18% grey card/colour card?

[Mr Whippy]

Anyone know where I can get one realtively cheaply. Everything I see is quite expensive and big (ie £20+ etc)

Basically I want to paint some balls 18% grey for environment lighting data capture, since I can simulate 18% grey in my application to calibrate virtual with real (ie, terminator position, hotspot intensity, shadow intensity yadda yadda... but I need a 'real' known starting point and 18% grey seems to be a commonly used one.

Any help much appreciated on a good source for 18% grey materials.

Dave

[bashful]

Mr. Whippy,

You might find the material itself is expensive anyway, as I recall that the key thing about a proper 18% target is that it's 'metameric', i.e. it remains neutral under different lighting conditions. That's why you can't just print out 18% on your inkjet and use that reliably.

[Snapper7]

For some thing that sounds so critical, £ 20 as a key tool is rather cheap IMHO. I use Gray Card all the time and wouldn't be without it

[Mr Whippy]

Hehe, it's not that £20 is too expensive, it's just that it seems expensive for some grey card.

However, if that is the kinda going rate then I will pay it... just don't want to be ripped off


I will post some results once I get them as some of it may interest readers on here. Aiming to simulate my setup in a 3d game engine, and cycle through the stops (exposure, like HDR) and make sure the highs and lows and terminators on the balls all follow nicely in sim vs real

Big task, but it will be fun and assure some lovely final graphics (I hope )

Dave

[Dogsey]

Which game engine are you using?

[Fordo]

Mr Whippy said:

Hehe, it's not that £20 is too expensive, it's just that it seems expensive for some grey card.

However, if that is the kinda going rate then I will pay it... just don't want to be ripped off

its more than just a piece of grey card though- mit'll have been thoroughly R&Ded and tested to make sure it is colour neutral and accurate in its lumaninace levels

If you think £20 is pricey, you should see the chart i want my company to buy- http://www.dsclabs.com/chromadumonde.htm

about £1000 ish, for the size id want! seems crazy for a chart- but all the colours are 100 % tested and accurate, and you can use one to perfectly colour balance broadcast cameras. Essential if your on a multicam shoot, and youve got all different makes and models of camera. hell even when you have same makes and models, its essential!

Boss always says its too expensive, but i've yet to calcuate the amount the colour grading in post actually costs, in order to get footage to match. That £1000 could seem quite cheap if over 5 years it saves X amount of hours of grading.

Anyways, im rambling now. Sounds like an interesting project your working on