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Does anyone still make small Thyristor sensor flashes?

Discussion in 'Accessories' started by anthonyrc, Nov 9, 2015.

  1. anthonyrc

    anthonyrc Mu-43 Regular

    55
    Feb 5, 2013
    Never could fathom how they worked but Vivitar and other flashes with a built in sensor were a little more user friendly than going wholly manual. Anyone still making flashes using this system?
     
  2. Clint

    Clint Mu-43 All-Pro

    Apr 22, 2013
    San Diego area, CA
    Clint
    Many if not most flashes still have this, however the ones I'm familiar with just called it "Auto" mode.
     
    • Agree Agree x 1
  3. MichaelSewell

    MichaelSewell Mu-43 Top Veteran

    507
    Sep 1, 2015
    Burnley, UK
    Michael A. Sewell
    Not so sure I would have described the process as "user friendly", to be honest, but I do understand the attraction.
    Clint's right when he says it's the "auto" mode, although I think the word "auto" is a little misleading to anyone new to off camera flash (OFC).
    Yes, the speedlight automatically quenches the flash once the amount of outputted light has reached a level that the speedlight determines is a correct exposure. To do this, it needs to have information regarding the settings of your camera for that exposure. This means you have to input the ISO and aperture setting, and this must be done for all speedlights in use.
    It doesn't sound like too much work, but should you adjust your camera settings, then you need to make the round trip and reset all the speed lights.
    I know it doesn't sound a lot, but two adjustments per speedlight x say 3 speedlights, becomes tedious on the fourth or fifth adjustment. Using manual settings is one adjustment, and usually quicker, because the ISO and aperture setting often needs to be accessed via a menu system, although not always.

    The other point to bear in mind is the fact "auto" mode measures the reflected light to gauge the exposure, in a similar way to iTTL or eTTl is managed within camera, although with far simpler tech.
    Basically, anything white within the image may fool the speedlight into quenching early, so underexposing. Blacks will do the opposite, and cause over lighting.

    It can be done, and I used thyristor guns in the late 70s and early 80s
    It was a lot of fun, but also frustrating.
    Treat it as a stepping stone towards full manual control. It'll certainly give you a good learning experience, and if you bear in mind the colour reflection influences, you'll shortcut that learning curve much quicker than I did.
     
    • Informative Informative x 1
  4. exakta

    exakta Mu-43 Regular

    84
    Jun 2, 2015
    Yes, non dedicated auto flashes are still made but not that many. If I go to the B&H photo site, they only stock 7 units. However they stock 94 units for Canon, 85 for Nikon and 23 for m43.

    While some dedicated flashes have a non-TTL auto mode, many (most?) do not. After all, why would you need it unless you are using one mfr's flash on another mfr's camera? My Lumix FL360L has an auto mode which I can use on my Fuji camera but my Fuji EF42 does not and is manual only when used on my m43 camera.

    Michael's advice for going fully manual with flash is great for studio situations, but for on camera flash shots with a single strobe a non-TTL auto flash is just as useful as a TTL flash is. The metering issue he mentioned is also an issue with TTL. All exposure meters assume they are looking at grey, that's why we have exposure compensation and manual modes on our cameras. More of an issue is the angle of view of the flash's sensor compared to that of the lens you are using. With longer lenses where the sensor is probably viewing a much wider area than the lens is.

    As far as having to reset a non-TTL auto flash for different ISOs that's not 100% correct. The thing that has to be changed for different ISOs is the aperture you use. If the flash dial indicates that you should use f4.0 for ISO 100, then you would use f5.6 for ISO 200, f 8.0 for ISO 400, etc. Since it's not TTL, the flash has no way of knowing what aperture you have actually set anyway. First generation auto flashes circa 1966 required using the same aperture at any distance. By the 1970s flashes started offering multiple ranges allowing smaller apertures at the cost of shorter maximum flash distance. Taking the same example, if you needed to cover a subject 20 feet away, at ISO 100 the flash might have you set aperture to f4.0, or f8.0 but only out to 10 feet, or f16.0 but only out to 5 feet. GN = aperture x distance, right? So you would choose an aperture based on your maximum working distance.

    BTW, thyristor has nothing to do with the type of automation. It refers to a circuit that can stop draining the capacitor once enough light has been produced. Early automatic flashes drained the full charge on every shot regardless of how much light was needed.
     
  5. MichaelSewell

    MichaelSewell Mu-43 Top Veteran

    507
    Sep 1, 2015
    Burnley, UK
    Michael A. Sewell
    Apologies.
    I had assumed we were talking off camera, rather than on camera, where iTTL/eTTL would probably have greater benefits than standard auto, although at a much greater cost.
    Full manual isn't just restricted to studio situations either, although I can appreciate why many may believe so.
     
  6. MichaelSewell

    MichaelSewell Mu-43 Top Veteran

    507
    Sep 1, 2015
    Burnley, UK
    Michael A. Sewell
    My comments regarding adjustment of ISO and aperture on the speedlight is accurate, when you are shooting to a specific camera setting.
    I certainly agree with your route of adjustment if you aren't particular to the depth of field required for your finished image, and are happy to adjust at the camera instead, therefore allowing the final look of the image to be dictated by the speedlight rather than your creativity. Certainly quicker to adjust the camera rather than the speedlight, I just prefer to set the camera to get the image I have in mind.

    Basically, we both approach the final result from opposite sides. We would still have a final image.
     
  7. exakta

    exakta Mu-43 Regular

    84
    Jun 2, 2015
    I'm not really sure what anthonyrc's application is, maybe he'll come back and let us know. When using multiple flashes only TTL allows autoexposure.
     
    • Agree Agree x 1