Sony 135 f/1.8 at least as sharp as the Hasselblad 120 f/4 Makro

[alanbrowne]

<p><br /> http://photo.net/photodb/photo?photo_id=9825952&size=lg<br /> <br /> The focus point is slightly off in each shot. The Hassy is sharpest at the bottom, the Sony at the top of the coin. For sharpness it's a wash (and the Sony "sweet spot" is actually at f/4, so possibly even sharper).<br /> <br /> Further, the Sony lens had a MC/NC (Nikon) filter, where the Hassy had no filter.<br /> <br /> Colour is a bit different, the Hassy being a little warmer.<br>

(Setup:<br>

Sony a900 shot at ISO 200, 1/250, raw image (WB:flash in camera, not changed in raw import).<br>

Sony 135 f/1.8 (Carl Zeiss design) shot just shy of closest focus.<br>

Hasselblad (Carl Zeiss built) 120 f/4 Makro CF shot just shy of closest focus.<br>

Hassy to A-Mount adaptor for the Hassy lens.<br>

1 Alien Bee monolight at same power setting for both shots fired by sync behind a beauty dish with sock.)</p>

[paul_de_ley]

<p>Yes, they seem pretty well matched Alan! The Sony actually looks slightly warmer to me as in a little bit more towards a red/magenta hue. And at this magnification it's clear your quid has been through a few rough spots in the past ^0^</p>

<p>One thing I wasn't able to wrap my head around before (not having any larger system lenses to try out) is how f-stops on lenses for larger formats than APS or 35mm really compare to f-stops of a lens designed for APS or 35mm when mounted on eg a Sony body. All settings between both your shots being equal and producing equally lit results clears that up for me - f8 really is f8 regardless of format.</p>

[alanbrowne]

<p>Aperture is a ratio, period, so the amount of light per unit area of film or sensor is the same regardless of ... well anything (unless you have an extender and/or filter in place).<br>

The lenses are similarly complex, so light loss to glass would be negligibly different. Though colour may be different (and appears to be so in this case).<br>

Actually I don't have a filter for the 120 Makro and I forgot to remove the filter from the Sony (a Nikon NC/multicoat) so it would have softened the image (negligible), coloured the image (should be neutral) and stopped some light (negligible) ... why do I even mention it?</p>

[benny_spinoza]

<p>It would have been better to have the title " Hasselblad 120 f/4 Makro as sharp as the Sony 135 f1.8". The point is, because the Hasselblad has a larger image circle, this speaks very highly of the Hasselblad. With a larger sensor that the Hassy lens is designed for, less enlargement would be needed if a larger sensor was used, and the resulting image would be better with the Hassy/large-sensor combo than with the Sony/smaller-sensor combo. Often, a medium format lens is not as a good as a 35mm format lens in terms of resolution. Similarly, usually a large format lens has poorer resolution than a medium format lens. But to say that the medium format Hassy lens has the same resolution as a smaller format lens is a wonderful compliment for the Hassy lens.</p>

[fast_primes]

<p>I agree with Benny--this is a mildly apples and oranges comparison. The key question is how the Sony 135F1.8 compares to the Canon and Nikon 135F2.0 lenses! If it is even close, then the Sony camera bodies built-in anti-shake will then give a decisive advantage. As for the 120 Makro, an interesting lens/format matchup would be a FF digital with the Sigma 70mm F2.8 macro (or APC digital and 50mm macro) against the 120 + scanned MF.</p>

[jiun_der_chung]

<p>I think that Alan is obviously trying to compare absolute sharpness of the 2 different lenses, all other things being equal, which is fair enough. Bringing in other factors such as anti-shake, different mediums makes it harder, not easier to compare.</p>

<p>I would say thought that it would be better to do the test again with the subject matter plane parallel to the sensor plane (as least as much as reasonably possibly anyway) so as to elimate focusing differences. Though I must say that at f8, I would have thought that the entire coin would be within the DOF.</p>