For sale: Iscorama 54 In: ANAMORPHIC Posted June 1, 2013 Interesting... when the 54 is stepped down to handle 72mm filters, does it vignette earlier than a 36? I believe @bootsie is using a +0.4 with his 54, and some stepping rings, but it vignettes, on wider lenses. Safest bet would be bigger filters. Also, now that you mentioned, I think mine is, indeed, a bit softer than the 36... But it was never serviced, and this might be the cause too.