How to make my picture brighter on Camera?

I have a Nikon D90. Don't know how to use it so well. I was reading that ISO is control for brightness of the shot, but i moved around, it doesn't seem to work so well. I moved from 4, 5, and to 32.it still look the same. What I'm suppose to change in the settings for brighter image?

By the way, I have 2 professional lights lighting up the object.

Uh… Read your manual.

(Psst… Try the exposure compensation control)

You need to understand exposure, that means ISO, aperture and shutter speed as well as power output from your two professional lights.

ISO relates to the sensitivity of the sensor - its has absolutely nothing to do with image brightness per se. Are you sure you're adjusting ISO? I've never heard of ISO 4, 5 or 32.

If you want a brighter image, then shoot in aperture priority (A), set the aperture to the one required for whatever depth of field you want and dial in some +EV (exposure compensation).

When you say you have 'professional lights' do you mean continuous lights or flash?

It seems that you are clueless about photography (and exposure in particular). I suggest you buy a good basic book on photography and read it in conjunction with the D90's user manual.

I would think what you were changing from 4 to 34 is not the iso but the aperture. ISO would be 100 200 ---up to 1600 and 3200. Also lower than 100 also.

You have many things that work together on your camera to produce an photo you are looking for.

LOOK UP:

ISO
Aperture
White Balance
Shutter Speed

You should learn one at a time and know how it effects your photo. Next use two and alter the settings to see the results, and so on. If its too much for you then be glad there's an Auto function.

The numbers you refer to in your question are aperture numbers, not ISO numbers.

You clearly need to take a photography class.

Unless you understand how to manually adjust aperture, ISO, and shutter speed to create a properly exposed photo, your DSLR might as well be a paper weight.

Set your camera mode to P, A, or S and dial in exposure compensation by holding down the exposure compensation button and turn the main control dial. To make your pictures brighter, you would want the exposure compensation to go into the plus direction.

Sorry to say but you need a photography class (or at least read up books and articles about basic photography). Owning or using "2 professional lights" or a DSLR camera doesn't automatically make you a good photographer.

Have fun and good luck!

Reading a book on Basics of Photography is a must. Borrow it from library. Also Website Ken Rockwell Nikon D90 User's Guide would help.