An Unscientific 5Dmk3 vs 1Dmk4 AF Comparison

March 23, 2012  •  Leave a Comment

I went out for a lunchtime walk today armed with the Canon 1Dmk4 and 5Dmk3, along with the 100-400 f/4.5-5.6L IS.  I wanted to do a subjective test on how they were to use, how they felt, and then when I got back a comparison of the percentage shots in focus from both cameras.

5D3/1D4 AF Test

 

As I said in the title, this was a very unscientific test.  It involved 20 minutes or so wandering around with the 100-400L on the 5Dmk3, then a swap to the 1Dmk4 and about the same length of time trying to shoot similar targets.  I’ll go through the images first with a bit of discussion about how I was taking the shot (conditions etc), and at the end I’ll talk through some conclusions based on processing the images.

5D Mark III

So, the 5D Mark III.  Processing wise, all shots are RAW, converted to DNG with the latest ACR Beta (6.6) which is the only ACR to support the 5D Mark III at the moment – then processed in Lightroom.  On the camera, I used a combination of normal single AF point and spot AF depending on the situation.  The lens had IS switched on all the time.

5D3/1D4 AF Test

5D Mark III (ISO400, 400mm, f/5.6, 1/80s)

First shot was a relatively distant squirrel running up a tree.  This ended up 1.25 stops underexposed because of the backlight, so it’s been pushed quite hard in Lightroom and still looks good.  The image files from the 5D Mark III continue the trend of standing up to more intense post-processing than previous cameras.

5D3/1D4 AF Test

5D Mark III (ISO800, 400mm, f/5.6, 1/160s)

It felt good shooting with the 5D Mark III.  The AF speed was very good – locking on exactly where I wanted without any issue.  I had the AF in the “Versatile multi purpose” case as I was planning on shooting more-or-less static subjects (like birds on the ground or squirrels).

5D3/1D4 AF Test

5D Mark III (ISO800, 400mm, f/5.6, 1/250s)

The light levels were quite a bit lower generally at the start of my testing, mainly because I was under more shelter.  This led to shutter speeds between about 1/80s and 1/250s for most of the shots.  I’m pleased with how sharp they came out considering the shutter speed on some of them.

5D3/1D4 AF Test

5D Mark III (ISO800, 400mm, f/5.6, 1/200s)

This little robin was sat on a log on the ground and I could get pretty close (the MFD of the 100-400L is 1.8m so I couldn’t go any closer than that, but I think I got pretty near to that).

5D3/1D4 AF Test

5D Mark III (ISO800, 400mm, f/5.6, 1/200s)

There were lots of blue tits around too – most of them high in tall trees so a bit out of the range of my 400mm lens, but I managed to get this one:

5D3/1D4 AF Test

5D Mark III (ISO800, 400mm, f/5.6, 1/2500s)

All in all, the 5D Mark III was a joy to use.  It felt like it got every shot in focus from quickly reviewing some of them on the LCD.  The subject lock was very quick and positive and it just gave a reassuring feeling.  However, it’s worth reading to the end as something surprised me when I looked at the images…

1D Mark IV

I did the same kind of thing with the 1D Mark IV after swapping the lens – just a quiet wander around Upton Country Park to hunt out some birds and wildlife that might stay still long enough for me to shoot!

Swapping over to the 1D Mark IV, it felt obviously heavier but in a way a little more balanced.  The 100-400L is quite a heavy lens, so the heavy body does match it quite well.  It was great to have the vertical grip back again – I find I naturally choose to shoot vertically with the 1D Mark IV (as you can see from the selection of pictures, compared to the 5D Mark III).

This first shot is not quite sharp at the face end as I was chasing the squirrel across the ground with the lens (you can see motion blur on the static objects like the tree trunk) and in a not quite appropriate focusing mode!  But I liked the action and for the purposes of this discussion on the AF performance, it did lock where it needed to (the squirrel was about 10m away from me for this shot):

5D3/1D4 AF Test

1D Mark IV (ISO800, 400mm, f/5.6, 1/400s)

Initial thoughts when actually shooting with the 1D Mark IV was that the delay from pressing the shutter button to the shot actually being taken felt longer than the 5D Mark III.  This was quite surprising, and it may be due to the fact that the shutter speed is so fast on the 1D4 (10fps) that the initial delay could feel longer than it actually is.  But it was an initially noticeable difference (after 5 minutes of shooting I’d forgotten about it and it felt natural again).

