Does Prog Scan matter on 3-chip displays?

[filmteknik]

Does progressive scan matter on a 3-chip DLP projector? (The question might equally apply to a 3 panel LCD but 3-chip DLP is what I have.) Isn't the picture there all the time, unlike a CRT? If progressive scan means the player gathers up the entire interlaced frame in memory then spits it out in its entirety I'm not sure that it would matter when using a display technology that basically does the same thing by its very nature.

I'm asking because I just purchased the Oppo player which does not do progressive scan on the component analog outputs. And all the superlatives in the reviews apply to the DVI output only. My projector (VistagraphX 2500) doesn't have a digital input. If it mattered I could spring for a converter box but that'll cost as much as the player. The projector will be superceded eventually anyway. But I'd like to know how much difference it actually makes.

[edDV]

Does progressive scan matter on a 3-chip DLP projector? (The question might equally apply to a 3 panel LCD but 3-chip DLP is what I have.) Isn't the picture there all the time, unlike a CRT? If progressive scan means the player gathers up the entire interlaced frame in memory then spits it out in its entirety I'm not sure that it would matter when using a display technology that basically does the same thing by its very nature.

I'm asking because I just purchased the Oppo player which does not do progressive scan on the component analog outputs. And all the superlatives in the reviews apply to the DVI output only. My projector (VistagraphX 2500) doesn't have a digital input. If it mattered I could spring for a converter box but that'll cost as much as the player. The projector will be superceded eventually anyway. But I'd like to know how much difference it actually makes.

Here's your manual. Basic projector (1024x768) accepts RGB over BNC and composite/S-Video interlaced sources. The optional HDTV component analog module makes no mention of progressive. Best call them and ask.

http://www.projektoren-datenbank.com/pdf/bedienungsanleitungen/christieVistaGraphX_2500.pdf

[BJ_M]

gezz that is a old projector from 1998

electrohome is no longer in business - they got bought by christie and that model and others were junked as those models just about bankrupted the company ..

a modern 1 chip DLP has better video quality and MUCH brighter --

i hope you got it real cheap because that model is famous for problems and very expensive to fix ... also the bulbs are expensive and it sucks power like it is is free ..

believe me - ive ripped many out and replaced them ..

that being said - the projector is not great for video compared to whats out there now and really should have a progressive input over rgb (non consumer) . It was designed really only for computer display and has only a very very basic video section .... you can input interlaced though , it will play it and as well play it progressive - but not by doing pulldown removal - just field blending ..


if you paid more than $1500 i would sell it right away if you can , ive seen dozens of these just sitting on shelves ... lots of old video projectors (some selling for more than 80,000 and up) are just landfill really ... like old main frame computers ... Its just sometimes some are money pits ..

[filmteknik]

I don't think I would do 1 chip iin my (professional) application. I've heard some people say they never notice any fringing but other people say they do. I think it's better to avoid it to be safe. Many of those units don't come with lens options anyway. I'm not going to do an in-theatre ceiling mount; I think they look tacky.

The projector has already earned its keep so when a 3-chip replacement comes into a price range I'm willing to pay (considering payback times) I'll replace it. My aim would be a projector of about 3000 lumens or so with lensing to produce an approx. 7.5' tall picture from about a 30' throw. I'd prefer 16:9 native but will consider another 4:3. If the latter then the lens must be able to zoom the cropped picture up to 7.5' H @ 30' throw. Brightness of the existing unit is fine at full frame but weak when blowing up letterboxed images to proper height. Existing rez is 1024 x 768 so I should be that much or preferably better. Trying to stay under $10K.

No one really addressed the question. Undoing 3:2 pulldown etc. is something the player does, not the projector. I have progressive scan on my old player but not on this new one. The projector does accept RGBHV and YPbPr and the latter is what I've been feeding from the old player. I'm replacing it because of occasional image freezes with certain studio-supplied "burned" disks.

Electrohome's projector operation did NOT go out of business when Christie bought them. It IS the digital projection division of Christie. The rest of Christie is a maker of 35mm film projectors, platters, consoles & lamphouses, and importer of Ushio xenon bulbs. I believe Ushio owns Christie.

