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John Kasaian
2-Jun-2012, 22:45
I've been going through my storage room trying to get all my photography stuff organized and I came across a rather large (5-1/4" long and 3-3/4" across) lens marked

McIntosh Stereoopticon Co.
Chicago
H-15

It looks to have a focal length around 12"
Any idea what type of lens it could be?
Perhaps a Pretzel?:rolleyes:
Does anyone here have one of these?

John Kasaian
2-Jun-2012, 23:05
Breaking news!
I found another marking
15 in. EF

I opened her up and there is one lens (group?) at either end of the long empty barrel.
Its a very simple looking lens

Louis Pacilla
3-Jun-2012, 06:41
Sounds like a Magic Lantern lens of either Petzval or triplet configuration as McIntosh was a Magic Lantern manufacturer.

John Kasaian
3-Jun-2012, 06:50
I need to find a board to stick this on pronto!
Imagine, stereo swirlies!:rolleyes:

Richard Rankin
3-Jun-2012, 10:19
Breaking news!
I found another marking
15 in. EF

I opened her up and there is one lens (group?) at either end of the long empty barrel.
Its a very simple looking lens

If it only has 2 pieces of glass, it isn't a petzval or a triplet as both have 3 pieces of glass. You may have only a partial lens and might need to focus at infinity to see if you really have a 15", usable lens there. You might also want to try just a single element alone if you have a lot of bellows.

Richard

John Kasaian
3-Jun-2012, 16:44
If it only has 2 pieces of glass, it isn't a petzval or a triplet as both have 3 pieces of glass. You may have only a partial lens and might need to focus at infinity to see if you really have a 15", usable lens there. You might also want to try just a single element alone if you have a lot of bellows.

Richard

I've only unscrewed the rear element and it is quite thick so it could be a triplet---there are three reflections anyway. It's uncoated, of course.

Richard Rankin
3-Jun-2012, 20:52
If there isn't another symmetric glass element between the font and rear, it isn't a triplet. If it is a petzval, turn the rear element over and find the ring that unscrews. If it comes off, there should be the ring you just unscrewed, glass, a metal ring and more glass. That would indicate a petzval.

Richard

John Kasaian
4-Jun-2012, 09:01
The rear element is definately made up from two pieces of glass.

E. von Hoegh
4-Jun-2012, 09:19
I need to find a board to stick this on pronto!
Imagine, stereo swirlies!:rolleyes:

Don't you need two lenses to make images or view in stereo??

Richard Rankin
4-Jun-2012, 10:22
The rear element is definately made up from two pieces of glass.

Should be a petzval then. The elements are often installed incorrectly, so you might want to check Dan's site and check the layout of the glass elements.

http://www.antiquecameras.net/

Richard

John Kasaian
4-Jun-2012, 16:35
Don't you need two lenses to make images or view in stereo??
"I say thats a joke, son, I say thats a joke"
---Foghorn Leghorn, celebrity spokesrooster for Warner bros.

John Kasaian
4-Jun-2012, 22:03
I calculated the f stop to be f/6.6666666, so I'll call it at f/6.5

John Kasaian
5-Jun-2012, 21:40
I found a 'dorff lensboard that almost fits as the hole is a bit large but is well covered by the flange, however I feel that I should fill in 4-5mm gap with caulk or putty or something. Any suggestions? Or would it be better to hog out a smaller hole on another board to fit?

E. von Hoegh
6-Jun-2012, 06:40
I found a 'dorff lensboard that almost fits as the hole is a bit large but is well covered by the flange, however I feel that I should fill in 4-5mm gap with caulk or putty or something. Any suggestions? Or would it be better to hog out a smaller hole on another board to fit?

As long as there is enough wood around the screws/bolts that they are secure, just put a thin layer of felt between the flange and board to prevent any light leaks.

John Kasaian
6-Jun-2012, 21:01
The funny thing about this lens is that this evening I discovered that the flange was on backwards! When I flipped it over it fits into the hole like a glove! now I need to get the screws for it and a lenscap and it'll be good to go!
Hot dog!