Wireless Flashes

[Partsrept]

Hi. I have 2 questions:

1.I have problems with Wireless Flashes. Is there a tutorial on where to set up flashes and what power settings for portraits and non-portraits images ?

I have 2 flashes. Difficult to find best place for them to light my subject and light it right. What settings do i need and what settings are bad settings to avoid ?

Also i get images too underexposed because if i do different settings then i get washed out images/too much light spots on faces... - is it because of flash positions ? where can i learn ???

2.
WB in my photos. You know you can use white/gray/black card for WB. I can take a picture with that card shown and in Photoshop in Levels for example i can point to right colors on that card. Question: why when i point to white (and it is right white ) Photoshop adds too much light to image and it is completly whashed out (it is like burned spot). Below is an examle of original image with card (original.jpg) - i was doing a test and result in levels bad . Please try to do Levels/WB in photoshop and post results if possible.
levels.jpg is what i got when clicked on white color.

[zona5101]

Wireless flash - check out strobist.com. It is a site dedicated to off camera flash using portable strobes.
To assist in answering your questions...
There are a number of variables in the shot: shutter, aperture, iso, and flash power output. Your shutter is going to max out at you flash sync speed but it can go slower. Your fstop and flash power output will work in conjunction to give you the correct exposure. For example, up your flash output and close down your aperture. Just like stops on your lens. the power output can be thought of in stops... full to 1/2 power is one stop, full to 1/4 power is two stops. Without a flash meter you are going to have to use your camera display and histogram to determine the correct exposure.

Light placement is more of an artistic choice, same goes for the light modifiers you choose (umbrella, softbox, etc). For even lighting you would typically place one light on each side of the camera at a 45degree angle pointed toward the subject. Flat lighting isn;t typically the best because it tends to eliminate the shadows we rely on to give the image a sense of depth.

Your on the right track for white balance but I think your image being underexposed is making your light balance adjustment do funny stuff to the exposure and contrast. Also depending on the tool...some white balance droppers want a gray or neutral color to base the correction on.

I hope some of that helps, very BIG subject area you're asking about so hopefully you'll have more questions...

[Partsrept]

Originally Posted by zona5101

... For example, up you flash output and close down your aperture. Just like stops on your lens....

is there a Flash aperture like aperture in camera too or you meant camera aperture only?

[zona5101]

Originally Posted by Partsrept

is there a Flash aperture like aperture in camera too or you meant camera aperture only?

no flash aperture, just lens aperture-
just like you control the quantity of light that is allowed to reach the sensor by adjusting the aperture - you have the same control over the light output of the flash by adjusting the power output of the flash. Just as one stop difference in fstop [2.8 to 4] is half as much light, so too is full power to half power 1/2 as much light.

Now I have assumed (and you know that is never very good thing) that you are shooting your camera in manual with manually controlled off camera flash. If you are shooting ettl(canon) or ittl (nikon) in commander mode then none of this applies because the camera is doing all the calculations.

[Partsrept]

Originally Posted by zona5101

Your on the right track for white balance but I think your image being underexposed is making your light balance adjustment do funny stuff to the exposure and contrast. ...

How do i know if exposure in camera is right for Photoshop ?

[inkista]

It should look right to your eyes, too. You always want to have the photo as close to what you want as you possibly can get it in camera, before you go to Photoshop.

You can also use the histogram to check that you haven't blown highlights or lost shadow detail. The histogram is the same as what you're seeing in Levels.