I recently did a [non-scientific] comparative test of the 1DS3 versus a couple of medium format backs.
First I shot an A3 size mono page of a newspaper, with a fine detailed illustration and typical news column text on a Sinar P2 with a 100mm lens at f.8 and a
54H back (22 MP) in one shot mode, at 50 ISO. I then shot the same item on the
1DS3, with identical Bron lighting (though I had to dial the pack down a stop or so), with a 45 mm T/S lens, at f.8 and at 100 ISO.
I processed the Sinar file through Capture Shot, and the Canon raw file through ACR, and set their color neutrality with a QP card.
I viewed both files at 100% on a calibrated Eizo Color Edge monitor. The Sinar file seemed more even and neutral, and had a hint more clarity. Conversely, the Canon tiff seemed to be slightly elevated in its luminance across its upper mid range pixels - somewhat 'boosted' in its contrast. Also, there was color fringing around the edges of the typed newspaper text letters from the canon, which was not evident at all with the Sinar. The Sinar had an undeniable edge in image quality.
Next, in conjunction with Denis Montalbetti, I put the
1DS3 up against the
ZD camera, and shot more typed material on white page at each cameras default ISO (100 and 50 respectively). We had a 120mm f.4 Macro on the ZD and the 85 1.2 L series on the Canon. The ZD file was processed with Raw Dev, and the Canon went through Lightroom. Again, in resolving fine text detail the Medium format clearly out performed the Canon.
In both tests the Canon was arguably being disadvantaged by the lenses that were used - though I had no 'better' lenses to draw on at time of testing.
Fine detail is critical for me in my work, which involves digitising paintings, rare books, and so on. Were I a portait photographer i would have no hesitation going for the 1DS3 - it is an exceptional camera, and very close to medium format in the quality it delivers. Its workflow capabilities are a dream. That said...I need that bit extra that MF delivers.
Nick
www.viewfinderdigitisation.com.au