Opacity Question - Photoshop

[Schizo]

i have photoshop cs3 and was just wondering when changing the opacity (for example to 70%) when you lift the pen off the tablet and paint over the same area it makes it a darker shade and effectivly reaching 100% opacity. Now i was wondering is there a button you can hold so that if you accidently lift your pen off the tablet you can have that continuous 70% opacity no matter how many times you go over it?

Sorry if thats confusing, if you need a better explanation just ask!

Thanks!

[chluaid]

I'd certainly love to see that feature.. maybe one of our photoshop veterans here can confirm for us whether or not that function exists.
Welcome to the forum btw

[Pieter]

As far as I know the only way to do that is to make a layer and set it to 70% opacity.
I anyone knows another way I'dd love to hear it aswell.

[Schizo]

Thanks Adam and Rubberhead for replying!

Rubberhead: That would work is suppose but you would have to keep chaning between layers to get thr right effect, because there maybe a point when you need to blend opacities and then you wouldn't which would be pain but thanks anyway!

Adam: Thanks, new to the new forum but posted quite a lot on the old one!

[Pables]

There's no button but here's a technique that you could try. But, once again, it involves more than one layer  ...

Make your first layer and start drawing whatever the hell you wanted in the opacity you need.
If you accidentally lift the pen off the tablet: create a new layer and continue drawing on that.
(If you lift it off more than once, create a new layer for each time.)
After it's completely finished, ctrl-click on the thumbnail of the first layer in the layers window.
Click on the layer above it and press delete.
(If you made more than one, just keep clicking on the layer above and deleteing.)
Merge those layers (ctrl-e).

Sorry if that's not what you were looking for or if it's too long. I made that up on the spot so it's kinda stupid 

[Markham]

Can't you just hold down the mouse button and wave the pen over the tablet?  Or map the pen's side button to also do a left click?

[Bugaloo]

Can't you just hold down the mouse button and wave the pen over the tablet?  Or map the pen's side button to also do a left click?

You would lose the pressure sensitivity of the pen, but that would probably work.
Sorry I have no ideas.