Flash adjustment (over/under): on flash or on camera?

Discussion in 'Nikon' started by hlwimmer, Sep 19, 2011.

  1. Sorry if this is covered elsewhere (I searched) and if so, links would be great...
    On my SB900 (and SB800), I can dial the flash up/down by a few stops through the menu on the flash. On my D7000, I can also do the same via the flash control menu.
    Question: Which should be used? Do they do the same thing? Would one cancel the other out or double up the effect? Is there a difference in what the two control?
    Thanks for any wisdom you can lend.
     
  2. It's the same. Doing it through the camera just offers an easier way of setting it without taking your eye away from the viewfinder. Well, it used to be easier... the SB900 makes adjusting the output pretty darn easy on the flash itself.


    The difference is, adjusting the exposure in the camera AND applying flash adjustment. For example, telling the camera to expose for -1 EV and then increasing your flashes output +1 EV. That will produce a different result than 0 Camera and 0 Flash.
     
  3. Matt, I believe Hunter is referring to adjusting the flash compensation on the flash directly as opposed to adjusting the flash compensation for the flash through the controls on the camera.
     
  4. They do the same thing, and they are additive, I believe. So if you bump it up +1 on the camera and +1 on the flash, it's +2. I've never tried to go + on on and - on the other.
    I do it on the camera, as it's easier than doing it on my SB600.
     
  5. thanks to you both.
    both are correct: i'm wondering which controls i should be using -- on-camera or on-flash... and if (a) one over-rides the other, (b) if it doubles-up the effect or (c) if the controls are somehow tailored to do different/independent things.
    essentially, i want to underexpose my flash output by 2 stops. should i use the on-camera or on-flash controls (and if i accidentally do both, will one override/correct the other).
    thanks again. photo.net once again proves to be invaluable.
     
  6. Hunter - use whichever is easier for you; they're cumulative (if you set +1 in the camera and +1 on the flash, you get +2). The reason for this is, in part, for multi-flash setups: you may want both to have "more flash" (set in the camera) and the ability to control the output of individual flashes within a group (set on the flash). Since CLS only lets you set up 2-3 groups (depending on your master), you need this manual override if you have lots of flashes.
     
  7. The on camera flash compensation is very limitted when compensating + value. It does not go much higher, since it is tailored for the built-in flash, that has little power, even if the built-in flash is not used. Perhaps this varies per camera model ?
    Use compensation on the flash, SB900/SB800, and you get full range of -3EV to +3EV.
    Compensating on both, the camera and on the flash, could possibly lead to confusion. By doing compensation on both, you are adding additional thing to remember and verify, while you would rather compensate on the flash only, and devote your attention to other shooting parameters, like picture composition, focusing, etc.
     
  8. It seems that at least with SB900 compensating on camera could lead to wrong maximum distance value displayed on the SB900 flash.
    Knoowing exact max range is important, especially in FP mode.
    Making -3EV on camera should drastically reduce max flash range shown on the flash, but somehow (!) it does not show the correct max distance display. Test your flash and camera, since I may have a problem with my equipment (?).
    While it seems that the minimum range get changed and shown on the flash (no idea why?), when you compensate on the camera, but the max range value somehow (?) dos not reflect actual flash max distance available with all current shooting parameters.
    Seems like my SB900 is not smart enough to account for all computations that would also accomodate and include compensation done on the camera.
    How does your SB900 react ?
    When I get a moment, I will test the same behavior for SB800, or you could do this.
    For now, compensate flash output only on the flash, perhaps making sure that on camera flash compensation stays at 0.0.
     
  9. "you need this manual override if you have lots of flashes" - I do not see why you need this?
    E.g. PRO cameras like D3, do not have built-in flash, and therefore do not have flash compensation on the camera, yet doing fine with multiple CLS flashes.
     
  10. thanks for the responses.
    it seems that adjusting on the flash will yield the best results -- but that either will work (with varying degrees of success/confusion).
    unfortunately on the SB900 (unlike the 800) there's only one button (rather than two) so you have to cycle around to go from (+) to (-) ... weird interface choice. this might be a reason why someone might want to choose on-camera.
     
