Rochester Premo Pony No. 3 Camera

[Pat Kearns]

I have a Premo Pony No. 3, 5x7 camera patented Feb. 4, 1908. The camera is an Eastman Kodak Co., succr's to Rochester Optical Co. The lens is a 5x7 Rapid Rectilinear Bausch & Lomb Opt. Co. F8 - F128, shutter speeds 1/100 - 1 sec. B & T. It folds up to a 8 inch square 3.5 inch deep box for easy transport. It sat in a trunk or closet for decades until a friend purchased it at an antique store and gave it to me about 5 years ago. It has stayed folded up on my bookcase until recently. It is in pristine condition, original leather with very little wear, and the bellows is perfect. I inserted a light inside and cranked out the bellows to full extension and there weren't any light leaks. Searching the internet I found info on other Premo cameras that were 4x5 plate cameras but nothing on Premo Pony No. 3 so I am guessing this used 5x7 plates. Now I want to take this Pony out and put it through it's paces to see how the images will look. The main problem that comes to mind is a focusing problem. There has got to be a plane of focus problem using modern film holders vs film plates. The thickness between the two is bound to result in out of focus images. I realize the lens is century year old glass and might have some softness which I expect. Any suggestions on overcoming a plane of focus problem that I expect to encounter? I don't want to burn up too much film trying to solve it on my own. TIA.

[Glenn Thoreson]

I have a Premo B from around 1896 that I used to love to use. Modern film holders work just fine in it. I gave the plate holders away to a collector. The Rapid Rectilinear lens is extremely sharp over most of the field. The shutter, however, will be another story. I wouldn't bet on it being anywhere near accurate. Mine was right on at 1/25. Period.
But that's the speed I use most of the time, so no big deal. Unfortunately, my bellows totally crapped out so now it sits on a shelf waiting till I decide if I want to fix it. It is pretty cool. A 4X5 that weighs in at 36 ounces.

[Jan_6568]

Pat,
I have and use similar camera, mine is 5x7 Century Grand also designed for glass plates. It a wonderfull with plenty of movements, it serves me very well even though it is a little bit fragile. It has new bellows and new ground glass.

There was a problem with focus shift. A previous owner, who is also contributing to this forum, machined an aluminium frame which can be inserted where the holders go. It compensate the shift. The thickness is 1/8 inch. I insert this frame for focusing, after this is done I remove the frame and insert the holder, it makes the trick. I assume there was some kind of standard for glass plate holders and such 1/8 inch thick distance frame would work to adapt any glass plate camera for modern film holders. Other then the focusing distance difference the camera works fine with modern holders and I suspect this is true with other 5x7 glass plate cameras.

I am also using RR lens. It is indeed very sharp. Mine came without shutter and iris. I mounted the cells in an old but still precise Compur shutter. I also have few additional lens boards so I can use most of my lenses with this camera as well as with my 4x5 Tachihara.

Hope it helps

Jan

[Jim Jones]

Pat -- the aperture may be marked in the old U. S. numbers, where 8 = f/11, 16 = f/16, 32 = f/22, 64 = f/32, and 128 = f/45. If it is marked thus, the aperture at number 8 should appear to be about 3/4 inch when viewed through the front lens cell from a distance, and at number 128, about 3/16 inch. At the modern f/8 number, the diameter should appear to be about one inch, and at f/128, about 1/16 inch.