Light Shielding an enlarger lens

Hello everybody!

I'm constructing a film digitizing rig composed of a Sony A7R4, an enlarger column + baseboard, a M42 bellows and and a Fujinon EX 75mm f4.5 enlarger lens.

I lay negatives strips (just B/W so far) over a 14mm thick piece of glass backlit by a led device. The Fujinon can cope with the A7R4 resolution better than my Sony 100mm f2.8 Macro, besides he bellows makes it much easier to focus with finesse.

But I found out that the various openings in the Fujinon generate light gatherings that lower the contrast and micro contrast a lot, producing dull and compressed pictures.

Which is the best way to shield the lens and fill the openings? Just black tape? Is there something I am missing out?

Thanks in advance.

You're talking about the illuminated aperture readout of the enlarging lens?

If so, simply taping up the small light-pipe opening inside the thread of the lens is all that's needed. Black vinyl electrician's tape does the job easily and reversibly. Otherwise you'll get a red cast on the negative copy, and a cyan fogging in the positive.

Good to know it's not so difficult! I got really foggy negs in B/W, though very detailed.

I hope there is not some other openimg, since the lens has a few gimmicks.