Vignetting

[HighPlainsDox]

What causes this vignetting? It's the darkening of the edges of my photos. I've seen this off and on with my 35mm photos, and even with digital cameras. I've seen it in low-light as well as bright daylight scenes. Is this a defect in the camera? Is there anything I can do to prevent it?

[lscottpht]

Are you using a lens hood? That could be the problem. I often have to take it off when I shoot with my wide angle.

[LoungeLizard]

Lens hood, filter, anything that may interfere with the field of view of the lens.

[HighPlainsDox]

Nope, I never use a hood. I almost always use the same setup. I do have/use a clear uV filter, but it stays on my lens.

[LoungeLizard]

Originally Posted by HighPlainsDox

Nope, I never use a hood. I almost always use the same setup. I do have/use a clear uV filter, but it stays on my lens.

OK, so let's get the specifics on the setup here. Camera, lens, etc. Is the filter a screw-on that goes right on the lens or does it use an adapter?

[HighPlainsDox]

Here it is:



Camera is the Pentax A3000, the uV filter is a screw-on 67mm directly on a K-mount Tempo 35-200mm macro/zoom on a KA camera body.

[LoungeLizard]

Well, it's nothing in front of the lens - so the only other thing I can think of is that the lens is not providing you a complete image on the very wide angles. Have you used this combination before - same situation? What were the results?

That's the only thing I can think of...

[HighPlainsDox]

Originally Posted by LoungeLizard

Well, it's nothing in front of the lens - so the only other thing I can think of is that the lens is not providing you a complete image on the very wide angles. Have you used this combination before - same situation? What were the results?

Yes, I use the same setup almost every shot. I can't swear to the focal length I use for each one, since I don't have EXIF info. I have been looking over my photos, and the ones that do it most appear to be those that are at the shortest focal length - 35mm on my lens. Much to my surprise, I can't find a comparable photo with the same setup and lighting, but did see some of the same scene at different FL's. There was a correlation there, in that the shorter FL, the more vignetting there was, but not near as pronounced as my sample above.

If the FL theory holds true, would it follow that vignetting would be more pronounced at lower light levels?

[Dennis_Benton]

At the 35mm focal length, the filter is blocking the lense. Try shooting at 35mm with and without filter. This happens on one of my camera with filter and zoom at widest angle.

[Bill Huber]

From what you have said and what you are using I would say it is the lens.
It is harder to transfer the light at the outer edges of the lens then in the center. some lenses are really very poor at doing this.

The lesser expensive lenses will have this problem a lot more the hight cost lenses. I do not know anything about the Tempo lenses, but I do know that some of my old Vivitar lenses would have the same problem on my old 35mm K1000.

[Dave-RR]

Originally Posted by HighPlainsDox

What causes this vignetting? It's the darkening of the edges of my photos. I've seen this off and on with my 35mm photos, and even with digital cameras. I've seen it in low-light as well as bright daylight scenes. Is this a defect in the camera? Is there anything I can do to prevent it?

A wide open lens is more prone to vignetting than the same lens stopped down.

[steve]

I have to agree with Dennis.
Take the UV filter off and shoot a couple at 35mm and see if the problem is still there.

With 35mm on a full frame sensor or film it is quite possible a filter (any filter) could cause vignetting.

[eurotrash]

light leaks!!! embrace it!!

[steve]

Originally Posted by eurotrash

light leaks!!! embrace it!!

I don't get it.
Does light have a bladder control problem :twisted:

[swanny338]

I am sure its not coming from the UV filter.. most likely its just cause its a lower quality lens... if you stop down to like f8 or 11 it most likely wont be there...