Hi @Steph,
Yes, it’s possible that the light shining through the sprocket holes is causing this issue, but it’s also possible (or likely) that there is something else in your setup that is making it worse. I’ve seen lots of people shoot sprocket holes but never get this cross flare as you see.
A few things I would try (in order) to see if you can eliminate the problem.
- Take a close look the film itself… do you see these cross patterns faintly on the film itself? I’m guessing not, but worth checking before moving forward…
- Remove any filters you may have on your macro lens (for example, if you have a uv or polarizing filter, take it off)
- Make sure your lenses / extension tubes are clean and smudge free
- Make sure your lens hood is on
- Make sure the “matte” side of the film is facing your camera lens (this should pick up less reflectance than the shiny side will). So, the film name you see on the border of the film should be reversed as it is facing you.
- Make sure there is no other ambient light on in the room
Try those steps above and see if that improves at all.
If not, you can try using some kind of black paper or other material to block the light from the sprocket holes, or another film holder which blocks the sprocket holes entirely and see if that improves things.
Hope that helps!
-Nate