ZM15 coding question

[JL2006]

I have coded the ZM15 as a WATE. I have tried 16mm/18mm/21mm settings and they all show considerable amount of over-correction of cyan drift. Has anyone coded his ZM15 as somethings else that works?
The 1st pic as WATE16
The 2nd pic as WATE18
The 3rd pic as WATE21

[Philippe D.]

Hello,
just one question because i would love using this lens.
Are the pictures here taken with the central filter please ?

[JL2006]

Hi - No central filter, just a 72mm B+W 486UV/IR cut

[Philippe D.]

Originally Posted by JL2006

No central filter

This could be the reason.
The lucky day i have a Distagon 15, i'll use it only with CF.

BTW, i don't use any Leica IR filter on my Distagon 18, i prefer the results without.
I would certainly NOT use the B+W IR filter either.

[sean_reid]

Originally Posted by JL2006

I have coded the ZM15 as a WATE. I have tried 16mm/18mm/21mm settings and they all show considerable amount of over-correction of cyan drift. Has anyone coded his ZM15 as somethings else that works?
The 1st pic as WATE16
The 2nd pic as WATE18
The 3rd pic as WATE21

It's tricky (even the WATE itself) because those corrections are based on some averaging assumptions. As such, they work better for some lighting than for other. Also the B&W filters tend to provide stronger filtration than the Hoy...um...Leica filters so the correction can be further mismatched.

Basically....if none of the WATE corrections work for you try coding for a longer lens or turn off coding detection and use Cornerfix.

Cheers,

[robertwright]

with the cv15 and the leica 39mm filter I use the 21mm WATE setting and have the milich mount coded for WATE. It generally works ok, but I see what you see similarly at the 21 setting.

It depends on what you shoot if the red corners appear and are noticeable. There is no magic bullet except for perhaps cornerfix but I have not had great results with that. It depends on how good your profiles are, plus it is aperture-specific if you want to get picky about it, and also you can get some posterization in the corners if there is a gradient present of dark colours, like a deep blue sky for instance. Initially the posterization might not be there but if you do any tonal correction it can rear up.

I use the cv12 unfiltered and with coding off and it works very well, you might just try without filters at all. Whatever you do run into might be easier to fix.

hth.

[JL2006]

Thanks Sean. I give up the idea of using cornerfix because 1) I cant setup the lense profile properly and 2) i always forget to turn off lens detection on M8 when i use un-coded lens.
Also, i find something funny happen when i use cornerfix.....the sky of the attached picture has circular pattern in the sky.
Since there is no 72mm leica uv/ir fiter I may have to try to code the ZM15 as a 28/2.8, using the b+w uv/ir.

[sean_reid]

Well then, maybe try coding as a 24 next. The thing is that might work well in some kinds of light and not so well in others. But it could be worth a shot.

Cheers,

Sean

[msadat]

have you tried it with cf filter and not coding or ir filter, it works pretty good like that

[adan]

Interesting. The Zeiss Distagon is more of a retrofocus design (more like a 14/15 for an SLR) than the Leica WATE or C/V lenses (thus its larger size). The name itself implies retrofocus design (among Zeiss lenses) since retrofocus lenses sit at a greater DISTA-nce from the image plane than symmetrical wideangles. Thus all the Hasselblad/Zeiss wides are Distagons (to clear the Hassy SLR mirror) except for the 38mm Biogon which does not allow room for a moving mirror and requires a dedicated "short" body.

You could try a Heliopan "Digital" IR filter - they tend to be stronger than Leica's UV/IR filters and thus might increase the amount in cyan in the corners, better matching Leica's software corrections, with less red over-correction.

I use a Leica filter on my C/V 15mm, and the correction, when the camera thinks it is a WATE set to 16mm, is just about perfect. For that very short lens, a Heliopan is too strong, and the M8 software under-corrects (corners are still green).

But Sean's suggestion to change your coding to "de-rate" the correction to that of a 24 or 28 lens may be faster and simpler if you already have the B+W filter in hand.

Plus, you avoid the necessity of punching in the focal length every time you turn on the camera or mount your WATE-coded lens (probably the single biggest PITA I have using the M8 system with the C/V 15mm, myself).

Just out of curiosity, which internal set of framelines appear when the Zeiss 15mm is mounted?

[JL2006]

I think the WATE frameline is 28/90, so i will have to try to code it as a 28mm. To code it as a 24mm I have to change the flange again......

[JL2006]

Also, is the cornerfix question on hand origins from an incorrect ZM15 lens profile ? I always see circular pattern in the sky after applying cornerfix.

[Philippe D.]

Hi,

Originally Posted by adan

Just out of curiosity, which internal set of framelines appear when the Zeiss 15mm is mounted?

50-75

[sandymc]

Originally Posted by JL2006

Also, i find something funny happen when i use cornerfix.....the sky of the attached picture has circular pattern in the sky.

A circular pattern in the sky almost certainly means that CornerFix is configured to operate in 8-bit "level compressed" mode. Unless you really need that (which should only be the case if you're using a pre-V4 version of Capture One) you should switch off Level Compression.

Sandy

[ghammer]

Originally Posted by Philippe D.

Hi,
50-75

Et voila : Coding works only with corresponding framelines. Coding as WATE makes only sense with 28/90 framelines. The EXIF data show which lens the camera thinks has been mounted (and which correction has been applied).

[JL2006]

Originally Posted by sandymc

A circular pattern in the sky almost certainly means that CornerFix is configured to operate in 8-bit "level compressed" mode. Unless you really need that (which should only be the case if you're using a pre-V4 version of Capture One) you should switch off Level Compression.

Sandy

Thanks Sandy - I will try again, looks to me cornerfix is the only solution for this lens

[Philippe D.]

Originally Posted by ghammer

Coding works only with corresponding framelines.

Exactly.
Good news, it is possible to have a substitution with the Zeiss 28-90 bayonet for the Distagon 15 and 18mm, the Biogon 21mm f/2.8 as well as 21mm f/4.5
For the Biogon 25mm a conversion to 24-35mm is useful.
All other ZM lens (28mm and up) shows the correct framelines.