Advice on Cleaning a lens from 1850 (approx)

[johnwsheldon]

Looks nice and solid! I'll make sure to post some images of mine once I get it all cleaned up.

[Steven Tribe]

To be perfectly Frank with you, the projector is a piece of junk! There are attractive projectors in good condition which are wothwhile the effort of shining them up - but this not one of these. The extra large lenses you mention are also mostly unloved, but are surplus to requirements from every scrapped enlarger and projector.

BUT Voigtlander serial number 3350 is veritable gem. Voigtlander made the first Petzvals in collaboration (and conflict!) with Josef Petzval.
It is possible, that the paper you removed from the barrel was fixed during manufacture to ensure light tightness behind the focusing track. Condition looks good (threads, glass) - but I think I can see that the front achromat has an alternative mounting in the front cell. This should be the same as the rear cell, but looks like the outer brass has just been turned over in a lathe rather the screw in/out. The edge looks like it has an awfully Fresh brass finish?

Sequence of the rear lenses is correct.
You worry me when you lift one heavy, slippery irreplaceable lens over another! I rarely lift lenses off from a work bench. The cloth you employ must be thicker!

I’ll give some data about your lens after I have checked the data sources.

[Steven Tribe]

The most reliable list of serial numbers gives 3350 as being made in 1850. It was in one of the last production runs before the engraving was changed from “in Wien” to “in Wien und Braunschweig” which, at latest, happened by 3933. Later developments were the correction the chemical/visual focus divergence (7200) and the adoption of Waterhouse stops and slots in 1859.

I am pretty sure the diameter of the lenses in your Voigtlander is 79.3mm! But the focal length could be anything from 214mm to 362mm!
Voigtlander had only a few “standard” lens sizes. This size was called the “3 Zoll (inches)”.

I mentioned that the front lens cell looked “adapted”.
I only have Voigtlander Euryskops here at the moment - but I can compare with the classic x section which does show a screw ring mounting. In the figure “1” if the cell/barrel thread mounting, whilst the finer thread “2” is the screw ring holding the achromat lens in the front cell.

I was surprised when you didn’t report that the Canada balsam holding this front lens together wasn’t degrading. Usually, a lens of this age, has been through one, two or even three, balsam layer replacements. I think it must have been renewed last when the vintage Voigtlander was deemed serviceable for use in the projector. I have found another interesting mid-century photographic lens used to improve the performance of a magic lantern.

[johnwsheldon]

BUT Voigtlander serial number 3350 is veritable gem. Voigtlander made the first Petzvals in collaboration (and conflict!) with Josef Petzval.
It is possible, that the paper you removed from the barrel was fixed during manufacture to ensure light tightness behind the focusing track. Condition looks good (threads, glass) - but I think I can see that the front achromat has an alternative mounting in the front cell. This should be the same as the rear cell, but looks like the outer brass has just been turned over in a lathe rather the screw in/out. The edge looks like it has an awfully Fresh brass finish?

Sequence of the rear lenses is correct.
You worry me when you lift one heavy, slippery irreplaceable lens over another! I rarely lift lenses off from a work bench. The cloth you employ must be thicker!

I don't normally look twice at projectors, but when I saw that lens I knew I wanted to get it and bring it back to life as an active photography tool, even if I don't keep it long term (though I definitely want to use it for a few projects before I'd consider letting it go).

I had never considered that the textured paper might have been original, but I'd rather live with the risk of minor light leaks for now than try to identify a material and adhesive to use inside the barrel. I'll make sure to get some more closeups of the front cell before I put everything back together to show anywhere it may have been modified and to show the condition of the balsam. It does look quite different from the rear cell. I later checked a couple optical diagrams for Petzval lenses to make sure the arrangement was correct.

The most reliable list of serial numbers gives 3350 as being made in 1850. It was in one of the last production runs before the engraving was changed from “in Wien” to “in Wien und Braunschweig” which, at latest, happened by 3933. Later developments were the correction the chemical/visual focus divergence (7200) and the adoption of Waterhouse stops and slots in 1859.

I am pretty sure the diameter of the lenses in your Voigtlander is 79.3mm! But the focal length could be anything from 214mm to 362mm!
Voigtlander had only a few “standard” lens sizes. This size was called the “3 Zoll (inches)”.

I mentioned that the front lens cell looked “adapted”.
I only have Voigtlander Euryskops here at the moment - but I can compare with the classic x section which does show a screw ring mounting. In the figure “1” if the cell/barrel thread mounting, whilst the finer thread “2” is the screw ring holding the achromat lens in the front cell.

I was surprised when you didn’t report that the Canada balsam holding this front lens together wasn’t degrading. Usually, a lens of this age, has been through one, two or even three, balsam layer replacements. I think it must have been renewed last when the vintage Voigtlander was deemed serviceable for use in the projector. I have found another interesting mid-century photographic lens used to improve the performance of a magic lantern.

Thanks for the extra info! I'll have to measure the front and rear cells before I reassemble everything, but my rough measurements before I disassembled showed a diameter of about 63mm for the rear elements (using a ruler across the back of the lens). I'm really curious to see what image circle it covers safely, and figure out the focal length and aperture once I have it mounted to my 4x5 camera - but that's going to involve some 3d printing or other fabricating to make an adapting board I can secure the mounting flange to and still fit the board holder on the front standard.

