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  1. #21
    Pragmatist's Avatar
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    Quote Originally Posted by Donald Qualls
    Just my opinion, but I think most of the difference between the old flashbulb photos and those made with strobes is the reflector size. A photoflash in a 6" bowl acts like a light source six inches across -- the biggest reflector I've seen on a factory-built strobe was about two inches across, and most are smaller than that. That makes a strobe act more like a "point source" compared to the extended source of a large reflector -- which means the shadows cast by the flash have relatively hard, sharp edges compared to those made by a large reflector, giving an effect like the difference between a bright overcast and direct sun.

    That said, it's a lot cheaper to shoot a few #5 bulbs now and then than it is to get a strobe with the same guide number and remount it in a large reflector. I wonder, though, if you couldn't mount a common strobe backward, with a diffuser on the lens, and then reflect that light from a bowl reflector to get a light quality similar to a bulb in a big bowl? Or use a bounce flash firing upward into an diffuse bowl? Anything that will get the light to shine from a larger area instead of what amounts to a point from several feet away...

    This is exactly the point I was making earlier. Most of the Heiland and some of the graflex bowls are adjustable in the distance from the bowl to the bulb (horizontal movement) to concentrate the light according to distance. It is focusing a parabolic reflector. Other reflectors are fixed, and "maximized" for working at distances of up to 25'. This tends to seriously vignette the lighting circle at very short distances.

    Putting the flash head itself into the optical path of the reflector would create a "shadow" or blank spot in the central apex of the parabola. This is quite the opposite of the bulb/parabola effect, in that the projected light would be brighter at the periphery than in the center of the projected cone of light.

    This cone is the primary difference between the parabolic reflector, and the reflector units used in xenon flashes.
    Cheers,

    Patrick

    When you come to a fork in the road, take it...

  2. #22
    benjiboy's Avatar
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    Don't think so.

    Quote Originally Posted by Lachlan Young
    Can anyone recommend an electronic flashgun of equivalent output to the GE#(?) No.5 flashbulb?

    All help much appreciated,

    Lachlan
    If you are talking about a portable electronic flash Lachlan I don,t think the output from most powerful ones will give the same output as some of the smaller flashbulbs.
    Ben

  3. #23

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    What about a sunpak 120 for the reflector look, though it is less powerful.

  4. #24
    Donald Qualls's Avatar
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    Dan, I don't see how a 1/200 flash is that big a deal if you're getting power comparable to a big magnesium bulb. Weegee used to shoot at 1/200 on the shutter, using the brightness of the bulb to let him freeze motion by clipping 5 ms out of the bulb's peak -- I don't recall seeing much motion blur in his flash images.

    If you have that kind of duration and a big reflector, what you've got is essentially just a fast flashbulb anyway, like a bright version of the SF gas-filled bulbs.

    You know, I've got a pair of old Strobonar flashes. They probably need new capacitors, and there's the issue of finding or making 510V batteries to run them (that's, what, 340 cells of carbon-zinc or alkaline chemistry -- maybe I could get them to run on $34 worth of those L76 button cells I can buy at 10 for a dollar?) -- but now I'm tempted to try mounting a diffuser and a big backward bowl on one and hanging it on the side of my Speed Graphic. I'd still have to use X synch, but I've got an X synch shutter I could mount on there...
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  5. #25
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    I can't imagine a portable strobe that has the output or "look" of a #5/#25 magnesium bulb! I always get a kick out of how people respond to them. They can feel the heat 10' away and see spots for a few minutes afterwards. My 3-yr old points to the ceiling and says, "Look! Sun!" after being photographed with one.

    If you're planning to use a strobe on the Speed Graphic, you'll be limited as to which shutter speeds you can use. I would suggest just locating some bulbs (preferably FP26 if using the Speed's focal plane shutter) and using the real thing. If you can't find a good cheap supply of the 25/26's, then you can always get a M3/M2-to-#5 adapter and use the smaller, cheaper bulbs. They still have a pretty high GN. I typically have to stop down to at least f/16 when using M3's in the house.

    Your actual GN will depend on the shutter speed, film speed, reflector size, finish and position. The Graphic 5" reflectors typically have Tele and Normal positions. The GN for the respective reflector size will be on the bulb packaging.

  6. #26
    Donald Qualls's Avatar
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    Actually, a strobe on the Speed isn't limited at all -- I can use any speed I like with the front shutter, if it has X synch, and can't use the rear shutter at all (at least on my Anny model, the only slit that uncovers the whole film plane at once is T, and it won't run through, only stops at full open and has to be released again to close). Since I doubt I'll ever see a 6 or 26 bulb, I'm limited to front shutter for flash anyway.

    I'm actually looking for good bayonet-to-M and/or M-to-AG adapters for a decent price. The ones I've seen on eBay when I had money always went for $20 and up, and the ones I've seen that went for a reasonable price (like the Dutch auction of a whole dealer card of them) came when I was broke. I've got a bunch of M2 and M3 bulbs, and an even bigger bunch of AG-1s (a couple hundred of those).

    I've never seen different guide numbers for different reflector positions, and I've got several "new" packages of #5, M2, M3, and AG-1 bulbs around. The P40s don't have guide number information on the individual bulb sleeves, and I don't have a flash that would work with the Speed that can use them anyway. Most of the bulbs you find these days are from the last year or two of production, when the factories were just starting to figure out that strobes were eating their lunch, and by then the Speed was pretty much out of the flashbulb picture, with professional having converted to electronic flash years earlier.
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  7. #27
    pandino's Avatar
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    Donald,
    You're correct, the packages don't have GN's for tele settings, but do have info for shutter speeds and sometimes adjustments for reflector sizes. GN's for tele setting could be arrived at by calculation (with known coverage angles) or empirically.

    I'm sure there are still hundred's of thousands of bulbs out there, though people like us are hoarding most of them. I have a case each of 25's, 26's and M3's. If you want them, you'll need to pry them from my cold dead hands...if there are any left by then.

  8. #28
    DBP
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    Quote Originally Posted by pandino
    I'm sure there are still hundred's of thousands of bulbs out there, though people like us are hoarding most of them. I have a case each of 25's, 26's and M3's. If you want them, you'll need to pry them from my cold dead hands...if there are any left by then.
    I'm still holding on to about two dozen No 22s for the night that I have to take action shots on a large field in the dark. Can't use them with the 1944 Anny Speed Graphic, oddly enough, as some prior owner re-synched it for electronic flash. (Went through a dozen No 5s and sheets of film before I figured that out.)

  9. #29

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    Quote Originally Posted by Donald Qualls
    Dan, I don't see how a 1/200 flash is that big a deal if you're getting power comparable to a big magnesium bulb. <snip>.
    Donald, its a huge deal when shooting hummingbirds. I've tried to deal with the duration by placing the flash close to the subjects and running it on TTL auto. Still pretty iffy.

    Its also a huge deal when the object is to overpower ambient, flash to subject distance is "far," and I'm shooting with a 35 mm SLR, max sync speed 1/250.

  10. #30
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    Quote Originally Posted by Dan Fromm
    Donald, its a huge deal when shooting hummingbirds. I've tried to deal with the duration by placing the flash close to the subjects and running it on TTL auto. Still pretty iffy.

    Its also a huge deal when the object is to overpower ambient, flash to subject distance is "far," and I'm shooting with a 35 mm SLR, max sync speed 1/250.
    Wouldn't you just cook them with a big bulb flash?

    Lachlan

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