Railfan Technology > Is this a lens flare issue???

I bought a new Tamron 17-50mm f2.8 zoom lens over the winter along with my new Canon EOS 70D DSLR.  The lens otherwise works great, but I noticed this red flare on some night photos when shot at the angle you'll see in the sample image.  Is the red dot (I've circled it) just basic lens flare?  This lens doesn't do this except when photographing from this angle and it doesn't ever do this during the day, and what you see here is showing up in different parts of the image, not exactly the same spot on every photo.  This was a 91 second time exposure shot at f9.0 at ISO 100.  I don't use any filters and I've read up on this subject but figured I'd ask the experts here to chime in, is this just a lens flare that I'll just have to photoshop out?

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After doing a further test with the camera, I think I figured out the red spot was a reflection in the lens from one of the headlights, because of light bounicng around in the lens. I didn't use a lens hood for this photo though I ran another test tonight with the same camera and lens and found little to no difference in the photo quality when I did and didn't use the lens hood.  If anyone has any further ideas on this or possibly if there's some way to avoid it happening, let me know...

Once in a while I'll get a reflection from within the lens...
It depends on what light is coming at it. Ditch lights give
me a very rare green blob, and this is without filters. Your
red dot sounds like a 'corner case.' Do you see your red dot
in a shot taken in good light?

John.

jkh2cpu Wrote:
-------------------------------------------------------
> Once in a while I'll get a reflection from within
> the lens...
> It depends on what light is coming at it. Ditch
> lights give
> me a very rare green blob, and this is without
> filters. Your
> red dot sounds like a 'corner case.' Do you see
> your red dot
> in a shot taken in good light?
>
> John.

It only happens at night on these long exposures, not an issue during the day, will try the photo again soon with a different lens and see what happens.

Do you have a protective haze or skylight filter attached to your len?   Those can also cause strange effects on night photos.  If so, you might want to try your night shots without that extra glass.    

Can we see the full image ?

Bill Miller
Galt, ON

As another reply has suggested, try removing any lens filters you have attached, i once found these to cause flare problems with bright headlights.



Edited 1 time(s). Last edit at 06/28/15 16:08 by exhaustED.