Hi guys, I have a situation here. Take a look at the link http://www.apogeephoto.com/july2004/jaltengarten7_2004.shtml that shows a neat chart of color temperatures for digital photography. On the other hand, let us consider the color correction done by 80/81/82/85 filters . For example, lets see the temperatures as given in the link: http://www.bhphotovideo.com/c/product/54822-REG/Tiffen_13881EF_138mm_81EF_Color_Conversion.html and if you go to "features", it shows a color correction table. We know that 81A is supposed to correct cloudy white balance and so on. How do the numbers in Kelvin correlate? For instance, if I want a correction of 9000K to daylight (digital convention) which 81/85 filter will I choose for me to do so? 81D can be an intuitive option but looking at b&h site, we see that it correct 3700 - 3200K which is way off from what I want to do (9000-5500K). Has anyone calibrated the filters to correlate with the digital camera convention? Thanks a lot and sorry for the long question.