Brush opacity question

I've got a question, and it might be a little hard to understand. Here goes anyway.

I've got a picture and I want to make certain parts of it lighter. I thought I would do it by selecting the brush tool, selecting white as the colour, and setting the opacity to, say, 50%.

But it seems I can only achieve the same opacity all over the picture by using one 'stroke'. If I use two or more, and I go over the parts of the picture that I've already lightened, it just makes those parts lighter.

Is there any way to achieve the same opacity all over, even when using more than one stroke?

alkalinemuse said:

I've got a question, and it might be a little hard to understand. Here goes anyway.

I've got a picture and I want to make certain parts of it lighter. I thought I would do it by selecting the brush tool, selecting white as the colour, and setting the opacity to, say, 50%.

But it seems I can only achieve the same opacity all over the picture by using one 'stroke'. If I use two or more, and I go over the parts of the picture that I've already lightened, it just makes those parts lighter.

Is there any way to achieve the same opacity all over, even when using more than one stroke?

yeah, do your white an a new layer above the pic, and set that LAYER opacity to 50%. paint on it w/ your normal 100% brush setting and then merge it down when you're finished.

Excellent, it works. Thanks man.