Internal Element Reflection - DPChallenge Forums

Canon RF 24-70mm f/2.8 L IS

10/28/2010 11:48:57 AM · #1

Hi. Please take a look at this image:

Notice the string of lights reflection above the house that are upside down and backwards. I assume this is due to reflections of the elements inside the lens. Is this correct?

I was a little surprised to see this because I have used the 28-75 Tamron for a while and although I haven't taken a lot of photos with bright lights like this in the dark, I have taken some and never noticed this before.

Thanks,
Paul

kirbic

Canon EOS R5

10/28/2010 12:02:29 PM · #2

Did you have a UV filter on the lens? If so, you may find that this contributes to the "ghosting."
If not, then yes, internal reflections. Some lenses are more prone to this than others.

10/28/2010 12:54:25 PM · #3

I USED to have a UV filter. I had recently taken all of them off all my lenses because I noticed how much light those filters were actually reflecting back away from the lens.

Is it possible that the reverse is true, that the filter would prevent the reflections?

Time for some experimentation.

Canon RF 24-70mm f/2.8 L IS

10/28/2010 12:55:12 PM · #4

One thing to note, I am noticing now because the shutter was so long.

kirbic

Canon EOS R5

10/28/2010 01:53:37 PM · #5

Originally posted by PGerst:

In every case I've ever seen, a filter makes it worse, sometimes much worse. There is no substitute for experimentation, would be interesting to see the results of an actual test here.
Yes, the long exposure is a part of the reason you are seeing it in this image. The brighter the point light source and the longer the exposure, the worse off you will be.

Kelli

Canon EOS-D60

Canon EF 28-135mm f/3.5-5.6 IS USM

10/28/2010 02:15:01 PM · #6

I think you just discovered a new constellation, one that only shows up about lit houses on long exposures! ;D