in out of focus and darker areas, and you can see it here a lot on the leaves and lamp above – note though that I've deliberately turned noise reduction to zero, so this is worst case. It's much less prominent with the 5D3.
• Conclusion: the 40D crop may be slightly larger due to higher pixel density, but then its a trade off between sharpness, colour and noise.  Too close to call.

Max resolution

There's no point in posting a comparison here, the 5D3 would simply destroy the 40D, however, I do just want to post an example of the cropping and resolution power of the 5D3 which is simply incredible. Here you go, here's a nice cow picture, and then the 100% crop (helpfully also showing the extremely accurate AF as well).

5D3, iso100

5D3, iso100, 100% crop

High ISO

OK, here are some high ISO images. I am completely blown away by the 5DIII. Firstly, just to showcase the 5D3, here are a few images I took at iso1600 and iso3200 with the 5D3. What amazes me is that I can quite happily shoot with these isos inside all day long and have no real worries about the sharpness, noise and focus of these images. This photo I particularly like, my daughter and brother. It also emphasizes very nicely the cropping power of the camera. You can end up with 2 completely different images purely by cropping. And just look at the 100% detail at iso 1600 - inside!

5D3, iso1600

5D3, iso1600, partial crop

5D3, iso1600, 100% crop

Here’s another example, iso3200. This is inside again but at night, so just an overhead tungsten light for illumination. Firstly, the noise is non-existent, and even in the blacks which is impressive. Admittedly these are processed, but the point is, you can get to a very clean image. Personally, the ‘model’ here looks a bit ‘waxy’ at 100%, but focus, lack of noise etc are all spot on:

5D3, iso3200

5D3, iso3200, 100% crop

Now for a quick comparison 40D to 5D3. I'm in the process of compiling a lot of comparison images in another blog (alongside the 5D2 as well), but here a few test shots. The lighting is deliberately awful, and there is a wide range between the highlights and lowlights here. Up to 12,800, these are all processed through LR3 from raws, but above that they are 5D3 out-of-camera jpegs - in the short time I had available to do this review, the camera jpegs simply ended up better than my processing (which, now that I think about it, means I should definitely always shoot raw + jpeg for high ISO images)! In LR3, I used as much noise reduction as I felt necessary to balance lack of noise with maintaining detail:

40D, then 5D3, iso1600  

40D, then 5D3, iso3200

Just 5D3 form here on (40D only goes to 3200), iso6400, 12,800, 25,600

Now it gets very bad, 5D3, iso 51,200, 102,400 

Thoughts:

• Now this test is obviously woefully inadequate. For a start, there are no 100% crops, but the point was really to provide a quick and dirty test of what is possible in very bad light.
• I'm actually quite impressed by the 40D, which traditionally I try and avoid shooting at iso1600, let alone 3200 because it's just not that good. However, I'd take both of those images above if the worst came to the worst...
• Look closer at the 5D3 images though, particularly towards the bottom. At this size, you really can't fault the images at all up to 6400 and I'd easily take 12800 as well
• It's after 12800 that things start to fall apart though, so time to beware
• From the (limited) shooting I've done so far I've been very happy with 1600 and 3200 pictures - even at larger sizes they are extremely clean, but it's too early to call whether I'd be consistently happy shooting above this...

Build quality

I guess I should start this by stating that in the 4 years I’ve had the 40D, it’s performed almost flawlessly through hot, cold, drizzle, snow, high altitude, sea water, you name it. Two exceptions though – the shutter eventually failed recently (common 40D problem) so that had to be replaced, and once last winter I got the camera so wet in a snow storm that it stopped working completely for 12 hours until it had dried out (in a plastic bag with rice inside…). I’ve therefore been hugely impressed by its performance. On the other hand, I like to think that I won’t have either of these issues with the 5DIII (until about 8 years time or so…). I’m expecting it to be more weather resilient and if there’s a shutter issue before I hit 200,000 images I’m going to be upset - all because the 5DIII is just in a completely different league, simple as that. It feels like a completely new design (OK, similar to 7D blah blah) that handles like a sturdy tank whilst the 40D feels like it was designed in 1995 (which given the modeling is not too dissimilar from the EOS30 back in the day, is not far off).

Unfortunately, after a week now of shooting the 5D3 exclusively, I picked up the 40D again. It was a sad feeling. It felt strangely archaic, I looked through the viewfinder and couldn’t see anything it’s so dark in there, and the screen is just awful in comparison. I felt very slightly ashamed, for years I’ve been totally happy with the output and functionality of my 40D and now I know I won’t be able to go back to crop. The image quality of the 40D is still very much there for low ISO, but the feel, the usability, the fun, may never quite return…

The screen and liveview

Just a quick note here. One of main reasons I waited for the 40D was that cameras were starting to pop up with liveview and I thought this looked like a really great feature. Then the 40D came out with liveview as well so I finally took the plunge. Sure enough, liveview was great, and the 40D's implementation was reasonable enough. I feel though that it was somewhat let down by the screen. It is possible to zoom in 10x on the 40D and it is possible to focus pretty accurately in manual (or using phase detect), but the 5D3 implementation is way better. Firstly I can now use contrast detect, though in all honesty it's pretty slow and really, it's just easier to use manual focus - by the time you've set everything up on a tripod you may as well use manual focus anyway. What makes the real difference is the amazing screen. The resolution is so high that you can't really see any pixelation and therefore when you zoom in at 10x, the limiting factor starts to feel like subject movement and the lens rather than the screen.

