Who Is Now Using The JVC RS-1/HD-1 For CIH?

I'm using an RS1 with a Panamorph U85. Takes some adjusting to get the geometry right, but then it's set and forget. This lens also needs a high throw ratio to work with the RS1. Using an HTPC to scale. HD-DVD's look surreal. Even dvds at 1.0x screen width look good if the transfer is decent. Like many have said. Absolute blacks aren't as good as my CRT, but having a dark and light image on the screen is amazing.

Hi Jagercola:

Is a throw ratio of 2 high enough for use with the U85?

Setup:
The Da-Lite High Power screen is 52" by 122" 2.35:1 AR with area of 44 square feet, to be squeezed by U85 VC anamorphic lens.

With a 20' 5" throw distance, this comes to a TR of 2, near the middle of the zoom range but closer to the brighter but lower contrast end of the lens' zoom range.

How does this compare to your successful installation?

TIA

I am, but I'm too poor for a lens and a scaler. That said, I'm still more than happy with it's built-in zoom and lens-shift features for doing CIH the ghetto way.

I just wish the black level on the JVC was a bit better for blackouts and very low APL scenes. But at least it's better than most everything else out there that weighs under 150 lbs.

Me too. (once I get the JVC)
How wide is your screen Wildfire?
Tony

My screen is, measuring it, 127x54", plain ol' blackout cloth. It is not optimal (in terms of brightness) shooting onto the whole screen, but it would be great with a HiPower screen with reasonable gain (2.0+). I can't fit a 12' wide 2.35:1 HP yet so I'm sticking with the el-cheapo cloth until I can, or until the bulb dims more, whichever comes first. 12' might be a bit too big (sitting 1.25x away), but I find the 16:9 area and especially the 4:3 area need a bit of 'embiggening' on my current 54" of height.

I thought the 65" of height on a 133" diagonal HP (16:9) was perfect for my sitting distance. Carrying that over puts me around 12' wide for a 2.35:1 screen, technically more but that would be seriously pushing my luck with brightness (as if this isn't already).

If I was somewhat more nutty I would consider doing an adjustable masking system with a taller screen, but I'm not there yet.

Wildfire99 / Tony S. - Appreciate your elaborating on the poor man's CIH w/RS1

(1) Do you find the zoom adjustment demands any refocussing - or does it "hold"
(2) Physically, are you able to comfortable operate the zoom without physically disturbing the focus wheel?

It needs to be refocused when you mess with the zoom and lens shift. It's not a dramatic shift but expect to tweak it just a little bit. The tiny pixels make it harder to focus than anything else, because there's no pronounced screendoor to help fix on.


Barely. That zoom gizmo is really chintzy and between that and the tiny space given for the plastic lens housing (to focus with), it's a task that you need to pay attention to, lest you bless the lens with a fingerprint. It's one of those things that could have been better, but as-is, it works.

I think the lens shift dial is more irritating, as it feels like it has a lot of slop even though it doesn't. All in all the system works, and it's far more accommodating than anything else I've used, even if it means watching where your fingers go.

If they had just enabled vertical stretch in that fancy Gennum chip I'd just get a lens and be done with it. But that's yet another "if they had only..." line-item on the RS-1 wish list.

Can't help you darknloud, still waiting for my PJ. Wildfire is the expert here.
Just a thought WF99... since I spent all my money on the pj and speakers, I'm looking at a painted screen solution. Been talking to the Blackflame contingent. (see screen forum)
Tony

As an off-topic: Several years ago I went the total DIY route for a screen. Making your own frame isn't hard but you have to be very careful or think ahead, because any imperfections will show. My first frame was solid but bowed out at the top (bad lumber), and some of the wood edges (from the internal bracing) telegraphed through the screen surface (blackout cloth). My test of painted materials didn't go well. Perhaps some people have perfect rolling technique or a special dust-free spray booth, but I don't.

By the time I gave up and called AVS for a proper screen, I was sold on a commercial screen. A few hundred bucks for a nice HP screen was well worth avoiding the frustration of DIY, and it was a better screen to boot. (And I'm not biased... being a cheapskate I DIY everything else in my theater, speakers, risers, equipment racks, etc.)