  11. I'm sorry, I don't understand what you mean by "cycling" to adjust your flash output... simply press the button under the indication "+" on the screen and turn the wheel to the left or right to add or remove power output... at least that's what I'm doing with my 4 SB900s and it's always worked great. I prefer it over the SB800 and SB600 - no questions asked. There's no need to keep on pressing a button again and again 4-5 times to go down 1 3/4 stops - i simply turn the wheel a bit faster and I'm there...;-)
    Unfortunately personally i use the SU800 commander whenever I'm using CLS (which is about 95% of the time when I'm inside closed spaces or on any outside conditions as long as it's not very sunny or very dark), so adjusting from there means hitting the buttons all the time (I'm still hoping Nikon will come out with a commander with greater capabilities and an adjustment wheel like the SB900, but I think I'll be waiting for a loooooooooooooooooooooooooong time)...
    Still, it's better than the totally non-intuitive PW solution (and yes, I know you can use the SU800 with the PW - I'm just making an argument...;-))
     
  12. re: "cycling" -- perhaps the wrong word to use when discussing flash stuff.
    my SB800 as i recall had a (+) and a (-) button. the SB900 just has one (+/-) and if you want to set it at -1, you have to press the button 16 times (through til +3, then back around)... "cycling through" the numbers in only one direction. kind of a pain.
     
  13. Hunter, are you aware that you can change the exposure compensation on the SB900 by rotating the dial clockwise for positive compensation and counter clockwise for negative compensation after pushing the compensation button once?
     
  14. "you need this manual override if you have lots of flashes" - I do not see why you need this?
    E.g. PRO cameras like D3, do not have built-in flash, and therefore do not have flash compensation on the camera, yet doing fine with multiple CLS flashes.​
    I'd been thinking in terms of CLS flash groups. You can only wirelessly control the exposure of three wireless groups (from a speedlight or SU-800, fewer triggered from an on-camera flash). If you want more flashes than that, or if you want to control multiple flashes with a single setting (which is why they're called "groups"), you may still not want all the flashes within a group to fire at the same power, but instead at a constant ratio, so you can add individual exposure compensation to the flash units.

    I'm surprised that you can't adjust the total flash compensation on a D3 by holding down the flash button and rotating the minor dial, like on the D700 - I would have expected a "global control" for balancing the flash and background to be useful; it's certainly how I do things on my D700. Reading some manuals, it looks as though there's no overall compensation control ("master" compensation control is different) on the flashes that can be a CLS master - at least on the SB-900 or SU-800; I would vaguely have expected setting exposure compensation at the flash without selecting the "master" group to do this, but if it does, I can't see it documented. It's all magic to me, because I only have SB-600s and they can't be masters.

    Am I missing something? This feels like a big usability issue for the D3, unless everyone just uses radio triggers with some kind of master compensation on them instead. (Spoken with the authority of someone who's only done a few multi-flash photos in my life...)

    Interesting about the distance error.
     
  15. "I'm surprised that you can't adjust the total flash compensation on a D3 by holding down the flash button and rotating the minor dial" - you cannot because D3 does not have a flash compensation button, since it does not have a built-in flash.
    What D3 has is a flash mode button, where you can change the mode how the camera shutter operates with an external compatible flash(es). By holding the button, you can change flash sync mode between: Fron-Curtain-sync, Slow-sync, Rear-Curtain-Sync, Red-Eye reduction sync, Red-Eye reduction with slow sync. This does not alter exposure compensation of an external flash.
    The internal in-camera flash compensation is for consumer grade cameras with built-in flashes, and not needed for PRO cameras. Adding an in camera flash compoensation for a non-existent not-built in flash does not make sense.
    Once you understand that the in-camera flash compensation is primarily for the built-in flash, there is no deficiency not having the built-in flash and no in-camera flash compensation in PRO models.
    "Am I missing something? This feels like a big usability issue for the D3" - there is no usability issue with cameras that do not have built-in flash and do not have in-camera flash compensation. The only usability would be that you need to purchase external flash for PRO type cameras.
     
