in need of MAJOR help!

Discussion in 'Lighting Equipment' started by elaine_r, Aug 14, 2007.

  1. Hey all, I'm new to the forums, but in desperate need of some assistance. I
    just purchased 4 Interfit Stellar 300 light units, two of which are being used
    as softboxes. I am using a Sekonic L-308S light meter and shooting with a
    Pentax K10D Digital SLR. All of my images are coming out severely underexposed.
    Occasionally, I'll get an image is the severely overexposed, even when I
    haven't changed the settings. I am at a loss for what is wrong. Are 300w
    lights not sufficient for studio shooting? Or could the lights not have enough
    power to be used with softboxes? Please, any and all help is greatly
    appreciated! Thanks in advance.

    Elaine
     
  2. Elaine,

    Can you give us some more information? <p>

    1) How far are the lights from your subject?
    2) ISO setting on the camera
    3) Shutter speed and f-stop.
    4) Where are you metering from? Reflected from camera position or incident at subject position?
    5) Setting on the lights? (Full power, 1/2 power, etc.)<p>

    4 x 300W should be plenty in a small studio.
    I'm using 2 x 300 in my 15 x 18 studio and I frequently have TOO MUCH light, doing portraits.
     
  3. Your meter will tell you if you are underexposed or overexposed. Do you know how to use your meter? Not trying to be smart.....but your meter will tell you the answers to all of the guestions you are asking.
     
  4. If your meter is working fine... are you allowing enough time for teh lights to charge ?
     
  5. http://interfitphotographic.com/Lighitng/Product%20Pages/Stellar%20flash.php

    With guide numer of 168 for feet this should provide pleanty of light power, about f11 at 7 feet to subject allowing a two stop loss for the soft box. That would be the fill.

    Main light at 5 feet flash to subject will make a nice lighting ratio.

    Recap try F11 at full power, ISO 100, fill at 7 feet to flash, not soft box, and the main at 5 feet. This is what theory says.

    Put your flash meter at subject position, set it to ISO 100, aim it at the camera and fire the flash. It should tell you something between 8 1/2 and 16.

    Always allow the flash to recycle completely which may be longer than it take the ready light to come on. Test to find out.
     
  6. whoa...more responses than i expected so soon. I'll start by responding to Blake:

    1) 5 feet at most
    2) ISO 400
    3) F stop 5.6
    4) not completely sure of this answer - but, I place the meter in front of the subject and take my reading there.
    5) the lights are at full power


    Now, in response to Russ (I also just got your email)

    I THOUGHT I knew how to use my meter. I have used other meters in the past, but this one is new to me and just recently purchased.


    I'm almost positive I am letting my lights charge long enough.
     
  7. Camera is in manual?
    ISO matches the meter?
    Holding meter in subject position and pointing white dome back at camera lens?
    Are you using a sync cord, or an optical slave? If optical, + TTL = trouble...


    I'm going to guess (wildly) you're triggering them with the camera flash... if so, google 'slave flash with ttl', & you'll see the problem. That's my 2 dollar bet.
     
  8. I'm also wondering if my camera and my flash units are synced properly. The K10D allows me to wireless fire my units. I also have a safe -sync, but when I attach it and attach the sync cord to it and try the "test" button, nothing happens. So, I plan on tracking down another safe sync to try tomorrow, so I can try firing the flash units while actually connected to the camera.
     
  9. I am using a sync cord with the meter but not with the camera (no PC sync cord plugin directly on the camera)
     
  10. Is the camera's built-in flash by any chance triggering the slaved strobes with a pre-exposure flash such as a TTL metering burst, or an anti-red-eye burst? Anything that might cause that flash to emit a small info/communications flash prior to the exposure will definitely result in a big under-exposure, since the slaves will have discharged too early. Turn off any metering flashes (go manual on-camera, not e/iTTL), and turn off any anti-red-eye behavior.
     
  11. if you aren't getting any light when hitting the test button on the safe sync, then the flashes aren't firing when you try to shoot, right?

    i had that camera and used it extensively with flashes, safe sync and with radio triggers. you might have some form of bracketing on, if the exposures are all over the place.

    but first things first.

    plug your pc cord into your flash meter. make sure it is set for "cord" or flash, or whatever it says when you are doing flash readings. set the iso on the meter to 400 and fire away.

    with your setup, you should be at least at 5.6 if not f 8.

    then make sure the camera is in manual, set the shutter speed no higher than 160th sec. just put it at 125th for now. then make sure that you have the iso set to 400, and that the ttl flash stuff is disabled in the menu. also make sure you have the right flash mode with the f button. plug your safe syn into the shoe, and plug the pc cord into the safe sync. forget testing it, just try a shot.

    if the lights don't go off, the safe sync is the culprit. if they go off, and you are still underexposing, make sure no compensation of flash is engaged, though i don't think any such things work in manual.

    is this a newer A type lens? or do you need to set the aperture manually?

    if you have problems from there, report back. that should do it.
     
  12. I'm slow. What shutter speed(s) are you using?
     
  13. bdp

    bdp

    Elaine, like Beepy said, what Shutter speed, if you're exceeding your sync speed, you'll see dark bands, or dark images if it's too fast.
     
  14. Shutter speed of 125.


    Dave, this is a newer lens, I don't have to set the aperture manually. I do it all through the camera. And no, the flashes do not fire when hooked through a sync cord to the safe sync when I try to shoot.

    Matt, I will have to attach my external pentax flash try all of this again.

    Thank you ALL for your help! Hopefully I can have this problem resolved by tonight!

    I'll keep you posted!
     
  15. make sure you have the safe sync pushed in all the way. or it may not be working properly. i'd get another one, or the thirty dollar chinese radio triggers from ebay. they work great.
     
  16. I shoot the K10D w/ Speedotrons. 125 is what I shoot at, and Pentax won't fire at all if you try to exceed it's maximum sync. The only thing that makes since to me, is that the metering is done incorrectly. I'd bet you are metering for shutter speed 60, or a higher ISO than what you are shooting at. Either that...or your lens is dropping light, since it's not a TTL meter.
     

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