rafael_macia Posted August 23, 2010 Share #1 Posted August 23, 2010 Advertisement (gone after registration) Sorry if this has been answered already. I have been away from the Forum for awhile, because I "thought" my M8.2 was working correctly. Recently on a trip out West, I experienced cyan corners. It would happen with the Zeiss 18, as well as the 35, and 50 Summicron. All have Leica UV/IR filters, and are coded. I tried downloading Corner fix, but it somehow does not work, or more likely, I am doing something wrong. I open my images in CS4, shoot DNG. here is an example; The lens used is probably a 50 Summicron, or a 35 Summicron Any ideas ? Should I take it to Leica thanks Rafael Link to post Share on other sites More sharing options...
Advertisement Posted August 23, 2010 Posted August 23, 2010 Hi rafael_macia, Take a look here Cyan corners. I'm sure you'll find what you were looking for!
ho_co Posted August 23, 2010 Share #2 Posted August 23, 2010 ... The lens used is probably a 50 Summicron, or a 35 Summicron ... Rafael--Looks as if you did not have the camera set to LENS ID + UV/IR ON. You say "probably a 50 or a 35."--If lens ID was on (and if, as you say, the lenses are coded), the lens would have been identified in the EXIF. The cyan edges indicate that the UV/IR-Cut filter was in place, but that the lens was shorter than the camera thought. If a lens isn't coded, or if it is coded but the camera isn't set to recognize the coding, then the camera defaults to a simple correction of average vignetting, but does nothing against the red absorption caused by the filter. As to using CornerFix: You first have to make a CornerFix profile duplicating the wrong camera settings present in the pictures. In other words, for each of the three lenses, turn off Lens ID and put the UV/IR-Cut filter on the lens. Take a picture of a white wall as directed in the CornerFix instructions. From each of those three pictures, make a CornerFix profile. Then use those profiles to correct the images that show the problem. I think all of us have had similar mishaps; it just takes a few minutes to correct. Good luck! Link to post Share on other sites More sharing options...
rafael_macia Posted August 23, 2010 Author Share #3 Posted August 23, 2010 Howard, Your guess was correct. Lens detection was set to OFF. (I don't know how that happened!). I will now try again to download Corner fix. Following your instructions; hopefully I can correct my mistake. thanks Rafael Link to post Share on other sites More sharing options...
ho_co Posted August 23, 2010 Share #4 Posted August 23, 2010 Rafael-- Glad it was so simple. Sandy has made CornerFix such a great tool because you and I aren't the only ones to mess up this way. Link to post Share on other sites More sharing options...
wda Posted August 23, 2010 Share #5 Posted August 23, 2010 Howard, Your guess was correct. Lens detection was set to OFF. (I don't know how that happened!). I will now try again to download Corner fix. Following your instructions; hopefully I can correct my mistake. thanks Rafael This is where using User Profiles helps. One simple check before shooting and you know you have set desired parameters. Inadvertent resetting of menu items catches us all at some point. But a SET check is easier to do. Link to post Share on other sites More sharing options...
rafael_macia Posted August 23, 2010 Author Share #6 Posted August 23, 2010 Some very recent work, for the first time, I discarded the DNG's. Was that a big mistake ? Can CornerFix work with the TIFF's I made from the DNG's ? re: "As to using CornerFix: You first have to make a CornerFix profile duplicating the wrong camera settings present in the pictures. In other words, for each of the three lenses, turn off Lens ID and put the UV/IR-Cut filter on the lens. Take a picture of a white wall as directed in the CornerFix instructions. From each of those three pictures, make a CornerFix profile. Then use those profiles to correct the images that show the problem." The CornerFix instructions mention taking a picture of a grey wall. So that is a little confusing. The CornerFix instructions are quite complicated. Anyway, I will shoot a white card or wall today under even light and try to follow the rest of the instructions. Does anyone have a real simple step by step? thanking all Rafael Link to post Share on other sites More sharing options...
rafael_macia Posted August 23, 2010 Author Share #7 Posted August 23, 2010 Advertisement (gone after registration) This is where using User Profiles helps. One simple check before shooting and you know you have set desired parameters. Inadvertent resetting of menu items catches us all at some point. But a SET check is easier to do. This is something I will need to do. and while I am taking up Forum space ..... As I asked above ... Will CornerFix work with converted images ? ... I know realize after re reading the Corner Fix instructions ... that DNG is probably the only form of image it handles. Thank G_d I only threw out a couple of DNG's ... and for no real reason except to "save space" or so I thought. Never again! rm Link to post Share on other sites More sharing options...
ho_co Posted August 23, 2010 Share #8 Posted August 23, 2010 Rafael-- CornerFix works only with DNGs. To correct TIFFs, use Photoshop. Apply a circularly graduated filter of the opposite color. That is, if your image has cyan corners, make the graduated filter color magenta. (I'm not using terms correctly here; I don't do corrections well at this stage. Others will correct me.) Looks like a nice trip, by the way--well worth spending the time on! Link to post Share on other sites More sharing options...
ho_co Posted August 23, 2010 Share #9 Posted August 23, 2010 Rafael-- First, don't let CornerFix inhibit you. Properly, you should have a completely evenly illuminated surface large enough to fill the frame when making your profiles. But in this case, you're just trying to get good (not perfect) color, and get rid of the obvious cyan contamination. ONE: So get something big and gray or white, make sure it's evenly illuminated, and shoot it. I recently used a gray building wall with some texture; I've previously used a large white postal envelope that had some folds and wrinkles. Neither of those is optimal, but they're a good start. Or get a large white posterboard at an art supply store if you want, and set it up in the sun. Get far enough away that you don't get a shadow of you and the camera, but close enough to fill the frame. Don't focus on the board. Set the lens to infinity or to closest distance, whichever is furthest from the actual distance. TWO: Then do again what you did wrong the first time: Here you left the camera set to LENS ID OFF, so you do that again. Take a picture of the gray or white card with the same lens you used before, again with lens ID off, and overexpose according to Sandy's CornerFix instructions. Then repeat with each of the lenses you used on your trip. (I don't think the 50mm will show enough of the cyan corners to worry about, but shoot with it as well if you want to.) THREE: Use CornerFix to make a separate profile from each of these intentionally wrong images. See CornerFix instructions. FOUR: Using the Default Settings, apply the profiles just made to the DNGs you want to correct. See CornerFix instructions. FIVE: Process in Photoshop or Capture One or whatever. MOST IMPORTANT: CornerFix is amazingly adaptable. Don't worry about not having the perfect subject for your profiles. Once you've played with the program, you can go back and reshoot the profiles to improve them if you need to. You'll still have the original DNGs, so you'll just run them through the new profile to get a better starting point. Link to post Share on other sites More sharing options...
rafael_macia Posted August 24, 2010 Author Share #10 Posted August 24, 2010 Your detailed instructions are most appreciated ! Rafael Link to post Share on other sites More sharing options...
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