Telenar 90mm f/3.8. First shots. One question.

sergtum · Joined: 14 Nov 2016 Posts: 735

Hi guys! Does anyone know the optical scheme of this remarkable lens? I could not find such information.

CamJPEGs:

CamJPEG with a few correction of colors:

Words of gratitude to Lorraine for this lens.

ps: camera - sony a7

devinw · Joined: 19 Aug 2016 Posts: 207 Location: Portland, OR

I can't answer your question, but those are fantastic portraits!! Like 1

luisalegria · Expire: 2018-01-18

Just a guess, but probably a triplet.
A 90/3.8 didn't really need to be anything else in those days.
And you can take great pictures with a triplet.

You can find out without too much trouble I think.

sergtum · Joined: 14 Nov 2016 Posts: 735

devinw, luisalegria, many thanks for Your messages.
I understand perfectly well that the optical scheme will not give me anything. The scheme does not teach me how to photograph better. Curiosity moves me to determine this scheme. The assumption of a triplet scheme pleases me, because I have a small collection of triplets. But! By external signs Telenar is very similar to the Telefogar, for example. Can these two lenses have similar optical circuits? How do you think about this assumption?

luisalegria · Expire: 2018-01-18

You can try check by counting reflections.

Alternately you can do a limited disassembly if you are really curious and the lens is easy enough to disassemble, which of course is not always so.

A triplet of will have three elements in three groups. The most likely alternative is that it is some sort of Tessar, where the rear group is a cemented pair. I don't see why it would be anything else, those were quite standard at the time.

The test will be that the rear element should be rather thick in a Tessar, and of course will be quite thin in a triplet, about the same as the front element.

Pancolart · Expire: 2013-11-18

calvin83 · Joined: 12 Apr 2009 Posts: 7554 Location: Hong Kong

From the size/spacing of the front and rear element, i would expect the Telenar 90/3.8 is a 4(or 5) elements telephoto lens.

luisalegria · Expire: 2018-01-18

Good point Calvin.
An easy check is to see if the front and rear elements are the same size or nearly so.
Triplets are symmetrical, Tessars nearly so, as far as front/rear diameter.

scsambrook · Expire: 2011-11-18

I came across http://www.martin-karwoth.de/wp-content/uploads_martin/2014/02/Braun_Paxette_Ob1.jpg - assuming that the lens is the Roeschlein Telenar for the Paxette. Its not a good image of the brochure and there's no diagram, but it does tell us that the lens had four elements. (The 90mm Telinear for the Agfa Ambi silette had five elements - just in case anyone needs to know ! )

sergtum · Joined: 14 Nov 2016 Posts: 735

Many Thanks to all!!!

scsambrook, Thank You for "url". Unfortunately this link does not open on my PC. However, the information on the four elements is sufficient to satisfy my curiosity.

Once again, thank You all for the discussion.

calvin83 · Joined: 12 Apr 2009 Posts: 7554 Location: Hong Kong

Yes. That is what I expected.

http://www.martin-karwoth.de/braun-paxette-ii-das-spitzenmodell-des-hauses-braun/

sergtum · Joined: 14 Nov 2016 Posts: 735

sergtum · Joined: 14 Nov 2016 Posts: 735

Few pictures of insects with Telenar 90/3.8 and with macrorings

pdccameras · Expire: 2014-08-11

Really nice results with this fine lens! The close ups are quite striking. Great work. I have a 135mm f/4 Telenear in Agfa Ambiflex mount - will have to give it try. Thanks for sharing.

P.

Alun Thomas · Joined: 20 Aug 2018 Posts: 631 Location: New Zealand

I recently got a copy of this lens, and took a few shots. The first 2 are center and corner test shots at F8 near infinity. As shown the far corner of the lens is not that good. At F/3.8 results are similar with the expected slightly lower contrast and slightly lower resolution. I think the image circle just doesn't quite make it to the far edge of the frame at any aperture. Apart from that, the lens is capable of reasonable, maybe not great, results, and, as shown in this thread and others, it's not a problem in the hands of a creative photographer.

I disassembled the lens to clean it, successfully. The lens is not a triplet, its a 4/4 scheme, quite similar to the various 4/3 sonnar type schemes with a central cemented tapered element. In this lens however, those two central elements are not cemented, there's a small air gap between them. In contrast to most Paxette lenses this one was easy to disassemble for cleaning.

The last exposure was taken at way less than the designed MFD of 1.5m, using an M42 helicoid, at F/3.8, and is also a 100% center crop. No PP done on any exposure here.