Adjusting Infiniti Focus on a Folding Camera

Vintage folding cameras usually have front element focusing. Over time, these may have been moved out of alignment.

The professional way to align the focus at infiniti is to use an autocollimator. There are other ways of aligning the focus using a second SLR as a collimator which is decribed here or here.

What you'll need:--Tiny screwdriver. My 1/16" screwdriver works, but its almost too big. --Magnifying glass or jewelers loupe (optional)

--Tripod (optional)

--Cardboard and Wax paper (or ground glass)

Steps (If you access to a piece of ground glass, you can skip step one.)

1. Wax paper can be used as a temporary substitute for ground glass. Cut a cardboard frame that will fit the base of the film gate. The cardboard provides some rigidity to the wax paper. Cut a piece of wax paper and tape it tightly against the frame.

2. The distance ring is attached through three small set screws. It is not the bigger screw which simply acts a stopping device when turning the focus ring. Unscrew the set screws and remove the distance ring. You can unscrew the front element all the way, but don't.

3. Mount the camera on a tripod. You'll need the camera to point at a faraway object. Place the camera in a shaded area and the subject to be bright so you can see the best. Out a window or and open door works well.

3. Open the back and tape the frame to the film gate.

4. Open the aperture to the widest setting. Open the shutter to "B" or "T".

5. Focus the lens. Use the jeweler's loupe to help determine best accuracy.

6. Replace the focusing ring and tighten the set screws.

Of course, if you have a piece of ground glass, it makes determining focus the easiest. This is a Hasselblad focusing screen

Handmade Graflex

My grandfather built a camera back in the day. In the below picture, it is the one on the left. After doing some research, I found it is copy of a Graflex 2x3 Crown Graphic. It takes sheet film in 2 1/4 x 3 1/4 format.

On the right, is a Graflex Miniature Speed Graphic. The Miniature Speed Graphic has a 11.5cm f/4.5 Carl Zeiss Tessar and the homemade camera has a 12cm f/3.5 Schneider Kreuznach Xenar. The lenses are roughly equal although the faster Xenar probably has a small edge. I got the Miniature Speed Graphic thinking it was the correct copy, but there is a minor difference.



The difference between the Speed Graphic and the Crown Graphic, is the Speed Graphic has a second focal plane shutter. There is also the Century Graphic which is the same as the Crown graphic, but with a plastic body. Many Graflex cameras, both the came with an accessory rangefinder. On the photo on the bottom left, the Miniature Speed Graphic, (looking at the rear right side) the levels and dials along the right for operating the focal plane shutter. The long metal attachment and tube is the rangefinder.

The focal plane shutter is really only needed if you attach a separate lens without its own leaf shutter. Alternatively, if you want a shutter speed faster than 1/250 Compur shutter maximum, then it also may be needed.

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The front of the cameras look very similar. The Speed Graphic has the rangefinder on the left side and a view finder on top.



The rear of the camera is where you load the sheet film holder. You can focus on the ground glass. The homemade camera is constantly exposed and the Graflex has a hood that pops up.



So is the camera really handmade? My grandfather was a tool and dye maker, so he had the skills and access to the tools. He also had a nack and a talent for making things. The numbers on the distance scale are punched



Notice the machined distance scales on the Speed Graphic.


I haven't tried to use either camera with film yet, although I will soon as I have both 2 1/4" x 3 1/4" film and sheet film holders. Only Efke, a Croatian manufacturer, makes 2 1/4" x 3 1/4" sheet film, in black & white in three speeds - 25, 50, and 100.