# SB-700 underexposure compensation



## prakhardeep (Feb 21, 2012)

I have a SB-700.

Last night i was shooting a stage show from a distance of about 15 feet. I was in i-TTL mode and my camera was in M mode at F/8, ISO 100 , 1/250s and Flash WB.

When i shot a scene the flash showed an underexposure of -1.3EV. So, i dialed in +1.3EV to compensate that. But, now it started to show -0.7EV on next shot.

Can't we use flash Exposure compensation to balance underexposure ?


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## BlairWright (Feb 21, 2012)

it sounds like you have something set for auto exposure compensation on the camera. The flash should not change camera settings, only adjust it's self to compensate for the exposure.

If this is your D7K go check the B3 menu item (Easy exposure compensation), it may be turned on.


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## BlairWright (Feb 21, 2012)

Sorry, forgot to answer your question about exposure comp and flash.

Nikon (*until the D4) does not have a flash exposure comp setting, it only has/had exposure comp which affects the entire exposure, not just the flash output but everything. You can in fact use it to balance your flash exposure but you would be better off exposing correctly with your flash, that may require you to place your flash in manual mode.

Best of luck, Blair


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## SCraig (Feb 21, 2012)

BlairWright said:


> Sorry, forgot to answer your question about exposure comp and flash.
> 
> Nikon (*until the D4) does not have a flash exposure comp setting, it only has/had exposure comp which affects the entire exposure, not just the flash output but everything. You can in fact use it to balance your flash exposure but you would be better off exposing correctly with your flash, that may require you to place your flash in manual mode.
> 
> Best of luck, Blair


My D90 has flash compensation.  +1EV to -3 EV.  And no I don't mean exposure compensation.  From the manual:

_Flash compensation is used to alter flash output from the level suggested by the camera, changing the brightness of the main subject relative to the background.  Flash output can be increased to make the main subject appear brighter, or reduced to prevent unwanted highlights or reflections._


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## jriepe (Feb 21, 2012)

Check the manual on your SB700 to see what the flash range is at ISO100 with an aperture of f/8.  You can increase the range by using a higher ISO, a larger aperture setting or both.  There should be a chart in your manual showing the range at different camera settings.  I have the SB600 and according to the chart for that particular speedlight the range at ISO100 at f/8 with a 50mm lens is thirteen feet.  At ISO400 the flash range doubles to twenty six feet.  If your flash is firing at maximum output then dialing up exposure comp. is going to do nothing.

Jerry


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## prakhardeep (Feb 21, 2012)

BlairWright said:


> Sorry, forgot to answer your question about exposure comp and flash.
> 
> Nikon (*until the D4) does not have a flash exposure comp setting, it only has/had exposure comp which affects the entire exposure, not just the flash output but everything. You can in fact use it to balance your flash exposure but you would be better off exposing correctly with your flash, that may require you to place your flash in manual mode.
> 
> Best of luck, Blair



Thanks for the reply Blair.

I have dialed the compensation in the flash unit itself.

On the point you have written i have another query, in M mode the exposure compensation through the EC button does nothing except change the metering display in the camera. Does it change anything in flash ? I mean to say does it change the flash exposure setting as it does not change exposure in camera ?


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## prakhardeep (Feb 21, 2012)

jriepe said:


> Check the manual on your SB700 to see what the flash range is at ISO100 with an aperture of f/8.  You can increase the range by using a higher ISO, a larger aperture setting or both.  There should be a chart in your manual showing the range at different camera settings.  I have the SB600 and according to the chart for that particular speedlight the range at ISO100 at f/8 with a 50mm lens is thirteen feet.  At ISO400 the flash range doubles to twenty six feet.  If your flash is firing at maximum output then dialing up exposure comp. is going to do nothing.
> 
> Jerry



How do i know that the flash is firing at maximum output when it is in iTTL mode ?

In the manual it says the range at ISO 100, F/8 and 70mm is .6-4.2m i.e. 2-14feet.


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## jriepe (Feb 21, 2012)

prakhardeep said:


> jriepe said:
> 
> 
> > Check the manual on your SB700 to see what the flash range is at ISO100 with an aperture of f/8.  You can increase the range by using a higher ISO, a larger aperture setting or both.  There should be a chart in your manual showing the range at different camera settings.  I have the SB600 and according to the chart for that particular speedlight the range at ISO100 at f/8 with a 50mm lens is thirteen feet.  At ISO400 the flash range doubles to twenty six feet.  If your flash is firing at maximum output then dialing up exposure comp. is going to do nothing.
> ...



There's the answer to your underexposure.  If the maximum range is 14 feet at those settings and you need a longer reach you need to compensate by increasing the ISO or using a larger aperture.  Lowering your shutter speed would probably also help.  Not sure why you would need it at 1/250 shooting people.

Jerry


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## SCraig (Feb 21, 2012)

jriepe said:


> There's the answer to your underexposure.  If the maximum range is 14 feet at those settings and you need a longer reach you need to compensate by increasing the ISO or using a larger aperture.  Lowering your shutter speed would probably also help.  Not sure why you would need it at 1/250 shooting people.
> 
> Jerry


Shutter speed only controls the amount of ambient light when using a flash.  The actual duration of the flash itself is about 1/10,000 second.  Using a slower shutter speed is not going to make any difference.


