SB-800 and SB-28 serevely underexposed with D200

Discussion in 'Nikon' started by hique, Jul 10, 2007.

  1. I started testing the SB28 and SB800 side by side with a D200.

    Shot the SB-800 bounced on the close ceiling. The distance showed 6.3mt which
    was enough. Shot TTL and TTL-BL. Both images were VERY underexposed.

    Opening up two steps on the aperture made the image ok.

    The impressions it gives me is that the 6.3mt is a lie and that in fact the
    range was up to 3 mt. Very strange.

    Shot the SB28 at Auto. The same result.

    Neither the camera nor the flash is setted at a negative Exp. compensation.

    Maybe something is not correctly configurated in the D200 menus? Any tips?

    Maybe the batteries? Should I try other ones?

    Thank you for the support.

    Cheers.
     
  2. "Opening up two steps on the aperture made the image ok."

    Bounced flash goes double distance, so you usually need fairly wide apertures.

    "The impressions it gives me is that the 6.3mt is a lie and that in fact the range was up to 3 mt."

    I'm not sure what you mean.
     
  3. We need more info on your camera settings--Did you use Aperture priority? What synch setting did you use? What ISO? What was the distance between the lens and the subject you were trying to light? Were you trying to light both the subject and the background? Were both underexposed? I do not know what you mean by 6.3 mt either.

    If you use front curtain synch your shutter speed is limited to 1/60 to 1/250 (or faster if you selected FP using Custom setting e1). If you selected slow synch the shutter can go to 30 seconds. To allow the camera to expose for more ambient light, use slow synch and aperture priority and select a larger diameter f stop. Do not use red eye reduction or there will be a delay of at least a second after you trigger the shutter before the flash goes off and the subject will have moved, etc.

    Make sure you understand the difference between TTL and TTL BL. There is a huge difference. I suggest you stick with TTL BL for what you are doing where flash is the main light.

    Joe Smith
     
  4. Bouncing off a wall will also take a stop of light. So you have to factor that in when shooting in auto mode. As auto mode on the SB28 and the D200 is not smart and only will rely on ambient, not on the position of the flash. If by two steps you mean 2 1/3 stops that makes sense and the wall both absorbs some of the flash light and also increases the light fall off.
     
  5. Bouncing off a wall takes off more than a stop. Inverse-square law, remember? I do a lot of bounce flash in my work and I gotta use an exteral powerpack or I simply don't have enough power. Even then I find myself shooting f2.8 ISO 800 a lot of the time.

    It's not the flash. I tested the guide number on my SB800 and it's about 120 when fully zoomed. For a speedlight that's pretty good. But bounce flash is a power-tool and it uses power-tool power.
     
  6. Looks like you are lacking basic understanding how your flashes work, and how you could possibly use them.

    You are using 2 incompatible with each other flashes. SB-800 will not be able to control amount of ligh of the SB28, and vice versa.

    Both can trigger each other if set to manual modes, (or SU4 mode).

    My guess: If SB-800 is set in any iTTL, then preflashes trigger SB28 before the shutter is open, so SB 28 does not contribute light to the exposure. You cannot catch this time difference with you eyes.

    You need to tell us how you connect the flashes to the camera or to each other, and what trigerring method do you use, as well as mode of each flash.

    I would suggest:

    Set SB-800 in iTTL, iTTL BL, etc. then
    connect SB28 to the socket on the side of SB-800 by a PC sync wire.

    Or better yet use a Pocket Wizard radio transmitter connected to the socket on SB-800 body, and use Pocket Wizard receiver to trigger SB28 set in manual mode.

    You could use optical wireless trigerring but only in manual mode on both flashes, or at least the master flash on the camera.
     
  7. My suggestion was based on SB-800 inserted in the camera how shoe.

    Another suggestion is use SB28 in Auto or Manual mode in the camera shoe, and use SB-800 remotely set in the SU-4 mode. Perhaps this will work, but you will loose the latest iTTL/CLS system capability.
     
  8. gdw

    gdw

    Were you possibly pointing the camera at a white wall?
     
  9. "Looks like you are lacking basic understanding how your flashes work, and how you could possibly use them."

    Hmm... I think that's not the case. Been using SB-28's, manual flashes, studio flashes, etc for years and years.

    I always bounced flashes at white walls and NEVER has this sort of problem. If the SB range said it will go until 4 meters and the distance from flash to ceiling is 1.5 meters and ceiling to subject is another 1.5 meters, then it is supposed to light the subject correcty.

    I have always done this with negative and slide films and never had any problem. The only problem is now that I am using the D200.

    So... I am really not getting it. The sync speed it 1/250 so no influence from ambiente light.

    I was using REAR curtain. I am not sure if it would interfere.

    Manual Exposure.
     
  10. "I always bounced flashes at white walls and NEVER has this sort of problem." - OK, so you are experienced, no intention to offend you.

    You just need to get experience with the new gear, so try to understand how the new flash system works. The new flash system (SB800/D200) that operates on totally different principle, as is mainly dedicated for the digital DSLR cameras, even though the SB800 flash has all the back compatibility modes built-in.

    What you were doing before, and what SB-28 would do well on film/slide, was to take the flash light measurement off the film/slide surface when the shutter is open during actual esposure time.

    However, SB-800 if set in any automated mode, measures the light off the measuring sensors behind mirrors and at the bottom of the camera chamber, and not off the sensor/film surface. This happens when the shutter is not open, and the mirror is down, during preflases, just few milliseconds before the exposure process starts. Most likely those iTTL preflashes, (or camera autofocus assist light, or Red Eye reduction light), triggers your SB28 prematurely, before the shutter is open.

    Think about possibility, that no matter how strong your SB28 is, if it gets triggerred before the shutter is open, it will never provide any light during exposure time.

    Just try ony of the advice given earlier, just for fun, to see that it works, as it works OK for many people, and it will eventually work for you.


    "So... I am really not getting it." - you will get it, after trying the other ways, and remember that SB28 is not compatible with SB-800 (except in Manual mode) - once you realize that, you will be on the way to success.

    Good luck.
     

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