Are there any fast Dialyte ~10" lenses

[Ethan]

Hey guys,

I'm searching for a lens to use for UV alt process enlargements. I've been talking with a guy who has already built a UV enlarger, and he has found that uncoated dialyte lenses are the best for UV transmission. He's using a kodak enlarging ektar 4" f/4.5, which is a dialyte lens, but the 10" f/4.5 version is a tessar type, not a dialyte. There is a 10" f/8 dialyte version, but that is a stop slower, which for alt processes could be significant. Do any of you know if there exists an approximately 10" or 240mm dialyte lens with a maximum aperture around f/5.6?

Thanks,
Ethan

[edit: I should mention that I need the 10" or 240mm focal length since I'm enlarging 8x10]

[domaz]

You could use a 305mm Repro Claron- 4 elements in 4 groups, although I have no idea if it would work for enlarging 8x10 in an enlarger configuration. In a camera configuration at infinity it will not cover 8x10. They usually are coated though and contain a much different type of glass than a Kodak Enlarging Ektar. This may or may not be good for UV transmission..

[Jason Greenberg Motamedi]

I once had a Goerz S-Dagor (or maybe Dagor-S?) which was a 10" f4.5 dialyte. I was told it was originally for reproduction.

[Ethan]

You could use a 305mm Repro Claron- 4 elements in 4 groups, although I have no idea if it would work for enlarging 8x10 in an enlarger configuration. In a camera configuration at infinity it will not cover 8x10. They usually are coated though and contain a much different type of glass than a Kodak Enlarging Ektar. This may or may not be good for UV transmission..

thanks for your suggestion. Are there any repro clarons faster than f/9? thats what most of them seem to be, but if there are faster ones I might give it a shot.

[Ethan]

I once had a Goerz S-Dagor (or maybe Dagor-S?) which was a 10" f4.5 dialyte. I was told it was originally for reproduction.

Are you sure it was a dagor? All dagors are 6 element double anastigmat style (same as plasmat) to my knowledge. Dagor is an abbreviation of "Doppel Anastigmat GOeRz" I believe.

[Dan Fromm]

Look for a Dogmar or Celor, both Goerz lenses.

[Jason Greenberg Motamedi]

It was labled Dagor-S or S-Dagor, but was not a 6/2 design, it was 4/4.

[Jody_S]

I wonder if you should be looking at photocopier lenses, I seem to recall taking apart a fast Fuji that was a dialyt.

Edit: I found the lens, 8 strong reflections, Fujinon-Xerox 260/5.6, no aperture, threading over entire barrel with 2 locking rings. Mine is in rather poor condition, but that probably wouldn't matter for your purposes. I obviously never took it apart to clean because it's filthy. They used to be pretty cheap on fleabay. Still are, I just found 2 for US$20 ea, and f4.5 though those might be Tessars.

[Ethan]

Look for a Dogmar or Celor, both Goerz lenses.

I just found a pamphlet about the Dogmar, but with the Celor being a symmetric design it will probably work better. Many thanks!

[Ethan]

It was labled Dagor-S or S-Dagor, but was not a 6/2 design, it was 4/4.

are you sure it wasn't a 6/4?

[Ethan]

I wonder if you should be looking at photocopier lenses, I seem to recall taking apart a fast Fuji that was a dialyt.

Thanks for the suggestion, I'll keep my eye out for them, do you know of any in particular?

[Jody_S]

Thanks for the suggestion, I'll keep my eye out for them, do you know of any in particular?


I edited my post above to add the following:

Edit: I found the lens, 8 strong reflections, Fujinon-Xerox 260/5.6, no aperture, threading over entire barrel with 2 locking rings. Mine is in rather poor condition, but that probably wouldn't matter for your purposes. I obviously never took it apart to clean because it's filthy. They used to be pretty cheap on fleabay. Still are, I just found 2 for US$20 ea, and f4.5 though those might be Tessars.

[Ethan]

I edited my post above to add the following:

Edit: I found the lens, 8 strong reflections, Fujinon-Xerox 260/5.6, no aperture, threading over entire barrel with 2 locking rings. Mine is in rather poor condition, but that probably wouldn't matter for your purposes. I obviously never took it apart to clean because it's filthy. They used to be pretty cheap on fleabay. Still are, I just found 2 for US$20 ea, and f4.5 though those might be Tessars.

nice, any idea if its coated?

[edit: they appear to have a red dot, which usually means coated]

[Oslolens]

nice, any idea if its coated?

[edit: they appear to have a red dot, which usually means coated]Mine was multicoated.

Sent fra min SM-G975F via Tapatalk

[Jody_S]

I have just opened the lens to have a look, it is not a dialyt, it's a 6/4 plasmat (not sure how I missed that faint reflection). Coated. Completely unsuitable for your purpose, unfortunately. I should have known just from the weight that it wasn't a dialyt.

221372221373221374

[Bernice Loui]

Cooke Aviar.

UV transmission of lenses varies lots. Some lenses have been designed to suppress UV transmission, others less so.
Quartz is often used in optics specific to UV..
https://www.largeformatphotography.info/forum/showthread.php?21549-Quarz-LF-lenses

There was another LFF discussion about common LF lenses and their ability to pass UV, not able to find it now.


Bernice

[Ethan]

I have just opened the lens to have a look, it is not a dialyt, it's a 6/4 plasmat (not sure how I missed that faint reflection). Coated. Completely unsuitable for your purpose, unfortunately. I should have known just from the weight that it wasn't a dialyt.

221372221373221374

thanks for checking!

[Tin Can]

Cooke Aviar

https://www.flickr.com/photos/kansalainen/albums/72157623671927481/

[Mark Sampson]

You might ask forum member Nodda Duma about this. He is a lens designer, after all.

[Jason Greenberg Motamedi]

are you sure it wasn't a 6/4?

Yes, I took it apart and it was a 4/4.

[Ethan]

Yes, I took it apart and it was a 4/4.

That's really weird, I was under the impression all dagor variants were 6 element. Not that its of any consequence, but could it have been re housed in a dagor barrel?

[ottluuk]

Is there a reason why a 3/3 triplet wouldn't work? There are 260mm Meyer Trioplans in f/3.5 and f/4.5 for example. You can probably find some other unusual candidates in Arne Cröll's excellent article on LF lenses from the eastern bloc: https://www.arnecroell.com/eastern-block-new.pdf