Need help regarding an Apo-Rodagon 150mm f/4

[Repko]

You are right, what I mean is fixed aperture. My apologies, but English is not my native language. I have a "fixed" aperture. I rated it F11. My lens looks exactly the same as the lens on the photos earlier in this topic. The front lensgroup can be unscrewed from the rear lensgroup and this is the location where my flimsy thin aperture disk is located. This is also where SKGRIMES makes the slot for the waterhouse stop adjustment. There is a small elevated rim to position the aperture disk and a metal ring to fill up a gap. I will take a picture later on and do some measurements on the aperture disk.

[EdSawyer]

You really shouldn't stop this lens down below f/5.6 if you want the best results. At f/11 you may as well be using any 150mm lens.

[Luis-F-S]

You really shouldn't stop this lens down below f/5.6 if you want the best results. At f/11 you may as well be using any 150mm lens.

+1! Maybe f/8. Hard to Focus at f/ 11. And just think they probably paid five times the price of a Rodagon.

[Bob Salomon]

You really shouldn't stop this lens down below f/5.6 if you want the best results. At f/11 you may as well be using any 150mm lens.

Optimal aperture is 1 to 2 stops down! Not wide open!