Hey guys, as I'm sure you all know I've been doing lots with RGB lighting which tho it combines into white is still very narrow band and looks strange. Ive been looking for a true way to show the CRI of some of my lights (especially the RGB only ones without a white die/emitter) as well as my new tint-shift project (Maxtoch DX21 based) and my recently repaired Imalent SA04 so I've been taking some time to learn how to take bette pic's, now I only have a PnS but I've improved my pictures greatly and learned how to lock settings and stuff.
This is is what I've came up with, this is a color pallet I've put together (this is only a cell phone pic) but I'll be taking good pic's of it in diffused sunlight as a baseline and will then compare the baseline pic to ones I take of it illuminated by the light I'm wanting to show the CRI on. I picked a brand of color swatches that are available at both Home Depot and kmart incase anyone else wants to do the same (I would also be willing to get and mail out a full set to one or two other members of requested, tho you'd have to make your own board with them)
this is is just a thread about the idea, results will go in individual threads pertaining to that specific light
Wow, as usually DJozz owns my method’s! I had not seen that before, thanks for the link. My purpose is different from his tho, where as he wanted to measure minute differences from one HCRI emitter to the next I simply want to show the real world CRI of a narrow band source as well as what the addition of narrow band “white” (made up of 3 individual wavelengths of R,G and B) does to wide band white (a true white emitter /die).
Are those “color checker” cards a single card or something he’s put together? Skimming the thread I see he mentioned switching to a black border between the colors so I guess he’s made them, perhaps I should switch to black too?
A Photographic tool, used to ensure the monitor profile is correct so that prints will be accurate.
I have a colorimeter that attaches to my Dell Professional monitor and keeps it calibrated to the proper colors. A necessity in the photography business…as is the right monitor.
They’re 70-100 bucks for an 8 1/2 x 11 printed card.
Which is why I added that larger version.
B&H Photo Video has em for about $69 if I recall correctly. This is one of those things that has to be the original, or it’s not accurate. The above is a photo of the card, shown on a website that I found with a Google Search. So it’s not likely to be 100% correct either. In fact, I opened it up in Photoshop CS5 and found the color balance off significantly. When corrected for Black, White, and Grey, it’s much more vibrant.
Could you send color swatches to someone with a real photo card, and have them photographed side to side?
(I really don’t know, just wondering — I know getting colors accurate is a serious exercise and hard work)
