Vertical alternated darker bands on 120 film with Epson V850 (staircase effect?)

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Hi guys. Hope you doing alright. I finally found the time to make the mod suggested in the FB’s Epson group by our saver, mr. Stephanus Christian Eka Adisetya. It seems that the banding problem is caused by uneven led lightning. I don’t know if all the V850 (might be interesting to do some surveys with a V750 that it’s not run by led) have the same problem or some are fortunate enough to never encounter these pesky things. A lot have manifested the problem though.
The solution, as anticipated from Harry, is finding a way to diffuse the led light by applying some kind of diffuser. Mr. Adisetya suggested a Lee Colour Filter 250 H.W. Diffuser, I followed the suggestion and found one: if you are in Europe like me, in Thomann.de website (link). I applied the diffuser onto the led strip by opening the lid (easy 6-7 screws) and taping it directly there.

(this is a mr. Stephanus Christian Eka Adisetya’s foto, mine is exactly the same). This seems to have resolved the issue, no more banding form the scanner (just my insufficient skill at developing. If you compare the first photo of the thread with this last one you will notice that the banding has disperar, the shift in color is due to a problem in development. It’s suttle, but it’s there). I’ll post a prescan with an empty scan bad so you can compare with the prescans I posted early on → there is no banding anymore. Also the test photo.
Thanks to everyone and I hope, for those that have my same problem, to find this thread. Bye.