TimSelim Offline Upload & Sell: Off
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p.1 #16 · Distagon 21/2.8 ZF vs. C/Y | |
Hello,
I have a ZF21 and a 5D, and I'm seeing cyan-tinted corners. It's only really noticeable in shots with white or grey in the corners, but look for it and it is there in every shot.
It's easy enough to fix in PS, by just creating a duplicate layer, adding a layer mask with a big fuzzy black circle in the middle (covering all but the corners), then using curves on the duplicate layer to raise the red channel a little (and drop the blue a touch). I'd prefer not to have to do that of course.
I also have a Contax 21 distagon, and with that I can't see any colour shift in the corners.
For anyone who's interested, here are the main IQ differences I've noticed between the Contax and the ZF so far. I'm using Kindai adaptors. As far as I can tell, infinity focus is spot on with both lenses.
Colour rendition - as above, plus the Contax is slightly cooler
Sharpness - no real difference (at least not with the 5D). If anything the ZF is a tad sharper across the frame, but I reckon a 'good' copy of either lens would outdo a 'not-so-good' copy of the other.
CA - the ZF shows very slight red/cyan fringes, the Contax purple/yellow
In both lenses you only see any fringes when viewing the corners at >100%, and then only when the contrast is high (eg: dark branches against a bright sky).
With the ZF what little CA can be completely killed by dialling in -8 in ACR or +1 in the PS Lens Correction tool.
Contrast - no obvious difference but the ZF might be a touch more contrasty
Flare - The ZF is a lot better than the Contax, but when shooting straight into the sun it's still far from perfect (as you might expect). The ZF does have a few 'sweet spots' where flare and ghost images are minimised, if you compose to get the sun (or whatever other bright light) in the 'right' place. It needs a few pictures to illustrate what I'm trying say here, but I've not stumped up to upload images yet.
The ZF iris has 9 blades, the Contax has 6. So the ZF renders bright point sources with 18 rays, versus the Contax with its six points. Which you prefer is entirely a matter of taste. I prefer the ZF, and with its better flare performance it suits me a lot better for shots where the sun is in the frame.
Sample variation - I'm a bit dumb so I've wound up with two copies of the ZF21 (for now). At least I can say that the two I have are nigh-on identical. One seems to have just a whisker less CA and flare. They both show the same cyan-tinted corners. FWIW the serial numbers are about 850 digits apart.
Focal Length - my copy of the Contax is a just little bit wider than my two copies of the ZF, both of which are the same.
Distortion - yup, the ZF makes straight lines wavy, just like the Contax.
Is the ZF worth buying then?
Well I can't speak for anyone else but I bought it because I'm seriously thinking of getting a Nikon body and didn't like the idea of giving up the 21 distagon. For a wide angle view, 20mm seems to be the ideal FL for me - not too wide, not too narrow.
Apart from the cyan-in-the-corners, IMO the ZF21 has all the virtues of the Contax 21 *and* it almost matches the very good flare resistance of the 3.5 AI.
The Nikon 14-24 might well have been a better choice, but I shan't know until I've tried one for myself.
Cheers
Tim
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