5d mkiv first impressions

[DavidEccleston]

Yup, AF isn't the only thing that goes into a sharp image, but once the image is blurred, it's very hard to determine if the AF was working. I can see on the second image that you were panning, because the head, back, and tail are all clearly delineated from the background, while the corner of the wall is a wide blur... so good technique, but with too low a low shutter speed... unless you like the "artistic look".

Did the AF lock on correctly? Maybe. Very hard to tell at this resolution. Since you're panning, the AF all comes down to detecting an edge in poor light, rather than all the predictive motion and Release vs. Focus priority stuff that kicks in when tracking a fast towards/away motion. So many things for an AF system to potentially be good at.

[Joel Eade]

Under these conditions you can up your keeper rate by adding a flash set to lower powers such that the flash duration is very short.

[Kayaker72]

So, when I borrowed a 5DIV last February, I did most of my tests indoors. I didn't noticed that much of a difference between the AF speed with the 5DIV and 5DIII.

But, last week, in general shooting, the 5DIV simply felt like AF was much faster, almost instantaneous.

As I still have both cameras, I decided to run a quick test. I set up two high contrast targets. The camera was about 3 ft from the near target, and about 15 ft from the far target. With only my lamp for light, the room was ~3 EV. I set up the iPhone stopwatch at the near target. Each camera was set up at 1/125, f/2.8 using the EF 24-70 II, single point AF using the center AF point

Alternating between the near and far target for 3 sets of ten at ~3 EV and the 5DIV averaged 1.28 seconds to AF and shoot per shot. The 5DIII averaged 1.29 seconds. So, low light they are identical.

Then, same target set up but adding lights to bring each target to ~10 EV and instead of 3 sets of ten I alternated continuously between targets continuously for 55 seconds.

The results:

• 5DIV: 82 shots in ~55 secs with an average (using the stop watch data) of 0.68 sec per shot to AF and shoot
• 5DIII: 65 shots in ~55 secs with an average of 0.85 sec per shot to AF and shoot

As I have seen test results that are lower, I might be able to do better with some effort. But I am more concerned about relative differences here.

Some other observations, with ~10EV of light, the viewfinder was sharp almost instantaneously with the 5DIV and I had to wait for the shutter to actuate. With the 5DIII, there was a perceptible period where the scene through the VF was OOF before it came into focus and as soon as it was in focus it would take the picture. With less light, both cameras had a perceptible period that was OOF.

What I noticed in real world shooting of eagles (unfortunately only had my 70-200 II with me) was the ability to throw the camera up and rattle off a few shots very quickly and they actually where sharp. This was a bit of a surprise as what I am used to with the 5DIII is needing to be locked onto the subject for a brief period of time before getting good shots.

Not life changing, but this is an improvement. You just need decent light to see the difference.