I have a 75mm El-Nikkor (non-Apo) which is highly satisfactory, but I think that Rodagons or Componons of the same focal length (or 80mm) would be essentially identical in overall quality. Right now, high quality enlarger lenses go for very low prices on E-Bay. Would you believe a 150mm Rodagon, in excellent condition, for $50?! The seller told me I got a good deal; actually it was more of a steal!
Just a follow-up to my previous post. I checked E-Bay a moment ago and found several listings for 75mm enlarging lenses and a whole slew of listings for 80mm's, including numerous El-Nikkors, Rodagons, and Componons. Bidders seems to be few and far between. It seems to be a buyers' market.
APO is a designation alluding to the apochromatic characteristics of a lens. This designation addresses the ability of a lens to focus all the wave lengths of light on the same film plane (whether that be film or enlarging paper). Different colors of light will have different wave lengths. These different wave lengths would tend to focus at different distances from the lens nodal point. This would lead to departure from sharpness at high degrees of magnification.
Most good quality lenses of modern design will prove to be sufficient for all but the most discriminating use. By these I would include the El Nikkor, the Schneider Componon, and the Rodenstock Rodagon.
The apochromatic lenses in each of the manufacturers product lines mentioned would be the lenses that are above the lenses that I have identified. One will normally pay substantially more for APO lenses.
An alternative to conventional enlarging lenses are lenses which were designed for the graphics field. These lenses are normally slower speed (won't open as wide). However these are normally APO lenses. There are normally a number of these listed on Ebay as well. These would normally be barrel mounted lenses as opposed to lenses mounted in shutter. If I were looking for a lens of this type, I would look to a Goerz Apo Red Dot Artar of the appropriate focal length.
thanks for the detail, Don. I suggested the El Nikkor over the Schneider or the Rodenstock as the El Nikkor was much cheaper when I was looking for an 80mm enlarging lens. The 80mm El Nikkor is reputed to be of a higher quality than the 75m El Nikkor from what I have read on the web--with a grain of salt...
Let's see what I've got in the magic trash can for Mateo!
I don't have experience with either the 75 mm or the 80 mm El Nikkor lens. For that reason I am not able to comment on any difference between them. My lenses in those focal lengths are Schneider(s) and Rodenstock(s). I do have a 150 mm El Nikkor that is extremely sharp. I prefer it over an older Schneider 135 Componon that I have.