Purple swamp hen with 5D Mk III

[rogerg]

Playing with the 5D Mk III on the weekend, it's most outstanding performance was when taking landscape and nature photographs, more so than astronomy I felt.

The sharpness and ease of focus was as I remember with my 35mm film. The 7D was a great leap in focus capability and when I first switched to it I felt I had arrived back at what 35mm film gave me. However the 7D's small pixel size makes manual focus and sharpness a challenge at most focal ratios, for me anyway - not so with the 5D Mk III.

http://www.rogergroom.com/items/purple_swamp_hen

The crop (main thumbnail image - click it for larger) is 100%. The link on the page shows a resized image of what the full crop was.

The photo was shot at 1600ISO.

Roger.

[Octane]

The focus and tracking on this camera is nothing next to phenomenal.

I am floored. :D

H

[rogerg]

Agree, although with respect to tracking specifically I can't distinguish it's behavior from that of my 7D, they seem to both track moving objects with obstacle much the same, and have much the same settings too. Focus overall, the 5D did seem easier to get a sharp image, I think it comes down to the pixel size and related factors such as the DLA, less so tracking.

If making money from landscape or wildlife photography I think the upgrade would be an easy choice. Alas, I only make negligible money from such enterprises :)

I'm looking forward to getting back to the location this shot was taken, with my 7D and seeing how I feel about it now, having used the 5D Mk III.

[Octane]

Does the 7D allow you to tweak the six focus scenarios?

Admittedly, I've not used the 7D.

H

[rogerg]

The 7D manual explains how you can use the “AI Servo tracking sensitivity”, “AI Servo 1st/2nd img priority”, and “AI Servo AF tracking method” in scenarios very similar to how they are now outlined in the 5D Mk III menu’s. Using them I've made quite different behaviours with respect to tracking objects with foreground obstacles etc. So from my experience what’s changed in the 5D Mk III is as much making this a lot more useable as the technical improvements I’m sure there are in the 5D Mk III. I certainly appreciated the easy menu selection in the 5D rather than having to fiddle with 3 custom functions of the 7D. The 7D has orientation linked focus too, which I’ve sometimes used but if I forget to turn it off can cause mayhem :lol:

The additional focus points of the 5D, for covering a larger area more so than density, I like in the 5D Mk III.

The 7D has the same types of focus settings in terms of spot, point, point expansion, zone, full AF. There might have been one extra in the 5D Mk III I have forgotten.

[gregbradley]

Nice shot Roger.

What does DLA stand for?

Greg.

[rogerg]

Sorry for the delay in replying Greg, have been away.

Diffraction Limited Aperture.

I have tested it at various times and definitely find that my 7D loses sharpness over F/10 and probably before then but it isn't so clear until about f/10. Take a shot at f/4 and f/22 and the area in focus will have better clarity in the f/4 shot.

http://www.the-digital-picture.com/Reviews/Canon-EOS-5D-Mark-III-DSLR-Camera-Review.aspx

Text quoted from the above site:

* DLA (Diffraction Limited Aperture) is the result of a mathematical formula that approximates the aperture where diffraction begins to visibly affect image sharpness at the pixel level. Diffraction at the DLA is only barely visible when viewed at full-size (100%, 1 pixel = 1 pixel) on a display or output to a very large print. As sensor pixel density increases, the narrowest aperture we can use to get perfectly pixel sharp images gets wider.

DLA does not mean that narrower apertures should not be used - it is simply the point where image sharpness begins to be compromised for increased DOF and longer exposures. And, higher resolution sensors generally continue to deliver more detail well beyond the DLA than lower resolution sensors - until the "Diffraction Cutoff Frequency" is reached (a much narrower aperture). The progression from sharp the soft is not an abrupt one - and the change from immediately prior models to new models is usually not dramatic.

Check out this specific diffraction comparison example using the ISO 12233 chart comparison tool. The mouseover feature will show you the degradation at f/11 compared to f/5.6.

[gregbradley]

Thanks for that.

On the D800 tests show diffraction tends to start around F8.

But not really significant until higher like F16.

Greg.