The following was in response to Chan Tran explaining his use of his optical color printer/enlarger... The issue of light meters and exposure meters is a different direction...
Color temperature changes throughout the day... from sun rise to mid day, to sun set again. So color temperature is not a constant in daylight, but a variable. You'll see in most editing software you have the option to select the temperature according to the effect you want or to match better the time of day you took the shot so it looks like what you had seen when taking the picture... sometimes just changing a photo to cooler or warmer helps with the effect you are trying achieve, that may not have been present when you shot the photo for affect. I'm not experienced in optical printing but I'm guessing you want to reach the exact or as close as possible to the film negative's color temperature in order to render accurate color reproduction initially and thereby reduce the need for post editing to fix it, and one may not be able to fix it, if initial setup is too far off.... just a guess. So, even though your EV is reduced after applying the color filters, it just means you have to expose the photo paper with the new EV. Am I correct in this?
So from reading post up to this point I take it that in order to check the exposure metering on a camera, one needs to use a stable light source, and simply using a dimer will not provide that stability. Hence, the LED's with physical modifiers to achieve desired output for a given or desired EV output. Interesting.
I got side tracked reading all this info... I came back to this thread to comment that I installed a little program onto my computer that allows brightness adjustment of my computer's LED monitor... Although with note pad in full screen mode and brightness at 100%, I get an EV from my DSLR of EV10, and as I drop brightness in 10% increments, I see a full stop of change in shutter speeds, indicating EV droping 1EV/10% reduction. I may be able to simply use my computer's monitor to check my exposure meters? And above EV10, just use daylight?
Last edited by xo-whiplock; 03-30-2013 at 03:34 PM. Click to view previous post history.