f/4.5 Process Lenses

[darinwc]

Sometimes I see process lenses on ebay with a max aperture of f4.5.
I assume they dont have much coverage, but I was thinking of picking one up for my Graflex SLR.

Are these f/4.5 lenses any good? Are they generally Tessar types?

[bnstein]

If you are thinking about the tominon lenses made for polaroid cameras they are tessars, the longer focal lengths will cover 4x5 (just!), and folks vary in their opinion of them (look around here and LFF). Ive been quite happy with a 105mm that I bought for the shutter and ended up using. They are generally well priced for what they are.

[Phillip P. Dimor]

There are these JML process lenses, 8 1/4" f8, identical to the Astro Goodkin. I think it's a planar type. They manufacture the iris to open up to f8 minimum but clearly the lens is f4.5 wide open. It's possible to hack/grind the iris to fully open. At f4.5 i'm not sure what the coverage is but i'm pretty sure they cover 8x10. I've used one at f8 and they are quite sharp but big and heavy.

[darinwc]

bnstein: actually im looking at focal lengths around 200mm.

ive seen kowa, process raptar, process ektar, jml, etc.

[k_jupiter]

The JML 210 is a nice looking planar lens but good luck getting shutters or filters for it. The 305 JML is a much smaller beast with threads on the front you could put a Alpax type lens on perhaps. Both cover 8x10.

tim in san jose

[Phillip P. Dimor]

I've a 10" Kodak Ektanon, very similar to a 10" Kodak Anastigmat I once had. Both are f4.5, the Ektanon is coated. I believe the Ektanon's were generally process lenses, many of the longer focal lengths were used with a prism.

Very sharp, big glass for a 4x5, barely fits on a speed graphic. Good coverage.
If I had to pick, i'd pick the Ektanon over the JML/Astro Goodkin lens I have. Although I wouldn't be surprised if it's just my sample.

[bnstein]

From what I recall and can dig up:

process raptar is like an apo-ronar (dialyte IIRC, not tessar). Raptars (which cover a wide variety of lens designs) were in general good lenses and the wollensak name doesnt command goertz like prices.

not sure about process ektars. they may be either dialyte or tessar type design. for a good overview of the ektars see http://www.prairienet.org/b-wallen/B...ktarsIndex.htm. I would expect good performance from an ektar though.

look at this thread which also discusses jml's etc http://www.apug.org/forums/forum44/1...ml-lenses.html Jim Galli who undoubtedly has forgotten more about lenses than I know feels both the JML and Kowa are excellent.

Remember with lenses of some age that the pedigree limits where you can get to, but a good sample of an excellent lens will outdo a poor sample of an outstanding lens. Chris Perez's tests of Angulons is quite illustrative of this.

HTH