This is interesting and all, but the real burning question is ....
what's the tattoo on Chris' ankle? :D

Heart. Circa 1969. Low-down, run-down biker shop, New Berlin, WI.
I had a lot of nerve in those days.

Allan, the best book, the palette of a master, the most expensive brushes, none of these can make me a perfect painter, but they can help.
Those glasses are deceiving, obviously you can't entirely rely on them.
I found them useful when checking the drawing, as by eliminating colour distraction they make it easy for me to see drawing mistakes.
I have checked them out by looking at pastels on the first day I got them, and they distort tones as much as a photo can distort perspective. Still we all use photo references and correct perspective with our own experience!
But anyway, I found your researches on colour and light relationship very interesting. Did you manage to start painting again? You sound as you are spending a lot of time thinking!
:sunnysmil
Ilaria

Ilaria,
please don

Oops, Allan, rereading my posts I sound like Mrs Red Glasses !

I use the "red glasses" mostly for checking my lights on figure drawings or paintings. I look through the lens and note which areas stand out as the lightest on the model and then I check to see if those areas are standing out as lightest in my work. It's different than using a black mirror - which is safe to use for checking value, unlike the red lenses.

I also use a reducing lens to check drawing; it looks like your typical Sherlock Holmes magnifying glass. You hold it next to your drawing so that you can see your model through it. It kind of compresses or shrinks the model to make it the same size as your paper. And you glance back and forth between the two to check drawing, value, and color. I'm not sure I'm explaining this well, I hope it makes sense. Just a note, if you hold it at an angle to the model it will distort.

One of my fellow students swears by paper towel tubes! She says they really help you focus in and define an area. I haven't tried that one yet, I probably will sometime when I'm desperate.

Something to try in lieu of red glass is a black mirror. It has the same effect of making the values easier to see while eliminating color distraction. The color red gets equal treatment with the black mirror so you don't have to compensate for it as with red glass. The added bonus is that since you are looking though a mirror you get a fresh look at your composition etc.

Mary

This reminds of me a tip that was given to me many years ago.

I was told to keep a pair of sunglasses always handy with my paintings and alternate painting with them on/off. This helps see the values also.

(I hope that wasn't mentioned earlier in the thread, I only had a chance to skim the responses!)