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Any suggestions to cure "red edge" with 28 Cron Asph?

baudolino

Active member
Hi, does anybody have specific recommendations to cure the "red edge" problem with the 28 Cron Asph? I received the lens today and put it to some testing and, volia, the red edge problem looks pretty serious on the M9, accompanied by a corresponding bluish edge on the right (see attached images, the first @f8, the second @f2.0, it actually looks much worse on a large screen). The lens is coded and my firmware version is 1.138. Looks like Leica don't have this issue under control yet. And then RF Leicas are supposed to be "wide angle specialist cameras". Oh dear..., looks like the M9 really is a 50mm and 35 mm specialist camera, for the moment (at least for me).
 

Bill Caulfeild-Browne

Well-known member
I'm surprised - I've been using the 28 Cron asph for 3 months or so and have never noticed this. (I see it in spades with the Voigtlander 12 mm!).

I'll have another look at my files. Could be the nature of the shots has disguised the problem.

Bill
 

D&A

Well-known member
The Exif data says "28mm", so it appears to picking up the coding alright. Maybe others have reported red edge with the 28mm cron, but I haven't heard of it before with this lens, and certainly not as much as evident in your images. I haven't seen it either with the 28mm cron. Have you tried any other 28mm or wider with your particular M9? This might give us some clue of which direction to turn.

Dave (D&A)
 

Bill Caulfeild-Browne

Well-known member
As promised, I've looked at a number of my 28 Cron files now including several with snow/grey skies and can't see any problem.

I wonder if your M9 is reading the lens properly as Jan suggests.

Bill
 

baudolino

Active member
The camera identifies the lens correctly - it is described as "Leica Summicron-M 28mm f/2 ASPH." in the EXIF data as picked up by LR. Perhaps the conditions where the shots were taken were a bit extreme (diffuse light, grey skies). I will continue testing. Thanks everybody for your suggestions.

Martin
 

Leicadoc

New member
The problem is even more acute on the Heliar 21/4.0.
Cindy Flood showed me Cornerfix (http://sourceforge.net/projects/cornerfix/), and I am now using on 21/28/35 mm lenses. It is simple to use, will let you process in batches, and is quite good, I believe You just need to shoot a white card/gray card/white wall, or some such. An example:

M9 and Heliar 21/4.0:
Before



AFTER:
 

Bill Caulfeild-Browne

Well-known member
For weeks I've been promising myself that I would make a Lens Color Cast (LCC) profile in Capture One, using the LCC white plastic panel supplied by Phase with their cameras, for my VC 12 mm Heliar.

I finally found enough time today to do it, and the results are outstanding - better than I have been able to achieve with Corner Fix.

I strongly recommend this approach. I'll try and post something tomorrow - it's -22C here today and I'm not going out again!

Bill
 

Chuck Jones

Subscriber Member
Baudolino, I'd immediately return that lens, or exchange it if possible. That particular lens has an element out of alignment and needs to go back to Leica for repair. Likely may need at minimum a CLA, and possibly an element replacement if one is cracked. This looks to me like a lens that has been dropped onto a hard surface, or taken the brunt of a fall when the photographer tripped, like the last time I saw this exact problem. My 28 'Cron is perfect on my M9 body.

You can try Corner Fix or whatever Photoshop tricks you like, but why deal with a defective lens in the first place if you just bought it? A proper functioning 28mm 'Cron on an M9 should be spectacular. One of the top lenses in my opinion made for the M camera, both digital and for film.
 
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Bill Caulfeild-Browne

Well-known member
Here's a shot I just took, -20C so I didn't spend a lot of time on composition! These are with the M9, VC 12 mm Heliar at ISO 320, F8 +2/3 exp.comp.

First, straight out of the camera at C1 defaults.



And here is the same shot with the Phase LCC correction but no other processing..



The sky was brighter on the left - the sun was setting in that direction.

Bill
 

baudolino

Active member
Bill, this looks superb - I really like the result. Now the previous owner from whom I bought the lens on the famous auction site desperately wants it back, saying he regrets having sold it. So I guess I will follow Chuck's advice... Having said that, I like the focal length and if I can get a good copy of the lens, I will buy it again (attached is a shot from two days ago, with corners fixed using the grad filter tool in LR). Thanks for your advice, everybody. Martin

----------

 

Bill Caulfeild-Browne

Well-known member
I think Chuck gave you good advice...good luck finding another copy. I found my 28 Cron used and am very very pleased with it - no red/cyan fringing!

And I like your last shot even if it did need correcting!
Bill
 

baudolino

Active member
I think Chuck gave you good advice...good luck finding another copy. I found my 28 Cron used and am very very pleased with it - no red/cyan fringing!

And I like your last shot even if it did need correcting!
Bill
Bill, the LCC thing in C1 really works well, thanks for your advice! And it is quick. There is one more benefit, as I discovered today - I took my white card with me, set manual white balance on the M9 and then shot the white reference (LCC file), in the same light. Now the benefit is, no surprise there, :) that my white balance setting was spot on, in addition to having the corners fixed. So the lesson for me is to carry the white card with me always, set WB manually at the beginning of the shoot and then shoot a white reference file for the lens. It really is quick and works perfect, at least as long as the light remains the same. The only remaining effort for me is to start liking the C1 :) (to C1's credit, I have to say that it also handles moire with the M9 much better than LR; in fact, what I considered a rather bad moire problem with my M9 - especially with tree branches, reeds etc - now seems almost non-existent).

I attach two files - the first straight out of C1, the second with the LCC profile applied.

View attachment 39803
View attachment 39804
 
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Bill Caulfeild-Browne

Well-known member
Glad it's working for you, Baudalino. Sure does for me!

I was a Lightroom user until I mastered C1, which did take a while, but now I find Capture One 6 far better for post processing and only use LR for cataloguing.

Bil
 
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