CurtPalme.com Home Theater Forum

Morettii · Guest

Hey Guys, what's the native contrast ratio of a Marquee 9500LC Ultra?

And which CRT has got the highest native contrast ratio?

ecrabb · Posted: Thu May 30, 2013 4:58 pm Post subject:

"Native contrast" is a term used to differentiate between a digital projector's contrast without the use of a dynamic iris, i.e. "native contrast" vs "dynamic contrast", so it has no applicability to CRT.

Are you referring to on/off contrast (inter-scene), or ANSI contrast (intra-scene)? CRT projectors, even 9" LC CRT's are terrible at the latter, and most excellent at the former.

If you're comparing contrast on CRT projectors, it's not really that helpful to compare models. The reason is that ANSI contrast is most heavily impacted by the lenses and CRT phosphor, as well as the screen and room. On/off contrast is mostly just how hard the tubes are driven. Even the oldest/lowest-end CRT projectors had good on/off contrast. Where LC projectors improve drastically over air-coupled machines is ANSI contrast. Still, even a high-end LC is still significantly inferior to most newer digitals in terms of ANSI contrast.

Where CRTs do differ significantly is MTF, or essentially sharpness, which is also somewhat relate to ANSI contrast. In addition to lenses, optical, and mechanical setup, electronics have a significant impact on ANSI contrast and sharpness.

In short, in terms of on/off contrast, there isn't enough difference between a 909, 9500LC Ultra, or a G90 to even talk about. Even ANSI is more heavily influenced by other factors than the projector itself.

SC

ecrabb · Posted: Thu May 30, 2013 5:17 pm Post subject:

Oh, and to answer the question that I think you were probably really after... A well-calibrated CRT projector, with gamma correction is probably in the 50,000:1 on/off contrast ballpark. If you crush black a little, you can probably double that. A CRT will do complete black, essentially nearly infinite on/off contrast, but you will lose significant low-IRE detail to do it, so the claims of 1,000,000:1 or greater significantly sacrifice picture quality to achieve that.

Also, those big numbers use a small window evaluate white. Use a 50% or 80% white window, and current-limiting compresses CRT's on/off numbers big-time.

Good digitals like the last generation or two of JVC's are now in the same ballpark with CRT in every respect other than absolute black.

SC

opv · Joined: 18 May 2010 Posts: 202 Location: Emek Hefer,Israel

ecrabb,
I think that a hi end CRT with good gamma correction (for example LUmagen), reaches much higher on/off CR ratios, maybe 500,000.
From my experience, you can get perfect black with no low IRE detail loss, it's a lot of work though.

stridsvognen · Guest

ecrabb im curious whats the ANSI contrast on your JVC.?

**kal** · Posted: Thu May 30, 2013 9:07 pm Post subject:

+1 to everything ecrabb wrote.

People like to compare numbers because numbers are easier to compare but picture quality is never that black and white. I know we have tables and lists here but they only tell part of the story. Don't compare projectors (especially projectors with different technologies) using numbers.

Kal

stridsvognen · Guest

**kal** · Posted: Thu May 30, 2013 10:00 pm Post subject:

For ANSI contract comparisons I don't need numbers: The first thing I did on my new JVC RS56 was put up a bunch of test patterns from the AVS HD709 disc, one of which is an ANSI contrast checker. On the digital it was insanely better than on my previous 8" LC CRT projector. The brighter scenes were barely washing out the darker scenes on the RS56. My brain really couldn't "get it" given that I was so used to CRT.

I'm not saying this is (or isn't) a major factor that defines "picture quality". Just saying that the difference between my old LC CRT and new digital LCOS was night and day as far as ANSI contrast is concerned. No need to measure anything.

Kal

stridsvognen · Guest

Im sure your right Kal.. But it would be a great help if you could measure your JVC.. you know there is to many opinions and tastes in play on a forum.. Nr. gives me a better understanding of your experience. I have seen CRT setup that i found compleetly washed out, so ill never say digital is not better, but im just not sure its better than the best CRT setup.

And if you have to be fair to the CRT it should be used as a 4:3 format, or the tube masked for 16:9 use, to elieminate the light from the tube face not used when the tube and chamber gets lid up.

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

km987654 · Posted: Fri May 31, 2013 3:34 am Post subject:

ecrabb · Posted: Fri May 31, 2013 4:15 am Post subject:

stridsvognen · Guest

ecrabb · Posted: Fri May 31, 2013 5:05 pm Post subject:

overclkr · Joined: 08 Mar 2006 Posts: 4227

Da stack OWNS da JVC. Nuff said.

ecrabb · Posted: Fri May 31, 2013 5:15 pm Post subject:

overclkr · Joined: 08 Mar 2006 Posts: 4227

ecrabb · Posted: Fri May 31, 2013 6:33 pm Post subject:

stridsvognen · Guest

Spanky Ham · Joined: 22 Mar 2006 Posts: 5643 Location: Comedy Central