Diffuser material for betterscanning.com 120 film holder

Hi

I've had an Epson 4180 for maybe 15yrs now. When I got it I quickly bought a betterscanning.com holder (pre ANR glass).

Recently, and I don't remember it always being there, I am seeing defined light/dark strips that line up with scanner lights. When I use the Epson film holder the light/dark strips are no longer visible. I'm not sure if this is a calibration issue.

I'd much prefer to use the betterscanning holder mostly because I can scan twice the amount of 6x4.5 frames and hold them flatter compared to the Epson one.

Can anyone suggest a diffuser material which I could try with the betterscanning holder?

i've attached images of the issue i'm seeing

Do the bars go away when you flip the film over with the betterscanning holders?

as in emulsion side up?

Since the betterscannng holder only has glass on one side, problems with the interface between film and glass may go away if the film is flipped over. I have the version with ANR glass and don't have the issue you have.

Tried it emulsion side up. Same thing.
Also remembered why I don't scan this way around. Film is awfully close to the glass

I've gone through some old negatives and discovered the issue isn't always noticeable. It's most obvious with frames with a more uniform tone, e.g. skies.

The negative shown so far was delta 400. The one below is FP4+

BetterScanning.com is back online and offers this glass insert: http://www.betterscanning.com/scanning/insert.html . (I don't know about overseas shipping, however.) This is the insert I have and it works well.

One other thing to check is the the bed of the Epson is clean. If the scanning bed, especially near the back, is not cleaned or the insert not properly oriented, the Epson calibration routine can produce artifacts (but those are generally narrow straight lines).

I might consider it but I hate paying customs and shipping fees that double the price of items from the US.

The bed is clean and I know about the artifacts you are referring to.

I'll look for a suitable diffuser material as it may come in handy for a future project.

Just an update.

I experimented with a limited selection of material. Firstly with the diffuser material inside TFT monitors. I tried various distances from inside the TPU to just above the film holding pieces. Better, but the inconsistent illumination remained.

I had a scour on eBay but didn't find anything promising.

On amazon i found this

I used the A4 sheet just placed on top.

I think i may move the diffuser down by removing some spacers.

No obvious illumination issues in first test scan. Not tested a colour scan but it's rare that I shoot colour on 120 film so not a priority.