08-10-2010, 04:19 PM
[quote name='genotypewriter' timestamp='1281454025' post='1647']
Hi Klaus,
Thanks for this review. I'm looking in to M mount lenses to use on my Sony Nex.
I found an interesting result and a comment in the [url="http://www.opticallimits.com/olympus--four-thirds-lens-tests/469-zeiss_zm_50_2_43?start=1"]ZM 50/2 review[/url] and wish you could explain it a bit more...
First the vignetting characteristic of this lens is very very good at 0.38 stops at f/2. For example the Panasonic Leica Macro-Elmarit 45mm f/2.8 is [url="http://www.opticallimits.com/olympus--four-thirds-lens-tests/490-leica_45_28?start=1"]1.22 stops wide open[/url]. And the ZM 50/2's review also confirms this by saying:
What I'm puzzled by is the comment you made regarding the lens' wide-open corner resolution figures:
After seeing mFT and Sony Nex E-mount cameras with significantly closer flange distances than the M mount, I'm very strongly inclined to think that this offset micro-lens tech of Leica is marketing hype and a hack job to deal with the outdated sensors they put in to their digital M bodies.
I can't see, at least for the FourThirds area, how an M mount lens will have difficulties in getting light to hit the sensor than than any other mFT lens. I think the (low) vignetting characteristics confirm this.
Plus I don't think LiveMOS can be blamed here because it's still just a Bayer pattern system with supposed improvements in sensor fill-factor, read-out and built-in NR.
So my question is... does this mean the ZM 50/2 is actually a "bad" lens in the corners when it's wide open? Could it have been something else that was not accounted for in the review like the field-curvature? I've heard lenses like the Noctilux suffer quite a lot from this.
Hope to hear your thoughts on this <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='B)' />
Thanks!
GTW
[/quote]
Field curvature is taken care of in all our tests.
e.g. the Voigtländer 15mm lens is supposed to be a very decent performer when used on the a Leica M6 (film) yet it performs poor on the M9 so there is a sensor dependency somewhere. The Z50 is a much more moderate lens so it SHOULD perform better especially on MFT.
If I had to guess we're primarily talking about the design of the micro-lenses on the sensors possibly in conjunction with the "depth" of the sensitive layer of the (retracted) photo-diodes.
Hi Klaus,
Thanks for this review. I'm looking in to M mount lenses to use on my Sony Nex.
I found an interesting result and a comment in the [url="http://www.opticallimits.com/olympus--four-thirds-lens-tests/469-zeiss_zm_50_2_43?start=1"]ZM 50/2 review[/url] and wish you could explain it a bit more...
First the vignetting characteristic of this lens is very very good at 0.38 stops at f/2. For example the Panasonic Leica Macro-Elmarit 45mm f/2.8 is [url="http://www.opticallimits.com/olympus--four-thirds-lens-tests/490-leica_45_28?start=1"]1.22 stops wide open[/url]. And the ZM 50/2's review also confirms this by saying:
What I'm puzzled by is the comment you made regarding the lens' wide-open corner resolution figures:
After seeing mFT and Sony Nex E-mount cameras with significantly closer flange distances than the M mount, I'm very strongly inclined to think that this offset micro-lens tech of Leica is marketing hype and a hack job to deal with the outdated sensors they put in to their digital M bodies.
I can't see, at least for the FourThirds area, how an M mount lens will have difficulties in getting light to hit the sensor than than any other mFT lens. I think the (low) vignetting characteristics confirm this.
Plus I don't think LiveMOS can be blamed here because it's still just a Bayer pattern system with supposed improvements in sensor fill-factor, read-out and built-in NR.
So my question is... does this mean the ZM 50/2 is actually a "bad" lens in the corners when it's wide open? Could it have been something else that was not accounted for in the review like the field-curvature? I've heard lenses like the Noctilux suffer quite a lot from this.
Hope to hear your thoughts on this <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='B)' />
Thanks!
GTW
[/quote]
Field curvature is taken care of in all our tests.
e.g. the Voigtländer 15mm lens is supposed to be a very decent performer when used on the a Leica M6 (film) yet it performs poor on the M9 so there is a sensor dependency somewhere. The Z50 is a much more moderate lens so it SHOULD perform better especially on MFT.
If I had to guess we're primarily talking about the design of the micro-lenses on the sensors possibly in conjunction with the "depth" of the sensitive layer of the (retracted) photo-diodes.