External flashes

Discussion in 'Film Discussion and Q & A' started by doobs, Dec 19, 2007.

  1. doobs

    doobs TPF Noob!

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    Hi, been away for a while :O

    Anywho, I'm needing a flash for indoor crap, etc and I'd like one that has a swivel head for bounce effects and can turn for using the bounce on portrait format pictures, etc. I have two Pentax SLRs that I use constantly (ME super, K1000), a hotshoe mount Holga and a Lomo Fisheye no.2 (with hot shoe) and I am now looking for a nice flash for all of them. Use on the Holga and fisheye are not required, but if they work, then that would be great. I don't know much about lighting and stuff, but at this point I do know I need a flash. I'm not interested in heavy, studio grade stuff, but more of medium grade for night/indoor stuff. Detachable would be nice, but I'm assuming I would need a cord thing. Any suggestions would be great. Cheaper == better. Any hints as to using the flash and anyone know of a good cheap diffuser? I'm guessing they all work the same.
     
  2. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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  3. doobs

    doobs TPF Noob!

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    What's the difference between dedicated and undedicated?

    Are my cameras TTL or what? I have no idea how these work.
     
  4. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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    A dedicated flash will communicate with the camera (if compatible). Most modern dedicated camera/flash combos will give you some sort of TTL (through the lens) metering. This means that the flash power is set based on the light that is being reflected and coming into the lens.
    This makes it easy to use, because the flash should know what aperture the camera is set to...so you just set the camera and shoot.

    A non dedicated flash only communicates with the camera for when to fire. There will have to be another way of metering. The one I linked to, looks like it has a sensor built into it...so it can meter it's own light. It's a fairly good system but you have to match the settings on the flash to the settings on the camera because the flash has no idea what aperture you are using. This flash can also be use with manual power settings.

    Some flash units only have manual power settings, in which case you would need to calculate the correct aperture to use.
     
  5. doobs

    doobs TPF Noob!

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    So when using my K1000, which is fully manual, I attach the flash to the hotshoe, set up my photo as I would want it (f/2 and 1/500 -- for example), then I enter the same data into the flash and the flash will fire according to the information or do I adjust the shutter speed to control the light and overexposure?

    EDIT: I just read that the max sync speed on the K1000 is 1/60 and I think it's 1/125 on the ME super. Does this mean you shoot at 1/60 sec and adjust the f-stop to the f-stop I choose on the flash? IE, pick f/2 on the flash and set camera to f/2 and 1/60? Won't I get overexposure at this rate? Or does the flash automatically use less light when it is fired? Does the picture still look fine?
     
  6. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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    Yes, you need to stay at or below (slower) than the max sync speed.

    Firstly, you need to know that a photo shot with flash, will really be two exposures. One is from the ambient light and the other is from the flash. In most cases, the exposures will line up or one will be much stronger than the other...so it looks normal.

    The ambient exposure is controlled by the aperture and shutter speed (as well as the ISO). But with the flash exposure, the shutter speed has no effect on the exposure. This is because the flash fires much faster than the shutter.

    That was the long way of saying that the shutter speed doesn't matter for setting your flash exposure...as long as it's within the max sync speed.

    So what you would do, is set the shutter speed at the max sync speed, then set the aperture that you want to use. You would then set the flash to the aperture that you are using on the camera/lens. The flash probably has an ISO setting as well, that should be matched up to the film you are using. That's it. The flash will measure it's output to the aperture that it's set to.

    Now, there are plenty of other little things to be aware of. Firstly, many auto flash units like this, may only have two or three aperture settings. So if you want to match it up with the camera/lens...you will have to set the lens to one of the settings on the flash. Of course, you have some freedom there if you can adjust the ISO.
    Also, you have to be aware of the working distance of the flash. If the subject is too far away, it may not be able to give you enough power. Many flash units will have a light that tells you if it received enough light for the setting it's on.

    Now, to make things really fun...you can start trying to match the flash exposure with the ambient exposure. This will help your flash photos from looking like they were shot in a cave. Basically, you adjust the shutter speed and aperture as if you were not using flash. Sometimes I like to set if for a slight underexposure. Then set the flash for the aperture of the lens...maybe plus or minus.
    This way, you get some ambient (background) exposure...but the subject is nicely lit up by the flash.
     
  7. doobs

    doobs TPF Noob!

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    Hmm, I expect to be running a few rolls of test film through.

    Thanks for the help, Mike.
     
  8. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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    Flash photography with film can be a bit of a guessing game...but once you get the hang of it, it's pretty easy.
     

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