CurtPalme.com Home Theater Forum

betel

Just scored a Zenith Pro 1200x with 994 hours and no discernible wear on any tube. Also noticed the unit was being run in economy mode when I started it up.

Currently I'm running a G70 with about 5k hours that has just enough wear on the B & G tubes to be noticeable during scenes with a lot of white. I intend to replace the G70 with the 1200x. I'm aware the HD-215 lenses on the 1200x have only one focus adjustment and focus suffers because of this. Physically, the G70's HD-18 lenses will fit the 1200x and vice versa.

I notice the HD-215 element closest to the crt is convex whereas the HD-18's is concave. Not sure of the correct terminology (maybe C-Element) but both the G70 & 1200x have convex mating elements to the lenses.

Kal had some questions about replacing his HD-215s in the " All about lenses (specs/datasheets/pictures/etc.)" thread. Some suggestions were made but there didn't appear to be a resolution.

I believe the HD-18 lens would be an upgrade to the HD-215 lenses as you gain center and perimeter focus adjustments. Best I can tell, no one on this site has reported on this upgrade before. Of course I'm hoping for the best.
I plan on doing a lens swap between the two machines. I'll report back on the results.

I'd appreciate any advice.

Thanks
Jimmy

betel · Posted: Tue Sep 16, 2008 12:43 am Post subject:

Okay, that didn't take long. Although the HD-215 will screw to the G70, the HD-18 will not screw to the 1200x. The G70 has two bolt patterns where the 1200x only has one. Not interested in modifying the 1200x to see how it works. Oh well.

**kal** · Posted: Tue Sep 16, 2008 7:56 pm Post subject:

For what it's worth, yes, the HD215 lenses are a bit softer than others on the screen edges but for movie content you'll never notice it. You may notice it in a DVD/Blu-ray status bar or other text (like from a PS3 or HTPC) but not during movies.

The one nice thing about the HD215's is the extremely short throw: You can install the projector a good 1.5-2 feet closer to the screen than most 8" CRT projectors so it typically fits directly under the first row of seats which means there are less bumped heads if you have a second row of seats. (Assuming you have a typical 7.5-8 foot ceiling).

Kal

betel · Posted: Tue Sep 16, 2008 10:31 pm Post subject:

I suppose from a practical standpoint, corner focus isn't that important, if as you say, it's not apparent in video. I need to mount this projector and see what it looks like. Probably be a little while though because I want to get rid of the G70 before I replace it with the 1200x (I have way too many machines).

I hope the 1200x doesn't need to be much closer than the G70 because I'll have to modify the mounting conditions. The G70 is a good bit closer than the 808s was so maybe it will be okay.

Kal, does your 1200x have a gamma adjustment? The one I purchased has this feature in the installation (or maybe it's service) menu. I know the 808s I have doesn't have this.

**kal** · Posted: Wed Sep 17, 2008 1:13 am Post subject:

It's not gamma as you know it. It's not the same thing. You'll still need some ways of providing a proper gamma boost to get details out of the dark scenes and achieve a proper average 2.2 gamma curve.

I've used the following projectors myself now in my HT:

Barco 800
NEC XG 75
Zenith 1200 (Barco Cine 8 Onyx)

And have seen countless others.

All CRT projectors need some degree of external gamma boost to get proper gamma tracking, either by HTPC or by some of Kim's Crescendo-System boxes, X-Vue Box???? boxes, Moome's HDMI coverters, or a scaler with gamma adjustment built in.

Many CRT projectors have what's labelled as "gamma" adjustment in the menus but it's something completely different.

Kal