Can someone tell me if a 105mm f=4.5 Skopar from an old (20's or 30's) Voigtlander folding camera is a 3 element or 4 element lens. I'm thinking it's a 4 element Tessar type, but not sure.
Thanks.

Dave

I should let the lens mavens answer, but AFAIK: all Skopars are four-element tessar-type lenses.

Quote:

On 2004-09-04 21:48, Dave wrote: I should let the lens mavens answer, but AFAIK: all Skopars are four-element tessar-type lenses.

That's what I had always thought, but while doing a Google search on "Skopar" I found a camera shop advertising an old 6x6 Voigtlander with a 75mm f=4.5 Skopar three element lens. I'm not sure if he knew what he was talking about or not.
The reason I wanted to know, I just bought an old Voigtlander with a 105 f=4.5 Skopar off epay. I plan on using this as my motorcycle backpacker's medium format camera (I wanted something inexpensive for this). I assumed it was a Tessar type lens, but now I'm wondering. I already had an old Kodak folder with a triplet lens (Anaston) and didn't want another.

Dave

<font size=-1>[ This Message was edited by: hurdy_gurdyman on 2004-09-04 22:11 ]</font>

<font size=-1>[ This Message was edited by: hurdy_gurdyman on 2004-09-04 22:12 ]</font>

I'll paraphrase the lens vade: 4 glass triplet [single front element, single middle element, cemented rear pair], intorduced after WWI, color Skopar after WWII. The currious Hellar type f was produced while Ziss held the patent on the tessar and may have been a prototype for the Skopar. These(the skopars) were really good lense especially the 4.5 versions. (50,55,83,105,114,135,150,165,180,210,240,300). The 105 was for 6x9 format. They were fitted on preminum quality cameras of the era.

_________________
While a picture may be worth a thousand words, a quality photograph is worth a million.

<font size=-1>[ This Message was edited by: 45PSS on 2004-09-04 22:34 ]</font>

Quote:

On 2004-09-04 22:10, hurdy_gurdyman wrote: Quote: On 2004-09-04 21:48, Dave wrote: I should let the lens mavens answer, but AFAIK: all Skopars are four-element tessar-type lenses. That's what I had always thought, but while doing a Google search on "Skopar" I found a camera shop advertising an old 6x6 Voigtlander with a 75mm f=4.5 Skopar three element lens. I'm not sure if he knew what he was talking about or not. The reason I wanted to know, I just bought an old Voigtlander with a 105 f=4.5 Skopar off epay. I plan on using this as my motorcycle backpacker's medium format camera (I wanted something inexpensive for this). I assumed it was a Tessar type lens, but now I'm wondering. I already had an old Kodak folder with a triplet lens (Anaston) and didn't want another. Dave <font size=-1>[ This Message was edited by: hurdy_gurdyman on 2004-09-04 22:11 ]</font> <font size=-1>[ This Message was edited by: hurdy_gurdyman on 2004-09-04 22:12 ]</font>

Well, you can answer the question yourself. Count reflections from the lens' glasses.

To do this, close the shutter. Shine a bright light at the front cell. You should see four bright reflections. Open the camera and shine a bright light at the rear cell. You should see two bright reflections and one faint one. The faint one will be hard to see.

If you're absolutely positively certain there are only the two bright reflections, then the lens is a triplet. If you see the dim one too, the rear cell contains two pieces of glass cemented together and the lens is a tessar type.

As for what you saw in ads, remember that people make mistakes looking up info, there's a lot of misinformation floating around, and some sellers just make stuff up.

Cheers,

Dan

Thanks for the input, all of you. I think I'll try the light in the lens thing when the camera arrives. Hopefully, the lens will be in decent shape. You just never know about epay purchases.

Dave

I may have looked at the wrong lens diagram due to diagram numbers that are confusing.

45PSS, I don't think what you initially said was wrong. I've seen the tessar design called a 'triplet' elsewhere, although it seems a little weird to do so. A tessar's three elements are similar to a triplet (positive - negative - positive), except the back glass is two cemented elements.

The lens diagram number in the text is V034 and all I could find in the lens diagram section was Voi034 as described in my first post. The design is very close to a Tessar as they did not produce it until after the patent from Zeiss ran out on the Tessar. Zeiss could have claimed it was a varrant of their design.

