D800 & sb900: can Not turn off red focus light

Discussion in 'Nikon' started by andrea_langer, Oct 20, 2012.

  1. Hi, I have a problem with my d800 in combination with sb900 flash: I can not turn off the red focus light the flash makes when you focus. I tried a lot already, maybe one of u can help? I use the flash on TLL, cam on manual. Thanks!!
     
  2. Check to make sure you have the AF-S mode selected and not AF-C.
     
  3. ShunCheung

    ShunCheung Moderator

    If you choose continuous AF (AF-C) instead of AF-S, the SB-900 AF assist LED will not come on. Not sure that is the solution you want, though.
     
  4. Sorry, I misread your post. My answer is opposite of what you are looking for... it should have read "AF-C mode selected and not AF-S" as per Shun.
    You can also use manual focus which will suppress the AF light. Or put a piece of take across the light. Live view also keeps the light off.
     
  5. You can also turn the light off through the flash's menu, 9th option down - the icon shows the letters AF and an image of the flash. Select the 2nd option, OFF.
     
  6. If your camera has "Built-in AF assist illuminator" OFF (I think a7 in menu) then the flash will not use its assist light.
     
  7. ShunCheung

    ShunCheung Moderator

    If your camera has "Built-in AF assist illuminator" OFF (I think a7 in menu) then the flash will not use its assist light.​
    Mihai, it sounds like you have not actually tried that.
    First of all, the Custom Setting for Built-in AF-assist illuminator on the D800 is a8, not a7, but that is besides the point. I also thought switching off the AF-assist illuminator would also switch off the AF-assist LED on the SB-900, but that is not the case. The LED remains on when I tried it a few minutes ago on the D800. (Mine is a D800E, but it works the same way.)
    You need to switch it off from the flash as Elliot suggests.
     
  8. Shun, I have not with me my D800 right now so I was using my recent memory :) I must be wrong but this is what I was remembering from a recent play with the settings on my D800... if this is not true I apologize for the wrong information. What I remember is that I was switching ON/OF that setting and the flash was following it as well... I need to check it again :)
     
  9. Andrea, I'm curious. Does the light bother people you are photographing? Or make them squint? I seldom get complaints about it. The white focus assist light on some camera bodies, yes, it's very intrusive, but not the one on the SB800 or the SU800 flash commander.
     
  10. ShunCheung

    ShunCheung Moderator

    Mihai, I don't mean to pick on you on something so trivial. As I said, I too thought that Custom Setting would control both the build-in AF assist light on the camera body as well as the red LED on the flash, but in fact, that setting has no effect on the AF-assist LED on the flash. I have checked that on the D600, D700, and D800E, with the SB-900 and SB-800; they all work the same way.
    What I don't want is incorrect info for the OP, who apparently has spent plenty of time trying to figure this out.
    I have captured wedding images where some other photographer's AF-assist LED casts some red light on my subjects. That can be very annoying. That red light essentially ruins my images.
     
  11. I am not sure if this works on the SB 900, but it is supposed to work on the SB-800. Check your flash manual to see if this procedure is described:
    "On the SB 800 itself hold the SEL button down for two seconds and using the direction pad on the flash to navigate to the option to turn it off. “No AF-ILL” will appear on the flash’s LCD once you have done it. "
    I thought that choosing rear curtain sync also turned it off, but I am not sure.
    Joe Smith
     
  12. ShunCheung

    ShunCheung Moderator

    Joseph, you are describing the procedure to switch off the AF-assist LED on the D800. Essentially you need to do the equivalent on the D900, but since the D900 has a completely different menu, the procedure is quite different, as Elliot already described earlier.
    Selecting AF-C instead of AF-S would also switch off the AF-assist LED, but that affects the way the camera works and I am not sure that is what the OP wants to do.
     
  13. Shun, what I was describing was the procedure to turn off the Wide Area Autofocus assist illuminator on the SB 800 flash and AF Assist Illuminator on the SB 900 flash. Procedures vary by flash. For the SB 800 flash see the flash manual pages 62, 63, 67-68. For the SB 900 flash see the manual pages, C-20, C 23 and D 58. I do not own the SB 900 so I cannot interpret the technical info on these pages I have listed.
    Using rear curtain synch eliminates the pre flashes before the main flash.
    Joe Smith
     
  14. ShunCheung

    ShunCheung Moderator

    Joseph, I understand you were describing the SB-800. However, the OP only asked about the SB-900. I own both flashes and am very familiar with their differences. For example, the SB-900 does not even have a SEL button. So unfortunately, a description of the SB-800 does not help much, and Elliot already provided the answer earlier.
    Incidentally, Nikon's i-TTL requires a pre-flash to measure the exposure. Rear curtain sync merely determines whether the flash goes off at the beginng or at the end of the focal-plane shutter opening. A pre-flash is required either way to achieve TTL on a DSLR.
     

Share This Page