Apo ronars 360 & 480 ~ infinity?

[dangal]

Folks, Are apo ronars 360 mm and 480 mm F 9 lenses useable when focusing to infinity? Or at least far away focusing, say 20 meters? thanks in advanced.

Renee

[N Dhananjay]

They work very well. The Ronars are based on the dialyte design, similar to the Artars. They are symmetrical lenses designed for close work, typically near 1:1. But the corrections of the dialyte design are quite stable over a wide range of image distances. You can use them for infinity subjects and they perform very well indeed. Cheers, DJ

[Arne Croell]

DJ is absolutely right. Apo-Ronars and similar Dialyte constructions (Apo-Artar, Apo-Germinar, Apo-Nikkor) perform quite well at infinity even when corrected for 1:1. Sometimes the manufacturers tweaked the performance towards infinity by changing the cell spacing a little, but even without that they are perfectly useable for long distances. I have used 240mm, 300mm, 360mm, and 600mm Apo-Ronars and all gave excellent results.