christo™ wrote:
Yes, but you didn't use the 'L' coffee filter...I already filed the patent and the copyright...it runs "rings" around the regular coffee filters...
Christo,
How much are you going to sell them for? I bought a hundred pack for $3.
Jim C.
Did a quick unscientific comparison using generic white coffee filters compared to my expodisc. Pointed at spotlight in kitchen and took one aRBG RAW shot. Brought RAW files into C1 to see what it said the white balance was in P mode aRBG.
Using Expodisc: 3900K -2 tone balance F2.8 1/45 sec
Two coffee filters: 4300 -1 tone balance F3.5 1/90
Three coffee filters: 4075 -2 tone balance F2.8 1/60 sec
Before taking the RAW files I tried two .jpgs, one using two coffee filters and one using the expodisc. PS CS showed that two coffee filters let 12% less blue light through than the expodisc. This compares fairly close to the RAW findings of two coffee filters which show about a 10% difference. Using three coffee filters narrows the difference to about 5%. This is far better than pringles lids or coffee can lids that I have tried in the past.
While I am sure that there are differences in brands of coffee filters and 50 trials averaged would give you a more accurate result, I think that if you used three coffee filters to set your custom white balance, you would be within 5% of what an expodisc will give you. Is that small difference worth the price of an expodisc? Only you can answer that. But one thing for certain, three coffee filters is a WHOLE lot better than AWB, a pringles lid, or a coffee can lid.
Hmmm...Tom, I think you need to buy a warming 'filter'...Maybe make coffee first? Anyway, I'm up for another 77mm ExpoDisc for a reasonable price if anyone really goes "the way of the coffee filter"...
At least this beats the last time we went through this: I couildn't imagine eating a whole can of Pringles to get WB, but coffee is a necessary element.
I guess the key here is excellent light diffusion properties and absence of color cast of bleached coffee filter paper. Stacking filters (I used two) only improves it. For even better light scatter I would recommend to maintain a gap between the filters.
The Olympics are coming, we will be seeing a lot of different coffee filter brands on the side line!
How does it work, with flash.
I mean can the flash illuminate the filters at such close distance, so as to give correct readings ?
Also this method is used only for setting custom white balance right ? Or do you also use it to determine the exposure settings.
Wow, I just took a couple of test shots and I'm amazed at how well this works. I tested it on my old G1 too, which has serious WB issues and it worked perfectly. Yet another strange "gadget" for the camera bag. Oh well -- people already think I'm weird when I start pulling stuff out of the bag...
Here is the instruction for an L type coffee filter based expodisk
When you guys like the idea of making your own poor mans expodisk, some filters are made in a way that it is easy to take the glass out and replace it with coffeefilters. Go to your local camerastore and ask for a broken or scratched filter (preferrably a big size); one that you could have for free or a very low price. Unmount the ring that clasps the filter glass so that you can take out the glass and replace it with (a few layers) of white paper tissue like in the coffeefilter. If you got a filter that doesn't work with a clamping ring but a plastic sealed screw mount just glue the coffeefilter paper. Cut the remainders carefully so that the thing looks 'professional'. Paint some red on the ring and put a tiny label with the text "1.0/L IS Expodisc" on the ring. Some other might prefer a green "DO" version.
Of course owners of a Cokin or alike system have it easy. They can just cut a piece of blackcardboard cut a square out of it and glue the coffeefilter in it.
BTW did you guys know that white tupperware or the plastic from a white PE bottle works as well?
This was our FM course: creative with coffeefilters
I actually wrote it because I would feel embarrassed if all our members would be recognized by the VooDoo of a coffeefilter next shooting! I know the faces of all those shutterfreaks already .
geez Peter... guess there is some value after all on our local camera shops!
Since some time now, Im buying everything on the internet... somehow feel guilty about going there asking for a broken filter... not to mention the kick in the butt i should get!
Plus the coffee filters fit all my lenses. 
.