Vickko
Veteran
APO Componon HM 45 f2.8 vs f4... any difference in performance that you've detected?
Vick
Vick
sepiareverb
genius and moron
There's this thread on apug.
I have both the above 45/4 and the Rodenstock APO Rodagon 50/2.8. I use the 45 for the slight increase in brightness I can squeak out of my enlarger in 16x20 and 20x24 prints due to the slightly closer light source, but tend to use the Rodenstock for 810 and 11x14 prints. Not sure if the brightness difference is theoretical or actual, I'd suspect theoretical. Both make superlative enlargements. I've not seen any difference between them in contact printing
I have both the above 45/4 and the Rodenstock APO Rodagon 50/2.8. I use the 45 for the slight increase in brightness I can squeak out of my enlarger in 16x20 and 20x24 prints due to the slightly closer light source, but tend to use the Rodenstock for 810 and 11x14 prints. Not sure if the brightness difference is theoretical or actual, I'd suspect theoretical. Both make superlative enlargements. I've not seen any difference between them in contact printing
jordanstarr
J.R.Starr
I highly doubt that you will notice any difference in quality. The idea of a faster 2.8 lens is that at it's "sweet spot" is likely f5.6-8.0 where the f4.0 lens will likely be optimized at f8-11. So, in practice, it's easier to work with difficult negative negatives that are over developed. But if you have a perfect negative and print at their "sweet spot" (where you can literally watch the grain jump up and hit you in the face through the focuser from corner to corner on the paper), I would bet my next paycheque you will not notice a difference in quality.