The other point of note is that even though the screen is not that much larger, 3.2in vs 3in, because of the 6x4 format, it just appears so much bigger, especially in review mode. It's really incredably good.

AF

 I don’t shoot sports or many birds so on the one hand I don’t have a great need for a snappy Al Servo system, but I do shoot a lot of low light (and have also done with the 5DII) and this new 5DIII rocks in that regard. No more lens hunting in the dark, and during the day it snaps on instantaneously. Very pleased. In every way it's miles apart from the 40D, with one exception – center point and good light and there’s no difference apart from a slight speed advantage to the 5D3. The 40D is always good in such ‘easy' scenarios.

Actually it’s funny, the AF was not the primary driver for me behind the 5D3 purchase, but it’s one of those things where you don’t know you miss it until you have it. The ability to select any point you want is fantastic, no more focus and recompose necessary. I really feel like it’s advanced my composition because i can focus on exactly what I need to without moving the camera.

One quirk though. I use a Canon 100mm macro a fair amount (the non-L version) and I have to say that the outside focus points ended up hunting a lot with this lens. If you look at the manual, you can see why, there are no cross types being used with the 100mm on the outside points, but this is a slight annoyance that I don’t really understand the basis for.

Video

The 40D doesn’t have it, the 5DIII apparently does, but who cares.

Behaviour with lenses

I’ve said it above, but I immediately planted a 50L onto the camera. This thing works incredibly with the 5D3. With the 40D, you needed good light and frankly you needed to stop down to get reliable focus. With the 5D3, focus is spot on, I have proper focus throughout the aperture range, and the greatest improvement of all: the detail and sharpness at higher ISOs. Above ISO 800 with the 40D and the 50L struggles to produce good pics at f2. The 50L can produce great detail and lively pictures right up through ISO 6400. It’s such a great combo. Really pleased.

Focus shift with the 50L? From the quick test I did, it’s there, but from my test pics it’s not really an issue. Why? Because even though the middle of the focus area (i.e. middle of the depth of area in focus) moves away from the camera, the front of the area of focus is still the part of the picture I want to be in focus. And regardless, that’s really only the case for pictures taken within 5 feet.

Colour

Just a couple of final points on image capture (colour and HDR below). Have a look at the pictures below. What I particularly like about these is the way that the reds render. In my experience, reds are captured particuarly badly on digital cameras, but the 5D3 manages to address this issue well. Too early to tell if this is universal in more wide spread situations, but it looks good so far.

5D3, iso800, 100mm, 1/80, f4.5

100% crop

HDR mode

I wasn’t going to put anything in here about HDR (mainly because I generally hate HDR images) but I thought I would because on certain occasions it works really very well. For me, the most important thing about an HDR picture is that it shouldn't look like an HDR picture, and the 5D3's "natural" mode is capable of making that happen. It didn't work in all the situations I tried, but here's a situation where it did, and where ordinarily it would have been pretty pointless even trying to make a capture. The top picture is the standard exposure, and the second picture is the 5D3s HDR mode (set to auto I believe). I have to say I'm very impressed with this (bare in mind these are hand held as well, so the camera is making the alignment adjustments as necessary)

f/4, 21 mm, 1/200 & 1/160, ISO 1600

Conclusion

So what do I particularly like about the 5D3:

• First up, high ISO shooting ability, it’s just fantastic and leaves the 40D in the dust. I've haven't tested much in the really high ISO ranges yet but from what I've seen so far, it's fantastic. The only concern I have here is processing high ISO images, as getting as good results out of Lightroom as the camera's doing is taking time! 
• Second, and I wasn’t expecting to rate this so highly, but the AF just makes shooting so much easier, and just nails focus virtually all the time. One of the biggest benefits I found was the ability to combine the amazing AF with low light and get crisp, in focus pictures with great detail.
• Third, build quality is just superb and the viewfinder and screen are a joy. I felt the 40D was solid enough but the 5D3 is something else, a reassuring lump of camera. In particular, liveview works great, it's much better implemented, and the screen image much crisper and clearer, than both the 40D and 5D2.
• Runners up: Resolution. To be honest, I would have been happy with 18MP and I’m very glad it’s no more than 22MP, my computer would have struggled and I simply don’t need more MP, however, I do love the fact you can take a heavy crop and still have a lot of detail left. In my mind it negates the only advantage of crop cameras, but then I don’t shoot a lot at long focal lengths...
• Colour. Actually the verdict is still out on colour. It’s sometimes different to the 40D and 5D2. I think it’s more saturated and I haven’t quite decided whether this is a good thing or not. I typically didn’t increase any saturation on my 40D & 5D2 pictures, so I may end up dialing down the saturation on the 5D3 on occasion. It works both ways though, the pictures are super punchy, but is it just a bit too much?
• Then there's the toys: the HDR mode which is unexpectedly competent, the multi-exposure which I've yet to play with, and video mode which again apparently exists and I'm sure one day I might use...

So there you have it, I’ve come full circle from my EOS3 to its digital equivalent and am incredibly pleased with my new toy. It's everything I hoped for, it's brought new life to my beloved 50L and I really do think this will keep me happy for many years to come (plus a few more lenses of course...). But is it really better than the old 40D? Maybe not quite in every way - it's ten times the price...