Solution: M 240 - Zeiss 21/4.5, and fixing red edges

I was actually a little bit surprised at how little effort people have put into the problem - particularly Lloyd Chambers, who when confronted with the existence of Adobe Flat Field (which is how I got onto this), basically just griped that it didn't work with ACR and that Leica should have designed its system better. This is not uncharacteristic of the professional reviewer ranks; there does not seem to be a lot of investment in solutions.* And in this instance, I wonder about professional reviewers' view of what is practical in real life, too - since Flat Field exports to a DNG, you can still pull the resulting file into ACR. Even if you wanted to control illumination falloff in ACR (which makes no sense to be since ACR and Lightroom are similar if not identical in these controls), Adobe Flat Field lets you correct only the color shift if you want.

Dante

*That's not surprising; in a world where people get free loaners to the point where the FTC requires disclosures, the emphasis is often on throughput, getting the scoop, and providing enough material of wide interest to justify the subscription charges. People who buy their own equipment have more time, less pressure, and additional incentives to learn how to make things work. In this case, the total time investment to fix this problem was actually about two hours; writing it up took half an hour.
 
I sincerely hope this works on the M9.
Having owned the Zeiss 21/4.5 on my M6TTL for a while, the results on b&w film were absolutely superb.
I foolishly sold the lens and am in limbo about which 21 to choose now I own the M9 alongside the M6TTL.
I may have to get another 21/4.5.

Steve.
 
Do you know if the 21/3.4 and zeiss 21/4.5 have similar distances from rear element to sensor? I tried the flat field plug in with the SA and wasn't very happy with it - the corners were mushy at all apertures. I didn't try at various focus distances + apertures like you did so maybe that would make a difference.
 
Do you know if the 21/3.4 and zeiss 21/4.5 have similar distances from rear element to sensor? I tried the flat field plug in with the SA and wasn't very happy with it - the corners were mushy at all apertures. I didn't try at various focus distances + apertures like you did so maybe that would make a difference.

Mushy corners aren't something that flat field is really designed to fix - but if you want to DropBox me some DNGs, I can see if the 21/4.5 corrections work for the color.

Dante
 
Dante,

Can I ask quickly have you shot at simply a single ISO setting and the various apertures, or whether you have expanded your profiling shots out over various ISO stops at all apertures?

I'd like to start creating my sets and after the incredible hassles of the lens correction profiling with charts and various other things I'm wondering if the time involved is as long for the edge fixes.

Regards
Steven
 
Steven -

The two variables I controlled were aperture and focused distance. I let ISO float from 800 to 2500. This helped keep exposure times manageable. Not sure that the ISO is going to matter (it didn't seem to introduce any noise), especially since the diffuser shots do not exactly tax the dynamic range of even high ISOs.

Dante
 
Dante,

I've finally got round to profiling everything and I can say the instructions were ideal. Across my M9 and the Sony A7 I picked up for the days when I feel like some automation it really does do the business. On the A7 so much so I'd say the Voigt 12mm is actually a close tie to the M9 as there is no single sided noise due to the usual red right shifts on the Sony sensor also the increased D-range it has. Alas no M-240 to compare it with.

Highly recommended to all. The inital pain is well worth the results when you really want that extra little bit of perfection in the digital M's with biogon style designed wides.

To add I used a flash gel frost folded over a fair few times, set a manual white balance against that whilst pressed to the window pointed at a lovely overcast grey Scottish sky and overexposed by 3 stops to get my profiles.

Steven
 
I've posted a review and tutorial here. In short, some new software makes the 21/4.5 completely usable on the M typ 240, and the same techniques could be used to process files shot with other M lenses or where an M or LTM wideangle is used with something like a Sony A7.

http://wp.me/p2RAff-7

Dante

agree totally. May I add Capture One which incidentally gives better results for M240 files in a number of cases, especially color shifts under Tungsten and very bright sunlight.
It has an extremely well thought out flat field correction called LCC profiles.
Once set up it is literally a one- click operation.
 
I'm about to start profiling my 21 mm C-Biogon (and 15 mm Voigt v2) in the coming days, and was wondering if shooting the reference shots against a light table would work, just by letting the lens rest on the edges of the hood agains the table and adding ~ +2 stops of exposure compensation.

Anyone done/tried that?
 
I just ran across this thread and thought it might work for my CV 25f4 Snapshot Skopar.
I downloaded the folder and all, but i have a problem. LR will not install the plug in... It's extracted and all, and I've tried saving it to various locations (thinking that was the problem), but no matter where I save it, when I tried to add it to the list of plug ins, it is somewhat "greyed out" and when I just press the "Add plug in" button, I get an error message from LR.... Any ideas how to fix this?

BTW, I'm running Yosemity 10.10.1 in my Macbook Pro

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I tried the 21 3.4 SA recently at the Leica Store
On the M240...
The Image looked Quite Good with that classic SA retro sharpness
however the edges had a purple hue ... Maybe your 'Fix' may be the trick for 21SA users
 
I'm about to start profiling my 21 mm C-Biogon (and 15 mm Voigt v2) in the coming days, and was wondering if shooting the reference shots against a light table would work, just by letting the lens rest on the edges of the hood agains the table and adding ~ +2 stops of exposure compensation.

Anyone done/tried that?

I just used a sheet of Yupo watercolor paper (plastic) against a window. But I have also done it against a Flos Glo-Ball halogen lamp. There is no reason in theory why a light table wouldn't work. I'd skip the hood.

Dante
 
Adobe is about to publish lens profiles to most of the Voigtlander Leica M lenses. Some have already been published. Stephen

Lightroom/CR profiles don't fix color shifts; they just correct for CA. For color shifts, you need full-sized, full frame masks or flat field calibration files.

Dante
 
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