AF question

if my 400 5.6 was dead on with the Mark IV (1.3 crop) does that necessarily mean that I would need to micro adjust it on the 5d III??

Hard to say. Every lens/body combo seems to behave differently.

Is the distance from first element to the sensor different with a FF? That's really my question. I nailed some shots this morning of a young hawk but they seem a tiny bit softer then with the Mark IV. Not much,, but a little. This is my first FF body. I'll post some sample shots shortly.

depends if it is a problem with the lens or body.

FlyFishingTN wrote in post #14781580
Is the distance from first element to the sensor different with a FF?

No, the distance between the lens and the sensor is controlled by the focal length of the lens. If you have for instance a 50mm lens and fit it either to a crop body or a FF body then it will be have to be the same distance from the sensor in order to focus.

It is very difficult to compare pictures between different sized sensors because of different pixel sizes / magnification and different moire filters that are fitted in front of the sensor so what may be perceived as an out of focus effect from one particular sensor may just be that the picture needs more sharpening.

Having said that all of our cameras and lenses are mass produced items built within a certain tolerance range, if you have a body that doesn't quite fall within the tolerance range of the lens then micro focus adjust can be useful. This has got nothing to do with sensor size.

Thanks for info. As I said this is my first FF and it's still new so I'm getting used to it. I've noticed some of the heavy crops look more like my 1D II did for some reason. I assumed with so many pixels the detail would be mind blowing. I'm not knocking this body in any way. It's amazing so far. Just pointing out some of my observations. Could just be a nut loose behind the viewfinder.

Here are some RAW images from this morning.

Crop

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You might want to Micro Adjust focus with that lens. That would resolve any slight focus mis-calibration. It doesn't appear there's much, from your sample images.

I suspect it's more a matter of learning different image post processing... perhaps using a bit more sharpening. I don't have either model, so can't say if it's "normal" or not.

It also could be as simple as your own habits when working with your images. The 1D4 image is 4896 x 3264 pixels max. The 5DIII's are 5760 x 3840 max. So if you are in the habit of checking focus at a paticular magnification, you are actually looking at the new camera's images larger and more critically. For example, on most computer monitors, 100% with the 1D4's files is like viewing a print 4 feet wide. The same 100% viewing with 5DIII's image is like making a 5 foot wide or 25% larger print with it. You can either scale down the 5DIII images to better match the size of the 1D4's. Or you can use slightly less magnification to view the larger files.