Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 74,474   Posts: 1,644,259   Online: 1081
      
Results 1 to 10 of 10
  1. #1
    M Carter's Avatar
    Join Date
    Jan 2013
    Location
    Dallas, TX
    Shooter
    Medium Format
    Posts
    512

    Flash bulbs - duration?

    Anyone ever test the actual duration of old school flash bulbs and cubes?

    There are times I could use a very slow duration (to fill an entire frame of video or movie film, for instance, at 24 fps... a modern strobe just leaves a white band depending on the scanning rate of the sensor).

    Yeah, I know, this is "A"Pug - but I doubt anyone knows this on the digital side!

  2. #2

    Join Date
    Apr 2008
    Shooter
    35mm
    Posts
    1,728
    The duration of light from a flashbulb/cube will be significantly longer than electronic flash. IIRC, there were even "long peak" flashbulbs at one time, for use with focal plane shutters which otherwise could give a similar problem to what you're getting.
    I don't have detailed info to hand at this moment, but I'm sure a few minutes with Google will track down exactly what you need.

  3. #3

    Join Date
    Jan 2009
    Shooter
    35mm
    Posts
    1,137
    Some of the technical information you're looking for, including a few time graphs, can be found at Cress Photo's website (no affiliation).

  4. #4
    M Carter's Avatar
    Join Date
    Jan 2013
    Location
    Dallas, TX
    Shooter
    Medium Format
    Posts
    512
    Ian C sent me a link to a pretty massive database - I had searched but never found something so complete. I see some models with close to a second duration, just at a glance.

    I'm guessing these could be a good lightning-through-the-window effect when there's no budget for the hollywood-style generators (for video or film motion shoots). You can do that in post, but nothing looks as real as reality. Now I can at least cross reference what's available for sale. Wondering if slightly lowering the trigger voltage might prolong the burst as well.

  5. #5

    Join Date
    Nov 2005
    Location
    Los Angeles, CA
    Shooter
    Multi Format
    Posts
    5,779
    Quote Originally Posted by M Carter View Post
    Ian C sent me a link to a pretty massive database - I had searched but never found something so complete.
    Would you mind sharing that with others, like me, who are also interested?

  6. #6

    Join Date
    Feb 2009
    Shooter
    Large Format
    Posts
    696
    Bulb data and time/intensity graphs

    http://www.flashbulbs.com/Philips.htm

  7. #7

    Join Date
    Nov 2005
    Location
    Los Angeles, CA
    Shooter
    Multi Format
    Posts
    5,779
    Thanks, Ian!

  8. #8
    AgX
    AgX is offline

    Join Date
    Apr 2007
    Location
    Germany
    Shooter
    Multi Format
    Posts
    9,634
    Quote Originally Posted by M Carter View Post
    Wondering if slightly lowering the trigger voltage might prolong the burst as well.
    Trigger voltage is not related to to flash duration. No incandescant flash from a light with electrical contacts is triggerd by that electrical impulse anyway, but by an explosive that is triggered by electrical heating. That heating though has a retardent effect on triggering.

    Keep in mind that there are different times to talk about.

    With the development of types the trigger voltages and all times involved had been reduced with those common consumer models of bulbs.

  9. #9

    Join Date
    Aug 2006
    Location
    Cincinnati Ohio USA
    Shooter
    Medium Format
    Posts
    674
    Quote Originally Posted by Sirius Glass View Post
    The flashbulb manufacturers published booklets with that information including plots and graphs of their products. I cannot find my copies at this time.
    See Post #25 here
    http://www.apug.org/forums/forum57/3...h-bulbs-3.html

    Sounds like you need a focal plane bulb like the No. 6 or 6B.

    They can be found on ebay or I have several bulbs in my basement, PM me if you want to buy a few to try out.
    Last edited by brianmquinn; 06-02-2013 at 09:25 AM. Click to view previous post history.

  10. #10
    Jim Jones's Avatar
    Join Date
    Jan 2006
    Location
    Rural NW Missouri
    Shooter
    4x5 Format
    Posts
    1,986
    Somewhere I have a device that used photoflood lamps at reduced power for modeling lights, and a surge of power from capacitors could be dumped into the photofloods for exposure. The exposure intensity would be fairly long, but with slow build-up and decay.



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin