marknorton Posted December 23, 2013 Share #1 Posted December 23, 2013 Advertisement (gone after registration) An interesting but slightly depressing follow-up article showing that there has been only modest progress from the M9 to the M and in the latest firmware in addressing the Italian Flag Problem (IFP). Any thoughts that the move to the CMOS sensor might solve this problem at a stroke were ill-founded and it must be frustrating trying to make a silk purse out of this particular sow's ear. LFI have gone to significant lengths to analyse the problem and have singled out the 28mm Summicron for evaluation. They conclude there is more to do with, ultimately, the need to fall back to a post-processing solution. Maybe the problem cannot be fixed by the sensor alone and a new generation of tele-centric wide angles is needed. Link to post Share on other sites More sharing options...
Advertisement Posted December 23, 2013 Posted December 23, 2013 Hi marknorton, Take a look here LFI 1/2014 - Italian Flag Problem. I'm sure you'll find what you were looking for!
rirakuma Posted December 23, 2013 Share #2 Posted December 23, 2013 Which lenses have this problem on the new M? I haven't come across any corner color problems with the 21sem and wate. Link to post Share on other sites More sharing options...
jaapv Posted December 23, 2013 Share #3 Posted December 23, 2013 Real world non pixelpeeping:On all more recent lenses the problems are basically insignificant. I extremely critical images you might want to use a flat field plugin in LR but that is a rather rare occurence. Only one or two vintage lenses exhibit more colour drift. And of course some third party lenses. Link to post Share on other sites More sharing options...
masjah Posted December 23, 2013 Share #4 Posted December 23, 2013 Obvioiusly I have read of this problem, but, since I don't have an M (yet) I have no direct experience. But can I ask those who know, would it be reasonable to think that using very wide R lenses (assuming the adapter actually exists) would cause less of a problem because they inherently are more telecentric? Link to post Share on other sites More sharing options...
dwbell Posted December 23, 2013 Share #5 Posted December 23, 2013 Real world non pixelpeeping:On all more recent lenses the problems are basically insignificant. I extremely critical images you might want to use a flat field plugin in LR but that is a rather rare occurence. Only one or two vintage lenses exhibit more colour drift. And of course some third party lenses. Seems odd of LFI to go to such lengths on what is a 'basically insignificant' problem. Seems even stranger to conclude that post processing is likel to be the fall back fix for something that affects 'one or two vintage lenses.' Link to post Share on other sites More sharing options...
jaapv Posted December 23, 2013 Share #6 Posted December 23, 2013 My 16 mm semifisheye has no problem at all. Link to post Share on other sites More sharing options...
jaapv Posted December 23, 2013 Share #7 Posted December 23, 2013 Advertisement (gone after registration) Seems odd of LFI to go to such lengths on what is a 'basically insignificant' problem. Seems even stranger to conclude that post processing is likel to be the fall back fix for something that affects 'one or two vintage lenses.' It appears you haven't read (or understood) the article. Link to post Share on other sites More sharing options...
dwbell Posted December 23, 2013 Share #8 Posted December 23, 2013 It appears you haven't read (or understood) the article. "Even with the latest firmware, concerns over Italian Flag issues with wide angles lenses, while reduced, are not fully laid to rest" Just doesn't tie with your claims that it's "basically insignificant" as far as I can see. But maybe I am, as you keep valiantly trying to imply, incapable of grasping things intellectually? Link to post Share on other sites More sharing options...
jaapv Posted December 23, 2013 Share #9 Posted December 23, 2013 It is not significant with most subject matter. Link to post Share on other sites More sharing options...
chris_tribble Posted December 23, 2013 Share #10 Posted December 23, 2013 My experience with M-240 + Zeiss 18mm / Leica 21 pre-asph / 28 asph is positive. NONE of the problems that I had with the M9. Link to post Share on other sites More sharing options...
dwbell Posted December 23, 2013 Share #11 Posted December 23, 2013 It is not significant with most subject matter. Further qualification on your opinion is welcome, thanks. My 35cron was terrible on both my M9's and shows no problems on the M240 even if I look. But it isn't in the 'wide angle' realm either. Link to post Share on other sites More sharing options...
jaapv Posted December 23, 2013 Share #12 Posted December 23, 2013 SEM 18 is fine, Elmarit 28 (iii) is mostly fine. Summicron 35 asph is fine. Link to post Share on other sites More sharing options...