  16. you cannot because D3 does not have a flash compensation button, since it does not have a built-in flash.​
    I know, I read the manual. :) The D700 doesn't have a separate flash compensation button either - the same button controls flash mode with one dial and flash compensation with the other.
    Once you understand that the in-camera flash compensation is primarily for the built-in flash, there is no deficiency not having the built-in flash and no in-camera flash compensation in PRO models.​
    Er. I hate to be argumentative, but "flash compensation can be used for the built-in flash" and "a lack of a global flash compensation control is not an omission" are two different claims. Except under duress, I don't use my D700's on-camera flash to illuminate the scene; I do use it as a wireless trigger.

    I can understand the omission of an integral flash on the single-digit D series (and F series) for reasons of resilience, and that adding either a speedlight or an SU-800 directly to the hotshoe (or cable) isn't a major problem. The absence of a global flash control is a completely separate issue - you can control the relative output of the built-in flash when using it to contribute to the scene as well as using it as a CLS master just as you can do this with a speedlight on a D3, so the integrated flash's presence doesn't differ appreciably from the result of attaching an under-powered strobe (that can't handle many groups).

    Scenario: You spend a while configuring a complex multi-flash scene, using three groups plus the master attached to the camera, and potentially multiple flashes in each group. You adjust the output of the groups from the camera and the individual flashes with their own exposure compensation controls. After doing all that, the natural light contribution changes because a cloud goes in front of the sun - the effect of this on the images is such that the automated exposure in CLS fails to produce an image to your satisfaction. You want to compensate by adjusting the output of all the flashes at once to balance the new level of light in the scene. On a camera with a built-in flash, you push the flash control button and spin a dial, and the output of all the flashes changes in lock step.

    On a D3, I had always assumed that either you could do the same, or that it was possible to set the exposure compensation for all the flashes on the CLS master, separate from the relative output control of the master itself (that is, there's exposure control as you set when using the flash in non-CLS mode, and a separate override for the CLS pseudo-group that's the master flash). Unless I'm failing to read the manual for the D3 and SU-800/SB-900, neither of these approaches work. Under the scenario discussed, all you can do is select each group in turn and adjust the output individually. Effectively, cameras like the D700 have an über-group that consists of all the flashes. To me, since adjusting the total output of a number of flashes that I've been balancing is not an unusual scenario (with the proviso that I'm no flash shooting expert), that feels like a considerable inconvenience.
     
  17. Hunter, are you aware that you can change the exposure compensation on the SB900 by rotating the dial clockwise for positive compensation and counter clockwise for negative compensation after pushing the compensation button once?​
    @ elliot: no i didn't... and now i do (thanks). much, much better. ... much.
     
  18. "You want to compensate by adjusting the output of all the flashes at once to balance the new level of light in the scene." - why would anyone want to do it with CLS multiple flash setup ? Providing that your CLS setup is optimal and within the known limitations, there is no need to compensate for variations in lighting , as the CLS/iTTL automation does it for you.
    "the natural light contribution changes because a cloud goes in front of the sun - the effect of this on the images is such that the automated exposure in CLS fails to produce an image to your satisfaction" - abviously you are doing something wrong if it is what you say. The CLS automation should compensate for change in the cloud or sun appearing, providing proper exposure in both cases. If you set remote CLS flashes to Manual power ratio, then CLS will not provide proper exposure, since in manual mode you are responsible for proper lighting.
    In manual mode, flash compensation does not work, as the remote flash will aoutput constant value preset, e.g, 1/8 power, regardless of any compensation.
    In remote flashes automatic exposure settings (not manual), the CLS will compensate any changes in lighting caused by clouds, or bu sun, as long as you operate withing the CLS limitations. Global compensation of all flashes, done by in-camera compensation that was designed for the built-in flash, could be part of your problem.
    ... and seems that you are quaoting something that I naver stated...
     