Quote:

On 2004-09-05 18:43, Dave wrote: 45PSS, I don't think what you initially said was wrong. I've seen the tessar design called a 'triplet' elsewhere, although it seems a little weird to do so. A tessar's three elements are similar to a triplet (positive - negative - positive), except the back glass is two cemented elements.

Dave, R. Kingslake used a strange vocabulary in his books, e.g., A History of The Photographic Lens. He counted groups, so all lenses with three groups of glasses was, in his language, a triplet. Most others talk about counts of elements and groups and apply words like "triplet" to a group of cemented elements. For example, B&L's Hastings Triplet, a widely used design for hand-held magnifiers. It is three lenses cemented together.

Widely-used designs that fit Kingslake's concept of triplet include the Cooke Triplet (3 elements/3 groups), Tessar (4/3), Heliar (5/3), and Sonnar (as many as 7/3, as figured in Cox).

This is another instance of fuzzy language leading to pointless wrangles.

Cheers,

Dan

Here's a fuzzy pic of the camera I bought.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=3836635494&;

If the lens proves to be clean, I suspect it will make a nice backpackers camera along with a small, light tripod, release cable and lens shade.
I picked this one over several other folders because of the way the lensboard slides down a track instaed of a pop-out type opening system. The lens board mount/folding door should be more rigid with less rivet wear (slop), thus less chance of fuzzy pics.

Dave

<font size=-1>[ This Message was edited by: hurdy_gurdyman on 2004-09-06 05:19 ]</font>

Quote:

On 2004-09-06 05:15, hurdy_gurdyman wrote: Here's a fuzzy pic of the camera I bought. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=3836635494&; If the lens proves to be clean, I suspect it will make a nice backpackers camera along with a small, light tripod, release cable and lens shade. I picked this one over several other folders because of the way the lensboard slides down a track instaed of a pop-out type opening system. The lens board mount/folding door should be more rigid with less rivet wear (slop), thus less chance of fuzzy pics. Dave <font size=-1>[ This Message was edited by: hurdy_gurdyman on 2004-09-06 05:19 ]</font>

Dave, I can't tell one old Voigtlaender from another. But yours just might be an Inos. FWIW, Eric Burtscher, who sometimes posts here and who, alas, doesn't know english at all, has one and is delighted with it.

Good luck, I hope it was a good snag,

Dan

[quote]
On 2004-09-04 22:29, 45PSS wrote:
These(the skopars) were really good lense especially the 4.5 versions. (50,55,83,105,114,135,150,165,180,210,240,300). They were fitted on preminum quality cameras of the era.

I can confirm that, as my pre-war Anny, came with a 15cm f4.5 Skopar that is a quite good picture taker after being stopped down past f5.6
Top

Quote:

On 2004-09-06 08:46, Dan Fromm wrote: Quote: On 2004-09-06 05:15, hurdy_gurdyman wrote: Here's a fuzzy pic of the camera I bought. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=3836635494&; If the lens proves to be clean, I suspect it will make a nice backpackers camera along with a small, light tripod, release cable and lens shade. I picked this one over several other folders because of the way the lensboard slides down a track instaed of a pop-out type opening system. The lens board mount/folding door should be more rigid with less rivet wear (slop), thus less chance of fuzzy pics. Dave <font size=-1>[ This Message was edited by: hurdy_gurdyman on 2004-09-06 05:19 ]</font> Dave, I can't tell one old Voigtlaender from another. But yours just might be an Inos. FWIW, Eric Burtscher, who sometimes posts here and who, alas, doesn't know english at all, has one and is delighted with it. Good luck, I hope it was a good snag, Dan

Sometimes I get lucky. I'll let everyone know if it's a good one once it gets here and I can check it out.

Dave

[quote]
On 2004-09-06 12:03, Top wrote:

Quote:

On 2004-09-04 22:29, 45PSS wrote: These(the skopars) were really good lense especially the 4.5 versions. (50,55,83,105,114,135,150,165,180,210,240,300). They were fitted on preminum quality cameras of the era. I can confirm that, as my pre-war Anny, came with a 15cm f4.5 Skopar that is a quite good picture taker after being stopped down past f5.6 Top

I have an old 135 f=4.5 Skopar on a trashed shutter. Lens has a few cleaning marks on it, but perhaps it's worth finding a replacement shutter for it. I've never had a chance to use it. I have a Century Graphic lens board all drilled for it.

Dave