|<font face="Verdana, Arial" size="2">Originally posted by Martin P:
Ken, I am finding some of what you are saying a bit confusing. I understand that one of the advantages of your system is the ability to get the correct screen for specific projectors but is it not also true that there will be less variables with a plain white screen. If the additives end up not being perfect to the projector you are shooting for you will still have a top quality white hi/gain screen that anyone would be happy to own. On the other hand if this same method is used for a grey screen the slightest mistake or over correction with the black additive could be disastrous. Is there a better way than just sending out the paints and saying go to it?
If for example I have a 106" 16x9 screen and a JVC G-11 Dila (approx700 lumens)and my seating positions are between 11 and 15 feet from the screen at a maximum of 40 degrees off centre and my preference is for as bright a screen as I can get that will also noticeably increase contrast,do you have a premix that will fulfil this goal? </font>
You could say that there are no variables with a plain white screen. This would be true. Would you want everyone to drive a LADA? The Politburo would like you to think so...
Perfectly white, medium gain screens are just about all that one can hope for when using a CRT projector.
The CRT is capable of a TRUE black. Complete light cut-off. This means that you can use a white screen,and get perfect whites, and perfect blacks (relative on the blacks, there are ALWAYS some shortcomings).
With the DIGITAL based projection units, there is a problem. They cannot at this time produce a TRUE black. What is needed is a falsified black, or a grey screen. This IS the falsified black level. (If you make the mixture TOO black, that's not good. you would get too much darkness in your shadowing, and your whites would look wrong.. slightly grey.
The very simple trick is to not mix in too much carbon black to the mixture. Get a grey of some sort. It is better for the digital projectors than any white screen, as the colors end up looking much more controlled, delineated, and saturated. In other words, the image appears -to the human perceptual mechanism- to have more contrast range, and better blacks. As I said, a slight grey is better than no grey, or complete white.
CRT projectors require complete white screens, otherwise you are wasting the limited output of such devices. In the same manner, you must conserve the output of your chosen projector,and then get what you need, want, or can deal with.
The very variability of the product may be an Achilles heel to the unadventurous. I will not hold anyone's hand on this. As the database of application notes from users grows, the risk factors will be removed to a large extent, as there will be specific results reported with specific mixes. At first all you can do is try. If you want to wait it out, that's fine. The risk level, financially speaking is very low. The quality that can be delivered by the paint... is very high. Small risk for such high gains to be had in viewing enjoyment.
KennyG took a risk on the product, as he knew nothing about it. Each day he uses his new screen, it gets better, and better, until if finishes drying. About 3 weeks, it takes. SO, if you get the paint, and add a small amount of carbon black, it will give you a great grey screen. What you can do, is play with different greys,and try and find one that you feel is suitable. Then, mix carbon black slowly into the paint until it is matched. Then, paint with the mixture. If your screen is LARGE.. which it probably is, you will need multiple coats anyway. Who says the final coats have to be the same grey?
Lets get real... how much does the perfect grey screen cost right now? and then calculate how many grey screens you can experiment with making, and only end up spending half as much, and end up with a better targeted grey. One for you, and your situation, exactly as YOU judge it, as you are properly, for once, the final arbiter of the screen's make-up.
Remember what I said, there is NO PERFECT GREY SCREEN. IT DOES NOT EXIST! There are too many different projection systems out there, and once you deviate from a true white.. you get into a WORLD of hurt. As I said, once the product gets off of the ground, then I will be introducing specific targeted greys, but even they will be 'minimally' grey colored, and will be set up so certain amounts of extra black can be added to the mixtures, to get them to a specific grey condition. These will mostly be the color corrected mixtures to deal with the changes in color output from different bulb types, and color wheels, etc. Not that economical (to manufacture quantities of paint) until it can be proven that people (and dealers and installers) are willing to go this route. Why they would not want to do so is beyond me. It just remains to be proven in their minds that it is a viable method of attack.
As I said, I will be producing specific targeted mixtures, but not today. You can make your own grey screen with the product, or wait it out. Your decision. To say that -in my mind- it is a simple task to blend up a grey screen that you would be satisfied with.. would be an understatement. It is not difficult at all.