Flash Bulbs on NEX-7

Discussion in 'Sony Alpha E-Mount Cameras' started by rkamarowski, Sep 13, 2014.

  1. rkamarowski

    rkamarowski New to TalkEmount

    6
    May 30, 2013
    Gainesville, FL U.S.A.
    I have some old camera equipment, and I was wondering if an old flash bulb unit would work with an NEX-7? Has anyone tried it?

    Bob
     
  2. José De Bardi

    José De Bardi Assistant in Virtue

    Aug 31, 2013
    Dorset, UK
    José
    You would need to be careful about trigger voltages. Many old flashes have very high voltages to trigger them, and modern digital cameras and their sensitive electronics can get fried!

    Lots of info here on common flashes and guidance on safe voltages for modern cameras.
    http://dpanswers.com/roztr/volt_finder.php

    Personally I would want to stay under 6V.
     
  3. roundball

    roundball TalkEmount Hall of Famer

    Oct 8, 2013
    USA
    If it's meant to be used "on camera", assuming the flash bulb unit has it's own power...could the NEX-7 pop-up flash be used to trigger it if it was sitting in a photo-electric hot shoe (not connected to the NEX-7 in any way) ?
     
  4. rkamarowski

    rkamarowski New to TalkEmount

    6
    May 30, 2013
    Gainesville, FL U.S.A.
    Thank you
     
  5. michelb

    michelb TalkEmount Regular

    198
    Oct 27, 2013
    Greater Montreal area in Quebec, Canada
    Michel Brien
    I did it on A7r with LA-EA4 and Minolta AF 24-85mm F3,5-4,5 zoom using an old Minolta Deluxe III flash whose capacitor seemed to work. This flash has both PC cable and Hot shoe connection. Found some 15,5 and 22,5 V batteries on the bay and it tested OK. I have couple more flashes that i will be trying that use 22,5V so the batteries are still available. The deciding factor will be if the capacitor is still working.
    15049774788_ae2319781b_b.

    Since these require 15,5 or 22.5V batteries, there was no way was going to mount this directly on the camera.
    The adaptors i mention below in my post are actually rated for up to 400V which covers almost anything except maybe some very antique studio flashes.
    15049594609_b57aac9de2_b.
    Sony e-mailed me to confirm Max Voltage on hot shoes for their cameras should be 6 Volts

    First i tried direct on camera using Sony ADP-MAA adapter and Sony FA-HS1AM hot shoe adapter. On NEX-7, you would only need the FA-HS1AM which is kind of a surge protector but when you see the price of this, you will probably forget about it.
    15049792707_4bd76f13be_b.
    That did not work so i tried another combination. Flash failure on the hot shoe connection ??? I did try this adapter with other flashes both on 77 and A7r and they worked. This Deluxe III did not work either with the A77 with only the FA-HS1AM.

    Flash on bracket and connected to the camera using again ADP-MAA adapter and this time a Minolta PCT-100 ( PC cord adapter, Sony has an equivalent called FA-ST1AM ) But again the price is ridiculously high.
    15049800417_cb7971f166_b.
    This worked !!!!

    First picture is at ISO 400 at 1/30 sec at F 11 ( This setting was a bad approximation since the flash bulb box said 1/30 sec at F11 for ISO 100 ) I did not set ISO properly since i did not notice i was at that ISO and i was kind of desperate to make it work )
    15236004332_060c523f63_b.

    Second picture was at ISO 100 1/30 sec at F 11 ( like the flash bulb box recommended )
    15049799668_a2f7d6487e_b.

    Third picture is at ISO 100 again but this time at 1/60 sec at F11( These flash bulbs have very long lasting light so your shutter speed (and synch with modern cameras designed for electronic flash) have a major effect on power as you change shutter speeds
    15049621099_74a20bec8d_b.

    I will be re-testing since i found a case of 12 packs of 12 M3B's
    I look forward to comparing power against a modern HVL-F60M
     
  6. Gandalf

    Gandalf TalkEmount Regular

    59
    Sep 5, 2013
    Apart from the possibility of problems with trigger voltage (which will probably be equal to whatever battery the flashgun contains) don't overlook the rise time of flashbulbs. The time for a flashbulb to reach its peak brightness can vary from about 10ms up to 30ms or more, so you'll be limited to fairly slow shutter speeds.
     
  7. José De Bardi

    José De Bardi Assistant in Virtue

    Aug 31, 2013
    Dorset, UK
    José

    They have transformers, voltages well over 300V is common!!!!
     
  8. michelb

    michelb TalkEmount Regular

    198
    Oct 27, 2013
    Greater Montreal area in Quebec, Canada
    Michel Brien
  9. rkamarowski

    rkamarowski New to TalkEmount

    6
    May 30, 2013
    Gainesville, FL U.S.A.
    michelb, thanks for all the info! I have an old Tilt-A-Mite I use with my Rolleicord. I have a friend who is an electrician. I'll get him to look at all this info. I certainly don't want to ruin the camera, i was just curious what the pics would look like.
     
  10. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    That is true for xenon flash tubes, they need something like 200 V minimum and with thyristor circuit all that voltage (but not current) is out in the hot shoe. Modern flashes have IGBT triggers and they need just few volts to trigger 300 V and about 200 A (that is 60 000 W of electric power!) that xenon tube uses.

    These old real flash bulbs contain burning wire and oxygenator to produce light. Current must be substantial but voltage small.

    These flash bulbs were used in industrial place photography just a few years ago. You know, you need lots of power to light a old factory or anything like it.