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  1. #41

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    Quote Originally Posted by Whiteymorange View Post
    The one that gets me in that picture of bulbs on display is the middle one, with two small blobs of...what, magnesium powder? at the end of the wires. I'm guessing that's a long-burning bulb for focal plane shutters, but someone else will undoubtedly know.
    Flashbulbs with two wires covered with black paste are SM bulbs (Speed Midget) made by GE, Westinghouse and others. They have an egg shape. Sylvania made a similar SF bulb that is more rounded. The wires are coved with primer paste and have no foil (fluffy wire) inside them. They are actually fast bulb and put out most of their light in about 1/200th of a second. The normal #5 or Press 25 bulbs put out light for about 1/30 of a second. The SM bulbs were mainly used with old simple box cameras that had a slow fixed shutter speed of about 1/30th of a second. In order to stop action one would use a SM or SF flashbulb. It is similar to what you get with electronic flash today.

    Also when it comes to the foil (It looks like steel wool but it is really very thin foil cut into extremely thin strips during manufacture) inside medium peak #5, or #25 bulbs vs the #6 or #26 focal plane bulbs YES they do differ. The 5 and 25 bulbs have just one type. The #6 and #26 have two types in them, one burns fast and one slow. That way the bulb stays burning longer and a relatively constant light output for so the bulb stays blowing at the same brightness during the travel of a focal plane shutter.

  2. #42

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    Quote Originally Posted by Ken Nadvornick View Post
    I'm not the OP, but I'll give some reasons from personal experience...

    First, the quality of the light is markedly different. This is primarily because of the much longer "burn" time of bulbs. At the shutter speed you choose you get the same exposure effect as natural sunlight because the light is present during the entire time the shutter is open. What you don't get is the strobe effect of ultra-high-speed xenon flashtubes producing maximum, clinical sharpness at 1/10,000-second bursts of light. Click here for an example of that maximum sharpness. The platform was in free fall at the moment of exposure. Such sharpness is appropriate for some subjects, but not for all.

    Second, using bulbs allows you to vary the GNs by varying the shutter speed. The higher the shutter speed, the lower the GN, because of the lower slice of the total bulb output that is caught on the film. Electronic flashes which implement a "power ratio" feature can simulate that same performance. But not all units have this feature.

    Third, the output from portable bulbs is generally higher, and in most cases much higher, than portable electronic flash units. Studio lighting trumps this, but with all of the disadvantages of equipment bulk and weight. The lowly Sylvania Press 25 and its cousins are rated by various manufacturers between GN 200-240 (tungsten, in feet) for 1/100-second shutter speeds at ASA 100. This surpasses just about all portable electronic units, including the monster Sunpak 622 Super handle-mount. (Rated by Sunpak at GN 200, but like almost all portable electronic units is actually a little less than that in the real world.)

    Fourth, when paired with older (antique?) cameras, bulbs affect almost total compliance from potential subjects. Most have never seen them, let alone seen them work, let alone been photographed by someone using them. It's like an amazingly alien magic trick to most. I always reward my subjects with the offer of either a scan or print, AND the used bulb popped from its reflector (after it cools). I suspect many are more interested in the burned bulb than the photograph it made possible. Go figure...

    Fifth, and not least important, the display and use of ultra-cool vintage flashbulbs and equipment is a highly effective chick magnet. Mostly because the guys are way too embarrassed to admit their ignorance about them. And the girls are often genuinely curious, and not afraid in the least to just walk right up and ask questions.



    Ken
    Maybe "old hen magnet"

  3. #43

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    Quote Originally Posted by StoneNYC View Post
    What gets me is the even-ness of light... If you used a modern on camera speedlight, the bright light would all be on the subject on the foreground and the background would be much darker...

    Is this a product of the press shutter being slower or the bulb itself?
    Modern electronic flashes, even big expensive ones, are weak compared to flashbulbs. To light a subject with and modern flash you need to focus the limited amount of light on your subject. This is why modern good flashes have zoom heads to help the flashes have decent reach. Flashbulbs have enough power that they don't need to be focused as much and can spread the light around more evenly. They are really great in big rooms or caves.

  4. #44
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    Oh great something else to spend money on. And they are not easy to find. gee thanks.

    Oh and BTW cool link to the O. Winston Link site too.

  5. #45
    AgX
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    Quote Originally Posted by Whiteymorange View Post
    The one that gets me in that picture of bulbs on display is the middle one, with two small blobs of...what, magnesium powder? at the end of the wires. I'm guessing that's a long-burning bulb for focal plane shutters, but someone else will undoubtedly know.
    Flash bulbs do not just employ a glowing wire to ignite the metal, but patches of a substance that is more easy to ignite, that will burst apart and by its hot burning morsels will finally ignite the metal.

  6. #46
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    Quote Originally Posted by MartinCrabtree View Post
    Oh great something else to spend money on. And they are not easy to find. gee thanks.

    Oh and BTW cool link to the O. Winston Link site too.
    Don't forget that you also get the excitement of being confused about what you're buying an end up buying the wrong bulb, and ruining a bunch of images by under or overexposing because you thought you had one bulb but had another that was a mysteriously unlabeled one etc etc... Hah!

    Such fun!
    ~Stone | "...of course, that's just my opinion. I could be wrong." ~Dennis Miller

  7. #47
    Ken Nadvornick's Avatar
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    Quote Originally Posted by sgbode View Post
    Maybe "old hen magnet"
    Ahh, grasshopper. When you become an old rooster, THEN you will understand...



    (And welcome to APUG.)



    Ken
    "They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."

    — Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs

  8. #48
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    They are fun. Shock your subject with a wave of heat and a FWOOSH! sound.

  9. #49
    Ken Nadvornick's Avatar
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    Quote Originally Posted by StoneNYC View Post
    What gets me is the even-ness of light... If you used a modern on camera speedlight, the bright light would all be on the subject on the foreground and the background would be much darker...

    Is this a product of the press shutter being slower or the bulb itself?
    It can be the slower shutter speed in the sense that although the overall background intensity is low enough to need flash, it's not zero. So independent of the flash exposure for near objects, the longer the shutter is open, the proportionately more of the ambient light registers from the far objects.

    But in this case, I don't believe that was the major factor. I noticed it too the moment I pulled the 4x5 hanger from the wash and held it up to the light. My first thought was, what happened to the inverse of the distance squared? There's no apparent falloff.

    The hanger at Paine Field that houses this aircraft is painted bright white inside, including the ceiling. Here's a link to the Flying Heritage Collection web page for this aircraft. Note that the bomber is painted in US Army olive green. A much darker color than white.

    I think what may have happened here is that the subject matter itself may have balanced the lighting ratios. The light ceiling reflected much higher than the dark aircraft, naturally bringing the ratio much closer together than it otherwise might have been at their relative distances. Had the plane been hanging by wires directly under that ceiling, the white ceiling would have been closer to pure white.

    Instead they just happened to balance each other very nicely at their relative distances from the single flashbulb.

    (Oh, and a correction. I checked my notes and the shutter speed was 1/100 of a sec, not 1/200. This would have recorded a longer slice of the flashbulb's total burn time for an effective increase in the guide number.)

    Ken
    "They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."

    — Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs

  10. #50
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    The even lighting from a big flashbulb is as much a function of the reflector as the bulb.

    A big reflector is a lot less like a point source than most electronic flashes.

    But to get the most out of a big reflector, you need a lot of light.

    Can you say "open shadows"?
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

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