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Modern Flashes and the speed graphic focal plane shutter

 
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Luke79



Joined: 18 Mar 2012
Posts: 3

PostPosted: Wed Apr 11, 2012 4:37 pm    Post subject: Modern Flashes and the speed graphic focal plane shutter Reply with quote

Greetings,

ive got one question concerning the 2 Bipost Pins on my Speed Graphic
is it possible to buy a bipost to pc female adapter cable and use the speed graphic with focal plane shutter to trigger the electronic flash tru the pins?

Luke
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45PSS



Joined: 28 Sep 2001
Posts: 3255
Location: Mid Peninsula, Ca.

PostPosted: Wed Apr 11, 2012 7:01 pm    Post subject: Reply with quote

Yes a BiPost to PC adapter cord will fit the BiPost connector on the body and if the contacts are not corroded it will fire an electronic flash but you will get a very under exposed image to a blank piece of film.

There are two contact strips at the top edge of the film opening and a short strip of metal on the curtain at the lead edge of the aperture opening. As the curtain travels the flash contacts make triggering the attached flash. Flash bulbs have a 15 to 20 millisecond (.015 - .02 seconds) rise time to reach 2/3 of their peak output. Focal plane flash bulbs for up to 2x3 cameras have a burn time ( 2/3 of peak up to peak then down to 2/3 of peak [useful light output]) of 20 milliseconds and 4x5 focal plane flash bulbs have a burn time of 50 milliseconds.
http://www.donsbulbs.com/bulbs/g623/l/ge1954/09.gif
An electronic flash has a duration (equivalent of burn time) of 1/200 - 1/1000 ( .005 seconds to .001 seconds).

A .005 to .001 second burst of light .015 seconds before the aperture opening reaches the lead edge of the film will not illuminate much.

You can set the curtain to T, trip the curtain, manually fire the flash, then close the curtain and get a good flash photograph. This is called open flash.
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Dyor



Joined: 12 Jun 2013
Posts: 3
Location: Moscow, Russian Federation

PostPosted: Wed Jun 12, 2013 11:22 pm    Post subject: Reply with quote

Dunno if my method works with FP shutters, but it's perfectly functional with Flash Supermatic on Crown Graphic 23. Probably this shutter was modified by one of previous owners, because delay lever is blocked dead and shutter X-syncs perfectly, being non-X model. I just soldered two-wire cord from some small flash to bi-post and covered the mess with duct tape (I'm thinking on something more aesthetical for disguise). On the other end of that two wires is a PC-sync connector. In my case it's male on 10" wire and a PC-sync to hot shoe adapter (I use Olympus T-32 flash on bounce grip until I find more powerful and practical hammer-type strobe, like Metz or Sunpak, cheap enough for my rather tight budget), but it seems better to use very short wires and a female PC socket. This way you'll get the same result as with modern shutters. In my case it works perfectly at all shutter speeds up to 1/400th.

If this won't work for curtain shutter, you might just stick to using lens shutter for flash work, usually it is more practical for either fill-flash on sunny day as well as studio work - leaf shutters synchronize at all speeds.
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Sometimes it's worth to measure, focus, frame, refocus, reframe, cock shutter, remove darkslide, sigh, adjust focus and finally push release, rather than just push one button to do all that 10 times per second.
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Dan Fromm



Joined: 14 May 2001
Posts: 1892
Location: New Jersey

PostPosted: Thu Jun 13, 2013 1:45 pm    Post subject: Reply with quote

Sorry, your proposed fix won't work. The reasons have already been explained.
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Dyor



Joined: 12 Jun 2013
Posts: 3
Location: Moscow, Russian Federation

PostPosted: Thu Jun 13, 2013 2:01 pm    Post subject: Reply with quote

It may not work with FP shutters, which I'll test soon with 4x5 Speed Graphic and try not to forget to report either result here. But with non-X Kodak Flash Supermatic lens shutter it works as good as any modern shutter, which I tested and explained above. If you need proof pictures of that, I have them.
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Sometimes it's worth to measure, focus, frame, refocus, reframe, cock shutter, remove darkslide, sigh, adjust focus and finally push release, rather than just push one button to do all that 10 times per second.
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Dan Fromm



Joined: 14 May 2001
Posts: 1892
Location: New Jersey

PostPosted: Thu Jun 13, 2013 4:09 pm    Post subject: Reply with quote

Dyor wrote:
It may not work with FP shutters, which I'll test soon with 4x5 Speed Graphic and try not to forget to report either result here. But with non-X Kodak Flash Supermatic lens shutter it works as good as any modern shutter, which I tested and explained above. If you need proof pictures of that, I have them.


Electronic flash will never work with a Speed Graphic focal plane shutter except when open shutter is used. This is a major limitation and there's no way around it.

I don't think you understand how the focal plane shutter works. Leaf shutters are very very different.
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Dyor



Joined: 12 Jun 2013
Posts: 3
Location: Moscow, Russian Federation

PostPosted: Thu Jun 13, 2013 4:18 pm    Post subject: Reply with quote

I DO understand that. But if Speed Graphic comes with original lens, and not something else, that lens is usually in leaf shutter. Thus you CAN use electronic flash with Speed Graphic, just not with focal plane shutter. Also, open shutter method is a solution for studio or other place dark enough, where flash is the only light source, AND for low-sensitivity film. Bright sunny day is no go, unless you get a stack of ND filters and push buttons really, really fast.

Anyway there is quite a supply of NOS flashbulbs in the US, and still there are some Graflites on ebay, on which ******** fans don't have their greedy hands yet (curse George Lucas, couldn't he make light sabers from something else back then... ).

Can't say that for Russia, future already effin' came here and most people don't have a clue about anything non-electronic, just some movie crews sometimes ask me and some of my friends where to get that "ancient big round plate flash on a stick, with a big lamp and smoke, ya know" for props. Kudos go to them for trying to make silver screen a bit more credible, but "big round flash on a stick" is nowhere to be found here, so they drop the idea fast.

When I or my friend walk around Moscow streets with open Graphic in left hand, more than half of by-passers, photographers or not, turn their heads like owls and sometimes stop to ask "what is that stuff, a Polaroid, Fotokor-1 or German?". Graflex is totally unknown here, people even don't know about anything American photographic, except for Polaroid 636, Kodak film and P&S cameras.
I assume that it's roughly 100-something Graphic and Graflex cameras in Russia altogether, not more, 99% of them off ebay in recent years. My friend (who also owns couple of SLRs from 1909 and 1925) and I are probably the only Graflex owners in all former USSR who systematically research everything on Folmer&Schwing (still can't find any portraits of either gentlemen) and Graflex company in all incarnations. This research might even make an excuse for getting US visa, which is not easy to obtain. I really want to dig original archives (LOC, Boston Public Library, Rochester City archive if it exists, Kodak... whatever), whatever they have on subject.
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Sometimes it's worth to measure, focus, frame, refocus, reframe, cock shutter, remove darkslide, sigh, adjust focus and finally push release, rather than just push one button to do all that 10 times per second.
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