biswasg Posted July 31, 2011 Share #1 Â Posted July 31, 2011 Advertisement (gone after registration) Recently, I have started noting that images created with my Summicron 50mm have a strange semicircular band on the upper right of the image. The band is seen clearly when that portion of the image is clear. The problem is repeating and occurs only with this lens. Nos such problem with my other Elmarit 28 ASPH. I am attaching an image as a sample. Â The lens was bought new about a month ago. Link to post Share on other sites More sharing options...
Advertisement Posted July 31, 2011 Posted July 31, 2011 Hi biswasg, Take a look here Need help in diagnosing lens fault!. I'm sure you'll find what you were looking for!
jaapv Posted July 31, 2011 Share #2 Â Posted July 31, 2011 It looks like a filter reflection. Link to post Share on other sites More sharing options...
JKphotography Posted August 1, 2011 Share #3 Â Posted August 1, 2011 Like Jaap said, it might be some sort of internal reflection of some sort. BUT: the bow has a jagged edge on the left side...are you sure it's not a tiny hair on the rear lens or something like that? Â Good luck! Link to post Share on other sites More sharing options...
lct Posted August 1, 2011 Share #4 Â Posted August 1, 2011 Or on the sensor. I would clean that dirty one to begin with. Link to post Share on other sites More sharing options...
JKphotography Posted August 1, 2011 Share #5  Posted August 1, 2011 Or on the sensor. I would clean that dirty one to begin with.  Well, the TS stated that the problem only occurs with this lens....so the problem couldn't be dust or something else on the sensor.  Try to eliminate every factor of the equation:  Take the filter off and test again  take the hood off and try again  check for dust, fungus inside or on the front and rear element  Regards,  Joël Link to post Share on other sites More sharing options...
lct Posted August 1, 2011 Share #6 Â Posted August 1, 2011 No hair or dirt on front or rear element will do that kind of mark imho. Link to post Share on other sites More sharing options...
pop Posted August 1, 2011 Share #7 Â Posted August 1, 2011 Advertisement (gone after registration) Well, the TS stated that the problem only occurs with this lens... Â That's easily tested by taking pictures of white walls from a distance of less than a meter, with the lens set to infinity and the aperture set as small as possible, i.e. to a large number. I think it's rather too early to rule out sensor dirt. Link to post Share on other sites More sharing options...
pgk Posted August 1, 2011 Share #8 Â Posted August 1, 2011 That's easily tested by taking pictures of white walls from a distance of less than a meter, with the lens set to infinity and the aperture set as small as possible, i.e. to a large number. I think it's rather too early to rule out sensor dirt. To completely check I'd suggest taking raw shots at all apertures of a white wall with ~ 1 stop overexposure (from indicated), then boost contrast until the problem is seen optimally. A dark shape would suggest light is being blocked from the sensor rather than anything else, but I would have thought that an obstruction blocking such a significant portion of the light reaching the sensor should be fairly obvious - an aperture blade bending out of shape perhaps? Link to post Share on other sites More sharing options...
250swb Posted August 1, 2011 Share #9  Posted August 1, 2011 Is it a very fine hair or thread standing just clear of the surface of the sensor? Or maybe a smear of oil? It doesn't look exactly like an arc of a full circle to me, and has a similar density to all the dust showing up on the sensor. A sensor clean would be the first thing to do. It would be worth checking to see if the 50mm and the 28mm (which the OP said doesn't show the problem) were being used at the same aperture. If the 28mm was wide open and the 50mm stopped down that would account for the discrepancy  Steve Link to post Share on other sites More sharing options...
Xmas Posted August 1, 2011 Share #10 Â Posted August 1, 2011 Get a third party hood and remove the filter... Â Noel Link to post Share on other sites More sharing options...
pico Posted August 1, 2011 Share #11 Â Posted August 1, 2011 Â There's a lot of heavy dust on the sensor, but that is a separate issue. Â As the sensor sees it - would it not be cheery news that the line is just the camera strap in front of the lens, or maybe one of those silly lens cap tethers? Link to post Share on other sites More sharing options...
Val Posted August 3, 2011 Share #12 Â Posted August 3, 2011 Hi I think is a hair inside. Is not on back elemet as it will be much clear as is closer to focal plane. Take a small flashlight and look iside the lens and on the lateral walls. I susspect is someware between elements. If you don't see anything it might be as well a separation of glass elements. Small chance I bet is a hair. Link to post Share on other sites More sharing options...
Ronan Posted August 3, 2011 Share #13 Â Posted August 3, 2011 This probably isn't it but... from my experience i had a D2h that had a scratched filter on the sensor (forgot what its called). It made a VERY similar mark. Â The answer was a sensor swap which was too expensive so i sold the DSLR for parts. Â But i'm pretty sure thats a tiny hair lodge inside the lens. I mean... they are hand assembled after all Link to post Share on other sites More sharing options...
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