tappan Posted March 25, 2013 Share #1 Â Posted March 25, 2013 Advertisement (gone after registration) Hello, I snapped these M9 photos tonight using a 50mm Summicron collapsible and a 90mm Elmarit. Notice the difference in the lights in the middle, with the 90mm lights being pink or majenta and the 50mm being more normal. I had the 90mm on lens dependent "Manual 90mm 11807" and the 50mm at "50mm 11817" I had a UV filter on the 50mm and no filter on the 90mm. Any thoughts on why the difference? Thanks, Mark Link to post Share on other sites More sharing options...
Advertisement Posted March 25, 2013 Posted March 25, 2013 Hi tappan, Take a look here Strange color difference, 90mm vs 50mm. I'm sure you'll find what you were looking for!
tappan Posted March 25, 2013 Author Share #2  Posted March 25, 2013 Here are the photos, sorry. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members!    Mark Link to post Share on other sites Simply register for free here – We are always happy to welcome new members!    Mark ' data-webShareUrl='https://www.l-camera-forum.com/topic/201248-strange-color-difference-90mm-vs-50mm/?do=findComment&comment=2281212'>More sharing options...
k-hawinkler Posted March 25, 2013 Share #3 Â Posted March 25, 2013 Hi Mark, Â With your .DNG files you could try to reduce chromatic aberration in LR4 or CS6. I wonder if that helps? Good luck! Link to post Share on other sites More sharing options...
pop Posted March 25, 2013 Share #4 Â Posted March 25, 2013 In the 90mm shot there appears to be much less ambient light than in the 50mm shot. Both the sky and body of water appear much darker. However, even with the darker sky and water the buildings and lights are much brighter. This makes me think that the lights are rather overexposed. In the white centers of the lights all colour channels are clipped while in the magenta border only the green one is. Are the funny lights also visible in the original raw image? Link to post Share on other sites More sharing options...
Paul J Posted March 25, 2013 Share #5 Â Posted March 25, 2013 I'm guessing you have it on Auto White Balance. The tighter framing of the 90mm is definitely going to give a different response. Link to post Share on other sites More sharing options...
tappan Posted March 25, 2013 Author Share #6 Â Posted March 25, 2013 Thanks for the replies. Yes, the raw image is the same situation and yes auto white balance on both. Mark Link to post Share on other sites More sharing options...
jto555 Posted March 25, 2013 Share #7 Â Posted March 25, 2013 Advertisement (gone after registration) Hi Tappan, was there a few minuets between taking the shots? The 90mm shot looks like it was taken at a later time. This would explain the colour difference. Â John Link to post Share on other sites More sharing options...
tappan Posted March 25, 2013 Author Share #8  Posted March 25, 2013 Hi Tappan, was there a few minuets between taking the shots? The 90mm shot looks like it was taken at a later time. This would explain the colour difference. John  Hi John, yes. Unfortunately I came upon this too late to set up a tripod. I just snapped a few with the 50mm and then put a beanbag on the roof of my car and snapped about 6 minutes later with the 90mm. The color shift that I am curious about is not the whole frame, just the middle lights. 90mm middle lights are magenta and blow out. Thanks, Mark Link to post Share on other sites More sharing options...
CheshireCat Posted March 26, 2013 Share #9 Â Posted March 26, 2013 Magenta may be caused by sensor blooming or back focus. To check for blooming underexpose by a couple stops. To check for back focus, focus nearer and see if blooming diminishes or disappear. Link to post Share on other sites More sharing options...
Ecar Posted March 26, 2013 Share #10 Â Posted March 26, 2013 Different lenses/optics, different coatings, different aperture used... I assume the 90mm exposure was also longer, hence more risks of blooming in the highlights. Link to post Share on other sites More sharing options...
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