Delay flash

Discussion in 'Lighting Equipment' started by marcy_vandeventer, Nov 2, 2009.

  1. I am using a Canon rebel XTI with my studio flash. I am using a remote wirless tigger. My problem is when I ake a photo my flash seems to be delayed. like it is not flashing when I hit the shutter.
     
  2. What sort of wireless trigger? Connected how? How do you have your camera set up? What sort of studio flash?

    It's hard for people to help out with the details when you don't mention the details. So... more details!
     
  3. Is it affecting your images? If you are using decent power strobes, even if there is a slight delay, as long as your shutter is open the whole time, you should be fine.
    That said, Matt asks good questions. What is the set up. I have experience with lights, but none with wireless triggers.
     
  4. Assuming you are using the built in flash as a trigger, then for all Canon DSLRs (like your Rebel XTI) the built in flash operate in ETTL mode only, which means that it admits a pre-flash to calculate exposure, then the shutter opens and the main flash is activated. If that is the case, I think your studio flash trigger is seeing the pre-flash and setting off the studio flash before the camera shutter is open.
    Perhaps the studio flash trigger has a setting to ignore the preflash, or else use a small manual shoe mount flash (or a Canon flash in manual mode set for low power), or use a wired sync cord (to the Rebel's hot shoe).
     
  5. The strobe is a SP 160 and it came with a generic wireless trigger...I bought it off ebay (1st mistake) But I cant afford alot right now.
    I problem I am getting is that the images are coming out blurry because the flash is firing too early ( I think) I have noticed the shutter is staying open longer
     
  6. Again, how are you triggering? Is there a device that goes in the camera's hot shoe, and a second device that plugs into the strobe? Is it a radio trigger, or an optical trigger?

    As for how long the shutter stays open... you're completely in charge of how long the shutter stays open. Just put your camera in manual exposure mode. Set the shutter speed to, say, 1/125th, set your ISO to 200, and set your aperture to f/5.6 or so. Your shutter speed shouldn't really matter as long as it's at or below your camera's flash synch speed. 1/125th should be fine. The only reason to go with a slower shutter speed would be if you want the room's ambient light play more of a role in the exposure.

    So, let us know how the trigger works.
     
  7. Sorry Its a radio trigger
     
  8. Sorry I am dork about this, I am kinda self taught as you might have guessed. The sync cord it came with does not fit my camera. So I have been useing the radio trigger, which hasnt been working out so good. I am thinking about going back to the good Ol continuous lights which I hate but at least they work.
     
  9. I am not familiar with your camera, but it sounds as though you may be shooting at a slow shutter speed and have the camera set for rear curtain sync. Try the fastest sync setting and, if your camera permits rear curtain sync, make sure it is NOT set for rear curtain.
     
  10. Marcy, can you post an example picture so we can see the problem that you are having?
     
  11. [​IMG]
    Check out the pillow in the little girls hand ....Blurry
    00UuQT-186319684.jpg
     
  12. And thats not even a that bad of a pic....Its been alot worse.
     
  13. OK, so you've got the shutter open for 1/15th of a second - which, if there is any source of light other than your strobe, means that the movement of the girl (or any movement of your camera) is going to produce softness from motion blur. At ISO 400, f/5.6, and 1/15th, I can only assume that everything we're seeing here is ambient light from other sources in the room, right? That would certainly account for all of your problems.

    So... can you fire the radio trigger manually? Just to see if it will even trigger the strobe?
     
  14. I think you shoot with some automatic mode on your camera. Try to shoot in manual mode (M) where you can set up your shutter speed and aperture manually.
     
  15. Your camera is in P mode, turn the dial until you're in M mode.
    In M mode, turning the wheel behind the shutter button adjusts the shutter speed. Raise that to 1/120th or so. Don't go over 1/200th. If you start getting the bottom of your shots with a line lower your shutter speed a click or two. You shouldn't have to go bellow 1/100th though.
    To adjust the aperture press and hold the AV+/- button next to the LCD screen while turning the wheel. The lower the number the wider the aperture.
    Use the aperture to control the exposure. If it's too bright stop down, if it's too dark open up. Don't adjust the shutter speed unless you get the shadow at the bottom of the frame or if you want to include some ambient light in the shot. If you just want the studio lights to do the work keep the shutter speed up there. 1/200th is the most speed you can go without getting the shadow at the bottom of the frame with even expensive radio triggers, it's the limit of the camera itself. So if you're trying to overcome ambient light and can't go fast enough use a lower ISO.
    What's happening is the camera being in P mode doesn't know that you have studio strobes going off. And even if it did it wouldn't know what their intensity would be. So it behaves as if you don't have anything connected to the hotshoe. That's why you NEED to be in M mode.
     
  16. Dear Dan...I just want to let you know that you are THE KING!! I did what you said and it WORKED!! OMG! You saved my a ton of money! I was going to go to Cord camera today and get what ever I needed to make this inexpensive set up work. Thank you so much! And thank you to all of the other posters for your help! I never thought that writing on this forum would help me, but it did!
    I have a shoot on Thursday and I didnt want any problems like I had before. I had been making everything work but I had to had my camera on a tripod and try to have my subject be still, but that very hard with children. If you want to see my photos my website is www.oakridgephotography.smugmug.com
     
  17. I just want to add that the sync speed on the Canon Digital Rebel XTi is actually 1/250, not 1/200. Whether or not you can use your wireless triggers at 1/250, however, is another story. I don't have experience with them myself, but my understanding is that with the wireless triggers, you slow it down to 1/200 to account for the 1ms delay required for the trigger to function. With some quick testing, you might discover that you can still get full-frame flash at 1/250.
     
  18. Canon USA has the XTi rated for X-sync at 1/200.
    http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&tabact=ModelTechSpecsTabAct&fcategoryid=139&modelid=14256
     
  19. Rated, schmated. I'm telling you MY XTi syncs at 1/250. I could do 1/320 if I wanted to. The first shutter is just barely out of the way at 1/320, and introduces the tiniest vignetting on the bottom of the frame. YMMV.
     
  20. Marcy, I'm glad my post got you past the hurdle of making your gear do close to what you thought it should do.
     

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