Graflex.org

[Dick Press]

I have changed the lens on my Century Graphic
from a standard 101mm f4.5 lens to a moderate
wide angle Schneider Super-Angulon 65mm f8
lens, with stops of 8,11,16,32,&45.
1.What is the proceedure that I should use
in re-setting the infinity stops? Should I do
this at f8 or f11?
2.Is it necessary to re-adjust the focusing
scale also?
I will only be using this camera for taking
landscape photos in the Colorado high country .I like the 6x9 medium format enlargements.
Dick Press

[alecj]

I'll let someone else explain the infinity stops procedure.

With regard to the focusing scale, you need a new focusing scale for each focal length lens you use. For 65mm, the outside scale you'll need is # 30882-27. Good luck in finding one.

[Henry]

Infinity focus is determined by racking the bed (almost) all the way back; then, use a loupe on the ground glass and move the front standard around until an object really far away, like several hundred yards, is in focus. Do this with the lens aperture wide open. Lock down the front standard and locate your infinity stops against the cross bar.

On my Century the Optar 65mm lens is focussed at infinity when the front standard is about 1/4" onto the long rails. Using a good quality steel rule, I also measure to make sure that both sides of the front standard cross bar are the same distance from the far end of the bed rails (this prevents unwanted swing). Rather than relocate the infinity stops, I marked the rails with a Sharpie pen---not a permanent solution, but for my purposes better than moving the stops around, since I use the 101mm lens much more often than the wide angle. Every so often I refresh the markings. Works for me!

[45PSS]

Graflex repair manuals state: retract the rails all the way into the camera body then foward approximately 1/8 inch, which translates into about 1/4 turn on the focusing knob. With camera mounted on a tripod or other sturdy support, focus lens wide open on an object at least 1/2 mile away. When said object is sharp, standard support is square to the rails, and locked then position the infinity stops to just touch the standard and secure. If the infinity stops would be positioned on the rail link then the stops get positioned behind the lens standard. And as Henry said use a loupe.
Charles

_________________
The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

[graywolf]

One can use a manual 35mm SLR as a collimator to set the infinity stops. Put a 200 or longer lens on the 35mm (the longer the lens the easier and more accurate the setting is to see). Set it up so there is light shining into the viewfinder. Set the lens to infinity.

Now point your Graphic into the lens of the 35mm. Rack the focus all the way back, then move it out 1/8". Lock it in that position.

You slide the front carriage in and out until the split image in the 35mm is in sharp focus. Lock the carriage. Slide the stops back against the carriage and tighten them down.

You should have infinity locked in. I usually point the camera out the window and verify that something very far away is sharp (just like to double check).

This method is easier then trying to focus on something far away to set infinity.

It is easiest if both cameras are on sturdy tripods, but you can set the 35mm on a table or something if you have to. The distance between the two cameras is not critical to the adjustment.

You will have to get the proper focus scale for the lens you have. There is a calculator somewhere on this site that will help you determine the exact focal length of your particular lens.

AFAIK, Graflex made scales in 1.5mm increments for all their normal focal lengths. For example: for a 135mm there as a 135mm scale, a 134.5mm scale, a 133mm scale, a 136.5 mm scale and a 138mm scale. You need the scale that is the closed to the actual focal length of your lens.



_________________

--graywolf
http://presscameras.graywolfphoto.com

[ricksplace1]

When I set the infinity stops on my century, I measure from the front of the rails with a dial caliper to make sure both sides of the lens standard are an equal distance from the film plane. Just racking out the lens standard and locking it in place does not ensure that it is square to fhe film plane. I have measured as much as .030 out of alignment without the use of infinity stops. Probably won't make any difference stopped down, but you might notice it wide open.

[alecj]

Graywolf said: "AFAIK, Graflex made scales in 1.5mm increments for all their normal focal lengths. For example: for a 135mm there as a 135mm scale, a 134.5mm scale, a 133mm scale, a 136.5 mm scale and a 138mm scale. You need the scale that is the closed [sic] to the actual focal length of your lens."

They did make a lot of scales, but not in that neat progression. For instance, for 101mm, there were only 5 scales. For 135mm there were 6, but for 127mm, there were 12! For some, there was only one.

I think it depended on the FL of the lenses being produced by their manufacturer and what FL Graflex would accept. Somewhere along the way they were colimated and the closest accurate scale chosen.