| Author | Thread |
|
|
03/23/2009 09:51:13 PM · #1 |
My 50mm lens is causing a blue spot in the center of my images. I've not noticed it in ALL my images, but maybe its so light that I can't see it... however in these photos you can see it, right in the center. What does this mean? There is no dust or flare (I was inside an enclosure taking this shot) or anything else I can think of. Obviously I don't plan to get it fixed since its a cheap lens, but if its something I can do myself to fix it? if not its only a hundred for a new one but I want to be sure its not something I am doing wrong or can fix. Opinions? Suggestions? Thanks.
 
|
|
|
|
03/23/2009 09:58:37 PM · #2 |
I can see it in both images but it's a problem I have never seen before.
|
|
|
|
03/23/2009 10:00:24 PM · #3 |
Did you check to see if its dust on your sensor?
|
|
|
|
03/23/2009 10:04:16 PM · #4 |
Try cleaning the lens -- front and back.
|
|
|
|
03/23/2009 10:25:56 PM · #5 |
It does not look like a sensor dust issue... that normally makes dark spots. It could be a smudge on the front or rear element of the lens...
|
|
|
|
03/23/2009 10:31:27 PM · #6 |
Take the lens off the camera and look through it both ways with the aperture wide open. Put a white paper or reflector in front of a good light, and look through the lens to see if you can see the spot. Turn the lens in front of a bright light, and see if you can see any smudge or a place where perhaps a drop of water has evaporated by watching the reflection in the coatings. If you are using a UV or polarizer with the lens, then the problem may be there.
If it only happens with the one lens, then it must not be the camera.
|
|
|
|
03/23/2009 10:44:45 PM · #7 |
I've ruled out the camera. Its definitely the lens.
Its not sensor dust or a cleaning problem.
However,  MelonMusketeer's comment made me realize, I DO have a UV filter on the front of the lens. I'll check the lens infront of a light, take some test pics with and without the UV and get back to you guys!
Thanks. |
|
|
|
03/23/2009 10:56:15 PM · #8 |
| I would get rid of the UV filter, more than likely it is the problem. |
|
|
|
03/23/2009 11:05:57 PM · #9 |
| I had a lens do that once; there was a tiny drop of oil on the inside glass that had leaked from some bad/worn aperture blades. However, it was an older lens...yours is fairly new, yes? |
|
|
|
03/23/2009 11:32:53 PM · #10 |
Originally posted by aerogurl:
Opinions? Suggestions? Thanks.
|
Couldn't find a source or URL, but I believe at certain F-stop
settings this lens will have that type of distortion. I notice it on mine, but only pointing at the sky. So try using larger apertures and I think it will go away. But first remove your UV filter and see if that helps. I think this problem happens because the lens was not designed for digital. When taking images of extremely bright light toned objects you're seeing the reflection of the back element of the lens. There's a good explanation over on nikonians, but alas they charge for membership now so I can't point you to it. |
|
|
|
03/23/2009 11:54:54 PM · #11 |
All of the above are excellent suggestions. Try them all.
I had a similar problem with my favorite lens -- it kept giving me a spot right in the middle of my best shots. I swear, I scrubbed that sensor trying to get rid of the spot, and the spot just stayed there laughing at me. I also scrubbed my UV filter (which went on the lens the day I bought it and never comes off), and that d***n spot was still there. Finally one day, I took the UV filter off. I couldn't see anything on the lens, but I cleaned it anyhow. I haven't had a problem since!
|
|
|
|
03/24/2009 09:31:28 PM · #12 |
| thanks again guys, I didnt have a chance to try it out today except inside, and I didnt see the spot in any of my shots. I'm going birding tomorrow if the weather holds and I will try some test shots then. Let ya know as soon as I get something figured out, again, thanks :) |
|
|
|
03/24/2009 09:48:32 PM · #13 |
Originally posted by Germaine:
All of the above are excellent suggestions. Try them all.
I had a similar problem with my favorite lens -- it kept giving me a spot right in the middle of my best shots. I swear, I scrubbed that sensor trying to get rid of the spot, and the spot just stayed there laughing at me. I also scrubbed my UV filter (which went on the lens the day I bought it and never comes off), and that d***n spot was still there. Finally one day, I took the UV filter off. I couldn't see anything on the lens, but I cleaned it anyhow. I haven't had a problem since! |
That's what I was wondering... I've been taking some indoor shots with lighting and also with candles--neither of which I had done before. Anyway, I kept getting a bright spot on the picture, and I couldn't figure out what was causing it. After about 15 minutes of trying to figure it out, I took of the uv filter and had no problem. It was like the light was going in and bouncing off and reflecting on the inside of the uv filter--or something like that. I've had it a couple of times now. |
|
|
|
03/25/2009 01:52:29 AM · #14 |
Sometimes you can get "ghosting" when shooting into a bright light source like shooting at car headlights. It appears usually as a colored reflection on the opposite side from the light source in the image. I don't think that the posted images are this effect though. I hope you get it solved before that "one time" shot happens. I would still suspect a filter smudge, or maybe the filter itself.
|
|
|
|
09/03/2009 09:24:24 AM · #15 |
I have had the same problem with my Pentax K10 when photografing dark objects on white background in a studio.
I had the same problem with my Pentax 50 mm 1.2 and my Tamron 90 mm 2.0 - both with Pol-filter attached in order to removed reflections in the products.
I found out that the problem was when you have back light going in a narrow angle towards the lens AND using a filter (UV, Skylight, Pol). Then the light is 'bouncing' between the from lens element and the filter.
Now, I had some problems in shooting without the Pol filter, so I mounted a lens hood to prevent the direct back light. Problem solved! |
|
Home -
Challenges -
Community -
League -
Photos -
Cameras -
Lenses -
Learn -
Help -
Terms of Use -
Privacy -
Top ^
DPChallenge, and website content and design, Copyright © 2001-2025 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 08/28/2025 02:33:24 PM EDT.
