Man I really suck at math and physics.

When using TXP or HP5+ for people, I normally use a #15 or #18 to place the skin tones where I want them, just a tad lighter to draw the viewer's attention to the face. Never a problem. I use standard commercial developers. Ambient light. Print using a 2.5 filter, condenser enlarger.

Now for the physics. When T-Max films are described as red sensitive, I don't know what that translates into on a practical basis. Does it mean that skin tones are darker or lighter? I'm guessing darker. If so, how does this film-stock respond to the use of filters mentioned above to lighten skin tones? Messy or decent?

Now, I should go out and shoot some film for tests. But, I have yet to invest $70 in a box of 4x5 film, unless it had promise in obtaining the lighter skin tones I prefer.

Can you folks break it down for me? Maybe even post an image or two? Thanks.