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David Kilpatrick | all galleries >> Galleries >> Nikon D3X - Sony Alpha 900 - Canon 5DMkII > A900-100macro-f11-iso100.JPG
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This set of shots was taken with the still life left set up, because the Nikon and Canon cameras were not here at the same time. It compares the A900, 5DMkII and D3X using the converters supplied by the makers - Image Data Converter SR2, Digital Photo Professional, and Capture NX2. All images are from uncompressed raw files at the maximum bit depth selectable (if a choice exists), at ISO 100, using 'Standard' picture look default as defined by each maker. NR and all other similar controls are turned off, and sharpening is set to the minimum or disabled in every case.

The point of focus, using the centre focus sensor for each camera, was the end of the fingerboard. Actual focus showed variations between repeated shots with all three cameras, tripod-mounted and working with two Elinchrom BXRi 500 flash heads. The exposure was set for the Canon and adjusted to be perfect at f/11. However, the Sony JPEGs indicated slight overexposure and the Nikon ones even more; -0.35 exposure compensation was used when processing the Sony files, and -0.65 for the Nikon. For comparison, a Nikon shot taken at the ISO 50 setting, with no exposure adjustment, is included.

The Sony used a Minolta 100mm f2.8 AF (1986) and a 28-105mm RS f/3.5-4.5 (1993). At 105mm, this lens still did not crop as tight as the macro at 100mm. The Canon used a Canon 100mm f2.8 EF macro and a 24-105mm f/4 IS L. Again, even at 105mm, this lens was not matched at all to the 100mm view. The Nikon, with no macro available, was tested using just the 24-120mm VR f/3.5-5.6. This was matched visually to the 100mm crop, and the focal length reported was 102mm.

f/11 is inadequate, with files of this size, to secure enough depth of field for 100 per cent viewing. But f/16 and f/22 (etc) reduced sharpness greatly by diffraction, and some tests at f/8 gave much better sharpness - with so little depth of field they would be unacceptable. So f/11 was selected as the best compromise, showing d-o-f, bokeh, minor focus errors, and being an aperture at which all the lenses used should be up to the demands of the sensors. All three cameras offer lens specific focus adjustment; it did not prove possible to improve consistency on this subject by using the micro adjustments. The A900 was consistently the most accurate in focusing as targeted. All three cameras had the centre AF sensor only active, in single shot mode.

On an iMac 24" 2.16GHz running OSX 10.5.5, the Sony IDC2 software was fastest for viewing and most stable (used in conjunction with its companion lightbox app). Nikon was stable and very fast to save files, but slow to view and to build 100% views for checking focus. Canon's DPP proved unstable, exit-crashing when asked to handle more than 1000 previews (517 files, raw+JPEG) but OK when prefs were changed to show raws only. All three programs were relatively tedious and slow in use compared to Lightroom or ACR. Canon appeared to apply a more subtle sharpening and a very steep midtone curve. Sony's sharpening was coarse and when set to its minimum (not zero) did not seem to aid fine detail recovery (checking these files in ACR revealed better detail, but the Canon files were also improved by ACR). Nikon's files could not be checked yet using ACR, not supported at the time of this test.

Sony Alpha DSLR A-900
1/160s f/11.0 at 100.0mm iso100 full exif

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