[Steven Tribe]

It appears you have the model whose data I don’t really understand! There is just a single Voigtlander Petzval that has a rear lens diameter around 63mm (unless you have been including the brass mount in this measurement?). This is the so-called “2 1/4 zoll/inch”. It is easy to see if this is yours, as there is a huge difference in the front/rear lens - 79mm versus 65.8mm.
It is shown as the last version in this table.
Unfortunately, it shows the focal length as 59.26mm - which is an impossible figure. A similar mistake appears in another version of this table (this time a German author!), so perhaps their source material (1860’s catalogue) was faulty.

[johnwsheldon]

My previous measurement was simply across the back of the slightly-misshapen brass of the rear cell with poor access to the optics. I've re-measured now that I have access to the two optical cells more directly, though without opening the cells to measure the glass directly. I'm also kinda eye-balling the measurement with a ruler, as I don't have a good set of calipers for this. My very rough measurements are:

Front elements: 53mm
Rear Elements: 56mm

These could be off by up to a full millimeter in either direction, which doesn't do a lot to narrow down which lens this is. My best guess for now (before I do measure the focal length) is it is one of the 2-zoll or 2.04-zoll designs, assuming there weren't design changes or moves toward standardization between this lens's manufacture in 1850 and the publication of that table's source catalogs.

Either way, I'll be glad to post all of my measured results and methods here in the interest of documenting more of these early Voigtlander Petzval lenses.

[Drew Bedo]

There is a lot of DIY advice on doing a cla yourself for these lenses. I bought an unmarked Petzval and loked it over. Just needed as few tweeks such as screws for the pinion housing, glass cleaning and the flange was stuck on.

Did a re-evaluation of my skills, experience and workspace . . .I felt that I could easily bobble and chip an edge of the ancient glass. Losing or bending something was also a concern. In the end, I chose to send it off to S.K. Grimes. They had it for several weeks and sent it back to me with everything fixed. Total cost was near, but under, $200.

The article described in the OP is a marked lens from a well known and historic maker, Voightlander. It is desirable as a collectable and a quality optical instrument. I would not hesitate too to have it worked on by experienced professional technicians for this first-in-a-hundred-years servicing.

Consider that we, who have these fine vintage and antique pieces are not actually the "owner" of any of them. Rather, we are custodians, stewards or curators, merely holding them and caring for them for another, future photographer, perhaps still unborn.

Sure, use it and create images with it , but cherish it too and preserve it.

[mhayashi]

Good evening from Tokyo.
Your sample would be No.2.
Check the leftmost column next to the title column of the VoigtlanderPetzvalTransitionSummary20230608.pdf.

https://www.largeformatphotography.i...=1#post1645764

[johnwsheldon]

There is a lot of DIY advice on doing a cla yourself for these lenses. I bought an unmarked Petzval and loked it over. Just needed as few tweeks such as screws for the pinion housing, glass cleaning and the flange was stuck on.

Did a re-evaluation of my skills, experience and workspace . . .I felt that I could easily bobble and chip an edge of the ancient glass. Losing or bending something was also a concern. In the end, I chose to send it off to S.K. Grimes. They had it for several weeks and sent it back to me with everything fixed. Total cost was near, but under, $200.

The article described in the OP is a marked lens from a well known and historic maker, Voightlander. It is desirable as a collectable and a quality optical instrument. I would not hesitate too to have it worked on by experienced professional technicians for this first-in-a-hundred-years servicing.

Consider that we, who have these fine vintage and antique pieces are not actually the "owner" of any of them. Rather, we are custodians, stewards or curators, merely holding them and caring for them for another, future photographer, perhaps still unborn.

Sure, use it and create images with it , but cherish it too and preserve it.

At this stage, I've cleaned the glass and given the barrel a very light cleaning and reassembled everything. I originally aimed to remove all of the adhesive residue from the brass, but decided not to move to any stronger cleaning methods when a light cleaning with naphtha didn't remove all of it; I don't want to do any more damage to the existing finish than was already done before I acquired it. I'm not taking any steps to address the modifications made to the barrel by the last user, so I take my role as temporary steward of most of my equipment pretty seriously - very few of the cameras and lenses I use were manufactured within my lifetime, and I hope all of them will outlast me. Now that I've done a cleaning, I don't anticipate having it apart again for as long as I have it.

I consulted SK Grimes about what it might take to restore the barrel to its original condition (remove the somewhat sloppy soldering and replace the missing pinion gear), and it was just out of my budget. That's too involved for me to do myself, so I'm just going to care for it in the current condition and make sure anything I do is non-destructive and easily reversible.

Good evening from Tokyo.
Your sample would be No.2.
Check the leftmost column next to the title column of the VoigtlanderPetzvalTransitionSummary20230608.pdf.

https://www.largeformatphotography.i...=1#post1645764

That seems the most likely by far! As soon as I have a lens board to mount it, I'll do some measurements to confirm that it is.