Lighting with a white backdrop

[NicoleScraps]

Hey everybody. I really need some help with something. I have been using my speedlite quite often lately. I do not have a stand and triggers so I use it on camera and bounce it off of my BA reflector. It works out beautifully....on a black background. On white....not so much. I really need to figure this out and am looking for any tips. This weekend is going to be dedicated to figuring out the white.

Here is an image, identical in camera settings (iso 200, f 2.8, 1/160, speedlite full power reflected), nearly identical positioning of the light and of the subject, but yet they turned out very differently. They are both SOOC for you to see. The white one sucks. Baby is underexposed and gray looking. The background is too perfectly exposed. Should have been blown out a little bit more. Now, if I were using natural light, like outdoors in the snow, I think I would have a pretty good grasp on what to do here. But I have very little idea as to what I can do differently with artificial light.
I think the black turned out great. I have wonderful success with that. I am sure that it has to do with black absorbing some of the light and white bouncing it back at me. But I cannot limit myself like this by only ever using a black background because I can't get white to look right. I need to master the white. Oh and I do have the raw file (LR3 and PSE8) if anyone has any tips for fixing up the white photo but that is my secondary concern right now. I need to figure out how to get this closer to the correct exposure sooc.

[zona5101]

Your assumption is correct...the white is pushing more light back and adjusting your flash exposure. Take your camera/flash off of auto or use exposure comp. With just the one speedlight you will not get the background white and the proper exposure on the subject. So you need to supplement the background with light or accept the fact that it will be gray. You can always change the background in post if needed.

[autofocus]

Originally Posted by zona5101

Your assumption is correct...the white is pushing more light back and adjusting your flash exposure. Take your camera/flash off of auto or use exposure comp. With just the one speedlight you will not get the background white and the proper exposure on the subject. So you need to supplement the background with light or accept the fact that it will be gray. You can always change the background in post if needed.

+1 on Bruce's comments...try bumping up your flash and see what happens

[NicoleScraps]

Exposure compensation? I can do that. I need to set aside time to watching this video that I bought for my speedlite. I am sure that would help. I just have not had time. How would you recommend lighting the backdrop without spending a ton of money? I know what you are talking about. I go to meet-ups once in a while in a studio and she has a main light angled in front of the subject and a smaller light behind the subject on the backdrop. But I only have one light. Would a smaller reflector on the opposite side help at all? Or would I need an actual real light source?
Thanks so much!

[autofocus]

Originally Posted by NicoleScraps

Exposure compensation? I can do that. I need to set aside time to watching this video that I bought for my speedlite. I am sure that would help. I just have not had time. How would you recommend lighting the backdrop without spending a ton of money? I know what you are talking about. I go to meet-ups once in a while in a studio and she has a main light angled in front of the subject and a smaller light behind the subject on the backdrop. But I only have one light. Would a smaller reflector on the opposite side help at all? Or would I need an actual real light source?
Thanks so much!

You can try more reflectors, but they'll still not equal what a light can do, and they won't give you the amount of control a light offers.

[zona5101]

Originally Posted by autofocus

You can try more reflectors, but they'll still not equal what a light can do, and they won't give you the amount of control a light offers.

tru dat.

SO you don't have to get another $500 flash you can get a manual flash and an optical trigger slave. Something like the lumopro160 - it even has a built in optical slave!
LumoPro: product

Also on the exposure comp - it's flash exposure compensation. As your two example images show, you shot with identical fstop and shutter but what changes was the flash output...it saw all the light coming back from the white background and shut down. You need to tell it not to by either +'ing your flash comp or putting the flash in manual...

[NicoleScraps]

Originally Posted by zona5101

tru dat.

SO you don't have to get another $500 flash you can get a manual flash and an optical trigger slave. Something like the lumopro160 - it even has a built in optical slave!
LumoPro: product

Also on the exposure comp - it's flash exposure compensation. As your two example images show, you shot with identical fstop and shutter but what changes was the flash output...it saw all the light coming back from the white background and shut down. You need to tell it not to by either +'ing your flash comp or putting the flash in manual...

Oh okay! Gotcha....to do list-must learn the manual controls on the flash!! I thought you meant in the camera.

[NicoleScraps]

Okay, I think that I have a mental grasp on this.
With leaving the flash on ettl, with the black background, it thought that the room was dark and gave higher level to the flash. But with the white on ettl, it thought that it needed less of an output.
So if I put it in M mode, 1/1 is the highest output? Is that correct? going down in output from there, to 1/64 as the lowest? How important is setting the focal length on the flash? Mostly I always use my nifty 50 but I am sure at some point I may need a wider shot. I am going to experient....wish me luck!

[NicoleScraps]

Originally Posted by zona5101

tru dat.

SO you don't have to get another $500 flash you can get a manual flash and an optical trigger slave. Something like the lumopro160 - it even has a built in optical slave!
LumoPro: product

Let me make sure I understand this. When you optical slave, that means that it will trigger automatically when it senses that my main flash has went off?

You all are awesome....you know that right?

[zona5101]

Originally Posted by NicoleScraps

I think that I have a mental grasp on this.
With leaving the flash on ettl, with the black background, it thought that the room was dark and gave higher level to the flash. But with the white on ettl, it thought that it needed less of an output.
So if I put it in M mode, 1/1 is the highest output? Is that correct? going down in output from there, to 1/64 as the lowest? How important is setting the focal length on the flash? Mostly I always use my nifty 50 but I am sure at some point I may need a wider shot. I am going to experient....wish me luck!

You got it - just need to practice to make it sink in... On the flash head setting, the wider the more it covers, when you go to zoom the head it concentrates it into a narrower beam and there is less spread. You can use that zoom head to control how the light strikes your subject (more as a spot or more as a flood).
On the power setting, I don't have that flash but I assume it will give you an fstop and distance for the power level...that would be your starting point for exposure.