You are correct, the reflections of the bellows are showing up when the negative holder is not in place. I have tried masking the stray lights out, but I have not been happy with the not-so-good Dmax I am getting with this enlarger because of the stray lights bouncing on to the paper. My prints from a Leica Focomat V35 are much contrastier in comparison. This is what led me to do the investigation.
Originally Posted by ic-racer