I've been doing some reading here but haven't found a specific answer yet so forgive me if this is duplicated somewhere on APUG.
I've been contact printing for over 4 years now and have never had a problem with Newton's Rings. I've used various films and Pyrocat HD. Recently I began shooting from a box of Tmax 100 4x5 film, developed in D-76 my contact prints were fine. I developed a group of six (in a slosher) in Rodinal and the negatives looked great. I've tried printing these negatives but so far I've gotten Newton's rings with the first three. I used my dichroic enlarger as a source, with and without filters and Ilford MGFB and Kentmere Kentona and got rings regardless. The tones and sharpness look really nice and I have a ton of Rodinal (more than I'll use with my limited roll film output) so I hate to give up on it.
Should I try an extended wash? Maybe a bare bulb?(Though I hate to do that because I like to split grade print my difficult negs). Is this typical, that some film/dev combos produce rings? Any thoughts or suggestion would be appreciated.
Happy New Year! Shawn