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## jriepe (Feb 21, 2012)

SCraig said:


> jriepe said:
> 
> 
> > There's the answer to your underexposure.  If the maximum range is 14 feet at those settings and you need a longer reach you need to compensate by increasing the ISO or using a larger aperture.  Lowering your shutter speed would probably also help.  Not sure why you would need it at 1/250 shooting people.
> ...



Thanks for clarifying that.  I honestly didn't know whether it did or didn't but I do know that ISO and aperture have an impact on the flash range.  But before I knew that I made the same mistake of using an aperture setting of f/8 with the smaller SB400 unit shooting animals indoors at a zoo and was confused as to why my images were underexposed. f/8 is fine as long as you're in range.

Jerry


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## SCraig (Feb 21, 2012)

jriepe said:


> Thanks for clarifying that.  I honestly didn't know whether it did or didn't but I do know that ISO and aperture have an impact on the flash range.  But before I knew that I made the same mistake of using an aperture setting of f/8 with the smaller SB400 unit shooting animals indoors at a zoo and was confused as to why my images were underexposed. f/8 is fine as long as you're in range.
> 
> Jerry


Increased ISO will have an indirect impact on the flash range in the same way that it has an impact on any exposure in that it increases the sensitivity of the sensor to light.  It doesn't change the output of the flash in any way, it just increases the sensitivity of the camera's sensor to light and as such at a greater distance whatever light level is present will have more impact on the exposure.  A wider aperture, of course, simply lets more of whatever light is available hit the sensor.


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## prakhardeep (Feb 21, 2012)

jriepe said:


> prakhardeep said:
> 
> 
> > jriepe said:
> ...



I need that speed as there were many dance performances.


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## prakhardeep (Feb 21, 2012)

SCraig said:


> jriepe said:
> 
> 
> > Thanks for clarifying that.  I honestly didn't know whether it did or didn't but I do know that ISO and aperture have an impact on the flash range.  But before I knew that I made the same mistake of using an aperture setting of f/8 with the smaller SB400 unit shooting animals indoors at a zoo and was confused as to why my images were underexposed. f/8 is fine as long as you're in range.
> ...



Yes. When i couldn't get proper exposure i increased the ISO to 200 and then the flash displayed correct exposure.


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## o hey tyler (Feb 21, 2012)

I'd shoot on ISO400 in those questions AT A MINIMUM no questions asked. It will give you more life out of your flash, and you will not have to worry about exposure from the distance that you're shooting. 

Your camera can handle ISO400 quite well, and there's no reason to shoot in a dark room with flash, unless it's a SMALL dark room. You'll find a great improvement in your photos I would suspect.


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## jriepe (Feb 21, 2012)

SCraig said:


> jriepe said:
> 
> 
> > Thanks for clarifying that.  I honestly didn't know whether it did or didn't but I do know that ISO and aperture have an impact on the flash range.  But before I knew that I made the same mistake of using an aperture setting of f/8 with the smaller SB400 unit shooting animals indoors at a zoo and was confused as to why my images were underexposed. f/8 is fine as long as you're in range.
> ...



Yes, I already knew that much.  I'm not a TOTAL dummy.  But no offense taken.

Jerry


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## Josh66 (Feb 21, 2012)

prakhardeep said:


> I need that speed as there were many dance performances.


As SCraig pointed out, the duration of the flash is around 1/10,000th of a second.  THAT is what is stopping motion, not your shutter speed.



prakhardeep said:


> How do i know that the flash is firing at maximum output when it is in iTTL mode ?


You don't.  But it would have to be, given the distance you were at.


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## SCraig (Feb 21, 2012)

jriepe said:


> Yes, I already knew that much.  I'm not a TOTAL dummy.  But no offense taken.
> 
> Jerry


I  didn't mean to indicate that you were.  I really wasn't clarifying it for you, I could tell from your responses that you understood, but for others who might read the post.


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## SCraig (Feb 21, 2012)

O|||||||O said:


> prakhardeep said:
> 
> 
> > I need that speed as there were many dance performances.
> ...


Keep in mind that flash doesn't necessarily "Stop" motion.  If gives that impression since normally the light levels are low enough that no background is recorded.  The camera exposes what it sees, and the flash from the strobe, being such a short duration, gives the impression that it stops the motion.  However, if there is enough ambient light you will get some level of exposure from that if you shoot with a slow enough shutter speed and wide enough aperture.  This can give a very unexposed background from the ambient with a properly exposed subject from the flash.


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## prakhardeep (Feb 21, 2012)

o hey tyler said:


> I'd shoot on ISO400 in those questions AT A MINIMUM no questions asked. It will give you more life out of your flash, and you will not have to worry about exposure from the distance that you're shooting.
> 
> Your camera can handle ISO400 quite well, and there's no reason to shoot in a dark room with flash, unless it's a SMALL dark room. You'll find a great improvement in your photos I would suspect.



