Canon DSLR's and old flashes

Discussion in 'Canon EOS' started by jay_jeffery, Nov 21, 2007.

  1. A friend of mine ruined the hot shoe on his Rebel XTi by hooking an old flash
    into it. I understand the voltage that come off of old flashes can damage
    digital cameras and there are devices out there that you can put between the
    camera and the flash to prevent the fash's high voltage from damaging something.

    My question is whether the PC terminal on the Canon DSLR's (shuch as the 20D)
    can handle the high voltage. Does anybody know.

    I'm about to get my first DSLR, I have an old thyristor flash, and am trying to
    decide between the Rebel XT and 20D. This might tip the scales.

    Thanks.
     
  2. Why not just get a new flash? I have a Speedlite 430EX and it works awesome. That ETTL stuff makes a big difference.
     
  3. Vintage flashes are not worth it on a Canon dSLR. Get any E-TTL-compatible strobe (even an old 380EX will be fine). The camera is built for modern flash technology and you are missing some very convenient features if you use it with old flash units. You will not regret it.
     
  4. Here is more information about this issue with a database of the voltage from new and old flash units. http://www.botzilla.com/photo/strobeVolts.html

    If you look around in there you can find out how to do the test yourself. It's pretty simple to with a half decent volt meter.

    However, starting with the 20D, and Rebel XT Canon's hotshoes and PC connectors are rated at 250 volts. Look at these posts and references to master Canon technical guru (Chuck Westfall) who says they are safe to 250 volts. http://forums.dpreview.com/forums/readflat.asp?forum=1031&message=20024380 http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00Bq8u&unified_p=1

    As its typical, not everyone on the net believes master technical gurus, and most Canon technical people still report the 6 volt max for non-1 series cameras.
     
  5. I have to second the opinion of Bueh - i went and got a 380ex (on his advice) and have been very glad that i did. i can still use my old flashes for slaves (with optical triggers) but for a camera mounted flash I think you would be wise to get an e-ttl capable flash.
     
  6. The trouble with getting new flashes is that they are way more expensive than they should be--frankly this is the price for all the intricate proprietary flash systems. Do you think that it is coincidence?

    In any case, the advice to not use old units is good. If you must try it you really need to get a Wein Safe-Sync that will step down the voltage.
     
  7. Hi Jay ,


    Last year I bought my 30D.And some months later I got a 550EX.But than my cousinne graduated and was giving a party.A nice chance to get familiar with the camera.Although I have done that before with a Canon AE-1 program which uses ordinary film.For that camera I bought the Nissin double head flash.Later on I could buy the sensor unit which mounts on the hot shoe of the camera.The sensor unit has a switch you can put on either dedicated ,slow sync and off.When I was going to my cousinne I couldn`t find the 550EX ,so I brought the Nissin instead.Connected it to the PC - pins of the 30D and made quite a lot flash pictures with it.Never noticed anything extra ordinary nor did I measure the voltage on the pins.My camera is still doing fine.Hope this helps.
     
  8. Vintage flashes (with manual controls and/or auto thyristor) work fine on digitals but be sure you check the sync voltage or get a Wein Safe Sync. That botzilla site will tell you the sync voltages of many flashes.

    As reported, the 20D sync voltage limit is 250 volts on the hotshoe and PC port, don't know about the XT, but I guess its the same. Most flashes don't have sync voltages higher than 250, but some do, such as older Vivitar 283s.

    Eric H.--sync voltage damage isn't immediately obvious and is progressive over time. You may not see or notice any difference in camera operation for a while, even though damage may be happening. I'd check your flash's sync voltage to be sure. Look at the botzilla site.
     
  9. I tried an EZ430 in a rebel XT and did not work but nothing bad happened. Today I have received a 580EX II from BH and it is much better that the other, that I have been using in an EOS 5.
     
  10. You could get a Wein safety device. It protects the voltage
     
  11. Antonio brings up a good point. You can use a lot of older flash units on Canon digital cameras, but the Canon units just a few years old, like the E and EZ Speedlites are a poor choice. There is no way to get them to do anything but fully manual flash. Antonio, if you set the camera and flash to manual it should fire. Exposure will be totally up to you though.

    Interestingly, if you go to even older Canon Speedlites, like the 199A, they work in auto mode just fine. No TTL, A-TTL, or E-TTL though, just manual and auto. Even many Nikon Speedlights will work in auto mode on Canon digitals.

    It's sort of like trying to use old manual focus lenses on Canon digitals. You can use Nikon, Pentax, and a lot others easy with the right adapter, but try doing it with older Canon lenses, and you run into problems.
     
  12. Hi

    for exactly the reasons that Jim suggests is why I use flashes like the Metz range that are so called "Auto flashes". A 32CT with a canon adaptor works nicely (nearly as good as my 430EZ worked on my film EOS)

    For small studio you can use the on camera flash to trigger a slave, if you wind down the flash exposure in the camera to as low as it goes, then its contribution to the image is minimised.

    This method might not work for you, but saves me lots of strife.

    Same setup works for my 10D and even my Coolpixes
    :)
     
  13. Hi Nadine ,

    Yes I did check the site for the voltage of my Nissin flash and it`s within the 3 - 6V range.
     
  14. Why use manual non-dedicated flashes? Because they are easy, simple, well-built, cheap, versatile, and their auto modes work fine. Don't let people convince you that you need something newer to make good use of flash. I have a 580 for full auto use, but rarely use it in favor of my Sunpak 555 and 383.

    I think what people mean is that you kind of have to know what you're doing with an old-style flash. Heaven forbid.

    Keith
     

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