For now my BO cloth (not painted) tacked to the wall works fine, but it's not ideal. My main concern was finding out what my desired screen size and mounting position was, but it's good enough that I'm presently too lazy to buy and install a permanent one (and I want to go bigger than my room allows). If I had nothing left to spend on a screen, I'm not sure I would try to paint it. It's too easy to screw it up, and paint and BO cloth is not free.

The only thing that tempts me to DIY still is the SMX material, but it doesn't have the gain to go to the size I want.

Seriously,
get a travel pair of binoculars.

scott

Yes agreed. My implied meaning was that it doesn't have a proper test pattern to check convergence and sharpness.

I haven't tried to get into the service menu yet.

Rich:

The loss of between 20-30% ANSI contrast, reported from users of the Panamorph and Prismasonic seems unavoidable due to optical scattering.

However, there is some confusion about the total lumen loss with anamorphic lenses, aided by a few intemperate posts based on improper measurement protocols.

When you diverge a light beam with a brightness of a particular lumen value, using an HE anamorphic lens (the simpler case to explain vs the case with a VC lens) over a larger area of coverage, of course the foot lamberts measured at the screen must go down compared to that measured with the smaller area of coverage.

But comparing apples to apples, by measuring the foot lamberts with the *lens in place* in both cases, and comparing full panel usage, using a scaler to use the complete vertical extent for a 2.40:1 film, to partial panel usage, where vertical pixels are trimmed to make the film fit the native 1.78:1 panel width, there is a gain of around 20% in brightness, simply from more of the panel radiating light versus radiating its black level.

From quality optics the transmission loss should be around an imperceptible 1-2% or so for anamorphic geometry warping, made up for by the additional pixels used by scaling to use all the vertical resolution you paid for.

The other confusion arises when people compare the brightness of a wide image, say 2.40:1 with the *lens in place*, which uses the full panel, to a native 1.78:1 image, with the *lens removed* and again using the full panel.

Of course, the same lumens over a smaller total area will produce a higher foot lambert reading in that case, as expected. This brightness gain is the primary reason some people prefer to move the lens away for 1.78, not the loss of some horizontal resolution, IMHO. Brightness rules the list of the eye's preferences.

Given that broadcast, satellite and cable HDTV feeds are generally already compressed down from 1980 to a range around 1440 horizontal resolution for distribution, the trimming of the panel width in a CIH, fixed lens setup, to a similar horizontal resolution when displaying 1.78:1 HDTV, is not losing significant information, when using a good scaling engine.

For those using a CIH, anamorphic-lens-in-place-at-all-times setup, the foot lamberts stay near constant for the narrower aspect ratios, as the image is trimmed by shutting off pixels from the width, but since the light engine/optical path combined lumens remain in the same proportion to the area radiated, the foot lamberts remain constant at the screen.

The issue of whether the 20-30% loss in ANSI contrast is a problem or not is all about tradeoff's.

For Cinemascope movies, the larger, immersive image seems to be a good trade for that small loss in ANSI contrast. For native 1.78 images from a native 1.78 panel, the tradeoff of CIH convenience, simplicity of masking or not having to move the anamorphic lens, for that loss of ANSI contrast, especially when viewing HDTV sources as opposed to film sources, becomes more problematic.

However, all the years when CRTs ruled the high quality projection scene, with their native ANSI contrast significantly lower than the ANSI contrast of the JVC RS1, even after accounting for the loss from an anamorphic lens, should tell us that the perceptible impact when watching film sources will be minimal.

I hope that helps!

Is it correct to presume using the poor manys CIH does not loose 20-30% contrast as a new set up lense elements are not added to the path?

UIsing a lens doesn't effect the on/off contrast, only the ANSI contrast, which is when you have both bright and dark elements in the image at the same time. The bright parts can scatter within the lens and effect the dark parts.

Depending on the quality of the lens depends on whether or not is is visible or not.

Gary

I am using my RS1 with the latest prismasonic 1500 lense firing on to a Stwewart 2.35/1 studiotec all thanks to Jason I have it directly underneath my Sony G70 CRT so a/b comparisons are easy. Needlass to say my new set up is jawdropping. Sure it wont hit the black floor level that the G70 has but I recon an ND2 filter will help there. In every other dept I am in awe.
As far as the lense is concerned I would liken the RS1 to a good 8" CRT without the lense but with the lense its as good as any 9" I have seen except for fade to black. I see hardly any reduction in sharpness with the lense in place.

