CurtPalme.com Home Theater Forum

ElTopo · Joined: 07 Nov 2006 Posts: 1608

Hi all,

i did a setup of a Barco Cine 8 yesterday with HD117-24 and P16LNP tubes with 800 hours on them.

We configured 1920 x 817p@72Hz on a 3m scope screen (width)

This projector is tack sharp ! Motion and black is amazing.

Love it Thumbs Up

**kal** · Posted: Thu Jan 04, 2018 7:43 pm Post subject:

Wow - that's nearly 10 feet wide?

What gain screen? How many foot lamberts are you getting on the screen?

Kal

Pzyked · Joined: 02 Apr 2017 Posts: 30 Location: Sweden

Sound amazing, a Cine8 was a great projector about the same as a G70, but your Cine9 way is better.
If you talk foot lamberts I guess max 3-5

**kal** · Posted: Thu Jan 04, 2018 9:52 pm Post subject:

3-5 ftL? Has to be more than that. That would be unwatchable. Standard is 14, below 8-10 I find dull and lifeless (but that's just me).

Kal

Pzyked · Joined: 02 Apr 2017 Posts: 30 Location: Sweden

Might be more if you use a high gain screen. But on a 1.0 gain I will say max 3-5.
If more you overdrive the crt.

**kal** · Posted: Thu Jan 04, 2018 10:12 pm Post subject:

Strange. My screen's a 1.1 to maybe 1.2 gain and with my Cine 8 I was able to do 13.8 ftL on this screen. Now this was 'only' an 8 foot wide screen, not 10. But I wouldn't expect it to drop that much.

Kal

Pzyked · Joined: 02 Apr 2017 Posts: 30 Location: Sweden

Not strange, just logic. Contrast over 60 will start to overdrive the crt.
3m scope screen, you use much less of phosphor remember that. Less light and run the crt hard.

**kal** · Posted: Thu Jan 04, 2018 10:45 pm Post subject:

garyfritz · Joined: 08 Apr 2006 Posts: 12026 Location: Fort Collins, CO

I agree with Kal (as usual Laughing

), 3-5 ftL would be unwatchable. Nobody would like that. If you're enjoying your image, I would just about guarantee you're getting at LEAST 7-8 ftL.

I ran my 8500 on a 98" diagonal screen (48" x 85", 122 x 216 cm), and as measured by 3 different light meters I was getting about 11-14 ftL with normal / reasonable contrast levels.

Are you saying your screen is 3m wide, so the scope image is 3m wide and 3m / 2.35 = 1.27m high? If so, your projected image is 3m / 2.16m = 1.39x wider, so 1.39x ^ 2 = 1.93x more area. So at worst your ftL levels should be half what I got, or 5-7 ftL or so.

Pzyked · Joined: 02 Apr 2017 Posts: 30 Location: Sweden

pj-toso · Joined: 19 Mar 2015 Posts: 69 Location: Norway - Oppland

ElTopo · Joined: 07 Nov 2006 Posts: 1608

As the tubes are nearly brand new we have plenty of light.

Brightness is about 35 and contrast 75.

Pzyked · Joined: 02 Apr 2017 Posts: 30 Location: Sweden

Then about 3-5 ft L /5-7 maximum ft if brand new tubes. If more you can fry some eggs on your phosphor for breakfast.
I also know that a cine8 will look good have seen it, but anyone's 9 inch including mine is much better than a 8 inch. Also recommended on smaller screen about 90-110 inch. Most important with all crts in my opinion are color filtering for a correct picture. Like Kal sais contrast is only one parameter in the signal chain that dictates how hard tubes are driven, yes I was talking in total.

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Last year I spent three weeks in Japan retubing 20 Marquees and that included calibrating to a defined luminance spec.

The target was 3 FT-L. Tube life will be decent at this level even in 24/7 operation.

Sitting in the cockpit, I'd say it was a bit dim for movie watching but for simulation purposes, it was fine. In fact, with as many as 11 projectors shooting into the dome via rear projection, if they were calibrated to 11 FT-L it'd probably have been stupidly bright in there.

Given the current end of life of CRT and my stock of spares, I'll run the machine a lot harder than I would have in the past. I run to the limits of acceptable sharpness. Not past the point of loss of detail.

I need to drag out my meter and see just how bright that actually is.

garyfritz · Joined: 08 Apr 2006 Posts: 12026 Location: Fort Collins, CO

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Or, he's beating the tubes like the proverbial rented mule to get decent light output, at the cost of a LOT of tube life.

Big or bright or long life, pick any one or two. You can't have all three at once.

A 3M wide image out of a single 9" projector guarantees a dim picture or short tube life. That's a lot to ask of a 9" machine.

It's CRAZY to try that with 8" tubes. I predict visible wear starting to happen within a couple hundred hours of use.

Some people think my 8 foot wide screen is larger than optimal for a 9" machine. Well, honestly I never turn the PJ on except for movies,
so I really put so few hours on the tubes that I've never put any visible wear on them yet.

Pzyked · Joined: 02 Apr 2017 Posts: 30 Location: Sweden

Agree

Zolzar · Joined: 26 Jun 2009 Posts: 252

I will be making the jump to digital in 2018 to a JVC RS projector. This changeover will be tied to a renovation of my basement in the spring. CRT has been so amazing and I have thoroughly enjoyed tearing them down, setting the back up, and making repairs. With to kids under two years old running around now I just don't have time to tinker anymore.

The journey started in 2001. It's been a good ride.

2001 - ECP 3101
2003- ECP 3501
2005 - (foolishly bought cheap digital)
2009- Electrohome 8500
2012 - NEC PG10

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

I have now scrapped down three old non-Ultra Marquee chassis in the past two days.

If it's not an Ultra then it's scrap. No point in even pretending that there's any value to a non-Ultra machine at this point.

I'm down to only 10 CRT projectors at this moment.