White Balance and Flash

[james_martin9]

Perhaps this is the wrong forum for this, but I am a Nikon shooter so here it

goes. As I understand it, my D200 sees things as 18% gray, meaning it will see

a white wall, or white card as 18% gray. In order to make the wall look white,

I need to OVEREXPOSE this image or use + EV, or some other means of

compensating correct? Conversly, if I have a dark subject, I need to use -EV,

or some other means of compensating.

 

I am adding this to my previous post about flash photography in dark settings.

If I understand properly, I should meter the scene without a flash, turn on the

flash to TTL and set to something in the neighborhood of EV-1 on the camera?

 

I will also try rear curtain sync, or dragging the shutter but most often my

subjects are moving so that is not a good option.

 

Any more suggestions?

 

BTW..using a 2.8 lens, will I encouter any soft focus issues on moving subjects?

[pete_s.]

James, you're right about the exposure but there are both exposure compensation (on camera) and flash exposure compensation (on camera and on flash).

 

In reality there are only four variables to control; shutter speed, aperture setting, flash output and ISO.

[pete_s.]

Also white balance has little to do with exposure, it is the color temperature of the light.

[ShunCheung]

Nikon's matrix metering takes colors into account. If you are shooting a white wall and use matrix metering, the camera may have taken the fact that it is white into account, at least to some degree. To be on the safe side, in that case I would use spot metering to meter the white wall and add about 1.5 stops, give or take. (Yes, you need to over-expose from the spot meter reading.)

[pete_s.]

Actually to help you I suggest having the camera in manual mode so you set the aperture, shutter speed and iso yourself. That will determine the exposure of the ambient background.

 

Then with the flash on TTL you can play with the flash exposure compensation to set the exposure of the image that is hit by the flash.

 

Personally I don't do that, I use the flash in manual too. But that is probably too daunting if you're just starting out.

[james_martin9]

SO I basically understand how EV compensation works in ambient light now. However, adding a flash seems to change the game. If I add EV +1 because my main subject was slightly underexposed, my background nearly dark and the overall photo looking underexposed as well as showing to be so in the hostogram, will the addition of + EV blow out my main subject? It seems like once when I added EV it made the entire scene look darker.

[ronald_moravec1]

This whole thing gets way complicated. Yes all reflective meters try to average a subject to grey.

 

Now are you using the built in flash? Added Nikon flash? or added third party flash?

 

now you have to decide if you want to use M, S, T, or P mode. Different flash metering modes are with different flashes in different modes.

 

The book is a bear to understand and I tried at least 10 times. My neighbor calls it Japanese English. You read the words, but the context makes no sense.

 

Here is what I do. M mode 1/250 to 1/50 sec, pop up the flash and shoot no compensation. Same with A. Seems to work fine.

 

If I want nicer light, I attach my Vivitar 285 with StoFen on a flash bracket and connect thru a Wein Safe Sync. Set my 18/70 to 5.6 because it is constant value. I let the Vivitar thyristor set the exposure. This seems to work fine also and of course the light is much nicer.

 

Studio flash, plug in and go like it was a real camera. Manual mode.

 

Can`t help with Nikons overpriced flashes.

 

Bring back simple totally manual cameras. They are a whole lot easier. All the work they try to save you doesn`t work 100% so they they make a fix, then the fix doen`t work 100%, so they add another step. Now you missed the shot figuring out all this stuff.

[Ed_Ingold]

3-D Matrix metering uses fuzzy logic to make many of the decisions described in this thread. Fuzzy logic actually reduces practical experience of real photographers to a set of "rules".

 

For example, the camera uses distance and light patterns to set the exposure of a dark subject in front of a white background. You might still need to adjust the flash compensation, but usually not more than one stop (whereas the "average" reflectance is probably 3 to 5 stops too high).

[ntv666]

The dedicated flash lights ,like SB800 ,will take in to account the exp com set in the D200 camera. Is there any need to see the output of the SB800 when attached with D 200?