008...
What video processor are you using with this setup? I have the RS1 and the 1500, and am trying to figure out which VP to use.

so if i go with the RS1 and the Prismasonic 1500 (1080p) do i have to move the lense out of the way?

also interested in what scaler is best for this setup?

i plan on a SMX widescreen and my distance from FP to screen is about 12'

thanks

brad

You may have some lens problems with a distance of only 12 feet.

Brad...
The Prismasonic has a pass-through feature where you don't have to move the lens out of the way. The prisms will rotate out of the stretch mode by either turning a manual knob or with a remote control...depending on which model you go with.

I highly recommend that anyone planning a CIH setup with the RS1 order their screen first and try out the "ghetto" (zoom) method for awhile before getting a lens and a scaler. I've got over 100 hours on mine using an 8ft wide 2.35 screen from about 1 SW, and I'm still just as excited to watch HD scope movies on it as when I got it. The PQ is so good that if a lens like an Isco III can make it look better, I really don't want to know. I think the biggest factors in whether a lens makes sense with the RS1 are how easy it is to access the manual lens functions in your setup and how often you plan on changing aspect ratios. I'm shelf mounting at minimum throw to make access and focusing easier. I'm also so blown away with HD DVD and Blu-Ray scope movies that I rarely seem to change aspect ratios. However, it could be quite inconvenient with different setups and viewing choices. And then there's the "uncool" factor of having to say you use the "ghetto" method. But with the money I saved, my HD movie collection is growing rather quickly.

Are there any disadvantages of a Prismasonic lens - as compared to an ISCO? For some reason (can't remember how I've been lead to believe this) I thought anything other than an ISCO was not recommended for CIH... Is there noticible geometry distortion, color shifting, or something else visibly determental to the image?

I had an H1000 Prismasonic lens, and now have an ISCO II which I prefer (I sold the H1000).

There was some focus uniformity difference across the screen and a little more geometric distortion with the H1000 compared to the ISCO, but you wouldn't really notice it with video content, just PC or test images. I think the ISCO also has a slightly larger aperture as I was just getting a very small amount of vignetting at the sides with the H1000 but none with the ISCO (I have an H78 and it wasn't noticeable during a movie). There's no reason you can't use the Prismasonic lenses unless you have the extra money an ISCO will cost you.

The newer Prismasonic lenses with the extra front element are an improvement so may be on a par with, or better than the ISCO now, but I've not seen one to compare.

Gary

I have an HD1 and am using a Prismasonic. Originally I had the 1200 series lens, but I have just upgraded to a new housing and front element. Believe everything Prismasonic says about it. The focus uniformity across the screen is excellent and there is no discernible focus shift between passthrough and stretch modes. I am very very happy with the results.

Hi Rich. I have really enjoyed reading your posts here on AVS particularly when I was just getting into Plasma. I purchased my Panasonic on the strength of your reviews.

I find no difference in sharpness with the lens in place or not. The new front element is a major advance. But really, the point of this design, as you know, is to leave it at all times. Prismasonic can explain some of the other benefits much better than I so I quote from their website -

# With variable Prismasonic lens one can adjust the picture width to match the screen perfectly no matter if the screen ratio is 2.35:1, 2.37:1 or even 2.40:1. This is not possible with the fixed moveable lens system.

# If the movable fixed lens introduces any horizontal or vertical offset, it will be shown as an asymmetric location for the 16:9 image on 2.37:1 screen, after moving the lens away from the beam. Since the variable Prismasonic lens has the same optics always in front of the beam, this offset is will be same both for 2.37:1 and 16:9 movies, and thus the perfect location for images of all aspect ratios is maintained on the 2.37:1 screen.

# With variable lens it is possible to achieve full panel resolution for also intermediate aspects such as 1.85:1 and 2.00:1. This naturally is not possible with fixed moveable lenses.


The first point is really interesting - With the ability to vary the lateral limit of the image you can set the image to fit your screen perfectly at the sides. I have a VP50
video processor and have set up profiles for different source aspect ratios. In this way you can also perfectly match the image to the screen on all sides whether it is 2.35 or 2.40:1. I do not think this would be possible except with the Prismasonic. I hope I have made myself clear.

I am not great at screen shots. These (Casino Royale, bluray) are on a 2.35:1 unity gain screen, 1120 mm height.

008,

not wanting to go off topic, but do you notice the loss of the black floor level compared with the G70 on actual movies or mostly on fades to black only?
joe