Testing a Used Camera and Lenses

[Scott Teven]

I recently purchases a used LF 4x5 monorail camera (Cambo 45SF) and 2 lenses:
(90mm F6.8 Rodenstock Grandagon MC and a 150mm F5.6 Caltar II-N MC). Both lenses are in Copal 0 shutters.

I am pretty new to LF and was wondering if there are some basic tests I can perform on this equipment just to verify everything is in working order. What sort of simple subjects should I photograph initially to examine my first exposures? I have color transparency film that I will be using. My longer range goal is to photograph architecture and landscapes.

[Gem Singer]

The first thing to check for is light leaks.

In a darkened room, extend the bellows all the way out. Using a flashlight, or similar light source inside of the bellows, move it around. If you can see tiny pin holes of light on the outside of the bellows, you have light leaks.

Small pin holes can be repaired. Large light leaks might require a complete bellows replacement.

If no leaks show up, just go out and shoot your favorite subjects. You'll soon learn that most goof-ups are caused by operator errors.

Enjoy your new camera.

[venchka]

Extend your flashlight search to include the lens board and film holders. Best way to do that is remove either the lens board or back. Look through the open end and move the flashlight around on the outside of the camera. Switch ends and repeat. That's how I tracked down a light leak between my camera back and a Grafmatic holder.

Make sure you have a secure connection between camera and tripod head. Do that at home before venturing out. In fact, make sure everything is secure. Shutters opening and closing for focusing and for picture taking. I spent several evenings at home going through the motions before actually taking the camera out to play. It helped.

Practice loading film holders.

Start with a building. Maybe just part of the building. A doorway? As you get the hang of it, back up and include more of the building.

Good luck!

[ic-racer]

I'd check the detents and focal plane and film flatness by shooting a distant (close to infinity) landscape or horizon wide open then stopped down to 16 or 22. If the center gets sharper when stopped down, its not focusing correctly. If the horizon is not sharp from edge to edge its not aligned on the detents.

I usually don't set the detents until I am sure I'm keeping it, but to do so I use a laser alignment tool.

I'd check for pinhole leaks on the bellows with a flashlight and/or by doing an exposure outdoors in the sun with the lenscap on.

I'd check the shutter speeds. Just as a screening I just do it by 'ear' just seeking something way bad that won't be fixed with a CLA. I'd double check the aperture scale is the correct one for the lens by measuring the entrance pupil size. If its an old beat up lens I may try to determine that the rear element isn't from some other lens formula.

I check all the movements and locks and other mechanical stuff. I look for evidence of tampering, like buggered screw heads, bent, broken or missing things.

I expect used equipment to be buggered to some extent, especially when it looks nice and the price was low. When I finally find the thing that is buggered up I feel good about figuring it out and go on and fix it up (rather than feel like getting screwed on the deal ;))

[Scott Teven]

I tested for light leaks both on the bellows and around the front & rear standards. I found no leaks. My equipment, although used, is in very good condition (bought it from KEH). The shutters on both lenses sound OK to my inexperienced ear. I hope to shoot some film this weekend.

[ic-racer]

I have had good experience with KEH. Happy shooting!

[David Karp]

Have fun this weekend Scott.

[Scott Teven]

Thanks to all for your tips and encouragement. Its a journey AND an adventure!

[Jim Rhoades]

You can test both camera and lenses in one. Mount some magazine pages on a board. Set the board up square to the camera from say, ten feet away. Also have some playing cards set up both in front and in back of the board.

Focus on the board. Take two shots. The first wide open. The board and magazine pages should be pretty sharp. If either of the cards are sharper you have a problem with the ground glass spacing. Shoot the second at a working aperture. I use f/16. Compare the smallest print with other known lenses or each other. Test all cameras and every lens. Keep good notes so you can repete the test as needed. I use two lights from three feet at 45 degrees. All shots for lenses are at f/16 and 1/8 sec. Tri-X, D-76 1+1, 11min. This is a standard I use and I keep all old negatives. Any lens that does not measure up gets sent back. This also checks the shutter somewhat.

A high price German lens with multi coating can be crap right from the factory. An old bargain lens that's been through a war might be sharp enough to cut your eye.

[John Bowen]

Fred Picker used to write about taking a photograph of bare tree branches. If the branches look like branches instead of steel wool, then the lens should be OK

[Scott Teven]

I'd check the detents and focal plane and film flatness by shooting a distant (close to infinity) landscape or horizon wide open then stopped down to 16 or 22. If the center gets sharper when stopped down, its not focusing correctly. If the horizon is not sharp from edge to edge its not aligned on the detents.

I usually don't set the detents until I am sure I'm keeping it, but to do so I use a laser alignment tool.


I performed the test that you suggested using my 150mm lens, I examined the 4x5 film under a loupe:

1 - The center and the right side of the horizon is a bit sharper when stopped down.

2 - The left side of the horizon is MUCH sharper when stopped down.

Perhaps I need to set the detents? Do camera repair shops have laser alignment tools?

[nikon_sam]

If you're just going out to do some testing...take good notes if you can or better yet place a sheet of paper in the shot with all your exposure and lens info on it...Later you know what's what...
You can also check for any problems with shutter speeds by comparing your results...

Good luck but remember to have fun and enjoy the experience...

[Emmanuel BIGLER]

Hello from France

Once you have passed different tests as suggested above, you can also make a classical sharpness test with test targets.
You can downlod here afile in pdf that generates something very simimilar to the USAF 1951 test target. Print the file in A4 (or letter) size, group 0 of bars features a grid with .5 millimetre bars separated by .5 millimetre white (1 cycle per mm)
http://www.takinami.com/yoshihiko/photo/lens_test/USAF.pdf
the explanations (in English) are here
http://www.takinami.com/yoshihiko/photo/lens_test/pdml-procedure_c.html


If the lens is excellent, do not expect to find the limits of your lens easily ; however if there is someting wrong in your camera like a gournd glass that has been improperly re-mounted, you can check for the focus defect by placing different targets at different distances and check whether the sharpest target on your film images is actually the good one, i.e. where you have focused on the ground glass. You can use a rollfilm holder to speed-up the process and check at the centre of the field. In principle, test targets will also detect any lack of parallelism between the front and the rear standard when everything is supposed to be set at null point for tilts. I say : in principle, since it becomes tricky to find and understand the origins of the defects in the images.

On of the members of the French LF forum galerie-photo.info has sucessfully used this method of multiple targets arranged "in depth" as a test objet, to discover that his ground glass was mounted on the wrong side, hence generating a systematic focus error of about one millimeter.