Thanks tyler. Yes, since flash compensation does't seem to be working i increased the ISO. Though i was confused why the compensation was not working.


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## prakhardeep (Feb 21, 2012)

O|||||||O said:


> prakhardeep said:
> 
> 
> > I need that speed as there were many dance performances.
> ...



Yes. But, there was lots of stage light present. So, if i would shoot at low spped then lots of that light would also sneak in thus i decided to increase the shutter speed. I think it is the correct way to reduce the ambiat light in picture ?

Ohh...OK.


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## MLeeK (Feb 21, 2012)

distance causes light falloff. 
You are shooting at settings that indoors without flash would produce a black photo and you are expecting your flash to overcome that while losing some of the light to falloff. 
You'd need the sun to overcome that. Well, not literally, but you'd need more power than your flash can put out.
How do you know? When your flash can't compensate or create the exposure you are looking for no matter what-exactly what it did. 

I also don't understand why you want to rule out the ambient light? Doesn't mean you aren't right, just that I need more information as to why you chose to do that.


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## Josh66 (Feb 21, 2012)

prakhardeep said:


> O|||||||O said:
> 
> 
> > prakhardeep said:
> ...


Yes, if you want to get rid of the ambient light, shutter speed would be the way to do that.  If 1/250 (or whatever the x-sync speed is for your camera) is still letting 'unacceptable' levels of ambient light in, you would need to lower the ISO (if possible) or use ND filters.  That would also require more flash power though.

Also, like MLeeK mentioned, getting rid of all of the ambient light isn't always the best thing to do.


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## prakhardeep (Feb 22, 2012)

MLeeK said:


> distance causes light falloff.
> You are shooting at settings that indoors without flash would produce a black photo and you are expecting your flash to overcome that while losing some of the light to falloff.
> You'd need the sun to overcome that. Well, not literally, but you'd need more power than your flash can put out.
> How do you know? When your flash can't compensate or create the exposure you are looking for no matter what-exactly what it did.
> ...





O|||||||O said:


> Yes, if you want to get rid of the ambient light, shutter speed would be the way to do that.  If 1/250 (or whatever the x-sync speed is for your camera) is still letting 'unacceptable' levels of ambient light in, you would need to lower the ISO (if possible) or use ND filters.  That would also require more flash power though.
> 
> Also, like MLeeK mentioned, getting rid of all of the ambient light isn't always the best thing to do.




I needed to rule out ambient light as i wanted to seperate the individual dance performers in a group dance. Also, did not want to have the background like empty stage and all. Though i can use larger aperture values but 18-105 has a sweet spot at f/8 so i wanted to use that.

However, i was not 100% successfull in my attempt as the subject background didn't go as dark as i wanted.

I have set my camera for High speed sync thus i can go above 1/250. Though i shot only a couple of shots at 1/320. I think i should have shot at around 1/500 then the background would have been even darker.

In all this one of my query went unnoticed. Does exposure compensation in Camera in Manual mode change exposure of flash ? Flash is set in i-TTL mode.


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## Josh66 (Feb 22, 2012)

You would need Flash Exposure Compensation (FEC).  The 'regular' exposure compensation won't do anything to the flash.


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## jriepe (Feb 22, 2012)

Prakhardeep,

The one question you had about whether the flash exposure compensation is functional with the flash unit in the I-TTL mode and the camera in manual mode could be easily answered by simple experimentation.  Set your camera on a tripod and shoot at a subject in these modes at different flash exposure compensations and see if the adjustments are making a difference in your exposure.  Very simple, right?

Now you mention using high speed sync.  Even though I have it on my cameras I have never used it so I'm not speaking from experience but from all I've read your flash range will be severely limited.

Jerry


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## prakhardeep (Feb 22, 2012)

O|||||||O said:


> You would need Flash Exposure Compensation (FEC).  The 'regular' exposure compensation won't do anything to the flash.



Thanks Josh.


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## prakhardeep (Feb 22, 2012)

jriepe said:


> Prakhardeep,
> 
> The one question you had about whether the flash exposure compensation is functional with the flash unit in the I-TTL mode and the camera in manual mode could be easily answered by simple experimentation.  Set your camera on a tripod and shoot at a subject in these modes at different flash exposure compensations and see if the adjustments are making a difference in your exposure.  Very simple, right?
> 
> ...



Jerry, i said Exposure compensation not flash exposure compensation.


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## MLeeK (Feb 22, 2012)

Exposure compensation adjusts the camera settings and works when you are in an assisted mode (aperture priority, shutter priority, program), not in manual at all-you are controlling everything in manual. In the assisted modes it changes the OTHER setting in order to compensate for what you tell it you want. 

FEC adjusts the flash output only-not the camera settings. 

Using a lower aperture would have helped to separate the dancers with a shallow DOF. As it was you were creating a very large DOF keeping EVERYTHING in focus. Had you let the background blur by using a wider aperture that would have definitely helped.

Even better yet take your flash off camera (or two) and place at the edges of the stage to get you more and more versatility from your flash. The farther you place the flash away from the subject the more harsh the lighting will be.


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