Question to a specialist

A forum to ask questions, post setups, and generally discuss anything having to do with photomacrography and photomicroscopy.

Moderators: rjlittlefield, ChrisR, Chris S., Pau

lonepal
Posts: 322
Joined: Sat Jan 28, 2017 12:26 pm
Location: Turkey

Question to a specialist

Post by lonepal »

Hi;

Does the CRI value of the light changes when we use diffuser?
What do you think?
Regards.
Omer

Beatsy
Posts: 2105
Joined: Fri Jul 05, 2013 3:10 am
Location: Malvern, UK

Post by Beatsy »

Interesting question! I know diffusers *definitely* change colour temperature and different materials have different effects, but I never considered the Colour Rendering Index.

So sorry, I can't give an answer, but will watch this thread with interest...

enricosavazzi
Posts: 1474
Joined: Sat Nov 21, 2009 2:41 pm
Location: Västerås, Sweden
Contact:

Post by enricosavazzi »

Strictly speaking, the CRI is defined by the spectrum of a light source, or more precisely its R, G and B components. Whether point-like or diffused does not matter.

Having said that, anything that changes the relative amount of RGB components of the light source (including a diffuser, reflector or filter) may (and often will) change its CRI.

PS - And of course one must always remember that the CRI just expresses the distance in color space between light source RGB and Planckian locus, so you can have light sources with the same CRI that look visually very different.
--ES

Post Reply Previous topicNext topic