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Discussion Starter · #1 ·
has anyone tried CC filters to colour correct CRT's? I used one on my old Digital, would it work on the Red & Green tubes?
 

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Hi,


I theory, if you get the right color filters and place them over the lenses, it will work. For the red you actually need a Magenta filter to get out the yellow tint. (I tried it with a red filter and it helped a little, but a magenta would really help. ) You can get them from B & H Video.


God bless...


Mark
 

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Discussion Starter · #3 ·
why has no one tried it then, seems to be a lot chaper then coloured C-Elements, or messing with dyes in Liquid solutions
 

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The rosco filters are not optical grade. There was a thread withing the last couple months about getting the correct optical grade filters to do this. I'll see if I can find it.


Dave
 

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I have been running my 8000 with a red filter with some amazing results. Everything really pops now... and I have the best grey tracking I have ever had on the set.
 

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Quote:
Originally Posted by YONEXSP
why has no one tried it then, seems to be a lot chaper then coloured C-Elements, or messing with dyes in Liquid solutions
The problem is that you can't find good quality color filters large enough for a CRT lens. A top quality filter around 57mm in diameter is between $100-$150, so even if they did make it, it would be MUCH more than a C-element.


People with Non-LC coupled lenses wish they COULD use a c-element on their projectors for color correction, it would be the cheapest and best solution.
 

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well, I don't know about what you would consider good.... but good enough to make a big difference (and a difference towards better colors) cab be had at a DJ shop for a couple bucks. I have my filter on he out side of the lens at the moment, so it's quite far from the focal plane of the image.
 

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Quote:
Originally Posted by Joshua Snyder
well, I don't know about what you would consider good.... but good enough to make a big difference (and a difference towards better colors) cab be had at a DJ shop for a couple bucks. I have my filter on he out side of the lens at the moment, so it's quite far from the focal plane of the image.
It may make the color better, but at the expense of the focus and halo.
 

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Discussion Starter · #13 ·
Does anyone know how many other Projectors the NEC HD144 lenses fit? I have them on my 110 and obviously the colour on the XG is fantastic. What other PJ's can use them?
 

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Hi,

do the search for "color filters" color correction" and "HD144", and you will find some answers! In fact, I participated in one of the treads and started another. I absolutely agree with Dave I(Person99) and Techman707. Roscoe filters are NOT optical quality and should NOT be used in image path (those are filters for light sources only). We discussed it at length in some of those earlier treads. As for filters in general, Kodak still makes large CC filters (they are plastic, but they ARE optical quality), I actually have some from my time in photography business. Problem is, they don't really make PROPER correction, even if subjectively effect is positive. This really apply to all the "other" solutions, like colored glycol etc... As I stated in "my" tread, IMHO the easiest way to achieve this goal, would be to measure transmission characteristics of HD144 lenses, and devise filters to duplicate those. That sure wouldn't be cheap solution, but certainly doable (again: look at "my" tread). Surprisingly - nobody was really interested...

As for HD144 and "other" projectors - you will find several solutions in form of different adapters for different PJs, including Marquee 8000 series. I have my doubts if they would focus correctly at the edges, since they are supposedly designed for PJs with smaller rasters, but then again, VDC is selling adapters for them too, and they should know... (or should they?).

Regards,

Kris
 

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Quote:
Originally Posted by k.berger
Surprisingly - nobody was really interested...
I don't think anyone was interested because of cost. There are colored glycol solutions for people that want to do it on the cheap and there is the HD144/145 adapter solution for those willing to spend somewhere up to $500. I would think if we could get optical grade filters at
 

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I figured that's what you were referring to... Cost-wise I think it would be viable solution, specially if we could get several people interested. You have to remember that HD144 + Adapters would run you way over $500.00. I spoke with some optical companies, and they were very reasonable, considering complexity of the job. I am still willing to pursue this idea. I am even thinking of getting HD144 just to measure them and maybe sell them later. (Like I am really going to sell one of my toys... :) ),


Regards,


Kris
 

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my understanding (and I could be wrong) is the Mitusbishi 1281 (one on ebay right now)uses.... DICHROIC coated lenes for color correction. Now try and find that lens out there, somewhere. good luck. As I said, this was the information we came arcoss at one time or another. it was never verified, but that is what the literature from Mitsubishi said.


btw,that's a 100khz scanning pj, there. and Mitusbishi tubes is cheap. It's bright, too.
 

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Quote:
Originally Posted by KBK
my understanding (and I could be wrong) is the Mitusbishi 1281 (one on ebay right now)uses.... DICHROIC coated lenes for color correction. Now try and find that lens out there, somewhere. good luck. As I said, this was the information we came arcoss at one time or another. it was never verified, but that is what the literature from Mitsubishi said.


btw,that's a 100khz scanning pj, there. and Mitusbishi tubes is cheap. It's bright, too.
Ah ha. that's what Sony did on those lenses that Mark believes are color filtered, they're DICHROIC coated. ;)
 

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Fair go, I don't know what they do, just that they are colour specific, unlike every other 12xx lens (PT-65/HD-8) that I've seen.
 

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Quote:
Originally Posted by Mark_A_W
Fair go, I don't know what they do, just that they are colour specific, unlike every other 12xx lens (PT-65/HD-8) that I've seen.
Yes, they are tube color specific, but not like regular filters where Red goes to Red and Green goes to Green. :)


They appear to look better than the HD-8's
 
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