I don't know anything about enlarger lenses, other than the fact the El Nikkors are supposed to be good. I know nothing about types, sizes, brands, etc etc.
I have an Omega B600 that has El Omegar 50mm and 75mm lenses with it.
I also have a Beseler 67c that has a 50mm lens on it.
I know that I have to have a 75mm lens to cover the 6x6 negative, so can I put the Omega lens on the 67c? Are they all threaded the same?
The el-Omegars are entry level lenses that come as standard equiptment on Omega machines. They are passably good, but an upgrade to el-Nikors or Rodenstock and Schneider glass is in order.
El-Nikkors are cheap plentiful and they are great. 50mm f/2.8 kind are the better 6 element type. Many of them have haze issues (all of them I bought did) but they are relatively easy to disassemble and clean. f/4 kind are 4 element. Not bad but for the price difference, I'd get f/2.8.
For the same token 75mm kind are 4 element where as 80mm are 6 element.
Schneider, Rodenstock are generally regarded as the best lenses for enlargers, the Nikkor ones are good but the Rondenstock 50mm I have is a much nicer design with a light pipe in the lens assembly to show what f-stop you currently have. A nice little touch that makes life much easier.
As for sizing, m39 is the usual fitting but as said above there are other sizes but you can get plates to convert a smaller lens to fit your enlarger.
Each film format has its on focal length that is to be used.
35mm film uses a 50mm lens
6x45 uses a 75mm
6x6 uses 80mm
6x7 uses either a 90mm or 100mm
As a guide look at what is considered a 'normal' lens for the format you are shooting and use an enlarger lens of that size.
Hope that helps.
I would strongly recommend having a mounting board for each lens you have. This will permit very accurate and quick lens changes with the 67C.
The El Omegar 75mm lens should work fine on the 67C. There are some unusual lenses though that are too big for the relatively small lens boards that the 67C takes.
"The single most important piece of photographic
equipment you’ll ever own is your enlarging lens."
I am once again setting up a darkroom and will start with EL-Nikkors based upon my experience with a 105-N that I used before. It was a very nice lens. It is my understanding that with all EL-Nikkors the later plastic appointed ones are better than the prettier all metal ones. With the 50mm, the 2.8 is significantly better than the 4 (six vs. four element).
When circumstances permit, I will probably acquire some of the latest greatest German glass (Apo-Componon HM, Apo-Rodagon N) but I will expect the improvements to be subtle.
you can use whatever fits and covers your neg.enlarging lenses are not just made for one enlarger. i use my el nikkors on several enlargerswithout problem, gtrat lenses!