I just bought a Speed Graphic from a yardsale. I am new to this type of camera. First thing I noticed was that the slower shutter speeds, Bulb setting, and T setting on the Graflex Optar 135mm lense were not working. With some good information I found on this forum I was able to find and download the shutter service manual. I carefully dismantled the lense and used the manual to reassemble the springs that had fallen off inside. I could tell that someone else had this apart before from all the markings and abuse of screwheads. I was able to repair the T and B settings but not the slower shutter speeds. Someone removed pieces of the 'retarder' assembly as the service manual calls it.

My question, after that long-winded explanation, is can I use the focal plane shutter as a substitute for my non working front shutter? Will there be any loss of quality or any other difference between using the focal plane shutter and the front shutter? I've only found information on the rear shutter relating to the use of lenses without shutters. Again, I am completely new to this kind of camera so maybe this is a dumb question.

If you can leave the front shutter open (T setting), then you have the equivelent of a barrel lens to use the rear shutter. Simple as that.

The only thing you may lose is X-synch. The rear shutter synch will only work with flash bulbs.

I would suggest you keep your eyes open for another shutter or whole lens/shutter combo. The 135's were very common and don't go for that much. And since you'll be buying one, make sure it's got x-synch as not all do.

The only other drawback of the FP shutter could come from moving objects. If you seach around here you can find info about that. It has to do with the way the slit goes across the film surface while an object is moving. It can produce interesting photos though And usually only with fast moving things like cars...

Congrats on working on that shutter. Most of us don't go that far in disassebly, or at least don't get them back together