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Dave Wooten
09-16-2007, 05:32 PM
I have a very old lens (14 x 17) and the numerical notation on the aperture ring is: 64, 44, 32, 22. When opened to its largest wide open aperture, it is in the 64 position. (?):confused:

RobertP
09-16-2007, 06:20 PM
Dave, I have an old Dallmeyer Rapid Rectilinear 18x16 that has the aperture settings...7.5-10-15-25-50-100. With 100 being the smallest aperture. I haven't seen one like this before either. This is about a 25" lens.

Dave Wooten
09-16-2007, 06:55 PM
Dave, I have an old Dallmeyer Rapid Rectilinear 18x16 that has the aperture settings...7.5-10-15-25-50-100. With 100 being the smallest aperture. I haven't seen one like this before either. This is about a 25" lens.


Robert this lens is between 22 and 25 inches when projecting on the wall...will try and get it on the camera this week....the brand is a Calhoun. I just loved the name and it has a 14 x 17 designation so just had to have it..."Calhoun Photo Materials Company-Rapid Perspective" 14 x 17....there was a Calhoun camera on e bay this week with an 11 x 14 lens on it with the same nomenclature etc...it was an 8 x 10 camera and name plate I believe Grand Rapids Mich. probably a wolly rectilinear ?

blaze-on
09-16-2007, 07:56 PM
I think that was camera on the bay was a Korona rebadged for Calhoun, whomever that was...

Hope to see you in Owens Valley next Month Dave.
Matt

freygr
09-16-2007, 08:50 PM
I have a very old lens (14 x 17) and the numerical notation on the aperture ring is: 64, 44, 32, 22. When opened to its largest wide open aperture, it is in the 64 position. (?):confused:

Could it be the daimeter of the opening, in mm?

Dave Wooten
09-16-2007, 09:11 PM
Could it be the daimeter of the opening, in mm?

Good thought,

Just measured, the smallest aperture is 22mm and the widest is 55 mm.

Interestingly the stop mechanism stops much short of the lens diameter which is 65 mm.

Jim Fitzgerald
09-17-2007, 12:06 AM
Robert this lens is between 22 and 25 inches when projecting on the wall...will try and get it on the camera this week....the brand is a Calhoun. I just loved the name and it has a 14 x 17 designation so just had to have it..."Calhoun Photo Materials Company-Rapid Perspective" 14 x 17....there was a Calhoun camera on e bay this week with an 11 x 14 lens on it with the same nomenclature etc...it was an 8 x 10 camera and name plate I believe Grand Rapids Mich. probably a wolly rectilinear ?

Dave, congrats on that lens! I had my eye on it but did not have the $$$ at the time. Just as well, need to finish the 8x20 before the Owens Valley workshop.

Jim

colrehogan
09-17-2007, 07:52 AM
Dave, I have a lens which has a scale on the shutter which reads in the EX scale with a value of 11.7 as the wide open aperture and 5 (I think) at the smallest aperture.

jimgalli
09-17-2007, 01:07 PM
Sure sounds like someone took that adjustable aperture completely out of the barrel and re-installed it 180 degrees out. What would happen if you took it out and flipped it over and re-installed it? Only possible on the most primitive of lenses, but........that be my guess :confused:

Ole
09-17-2007, 01:58 PM
It's either reversed, or it could be a classic example of the AN aperture system.

There were several different aperture systems in use around 1900: The familiar f-stops (but as often as not with a different base number than 1, Germans liked the 4.5 - 6.3 - 9 - 13 - 18 - 25 - 36 - 50 series), Stoltze, "French", US, mm opening, 1/32" opening, and several others I can't remember at the moment.

But by far the most popular one (especially in the UK) seems to have been the dreaded AN. I have one very fine lens marked with 1-2-3-4-8-10, and through trial and error I have determined that these are entirely Arbitrary Numbers.