marknorton Posted December 23, 2013 Author Share #13 Posted December 23, 2013 Looking at the graphs, the performance seems fine along the 24mm vertical gradient. Different matter with the 36mm horizontal gradient which then impacts the diagonal result. It's clear there's more work for Leica to do. It might be that further improvements will come from firmware updates but sensor and lens developments will be key too. The 28mm Summicron - about the oldest lens in the wide-angle stable - is ready to be replaced and it's likely its replacement and other newer lenses are/will be better behaved. Remember the early results of using M lenses on an MFT camera? The 28mm Summicron had quite poor edge performance which is presumably down to the proximity of its exit pupil the the sensor. An interesting piece of work by Michael et al. It might be newer wide-angle designs from Leica would have shown better performance. The M is an improvement on the M9 and it will be interesting to see where Leica go next. Link to post Share on other sites More sharing options...
bocaburger Posted December 23, 2013 Share #14 Posted December 23, 2013 21 CV, 21 Pre-Asph, 28/1.9 CV, 28 Elmarit IV, 35 Cron III and IV, 35/3.5 CV, never encountered Ital flag. That's on the M9. Only tried the Cron IV on an M and no problem. I can't say I ever saw it with the CV 12 or 15 either, but I don't shoot those all that often. Maybe if I tried my 35/3.5 Summaron from the 50s I'll see it, that being the most vintage W/A I own. Link to post Share on other sites More sharing options...
thsc Posted December 23, 2013 Share #15 Posted December 23, 2013 In real life I've never had this problem. I use the M240, and have made many thousands of photos with 2/28 and 3.4/21 ... without italian flag. Link to post Share on other sites More sharing options...
thighslapper Posted December 23, 2013 Share #16 Posted December 23, 2013 Seems odd of LFI to go to such lengths on what is a 'basically insignificant' problem. Seems even stranger to conclude that post processing is likel to be the fall back fix for something that affects 'one or two vintage lenses.' I would imagine this was provoked by several long threads here a few years ago speculating on the actual cause ....... And finally some half sensible explanations (which I am pleased to say are along the lines of my original conjectures ) which go some way to explaining why the issue is so damn difficult to completely eradicate..... Link to post Share on other sites More sharing options...
albireo_double Posted December 23, 2013 Share #17 Posted December 23, 2013 I am experiencing very slight "italian flag" / red edge with the 24mm Elmarit Asph and also very slightly with 21 SEM. It only shows in situations such as white clouds in the sky, and only if I look for it. It has always been quick to fix with the gradient tool in LR, just by dialling in a bit more green / red, without any science or exact method. My experience with the M240 is better in this regard than with the M9 - with that camera, I found the 28 Cron Asph the worst offender, to the point that I sold it after a short time. Link to post Share on other sites More sharing options...
hoppyman Posted December 23, 2013 Share #18 Posted December 23, 2013 I am waiting for my LFI copy to arrive. I enjoy learning from these articles as part of the magazine. Adobe has published an interesting note on addressing this with their flat field plug in. http://labsdownload.adobe.com/pub/labs/lightroomplugins/lightroomplugins_dngff_docs.pdf Link to post Share on other sites More sharing options...
marknorton Posted December 24, 2013 Author Share #19 Posted December 24, 2013 Well it's good to have that ability but a bit of a hassle isn't it and I wonder if it's smart enough to recognise you've taken the calibration shot after the real shot rather than before. You can hardly ask the subject of your street shot to hang on for a moment... Any thoughts on what to use as a diffuser? Link to post Share on other sites More sharing options...
photolandscape Posted December 24, 2013 Share #20 Posted December 24, 2013 An interesting but slightly depressing follow-up article showing that there has been only modest progress from the M9 to the M and in the latest firmware in addressing the Italian Flag Problem (IFP). Any thoughts that the move to the CMOS sensor might solve this problem at a stroke were ill-founded and it must be frustrating trying to make a silk purse out of this particular sow's ear. LFI have gone to significant lengths to analyse the problem and have singled out the 28mm Summicron for evaluation. They conclude there is more to do with, ultimately, the need to fall back to a post-processing solution. Maybe the problem cannot be fixed by the sensor alone and a new generation of tele-centric wide angles is needed. Even with the latest FW, which offered some improvement in dealing with the Italian Flag Syndrome on my M, I still encounter it with my 35mm Summicron ASPH and 24mm Elmar ASPH. I apologize upfront if I am a bit of a purist, but to me, this problem should have been solved long ago by Leica, not through on-going post-processing. I also believe it varies from body to body and lens to lens, and I am sending my M and lenses in to see if Leica can make some adjustments. Leica did an excellent job via FW with corrections to the problem on the M9, so I would hope further tweaks with FW might improve on the situation, though again I realize it varies from camera to camera, etc. Honestly, if the next Leica rangefinder comes out and exhibits Italian Flag Syndrome, I will probably move on to some different camera line in the future. It is that big a deal to me. Link to post Share on other sites More sharing options...
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