This may be so but will the difference be visible in 6-7x enlargement and relevant when stacked up against other factors such as grain emergence?
Originally Posted by Early Riser
One thing I found interesting was using an old 150 rodagon at f5.6-f16 for a 20x24 print off a 5x4 neg (I realise that this is a smaller enlargement factor). I could see no difference whatsoever....so I cranked up the column and printed a small section (no Idea what the enlargement factor was but print would prob have been 40+" and again I could see no difference. I therefore concluded that I could use whichever aperture I wanted to give the exposure time I wanted for any print size I wanted The enlarger was wall mounted to a VERY solid wall so I knew I had one hell of a solid mount for this not very scientific test.
If you were using Fuju acros on 6x7 and shot the neg at optimum camera lens aperture off a tripod ....and then enlarged to a very large size using an APO vs a non APO lens at their optimum apertures (on a very stable and perfectly aligned enalreger) then maybe you would see a tiny difference. However I am pretty confident that this difference would be so small and irrelevant as to be not worth thinking about. I cannot prove this however.
This might sound weird coming from someone who has just bought a 72XL and a 110XL. However I bought these for 5x4 & 5x7 because they cover so well and in the case of the 110 are small too. I am very confident that my(sadly departed - did not cover 5x7 well enuff) 203 Ektar from the 50's would easily match them image quality wise (as it matched everything else I have ever owned). Enlarger lenses are no different.