CurtPalme.com Home Theater Forum

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

OK, so I got reminded of this via the AC/LC discussion going on somewhere else right now, and it occurred to me to ask: What are the main differences between the BG808s and the Cine 8 Onyx, and how important are they to PQ?

The main ones I can think of would be LC vs. AC, tube resolving ability, color filtering, and... anything else? Signal path differences? The basic specs seem similar.

I've also heard of people upgrading 808s to Cine8s, so I'm curious what it takes to do that, or whether it's even worth it even if you can find good tubes...?

**kal** · Posted: Thu May 08, 2008 8:36 pm Post subject:

The Onyx adds the following important things:

- Liquid coupled lens/CRT assembly for greater contrast and less halo'ing. HD-215 lenses are used instead of HD-8's. The Cine 8 Onyx is in fact the only 8" Barco front projector with liquid coupling.

- Tinted (colour filtered) c-elements are used in the LC'ed assembly for the Red and Green lenses for more accurate colours. Other than the Cine series, all other 8" and 9" EM focusing Barcos are use clear c-elements or clear glycol. Projectors without tinted glycol/c-elements tend to display red as red/orange and green as green/yellow.

- Less important: The optional Contrast Modulation board is installed for even colour/brightness across the screen (left to right). See the document from Barco for more information on the Zenith 1200 page.

It also adds the following less important things:

- The Cine 8 Onyx (and the Cine 9) are equipped with the Limo Pro built-in scaler. The Cine 8 and Zenith 1200 do not include this feature. (No loss, external scalers are much better anyway. Anyone running a Cine 8/9 with the built in scaler is doing themselves a disservice!)

- Black case.

Kal

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

Hmm, so I'm pretty much there aside from LC. I'm going to be filtering the lenses, I'm going to do contrast modulation in software with avisynth, and I'm scaling with ffdshow! Also I'm planning on painting it black. Razz

Yeah, I did some experimenting with the filters, and it makes a HUUUUUGE difference. If you look at it side by side, the unfiltered red looks almost ridiculous!

I wonder if there'd be some way to get the optical effect of LC while using the same tubes... eh, probably not without hosing the image up completely in other ways. Too bad tubes are so expensive. Sad

Person99 · Joined: 09 Mar 2006 Posts: 4899 Location: Flower Mound, TX

The signal path is better. The port 5/switcher board is two minor revisions (if memory serves) newer.

I do not consider the CM board minor. CRTs have terrible uniformity. A CRT has around 67% uniformity (or worst on larger screens) compared to some of the better digitals in this regard which get close to 90% uniformity. You can get over 85% uniformity with the CM board.

**kal** · Posted: Thu May 08, 2008 8:58 pm Post subject:

How'd you adjust CM on your Dave? Just eyeball it? Moving a colorimeter around to measure levels at various points of the screen seems too much of a pain to me.

Kal

r.bauer · Joined: 08 Apr 2006 Posts: 280 Location: The Netherlands

The Cine 8 has color filtered HD8 lenses, which are very rare.
The original Cine 8 was later updated to the Cine 8 digital: http://www.curtpalme.com/docs/BarcoCine8Digital_Brochure.pdf

EDIT: Reading the first post for the second time, you are not comparing the regular Cine 8, but the Cine 8 Onyx. So this is a bit OT.

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

CRT_Ben · Joined: 28 Aug 2006 Posts: 1684 Location: Northern Virginia

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

I make viewports and outer lenses for underwater cameras from cast acrylic. What are the temperatures involved in this area of the tube? Could an insert be coupled (glued?) to the tube face well enough (physically and optically) to have no negative influence on the image? I can create almost any curvature on a surface, and polish it to optical quality. I think it would be easy to make something to essentially replace the c-element, and then all you need are the correct lc type lenses to fit. Wouldn't that work?

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

In that case, couldn't you just mate the flat back of a c-element with the flat face of a tube, and switch to an LC lens? Seems like more people would do this if it was that easy. Obviously you'd have to machine new mounts, but that wouldn't be that bad (at least for me, since I have a machine shop... Razz

). Unfortunately c-elements + lenses are kind of out of my budget right now, but it'd be great if possible, and a hell of a lot cheaper than a new set of tubes!

CRT_Ben · Joined: 28 Aug 2006 Posts: 1684 Location: Northern Virginia

Person99 · Joined: 09 Mar 2006 Posts: 4899 Location: Flower Mound, TX

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

Ben,

The reason I'm confused is that every time I hear about someone doing an LC conversion, they're changing the tubes. And whenever I hear about LC vs. AC projectors of the same basic type, the tubes seem to be different. So I kind of thought there was an intrinsic difference. If there isn't, that's great, because it means I can do a conversion without breaking the bank! (I haven't got a lot of time, but I've got more time than money... if only a little bit...)

At any rate, I don't have the money to just go out and buy the appropriate hardware. My entire HT budget, after I resell components I've fixed to flip for a profit, will be less than the cost of three c-elements. Yes, it would be great to get the right hardware and have it be less hassle and a more certain result, but I haven't got that luxury. And I get a charge out of finding new ways to do things, which is why I'm asking the questions!

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

CRT_Ben · Joined: 28 Aug 2006 Posts: 1684 Location: Northern Virginia

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

I've already got the PJ, though the tubes aren't fantastic. Like I said, if I had the money for new tubes... Smile

But I'm quite familiar with swapping tubes, and swapping the hardware on the tubes, since I swapped all there (and then another) from bare tubes. It'll be tricker with the best on the ceiling, but I think I can swing it if there's a good upgrade in the offing.

At any rate, I've managed to get myself together a pretty good HT room for almost nothing when all's said and done, so I'm sure that if I concentrate I can manage the hardware for an LC conversion somehow...

That's part of what I love about this hobby. If I had a bucket of cash to throw at it, and BANG, had an expertly set-up G90 blend, a kick-ass audio system, perfect seating and lighting, etc, and hired somebody to come in and have it done NEXT WEEK, I don't think it would be nearly as satisfying.

I've loved every minute of the time I've spent figuring out my HT stuff, because the community kicks ass, and there's just so much stuff to learn! It's fantastic! And when I get done learning the latest thing, I get to crank it all up and watch Transformers! Very Happy

**kal** · Posted: Fri May 09, 2008 1:35 am Post subject:

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

I don't really notice uniformity too much in *general* but it really seems to jump out and smack me in the face in super high contrast bright scenes - the reaver planet scenes in Serenity, for instance, where there's a lot of blown out white, and panning to go with it.

It might matter more to me because my tubes are worn, too - so it's much more obvious. I'll have to do some A/B watching when I get everything up and running. I'd do it double-blind but then I wouldn't be able to see anything. *rimshot*