I have been doing a lot of testing lately with the 1/4 CTB filter on my RED One Camera and I definitely like it for build 17 material. You have to add a little more light to the scene but it helps a lot to really clean out that deep blue noise in tungsten lighting situations. Here is some other info I culled from other places which outlines exactly what the differences are between all the options.

As we all should know by now the Mysterium and all silicon based sensors are inherently more red light sensitive. The 1/4 CTB is the best compromise for this issue. You can use the filter with the camera set to 4200k or higher and Iso 400 (1/2 stop correction) under tungsten light and achieve a very well controlled blue channel with little or no sensitivity hit.

Furthermore the 1/2 CTB is equivalent to the 80C, the 1/4 CTB is equivalent to the 80D and the 1/8 CTB is 1/2 the density of the 80D (which I guess could be nice in outdoor tungsten lit night without losing too much light.

As I have outlined on the Finding Hope Now pages I am a big fan of screw on filters and always use the IR filters when I am using more than .6 ND in front of the lens whether it is screw on or 4x5.65 it doesn't matter. When I am doing a RED Camera Rental I always also carry a 1/4 Pro Mist or two, a Polarizer and a soft edge graduated ND .9.

Usually I like putting in diffusion later in post where I can dial it in a little more but if I have the client looking closely then sometimes I need to add filters while shooting. We were doing a shoot the other day with some high profile skin care clients and we needed to crank the sharpness all the way down on the monitor so that they could let us continue shooting without worrying so much.

I have not had any hands-on experience with Fluorescent correcting filters but I know they are hard to make work correctly because the green spike is all over the place in typical fluorescent lighting conditions when shooting in random places with my red one camera. I did however use the 1/4 CTB in many occasions with fluorescent lighting with great results.

As i said elsewhere I am also going to buy a CTO of some sort. I believe I will be getting a Schneider 4x5.65" Combination 81EF Color Conversion/Neutral Density 0.6 Water White Glass Filter which should work perfectly in those blusih overcast outdoor situations.