5d mkiv first impressions

[DavidEccleston]

Pat, I'd love a 1DX... but my wallet can't take it, unless you're feeling really, really generous. But, I'm curious how the 1DX would handle an agility event.

Depending on your framing your meter can do very odd things. If the dog doesn't fill the majority of the frame, the exposure is based on a lot of background. A black dog loses detail, which on a crop body isn't very recoverable. A white dog clips to unrecoverable super-white levels. A black and white dog in a mix of full sun on it's back and shadows below clips on both ends of the histogram at once!

You can throw on some EC (I have EC tied to the AF-mode switch lever thingy so I have fast access to it), but if the black dog starts filling the frame, you start getting a very bright black dog and clipped surroundings. If a white dogs start filling the frame, you start to get a very dim grey dog and blackened surroundings.

In the end I tend to just set everything manually, and do a slight + or - adjustment between dogs, based on the brightness of the last image, and the color difference between the two dogs. I do get it wrong sometimes, and add in mid-run light changes due to clouds, and I definitely miss shots that should be awesome, but I lose less this way than using the meter.

The 1Ds2 had an interesting difference from the 7D bodies. It seemed to understand highlights. It would expose such that highlights wouldn't clip, or not much. In an image with a bright reflection or highlight, it would underexpose, which, on a more modern full-frame sensor you could bring the shadows up and recover that detail. A 1DX, if it behaves the same way, would be nice... It's like an over-exposure safety-net. If the 5DIV behaves the same, AND you get its improved dynamic range and shadow-boost capabilities along with highlight smarts in the meter, that would be a killer combo. But, I'm guessing the highlight thing is 1D specific. I heard (so could be wrong), that the 1D series does the gain processing in analog, while every other body does it digitally. It could be that the 1D analog circuitry can detect the highlight and compensate in ways that the other camera can't.

Brant, I would say that wasn't a fair test of the AF. People will blur at 1/100. A fast dog stands no chance. Typically for a fast running dog, we aim for 1/1600s as a minimum. If the dog is running sideways across the frame, you'd best be panning to match them, too. This shot is at 1/1600s (85mm, but AF isn't taxed because it is sideways action, not front/back). I was panning to match Zuni. Note the level of blur on the grass and hind leg. If I weren't panning, Zuni would be as blurry as that grass... Potentially more, as the dog's leg moving forward is moving faster than the dog as a whole, and would would blur more.


Zuni running for a ball by Dave E, on Flickr

[Kayaker72]

Brant, I would say that wasn't a fair test of the AF. People will blur at 1/100. A fast dog stands no chance. Typically for a fast running dog, we aim for 1/1600s as a minimum. If the dog is running sideways across the frame, you'd best be panning to match them, too. This shot is at 1/1600s (85mm, but AF isn't taxed because it is sideways action, not front/back). I was panning to match Zuni. Note the level of blur on the grass and hind leg. If I weren't panning, Zuni would be as blurry as that grass... Potentially more, as the dog's leg moving forward is moving faster than the dog as a whole, and would would blur more.

As usual, some good discussions on this forum that make me think a bit more about what I am seeing. My sense of AF is different than just what it takes to get a sharp image. And I do not hold AF accountable for times when I do not get sharp images. It is not that simple. Some common factors that go into getting a sharp image:

• Shutter speed/tripod. I am constantly impressed when pixel peeping at how much resolution and sharpness I have coming off shots taken on a tripod vs shots taken even using the 1/focal length. Shots from a tripod are almost always sharper, when pixel peeping, than hand held shots until you get to very fast shutter speeds. That is with stagnant objects. For a rapidly moving object (BIF, dogs, kids, etc), you really need fast shutter speeds to freeze action.
• Noise. All sorts of types of noise, but the loss of detail at higher ISOs will affect the ability to get a sharp image.
• Vibrations/movement due to pressing the shutter, mirror movement, etc.
• Then there is quality of the pixels, quality of the lens, etc, etc.
• DoF

None of those have anything to do with AF. But even within "AF" there are many factors:

• Sensitivity/type of AF points (f/2.8, f/5.6, etc; Phase detect, vs contrast detect, etc)
• Light hitting the AF points
• Amount of contrast of subject at the AF point
• How rapidly does the camera move the plane that is "in focus". One of the great advantages I continually hear about the 1D series is the more powerful (V) battery and its ability to drive focus faster than less powerful batteries found in smaller cameras. But this also gets down to computational power, etc.
• For moving objects, shutter lag.

If I thought more, I am sure I could come up with others. But these will cause a non-sharp image in different ways.

I do not think any of these are great images, nor was this ever intended to be a well controlled test. It literally is a puppy running around under awful and varied light conditions. But a few examples (no mods to shots, just printed from LR):

Actually not awful, not great. My wife just walked in and saw those two and loves them . Technically, moving side to side, much of the blur is likely due to the shutter speed, high ISO, and maybe shutter lag. In terms of the 5DIV controlling the focal plane, probably pretty good. But my 5DIII is about as good here.

I have a lot of pictures like this. The focal plane is behind Etta's head. Not surprising, one of those classic's that it is harder to AF on a subject coming straight at you (focal plane has to move more, etc). But, I attribute this to everything that goes into shutter lag, which is greatly affected by low light.

So, overall, and trying to bring this back around to impressions, this "test," fair or not, did tell me exactly what I wanted to know. The 5DIV isn't that different, under these conditions, than the 5DIII. Maybe a little bit better. It actually performs well, in my opinion. But, I have very similar shots and have had similar issues with the 5DIII.

If I had the time, the AF test was going to be something like 2 high contrast targets, one set 10-15 ft behind the other. Have a timer right next to the near target and then going and AF back and forth taking pictures and measuring how fast the camera would AF by averaging the time based on pictures that included the timer. Then vary the light conditions. But, I ran out of time for that set up.

Ultimately, I think the reason that so few review sites measure AF is because so many factors do go into AF. Popphoto was measuring shutterlag, but I didn't see it on the recent 5DIV. Imaging-resource has measured values, which provide some good information, but I have seen some real world differences (the shutter lag of the 5DIII (0.12 sec) is not the same as the M3 (0.126 sec) in the real world). I have both, the 5DIII smokes the M3.

So, hopefully this is interesting. I also hope that people know the above pictures are not intended to be "great"....just quick tests.