process lens or how to ID them

[ac12]

I've read some of the threads about process vs. enlarging lens, and understand that I should NOT get a process lenses.
But on the used market, how do I tell what is a process lens from an enlarging lens?

I got more confused when I read a post that said that the Rodenstock Rodagon was available in BOTH process and enlarging lens. So that post told me that I could not even depend on the name Rodagon to be an enlarging lens, I could accidentally purchase a Rodagon process lens thinking it was a Rodagon enlarging lens.
Are there any visual clues on the lenses of the different brands to indicate enlarging vs. process?

For enlarging, I am limited to printing 16x20 or slightly larger. So no large magnification requirement. 4x5 will be max 5.5x enlargement and 6x6 will be max 11.5x enlargement.
I am looking first for a 135 (4x5) and next for a 105 (6x9) lens.
And for now, because of lack of budget, I will not be looking at APO lenses. Unless someone offers me a godfather deal.

thanks

[ac12]

This is an example of what I found on eBay.



The left lens looks like an old lens that I used to use in high school.
The middle lens I have never seen before. Is it a process lens?
The right lens looks like the current enlarging lens.

[Len Middleton]

If you want to get an enlarging lens from one of the big four, then understand the names they use to identify their enlarging lenses.

For example, enlarging lenses for Rodenstock are Rodagon; Schneider are Componon S; Nikon are EL Nikkor; and Fuji are I think Fujinon EL (although not certain about Fuji). For Process lenses, Rodnstock are Apo Ronar, Schneider has used G-Claron, Repro-Claron, Apo Artar; Nikon are Apo-Nikkor; and I do not know about Fuji.

In terms of mechanical construction, enlarging lenses (especially recent examples) may have illuminated scales for the aperture, while process lens do not. Process lenses may have slots for inserting filters or waterhouse stops, while enlarging lenses do not.

hope that helps,

Len

[Bob Salomon]

Most enlarging lenses have a pre set aperture ring, an illuminated aperture ring and a switch to defeat the aperture click stops. No process lens has any of those features. Moët enlarging lenses are around 5.6 while most process lenses are around f9,

[Jim Jones]

I wouldn't worry about using a process lens for enlarging. They were both designed for somewhat similar tasks. As for differences, enlarging lenses often have the Leica 39mm 28 TPI thread while all of my process lenses have larger mounts. Older enlarging lenses usually lack preset aperture rings, illuminated aperture scale, and a switch to defeat the aperture click stops. Enlarging lenses often don't stop down to as small an aperture as camera or process lenses to prevent photographers from using them at diffraction limited openings.

[ic-racer]

If the lens in question does not say "Rodagon" "EL-Nikkor" "Componon" or "Componon-S" "Fujinon EP" "Fujinon-EX" then keep looking.