Schneider Kreuznach 7.5cm f2.8 coverage

[photobizzz]

Hi all,

Well I am starting a project - a scale focus 6X9 built from a Polaroid 600SE that is going to be chopped, a 127mm helicoid - a Graflok back - and now the lens search...

I want it to be wide but I am on a budget. I found a Schneider 75mm f2.8 from a Welta Perle that is made for 645. I am wondering if the lens will cover 6X9. I could go with a Kodak Ektar 127 and be safe but really want this to be a wide camera (the whole point)

Anyone have any experience with a 75mm lens made for 645 being able to cover 6X9 with no movements?

Thanks for any help in advance...

[eddym]

I once had a cammed 80mm f2.8 Schneider Xenotar for a Linhof Technika 70. That covered 6x7 without much extra for movements. I kinda doubt that a 75 f2.8 will cover 6x9, but I can't really say definitely. It might be close.

[fschifano]

I kinda doubt it too. The fact that the lens was designed of a 6x4.5 camera would make me doubt that it will cover anything wider than 6x6. The lens needs to cast a sharp image circle with a diameter of 7.5 cm. at infinity for it to work. Maybe you can rig up a jig to hold the lens and a piece of white matte board exactly 7.5 cm from the center point (usually where the iris is located) of the lens. Then measure the image circle cast by the lens onto the matte board. See this youtube video by J Brunner, a conrtibutor here about how to figure focal length and f stops.

http://www.youtube.com/watch?v=CIFNd...eature=channel

[David A. Goldfarb]

75/2.8 is a standard 6x6 focal length, so I also suspect it won't cover 6x9.

[2F/2F]

It won't cover, and it also probably won't focus to infinity, given the depth of the body of the 600SE.

I feel obligated to tell you that I think flat topping one of these cameras is not necessary, and IMHO, a waste of a good camera and good time. It doesn't give you any really helpful advantages, and it takes away quite a lot. It is also irreversible, as it is quite a hacking of the camera. All it gives you is a slightly lower profile and a little less weight. You still have a big and heavy camera in the grand scheme of things (it is 6x9 and made of metal, after all), and you still need to track down or fabricate a WA viewfinder, but now the camera can only be hyperfocal/scale focused (or on the Mamiya Press models, ground glass focused, if you have the ground glass back).

The coolest and most unique thing about the system is the coupled rangefinder focusing with several different lenses. Hack the RF, and you lose that, and might as well just have a 2x3 Graphic at that point. Smaller, lighter, more versatile, more common, and cheaper.

The way to reduce weight with this system, and still maintain its full function, is to get a Universal or a "plain" Press (as opposed to a Super 23). The Super 23 is the heaviest camera in the system (and also the coolest), due to the tilt/swing back. Additionally, you can shoot Polaroid (now Fujiroid only, of course) pack film with the Universal (and the 50mm will cover Polaroid and 4x5, which makes it even wider than it already is on 6x9).

Finally, the 600 SE is more rare and more valuable than any of the similar Mamiya Press cameras. I would never hack one unless it was thoroughly trashed to the point where it should just be thrown away.

IMHO, you are far better off with a 2x3 Crown/Speed/Century. They are cheap, and you will have very little problem getting them to focus at infinity with any lens. They are smaller than a flat-topped Press, and are much lighter, fold down, are more versatile, etc.