Kent10D Posted February 10, 2008 Share #1 Posted February 10, 2008 Advertisement (gone after registration) Just developed and scanned some images taken with the CV 15/4.5 on an M6, no filters, Fuji 1600 film. There is an effect/artifact in many of the shots that I haven't seen with any other lens. Objects to the left and right of the frame have "echoes" extending in the corresponding direction. You can see it to the left of the curly sculpture and to the right of the tree. Haven't seen it near the center of the frame in any of the shots, so I'm assuming it's lens related. I chose this shot with the almost-blown sky (it isn't totally blown ... really!) because the effect is easier to see. It's very obvious in the crop. Has anyone seen this before? Know what it is? Link to post Share on other sites More sharing options...
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reality Posted February 10, 2008 Share #2 Posted February 10, 2008 Hi Kent, I recently had the same kind of fringing on two or three TX-2 shots with the Fuji 45mm on Portra 400VC. Didn't know what it was, so put it down to either the film or developing. Didn't happen on any roll of film before, nor has it since. Also have the CV 15 and have never had this kind of effect with that lens. Sorry, this probably isn't much help. All the best, Brett. Link to post Share on other sites More sharing options...
Kent10D Posted February 10, 2008 Author Share #3 Posted February 10, 2008 Thanks Brett. It does help actually. At least I know I'm not the only one who's experienced this type of artifact. It's visible on a couple of shots on this one roll, but I've never seen it before (and hope I don't see it again). Just a bit mystified. Link to post Share on other sites More sharing options...
LeonardT Posted February 10, 2008 Share #4 Posted February 10, 2008 Hi Kent, I have never seen anything this pronounced on a BW photo but if I had to guess I would say it was bad CA caused by the extreme contrast of the black against the sky. It might be aggravated by the very fast film. The only place you see this ghosting is against the sky, even fairly close in to the center. The less contrasty areas around the grey building don't show it. I see a less exaggerated form of this in my bird pictures where tree limbs against the sky will have green or magenta edges. Very interesting though. Len Link to post Share on other sites More sharing options...
Photoskeptic Posted February 10, 2008 Share #5 Posted February 10, 2008 Hi Kent, man that is really strange. May be a bit of everything - that film, those lighting conditions and that lens. I've shot a similar configuration but I dumped 1600 film years ago due to grain issues. Today I never shoot anything over 400 speed. Good luck with the problem. Link to post Share on other sites More sharing options...
Kent10D Posted February 10, 2008 Author Share #6 Posted February 10, 2008 Thanks for the feedback guys. The exaggerated CA theory sounds good, but check out the example I've posted below (a close crop ... so you won't be bored by the otherwise dull photo). The faint ghost image of the lamppost is actually separated from the lamppost itself. Like a shadow in the sky. Very weird. But there's no doubt that it does only appear in high-contrast areas like these, so I suppose some kind of CA might be a viable explanation. Anyway, the upshot is that I'll probably avoid that particular film for the time being. If I get a chance to shoot the CV 15/4.5 with a different type of film I'l be sure to take some high-contrast shots like these to see if it's the lens. So for now, we have a mystery (cue X-files theme music ...). Link to post Share on other sites More sharing options...
luigi bertolotti Posted February 10, 2008 Share #7 Posted February 10, 2008 Advertisement (gone after registration) Sorry, maybe a stupid question, but are you sure the shadows ARE into the NEG ? I ask because my first thought would go to a problem of scanning. Link to post Share on other sites More sharing options...
Kent10D Posted February 11, 2008 Author Share #8 Posted February 11, 2008 Sorry, maybe a stupid question, but are you sure the shadows ARE into the NEG ? I ask because my first thought would go to a problem of scanning. Not a stupid question at all, Luigi. It just meant that I had to get off my lazy derriere and drag out the light box and some loupes. OK, I just spent some time examining the negs on a light box with a variety of loupes, including a good 25x measuring magnifier, and yes, I can see a change in the density of the grain around the edges in question. It's subtle on the negs, of course, but it's there (unless my mind is playing tricks on me ... wouldn't be the first time). The fact that I hadn't seen the effect in the past with scans made on the same scanner (Nikon Super Coolscan 5000 ED) led to me eliminate that possibility without really examining it, so thanks for the motivation. Link to post Share on other sites More sharing options...
vickersdc Posted February 11, 2008 Share #9 Posted February 11, 2008 My thought was that it had been caused by the scanning too. David. Link to post Share on other sites More sharing options...
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