Brass lens manufacturer identification - KORN

[dustspots]

I recently purchased a large brass barrel lens with waterhouse stop slot and rack and pinion focusing possibly made around the 1870's - 1880's. The lens has no engraving on the exterior of the barrel identifying its manufacturer but has the letters KORN stamped on the waterhouse slot partition inside. I have tried to research the name KORN without any success, and wonder if anyone here in the forum has come across a brass lens manufacturer named KORN or can enlighten me as to its possible place of manufacture. Thank you in advance for any information you can provide!

[Steven Tribe]

I don't like giving this suggestion as it doesn't get you very far. A photo would be helpful.

My guess is that this is a construction allignment mark (inside/outside or up/down) for the internal waterhouse split ring.
Korn (German) is the same as corn. In german, my dictionary tells me this also has the additional meaning (as in English) of a sighting line!

So this is perhaps in the same category as the French maker "FOYER" - meaning focal length - and numerous others!

[dustspots]

A photo would be helpful.

Thank you for your suggestions Steven, much appreciated! I'll post a few photographs tomorrow... perhaps they'll help to shed more light on the matter!

[dustspots]

Thank you for your suggestions Steven, much appreciated! I'll post a few photographs tomorrow... perhaps they'll help to shed more light on the matter!

Here are the photographs Steven... The lens barrel is approx 115mm high (without the hood) and the lens is approx 90mm in diameter. The glass is of petzval configuration. Estimated 12" f3.5. There is some very faint text written in pencil on the front element but sadly it is impossible to read. The flange is obviously not original.

[Xpres]

I don't think you'll ever know as there were so many made without markings for own branding. I have one very similar with not a mark on it. Maybe your only chance is if there is something legible written on the edges of one of the elements. Perhaps a photo of the faint text is possible?

[Steven Tribe]

It does look German or Austrian to me.

Someone could perhaps recognise the faint lens text?

[dustspots]

Perhaps a photo of the faint text is possible?

Thank you for your input Xpres and Steven... much obliged! I suspected it might be a German lens... hopefully someone can confirm this by deciphering the text around the edge of the front element! Sorry the images aren't great!

[Steven Tribe]

What a lot of text and numbers!

When there is this much, I automatically think it might be artisan/quality control/repairer information, rather than the lens maker.
The lens has been recemented long ago ( when this was done as soon as balsam age was evident - perhaps 50 years! ) as the pencil or ink marks are washed away to some extent.

[dustspots]

What a lot of text and numbers!

Thank you for your reply Steven! Yes, there are a lot of numbers and letters! I agree there is a lot of text for it to be the makers mark alone! After staring at the text more intently for the past half hour... I believe the last four letters may actually be the word Korn - which obviously links the element to the brass barrel mark in some way!

I wish whoever had recemented the lens in the past had done a better job of it as its delaminating slightly now! I love this lens... it's fabulous for portraits... thankfully the delamination does not effect my images!

[Jim Graves]

You sure this is not KOHN rather than KORN?

[dustspots]

You sure this is not KOHN rather than KORN?

Hello Jim, As far as I can tell the third letter of the word certainly looks more like an R than an H!

[Steven Tribe]

I have seen a few cemented lenses that are still in good condition with indications that it is still the original balsaming. But I have seen many more with deteriorated balsam. I think that, apart from known problem lenses with 3/4 joins, you must expect a cemented lens to last about 50-100 years. It must be function of:

- quality of the balsam involved and the degree to which this has been diluted to lower the viscocity.
- how thick the balsam layer is.
- if the lens edge has been "sealed" by black paint.
- extreme temperature fluctuations (beyond room temperature).

There is no doubt that most problems with balsam come from edge effects. Drying out, crystalisation and oxidisation of the natural (and therefore different for various vintage productions). I suspect that this caused by slight loss of balsam seeping from the edges, followed by entry of air and etc.

Fortunately, no permanent damage ever occurs. Your lens can as good as new. More difficult are those lens which have the front achromat mounted in turned brass!

[dustspots]

Hello Steven, Sorry for the delay in my reply! Thank you for your positive thoughts on ageing balsam... I shall endeavour to keep the lens in a relatively stable environment so that it's next owner (perhaps in about 20 years time) can enjoy using it as much as I have!