SB-700 underexposure compensation

[Josh66]

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.

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.

 

[SCraig]

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.

 

[SCraig]

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.

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.

 

[prakhardeep]

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.

 

[prakhardeep]

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.

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.

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.

 

[MLeeK]

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.

 

[Josh66]

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.

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.

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.

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.

 

[prakhardeep]

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.

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.

 

[Josh66]

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

 

[jriepe]

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

 

[prakhardeep]

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

Thanks Josh.

 

[prakhardeep]

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

Jerry, i said Exposure compensation not flash exposure compensation.

 

[MLeeK]

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.