The other thing I noticed was that the AF could often miss the subject I was aiming for and start to hunt.  I’ll put this down to not having quite the right AF setup in the camera, but it does go to show that the new 5D Mark III (and 1D-X) AF menu structure – with AF “cases” easily setting up the system as you want for certain situations – is massively better than 10′s of interacting custom functions hidden away in various menus on the 1D Mark IV!  I liken the AF Cases on the 5D Mark III to Picture Styles for AF – each “case” sets a number of parameters up with a single button press.

Here’s another blue tit shot – this one higher in a tree against blue sky.  The metering did a good job as this was in aperture priority with no exposure compensation:

5D3/1D4 AF Test

1D Mark IV (ISO800, 400mm, f/5.6, 1/4000s)

The bird flew to almost directly above my head – so I got another shot.  Both of these were through fairly dense branches, using the centre focus point, and the camera got what I was after.

5D3/1D4 AF Test

1D Mark IV (ISO800, 400mm, f/5.6, 1/4000s)

This, again, was a shot with some dense background and complexity in the image, and the AF system got the bird nicely.  This is a heavy crop of a pretty distant bird (10+m).

5D3/1D4 AF Test

1D Mark IV (ISO800, 400mm, f/5.6, 1/640s)

Finally, a squirrel with the 1D Mark IV.  Nicely lit, nicely detailed, nicely in focus.  No problems.

5D3/1D4 AF Test

1D Mark IV (ISO800, 400mm, f/5.6, 1/1000s)

Discussion

Now, this is where it gets a bit more interesting.

When I left the park, my gut feeling was that the 5D Mark III AF performance was snappier, locked to subjects better and almost all the shots were in focus from a quick review of the LCD.  The 1D Mark IV felt like a bit of a let down – AF missing the subject early on and hunting, and from quick reviewing on the LCD several of the shots were obviously out of focus.

So I got home, downloaded the images on the to the computer, then went through in Lightroom and marked them on acceptable AF (not composition or anything like that – just whether the AF hit the spot acceptably at pixel level).  I was surprised by the results.

I had 74 images (once I had thrown away a couple of accidental misfires) – by chance I had 37 from the 5D Mark III and 37 from the 1D Mark IV.  After I had rejected the shots which were not acceptably in focus, I had the following:

  • 5D Mark III – 18 of 37 remaining (49% in focus)
  • 1D Mark IV – 21 of 37 remaining (57% in focus)
First, before we end up with a “Canon can’t focus” type of argument – the reason the numbers are around 50% rather than 90% is because I was shooting tough subjects and I took quite a few chances with unlikely shots without giving the AF any time to settle.  I did the same thing with both cameras, so I left those shots in the pile.

So… it goes to show that gut feelings can be wrong.  I really thought the 5D Mark III had nailed most of the shots, and the 1D Mark IV had messed up, but it turns out the end results were the other way round.

Why?

It turns out that when the 1D Mark IV missed focus, it tends to miss big style.  So you can see immediately on the LCD that you’ve missed the shot.  The 5D Mark III tends to get much closer to the mark and it can appear that it’s in focus until you really get down to pixel level.

When I was reading comparisons of the 1D Mark IV and the Nikon D3s  (before I got the 1D Mark IV), I saw several times that people had said the same about the 1D Mark IV – in bursts it could tend to have several shots wildly out of focus whereas the D3s were all more-or-less OK.

Depending on what you want to do with the image, slightly out of focus may mean you can still use the image without any issues, so it may just be that the 5D Mark III has a more real-world useful AF system.

Conclusion

This really was an unscientific test without.  I didn’t take identical shots with both cameras, the lighting was different, the subjects were both different and difficult.  It’s important not to draw too many conclusions from this test, but I think I can say that in this small test, if the AF misses then the 5D Mark III tends to get closer to the mark than the 1D Mark IV.

I will say, however, that both cameras performed very well considering the shooting situation today.  I’d be delighted with either of them – it’s just worth noting that the although the 5D Mark III isn’t a 1-series camera, it does have AF performance at least on a par and quite likely somewhat better than the 1D Mark IV.

When I finally get FoCal working with the 5D Mark III I’ll be doing some detailed quantitative analysis on the AF systems of both cameras.  There are new tests I want to add to FoCal which will quantify the AF tracking and low-light performance of the cameras, so  hopefully I’ll be able to say for definite whats good and what’s not so good with the AF systems.


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