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View Full Version : Any info/experience with a Micro Raptar 115mm/12.5?



Vaughn
29-Nov-2018, 16:18
A Wollensak Micro Raptar 115mm, f12.5...coated...barrel...I picked this wee little thing up years ago -- advertised as a good close-up lens for 8x10. I just found the lens again. A little bit of research came up blank and I will not have time to devote to it until the New Year. I'll be giving it a try later this winter...possibly up to 4x.

Anyone familiar with this lens?

Dan Fromm
29-Nov-2018, 17:47
Oh, my, another mystery lens. Does it have a fixed aperture?

Vaughn
29-Nov-2018, 18:48
Oh, my, another mystery lens. Does it have a fixed aperture?

f12.5 to f32 -- and as I mentioned a wee little thing. About 1.5 inches in diameter and an inch tall.

scheinfluger_77
30-Nov-2018, 14:53
Hmmm... I have a 108mm f/6.8 raptar that covers 5x7. It is the later version of a 4-1/4” Wide angle series III. Yours must be something similar if it is a Raptar. Mine is about that size without the shutter.

Dan Fromm
30-Nov-2018, 16:01
Yours must be something similar if it is a Raptar.

Raptar is a trade name, not a design type.

Vaughn
30-Nov-2018, 19:15
I have a 210 Graphic Raptar -- a whole different beasty.

Supposively the Micro Raptar is designed for close-up work, and being a 115mm, it should not tax my bellows too much. If I remember what I just read on the info pages, one doubles the focal length (bellows extension) for 1:1, and add another focal length for every single digit increase (230mm for 1:1, 345mm for 1:2, etc), I should get up to 4x with my bellows (575mm), if I got the theory right:

"You need an extension of two focal lengths to get a lifesize picture. After that, every increase of one focal length gives you one whole number of magnification. Example: A four inch lens at 12" extension (three focal lengths) magnifies by two."

Dan Fromm
30-Nov-2018, 19:43
Vaughn, you got the calculation right, but not the notation. 1:1, 2:1, 3:1, and so on for magnifications greater than 1:1.

If your lens didn't have a diaphragm I'd suspect it was a gauge projection lens.

Vaughn
30-Nov-2018, 23:21
Dang I had it your way first and thought I read different so I changed it. I thought it was subject size to image size. Thanks!

In the Info section it said, "You can take a picture of a small object with any lens, but for really good results you need a lens made for an appropriate conjugate ratio. This is a fancy way of talking about the ratio between the subject and the image."

ic-racer
1-Dec-2018, 08:24
Picture of the lens?

f62 wide open at 4x magnification.

8x10 at 4x conjures the notion of 'something special' not spoiled by some diffraction or vignetting. I'd be interested in seeing what you do with it.

Vaughn
2-Dec-2018, 13:46
Any new project will have to wait to the New Year!

ic-racer
2-Dec-2018, 18:18
Barrel looks like the Enlarging Raptar barrel. It is a unique focal length compared to the Enlarging Raptars.

Keith Fleming
2-Dec-2018, 22:14
Could it be off an old microfilm camera--or even a microfilm reader for reading reels of microfilmed documents.

I spent a good bit of time in the 1980's on microfilm readers going through historical documents researching a volume on one year of the Vietnam War. The lenses on those machines enlarged the image onto a roughly 8.5X11-inch ground-glass type screen.

However, the one lens I examined back in that era was a 50 mm Componon enlarging lens on a microfilm camera in a government lab that had been closed down. Other agencies were scavenging through the left-over equipment. The lens had a screw-mount of about 29 mm, and I later learned there were adapter for using such Componon lenses on enlargers taking 39 mm screw-mount lenses. At my own historical center, researchers like me were discouraged from examining the innards of the microfilm and microfiche machines.

Keith

Vaughn
2-Dec-2018, 22:19
Thanks! I do not think a microfilm reading lens would need an adjustable aperature -- especially going down to f32. But at this point your guess is as good as mine.

Louis Pacilla
3-Dec-2018, 07:17
Hey Vaughn, my guess would be that it's Wollensaks version of the B&L Photomicrographics set of lenses.

Dan Fromm
3-Dec-2018, 08:11
Lou, all of B&L's Micro Tessars except the 158, which is f/6.3, are f/4.5.

F/12.5 is an unusually small maximum aperture for a high performance macro lens. 100 - 120mm macro lenses from, in alphabetical order, CZJ, Leitz, Nikon, Reichert and Zeiss Oberkochen are all at least two stops faster.

FWIW, I've had a 50/4.5 Micro Raptar for years. The barrel is enameled black, otherwise it looks just like an Enlarging Raptar; these beasties are usually in chromed barrels.

Micro Raptars may have been intended to compete with Micro Tessars (late ones are engraved Macro Tessar) but they seem to be much less common in the market for used lenses and, if I recall correctly, aren't mentioned in any of my books on photomacrography. Some of them, all fixed aperture, seem to have been intended for microfilm readers. Until someone turns up Wollensak documentation or promotional literature on them they're all mysteries.

Bob Salomon
3-Dec-2018, 08:39
Lou, all of B&L's Micro Tessars except the 158, which is f/6.3, are f/4.5.

F/12.5 is an unusually small maximum aperture for a high performance macro lens. 100 - 120mm macro lenses from, in alphabetical order, CZJ, Leitz, Nikon, Reichert and Zeiss Oberkochen are all at least two stops faster.

FWIW, I've had a 50/4.5 Micro Raptar for years. The barrel is enameled black, otherwise it looks just like an Enlarging Raptar; these beasties are usually in chromed barrels.

Micro Raptars may have been intended to compete with Micro Tessars (late ones are engraved Macro Tessar) but they seem to be much less common in the market for used lenses and, if I recall correctly, aren't mentioned in any of my books on photomacrography. Some of them, all fixed aperture, seem to have been intended for microfilm readers. Until someone turns up Wollensak documentation or promotional literature on them they're all mysteries.

Left out M Componons.

Vaughn
3-Dec-2018, 13:58
Thanks, everyone!