Spotlight-like issue on the photos

I've recently started using reversal rings for macro photography on a couple of my lenses, and among some of the problems I'm running into I seem to be getting some sort of cloudy spot in the centre of the image. Any idea what's causing this?

Hmm. Could be veiling flare caused by internal reflections. Are the reversing rings interiors shiny?

Hmm. Could be veiling flare caused by internal reflections. Are the reversing rings interiors shiny?

Interesting possibility... they are a bit shiny. If that's the problem, it seems like a problem for black electrical tape. They're the Fotodiox ones, if you have any experience with them.

Agree. Veiling Flare would be the first issue that I’d investigate.

 

Matte black paint is better; typically electrical tape shiny.

 

Additionally, if you have a filter on the reversed lens, remove it.

Avoid any point light source directly entering the reversed lens.

 

Veiling Flare is usually exacerbated by using large shooting apertures, for both normal fit and reversed lenses.

Typically (generalization) Veiling Flare is more prone to Zoom, rather than Prime Lenses

 

More tailored responses may be forthcoming knowing the details of the lens, lighting scenario and the camera.

 

WW

A reversed lens usually has little shading. Make up lens shades from black construction paper. Avoid dark subjects on light backgrounds. Obviously, reversal is only used at 1:1 or greater, when the sensor distance is greater than the subject distance.

Agree. Veiling Flare would be the first issue that I’d investigate.

 

Matte black paint is better; typically electrical tape shiny.

 

Additionally, if you have a filter on the reversed lens, remove it.

Avoid any point light source directly entering the reversed lens.

 

Veiling Flare is usually exacerbated by using large shooting apertures, for both normal fit and reversed lenses.

Typically (generalization) Veiling Flare is more prone to Zoom, rather than Prime Lenses

 

More tailored responses may be forthcoming knowing the details of the lens, lighting scenario and the camera.

 

WW

The lens is a Sigma 35mm f.1.4 that's usually set to F/8 (although the sample shot may have been a fair bit wider) with no filter, and it's mounted on an R5. This particular shot was back-lit, which might be a large part of the problem right there.

The lens is a Sigma 35mm f.1.4 that's usually set to F/8 (although the sample shot may have been a fair bit wider) with no filter, and it's mounted on an R5. This particular shot was back-lit, which might be a large part of the problem right there.

 

Concur. I'd adjust the lighting scenario to front lit and adjust nothing else: that could provide conclusive evidence and your solution.

 

WW

A reversed lens usually has little shading. Make up lens shades from black construction paper.

 

For a lens shade on a reversed lens, something a bit more substantial would be to cut out the bottom of a rear lens cap. Canon made a macro photo hood way back when which was nothing more than a bottomless rear lens cap.