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NEC's and blue defocus...I need to say this again!!

 
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benareeno



Joined: 22 Mar 2006
Posts: 1614
Location: ottawa, canada

Posted: Mon Jul 19, 2010 5:45 pm    Post subject: NEC's and blue defocus...I need to say this again!!

If you have an NEC and you are not seriously defocusing the blue...then you are missing out on a lot more image quality.

For all you test pattern viewers, sharpness is not affected much....but movies will take on a whole new meaning!!

Without the blue defocus the image is ok...nothing great..but add in the defocus and there is now a lot more punch and I believe an improved contrast in the pic.

Again...it's not a small difference....do it!
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yonexsp



Joined: 25 Apr 2006
Posts: 311


Posted: Mon Jul 19, 2010 6:11 pm    Post subject: Re: NEC's and blue defocus...I need to say this again!!

benareeno wrote:
If you have an NEC and you are not seriously defocusing the blue...then you are missing out on a lot more image quality.

For all you test pattern viewers, sharpness is not affected much....but movies will take on a whole new meaning!!

Without the blue defocus the image is ok...nothing great..but add in the defocus and there is now a lot more punch and I believe an improved contrast in the pic.

Again...it's not a small difference....do it!


Would that be my old one your referring to? I agree, I was fiddling with it recently to see if the improved sharpness made up for punch. It didn't as I recall as you correctly point out Smile

FWIW, my Sony Digital also defocuses blue as well
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benareeno



Joined: 22 Mar 2006
Posts: 1614
Location: ottawa, canada

Posted: Mon Jul 19, 2010 6:13 pm    Post subject:

really?? The digital does too? Hmmm.....

well yes, it's yours I'm referring to...I've owned about 10 NEC's now, and I guess since there's a good amount of life in these tubes, the defocus made the biggest difference I've seen yet.

Really punchy and increased contrast...the image without it was just plain flat.
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yonexsp



Joined: 25 Apr 2006
Posts: 311


Posted: Mon Jul 19, 2010 6:32 pm    Post subject:

benareeno wrote:
really?? The digital does too? Hmmm.....

well yes, it's yours I'm referring to...I've owned about 10 NEC's now, and I guess since there's a good amount of life in these tubes, the defocus made the biggest difference I've seen yet.

Really punchy and increased contrast...the image without it was just plain flat.


It makes sense, blue is blue. Whether it is digital or analog, it still has the same characteristics. I noticed it when we set it up. The blue is defiantly a little more blurred than the R/G.Not as much as the CRT, but a tad for sure, or coudl have been the beer.

Blue is a bitch to see properly at the best of times
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benareeno



Joined: 22 Mar 2006
Posts: 1614
Location: ottawa, canada

Posted: Mon Jul 19, 2010 6:35 pm    Post subject:

also...when doing it on the NEC...don't just defocus it a little...defocus it a lot!!
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Artinaz



Joined: 15 Jun 2009
Posts: 110
Location: SF Bay Area

Posted: Mon Jul 19, 2010 8:16 pm    Post subject:

I havent yet got around to dialing in teh grayscale correction on the lumagen hdp. Would you suggest the defocus with the lumagen in the chain ?
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benareeno



Joined: 22 Mar 2006
Posts: 1614
Location: ottawa, canada

Posted: Mon Jul 19, 2010 8:45 pm    Post subject:

There's no way the lumagen can add the punch that the blue defocus will add...
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AFryia



Joined: 09 Mar 2006
Posts: 965
Location: S.E. Michigan VPH-G70Q

Posted: Mon Jul 19, 2010 10:31 pm    Post subject:

I've run...

1) full focus blue with full gamma correction

2) defocused blue no gamma correction,

and have found the IQ best with a defocused blue.

Pushing the gamma correction too far made the image look odd even though the colormeter said greyscale and luminance were good. It wasn't the usual banding one might get it was a "flat" looking image, it's hard to describe.

I settled for an in between, modest gamma correction and defocused blue. Without gamma correction I had to turn the gain down too low to get a delta E less than 3 from 20-80IRE. This combo gives good light ouput and very good greyscale, gamma and luminance.

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garyfritz



Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO

Posted: Mon Jul 19, 2010 11:19 pm    Post subject:

yonexsp wrote:
benareeno wrote:
really?? The digital does too? Hmmm.....

It makes sense, blue is blue. Whether it is digital or analog, it still has the same characteristics.

NOT true. The only reason to defocus blue is that the blue phosphor has a lower output than the R/G, and it gets overdriven and maxed out sooner. You defocus blue to spread the electron beam across more phosphor so you can get more light out of it before it starts to soft-clip. Your eye can't focus on blue very well so it doesn't really notice the fuzzy blue.

That's **entirely** a CRT phenomenon. Has nothing to do with the color blue. As far as I know there is no reason for digitals to defocus blue. Your eye won't see it as sharply as other colors, but that has to do with the optics of your eye, not defocus in the digi PJ.
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yonexsp



Joined: 25 Apr 2006
Posts: 311


Posted: Tue Jul 20, 2010 1:23 am    Post subject:

garyfritz wrote:
yonexsp wrote:
benareeno wrote:
really?? The digital does too? Hmmm.....

It makes sense, blue is blue. Whether it is digital or analog, it still has the same characteristics.

NOT true. The only reason to defocus blue is that the blue phosphor has a lower output than the R/G, and it gets overdriven and maxed out sooner. You defocus blue to spread the electron beam across more phosphor so you can get more light out of it before it starts to soft-clip. Your eye can't focus on blue very well so it doesn't really notice the fuzzy blue.

That's **entirely** a CRT phenomenon. Has nothing to do with the color blue. As far as I know there is no reason for digitals to defocus blue. Your eye won't see it as sharply as other colors, but that has to do with the optics of your eye, not defocus in the digi PJ.


Guess that makes sense, Blue is hard to see for sure
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