I often see TT&H lenses from Xerox machines for sale. I've been looking for info but can't find any. Anyone know much about them? The one I saw recently had a 12 bladed iris, are these Apotals in disguise? I'm guessing they are a 4/4 dialyte type, that would give them around 45 degrees of coverage, right? Anyone used one as a taking lens?
They're too fast to be Apotals.
Not all of them, some are f4.5, some are f5.6, some are f9 and f10 like this one:
The 10.16"/9 is an Apotal, has a radioactive element in the rear group. I have one, badged TTH Copying Lens. Lovely little lens. Apotals are f/9 and f/10. It seems that the 10.16”/9 was originally made for the Haloid Model D type VR, later sold as the
Xerox 1385, an electrographic plate-maker with a reproduction camera on top that allowed variable ratio enlargements and reductions.
The run-of-the-mill f/4.5 and f/5.6 lenses taken from Xerox copy machines are not Apotals. These are relatively common and I thought they were what you were asking about. It pays to be as specific as possible when asking a question. The 10.16"/9s are much less common.
I was just asking in general about TT&H lenses with Xerox on them, there appear to be a very large variety of them and judging from pictures, there appear to be several types as the curvature and diameter of the external glasses appears to vary quite a lot.
I wasn't specific because just wondered if anyone had used any of them and could report on that particular one, I doubt anyone, unless they have tried a good number of different ones can say much about them as a whole.
Good to know the f9 ones are Apotals, that makes them a 4/3 tessar type, right? Any idea what the angle of coverage is? Interesting that TT&H adopted a different design approach to Wray and Ross who also made f8 and f10 process lenses but of 4/4 dialyte type, I have a Ross APO Xpress 12" and a Wrap APO Lustrar 12" and they are both dialytes.
Apo-Tessars have recently been discussed on the French LF site. See http://www.galerie-photo.info/forumgp/read.php?3,15895 ; the discussion is partly in French, partly in English.
Also visit Arne Croell's site, see his publications page (http://www.arnecroell.com/publications); it includes a thorough discussion of CZJ Apo-Tessars. And see http://www.galerie-photo.com/apo-pro...ikkors-en.html for information on asymmetrical (that's tessar type) Apo-Nikkors. I have the impression (great stress, impression, I haven't counted) that focal length for focal length apo-tessar types have narrower coverage than dialyte type process lenses.
The other Apotal in a smaller mount than usual that I'm aware of its the 6"/9 Copying Lens. Mine is engraved Cooke Copying Lens, I wouldn't be surprised if other examples were engraved differently.
The image you posted, Ian, bears a strong resemblance to one on the Joe Rock, purveyor of damaged goods to the crown, site.
Cheers Dan. Marco Cavina has written about the Apo-Tessar too but I don't recall the specific info. If I were to hazard a guess, I'd say the area they illuminate is quite large but only a portion of that has an MTF that is high enough for repro work, I say that because 'normal' 3.5 and 4.5 tessars seem to have a sharp central area and mushy outer area, or at least, some I have played with were like that.
I collect British lenses, and try to pick ones that are at least somewhat useful, so the TT&H copying lenses are on my list of ones to keep an eye out fr, but these days, it seems anything with the Dallmeyer and TT&H names attracts Asian buyers with deeper pockets than mine. They don't seem to have caught onto Wray yet though so I have acquired a few Lustrars, the HR Lustrar 5.6 is very good, sharper than the regular Lustrar and the dialyte type APO-Lustrar seems just as good as the other process dialytes I have. I only bought a tiny f8/8" Lustrar in Compur #0 recently as it would make a much lighter 'normal' lens for my 5x7 camera than the Ilex Acuton 4.8/215 in Ilex #3.
Well spotted, the image is indeed from his site. The one thing he's useful for is his pictures of items, even after selling them the page and image remains on his site.
I have one of these, an 8 1/4" f4.5 Tried it on 4x5 years ago and was not impressed. Had low contrast but I don't remember how sharp it was. Never used it again so it can't have been that good.
Nice round iris with what looks like 16 blades.
You piqued me curiosity so I visited Marco's site. I found one entry, may have missed others, that mentions an Apo-Tessar in passing. When he's goes into details he's good, when he doesn't he's not particularly informative.Originally Posted by Ian Greenhalgh
Your comments re fast Tessars may reflect lens abuse, in the form of using the lenses near wide open. I've never seen the point of fast Tessars, except braggin' rights or, perhaps, getting the shot when the light is dim. They have to be stopped down to be good across the field. And they're not all the same. Redesigns over time have improved fast tessar types' coverage. You may have been misled by using old lenses. With these things, newer is usually better.
If you'd followed the links I gave you you'd have seen that the makers of Apo-tessars and clones claim relatively narrow coverage for process lenses. Sorry, no TTH documentation, I've never found any for Apotals and such.
Posting Permissions
Reply With Quote
Bookmarks