Speed Graphic Curtain Test and Lens Suggestions

Ariston · Dec 29, 2019

I got around to testing the speeds of my newly repaired rear curtain using the methods suggested by several here.

I took four exposures on one sheet of HP5+ at box speed, and developed in HC110B for five minutes.

I am really pleased with the results. The images are a little underexposed, but much closer than I could have hoped for the first test, and consistent across the apertures.

I tested at the lowest tension, and using A, B, C and D curtain apertures. So the shutter speeds were 1/10, 1/70, 1/200, and 1/500.

Please give me your thoughts on the following:

1) Should I try and loosen the tension on this lowest setting to slow the curtain down a bit (and thereby bumping up exposure), or just work with it as is and adjust my exposure in the field?

2) This opens up barrel lenses to me, which is the biggest reason I wanted to get the curtain working (I am excited!). Can you make any suggestions on a cheap barrel lens to start off with?

Thanks again to everyone who has helped me with this project, and thank you yet again to John, who gave me this camera. I now have a fully functioning Speed Graphic with the bellows sealed, the rangefinder working, and the rear curtain working - all for free! I am in bliss!

EDIT: Oops - I meant to upload a pic of the negative. The top left is A, lower left is B, top right is C, and lower left is D. Ignore the motion blur from my bad technique.

I should mention that the lighting was VERY flat on this overcast day, and this entire scene only had two stops of range, excluding the black tarp in the bottom. But even the tarp only added one more stop. I feel like that tarp should have more detail with how I metered.

Dan Fromm · Dec 29, 2019

Testing with negative film is problematic because of its exposure latitude.

When I got my 2x3 Speed, I tested its curtain shutter with ISO 100 Ektachrome, did the equivalent of shooting test strips. Metered, set the aperture for 2 stops underexposure if the shutter speed was right, pulled the dark slide out a little, took a shot and the shutter speed being tested. Rewound (with dark slide in, of course), pulled the dark slide out two littles, repeated. Took five shots in all, I ended up with strips on the test tranny overexposed by 3, 2, 1, 0, -1 and -2 stops, could easily see which was right for the shutter speed set. Much to my surprise, all all speeds the 0 strip was best.

About barrel lenses. I have heaps of them, nearly all set up to be hung in front of a leaf shutter. The only ones I use with my little Speed's curtain shutter are too fast to work well in front of a leaf shutter. They're heavy, expensive now (not when I bought them), and no better at the apertures I normally use than lenses in shutter.

If I haven't discouraged you enough -- please understand, tinkering is fun and educational, I'm all for it -- then start shopping. Avoid enlarging lenses. None of the ones I've tested was much good at distance. If you look at enlarging lenses offered on the great auction site, every once in a while you'll find a Symmar or Xenar in barrel offered, usually for little money, as an enlarging lens. These are capable taking lenses and worth using. Just make sure to get one that will cover and whose focal length extends what you can do. Also look for Wollensak Tele-Raptars/Graflex Tele-Optars in barrel. Also look for process lenses. Apo-Nikkors, Apo-Ronars, Apo-Saphirs, G-Clarons, Konica Hexanon GR IIs and ReproClarons are all good. Beware, all have less coverage than you'd expect and GR IIs are a bit flary, with them a lens hood improvised from black construction paper will help.

Ariston · Dec 29, 2019

Dan Fromm said:
Testing with negative film is problematic because of its exposure latitude.

When I got my 2x3 Speed, I tested its curtain shutter with ISO 100 Ektachrome, did the equivalent of shooting test strips. Metered, set the aperture for 2 stops underexposure if the shutter speed was right, pulled the dark slide out a little, took a shot and the shutter speed being tested. Rewound (with dark slide in, of course), pulled the dark slide out two littles, repeated. Took five shots in all, I ended up with strips on the test tranny overexposed by 3, 2, 1, 0, -1 and -2 stops, could easily see which was right for the shutter speed set. Much to my surprise, all all speeds the 0 strip was best.

About barrel lenses. I have heaps of them, nearly all set up to be hung in front of a leaf shutter. The only ones I use with my little Speed's curtain shutter are too fast to work well in front of a leaf shutter. They're heavy, expensive now (not when I bought them), and no better at the apertures I normally use than lenses in shutter.

If I haven't discouraged you enough -- please understand, tinkering is fun and educational, I'm all for it -- then start shopping. Avoid enlarging lenses. None of the ones I've tested was much good at distance. If you look at enlarging lenses offered on the great auction site, every once in a while you'll find a Symmar or Xenar in barrel offered, usually for little money, as an enlarging lens. These are capable taking lenses and worth using. Just make sure to get one that will cover and whose focal length extends what you can do. Also look for Wollensak Tele-Raptars/Graflex Tele-Optars in barrel. Also look for process lenses. Apo-Nikkors, Apo-Ronars, Apo-Saphirs, G-Clarons, Konica Hexanon GR IIs and ReproClarons are all good. Beware, all have less coverage than you'd expect and GR IIs are a bit flary, with them a lens hood improvised from black construction paper will help.

I am going to do the over- and under-exposure test you mentioned. I need to test the speeds when tensioned up, anyway. You have a good point that slide film would be a better test, but I won't be shooting slide film in this camera just yet, so I may put that off. I don't have any sheet slide film on hand.

I've heard of people using experimental type lenses with the curtain, too - like popped out binocular lenses, etc. I just want in on the fun. We'll se where it takes me.

Thank you for sharing your expertise.

shutterfinger · Dec 29, 2019

Ariston said:
1) Should I try and loosen the tension on this lowest setting to slow the curtain down a bit (and thereby bumping up exposure), or just work with it as is and adjust my exposure in the field?

Graflex FPS requirement for the initial tension is 1). With the curtain at O and tension on 1 the curtain should close and lock. Lock is the wind key will not turn opposite the wind arrow. This requirement should be true with the camera in any position, portrait with the shutter controls pointing down is the most strenuous on the curtain; 2). With the tension at its highest setting the curtain should wind to its smallest aperture.
When both are true then the shutter is properly tensioned and one should work with the speeds as they are or make a new tensioning spring and try again for table speeds.

Ariston · Dec 30, 2019

shutterfinger said:
Graflex FPS requirement for the initial tension is 1). With the curtain at O and tension on 1 the curtain should close and lock. Lock is the wind key will not turn opposite the wind arrow. This requirement should be true with the camera in any position, portrait with the shutter controls pointing down is the most strenuous on the curtain; 2). With the tension at its highest setting the curtain should wind to its smallest aperture.
When both are true then the shutter is properly tensioned and one should work with the speeds as they are or make a new tensioning spring and try again for table speeds.

There are two winding keys - one for the aperture on top and one for the tension spring on bottom (I know you know this, I'm just describing to make my question clear). The one on top works as you describe. When I was working on the camera, I had unscrewed the mounting plate for the bottom (tension) key, and it spun around a bit. I spun it back to what felt about right and put the mounting plate back. My question is whether I should loosen that spring one or two more turns to increase the exposure.

Forgive my rudimentary description - I am not good at this.

shutterfinger · Dec 30, 2019

The wind key is the top key for the aperture. The bottom knob is the tension setting. You can experiment with lowering the initial tension ( tension 1 setting ) in 1/2 turn increments if you wish but I would only do it if the closing from O closes hard with the camera in portrait position.

Speed Graphic Curtain Test and Lens Suggestions

Ariston

Dan Fromm

Ariston

shutterfinger

Ariston

shutterfinger

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