How do shutter speeds work on the back of a Speed Graphic

[george1956]

I was wondering how the shutter speeds with the back shutter on a Speed Graphic that can be used with barrel lenses. I know it has T, 0, 3/8 and so on when the winder is wound, but the bottom lever has 1, 2, 3, 4, 5 and then a chart. What would be a basic 1/125th, or 1 second. I know T is for time exposure, but how do the other shutter speeds work. Maybe someone knows a website that lists that data.

 

[cmedin]

The camera should have a plate on it that 'decodes' the settings into actual shutter speeds. 0,A,B,C,D all correspond to the size of the slit in the shutter curtain, and 1-5 (or 6) corresponds to the tension of the curtain. You combine them using the table on the camera to set a specific shutter speed. (At least that's the case for the Anniversary Speed Graphic)

edit: here you go, should help...
http://www.butkus.org/chinon/graflex/graflex.htm

Check out the Anniversary manual, page 12.

 

[rogue_designer]

I believe that the break down was 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000

But I'm not sure.

 

[David Goldfarb]

3/8, and so on are the width of the shutter slit in inches, and the other setting is the spring tension, as described above. The higher the tension, the faster the slit travels. The smaller the slit, the briefer the exposure. The chart tells you what the shutter speed is for any given combination of slit width and spring tension, with an "X" in the boxes for combinations that are not recommended.

 

[george1956]

Thanks, I've learning something!

Thanks, I've learning something!

With the back shutter you can use lenses without shutters, but what about enlarging lenses? Do you just have to check on the ground glass and see if it covers? I know some of the older generation barrel lenses can get good results, but any recommendations on enlarging leses that would cover 4x5?

 

[venchka]

Or you could get a newer body (Pacemaker for example) with the shutter speeds indicated as usual.

135mm was/is the "normal" enlarging lens for 4x5. They should cover but I have no idea if you'll get sufficient coverage to allow movements. 150mm to 210mm enlarging lenses are also around. i'm guessing, but enlargeing lenses should work best close up. They may not work as well at infinity as a lens designed to work at infinity.

Good luck! Enjoy your Graphic.

 

[venchka]

One more thing to be aware of: the shutter curtains on my 1953 Pacemaker seem to move slowly on T, 1/30 & 1/50. I've been exercising it regularly (10 trips on each speed) and the parts seem to be moving better. There's no doubt in my mind that a CLA is in order.

How easy/difficult is it for a mechainical & tool challenged Klutz like me to get at the innards of the focal plane shutter and clean and lube everything?