  19. Providing that your CLS setup is optimal and within the known limitations, there is no need to compensate for variations in lighting, as the CLS/iTTL automation does it for you.

    - obviously you are doing something wrong if it is what you say. The CLS automation should compensate for change in the cloud or sun appearing, providing proper exposure in both cases.​
    CLS will compensate for changes of intensity of the scene as it meters it. That's not the same thing as knowing exactly how your artistic vision would like to interpret the changing of light falling on some portion of the scene. A cloud will change the distribution of light, may alter the scenery in the background and leave the foreground unchanged, may dim the part of the scene that is sunlit but not the portion that is lit by other non-flash light sources. CLS is no more infallible than the matrix meter, and that certainly needs exposure compenation sometimes.

    You may want to adjust each flash individually to compensate for this. Or you might think that the changes are simple enough that bumping all the flashes up or down would be sufficient, especially under time constraints. I also use the global control to balance CLS flashes with non-CLS strobes. It's useful to do this with multiple flashes under a single flash group, there's no reason it wouldn't be useful with all the flash contribution to a scene. I can't imagine why Nikon wouldn't just disable the flash compensation set on the D700 if you were using a speedlight if they didn't also think this functionality could be useful - but then I never imagined that the D3 would be missing it! I can't see the down side to offering this functionality, and I can't see why it wouldn't be seen to be potentially useful: I use it.
    ... and seems that you are quaoting something that I naver stated...​
    If you mean "flash compensation can be used for the built-in flash" and "a lack of global flash compensation control is not an omission", I'm sorry if they looked like quotations - I was paraphrasing two statements. It appeared to me that your premise was that the D3 has no internal flash and no need for flash compensation to control one, and that you were using this to argue that there was no benefit in having a global flash exposure control, as provided by the D700 and other cameras with CLS master integrated flashes. If so, I accept your premise, but not your conclusion - but I'm also perfectly prepared to believe that I've misunderstood. I would agree with this position if peripheral CLS masters had the ability to apply a global flash exposure compensation in addition to the individual compensation used by the master in its contribution to the scene (therefore completely duplicating the D700's behaviour with the built-in flash), but I can't find this functionality in the speedlight manuals I've read.

    (Oh, and Hunter: apologies for wandering off-topic.)
     
  20. The answer to the original question depends on the exposure modes set on the camera and flash.
    If the flash is set to manual mode and the camera is set to manual mode, the on-camera compensation does nothing.
    If the camera is in manual exposure mode (common if using a flash) and the flash is in TTL mode, the on-camera compensation will adjust flash output but won't change the camera output. In this configuration, the on-camera button would certainly be more convenient than the flash control panel.
    If the camera is in Aperture priority with the flash in TTL mode, the on-camera compensation will adjust the camera shutter speeds within the flash sync limits (default: 1/60 - 1/250). I didn't try to figure out what happens to the flash output.
    If you are using one of the automatic exposure modes (Aperture, Shutter, or Priority) with a speedlight, I can't think of a situation where exposure compensation makes sense.
     
  21. If you are using one of the automatic exposure modes (Aperture, Shutter, or Priority) with a speedlight, I can't think of a situation where exposure compensation makes sense.​
    the question is about flash compensation (not necessarily about overall exposure compensation). for instance, i'f i'm using the flash as a fill light and i wanted to bump down the flash output (vs. gathering more ambient light), i might want signal the flash to fire 2 stops under.
     
  22. If you want to compensate the flash output while using the flash as fill light, then you must use the on-flash compensation. If you use the on-body compensation, you will also change the ambient exposure.
     
  23. If you want to compensate the flash output while using the flash as fill light, then you must use the on-flash compensation. If you use the on-body compensation, you will also change the ambient exposure.​
    No. If you use the on-body exposure compensation, you will change the ambient exposure. If you use the on-body flash compensation, as present on the D7000, D700, etc. but not on the Nikons without integrated flashes, only the flash exposure changes.
     

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