[edDV]

No one really addressed the question. Undoing 3:2 pulldown etc. is something the player does, not the projector. I have progressive scan on my old player but not on this new one. The projector does accept RGBHV and YPbPr and the latter is what I've been feeding from the old player. I'm replacing it because of occasional image freezes with certain studio-supplied "burned" disks.

I addressed the question by saying nothing in the manual spec says that the Y, Pb, Pr inputs accept progressive inputs. You would probably need to use an external projector "line doubler" and go in the RGB inputs.

http://www.dvdfile.com/news/special_report/production_a_z/3_2_pulldown.htm

[BJ_M]

i also addressed the question -- this old projector does not have a proper video section .. projectors DO have pulldown removal in many models .. they often use the same genisys

i know electrohome and projectors more than what you possibly could know -- believe me when i say that when Christie bought out electohome, they were in trouble ..


a decent 3 chip latest generation dlp costs $20k and up , some excellent ones in this range , 1280x720 native with 2800:1 to 6500:1 contrast .. but some single chip models are out with greater than 5000:1 and 5000lm for less than 20k for a real tough higher end model to a compact 8-12k model with almost the same specs otherwise ..

you don't use line doublers with dlp's , you use a scaler -- something even like the kramer would work well ... lots to choice from ..

[edDV]

you don't use line doublers with dlp's , you use a scaler -- something even like the kramer would work well ... lots to choice from ..

I'm not a projector expert and never was Does that mean DLP can't do 60 frames per second?

Although we did do a dual Eidophor 24x9 Grand Canyon helicopter tour presentation in Las Vegas way back in 1984. (2 Broadcast Betacams adapted for special film style lenses). Eidophor sent 3 guys in white lab coats from Switzerland. They used to stangest test patterns to get the thing registered.

(edited)

[BJ_M]

it is not that they do not do 60fps ,

a line doubler doubles the scan rate and blends the 2 fields - a quadrupler is 4 x the scan rate and interpolates an extra line ..
Many people mistakenly think that line doublers output twice as many lines as the original video picture, and quadrupler, four times. This is not exactly true. Line doublers double the number of lines painted on the screen in each individual top-to-bottom pass, and quadruplers quadruple it. However, the total number of lines comprising the picture remains the same as the original when using a doubler and is doubled when using a quadupler. (Yes, this is a bit confusing!)

“Doubling” and “quadrupling” may also refer to the change in the horizontal refresh rate of the output video in relation to the original TV video. In other words, each individual horizontal line in the converted output from a line doubler is “painted,” left to right, twice as quickly as each individual line in the original TV video. And using a quadrupler, each individual line is generated four times a fast.

Later some models (mostly better higher end models) added motion compensation, which can be thought of as adaptive deinterlacing.
The limitations of line doublers and quadruplers are due to the very nature of how they work. Because the format of the input affects key aspects of the converted output, namely the number of lines and the vertical refresh rate, line doublers and quadruplers are limited in the types of output they can provide.
When starting with an NTSC signal, line doublers always produce a signal with 483 non-interlaced visible lines; quadruplers generate a picture with 966. When using a PAL or SECAM signal, line doublers create a picture with 576 non-interlaced visible lines; quadruplers create 1152. Line doublers and quadruplers (i have 2 extron quadruplers still) are used for crt projectors and were very popular years ago..



The line doublers resolution is wrong .. a scaler is used on lcd's and dlp's to match the native chip resolution and as well increase the refresh rate to often 75hz or better - as much as 100hz , and as well nowdays have better video proccessing and adaptive deinterlacing...

Scalers today are often much cheaper than doublers were 5- 10 years ago and are better quality ...

[filmteknik]

I would consider a good used machine in order to hit my price point. I figure I won't find new at that price at the present time.

In so far as the existing projector not doing progressive scan I don't know what to tell you except that it does. Player (Toshiba SD-4900) hooked up to component inputs and set to progressive scan and there you go--a picture. I imagine the inputs handle anything within a range of scan rates.

BTW, the manual claims that the projector can't tell the difference between YUV (YPbPr) and RGBHV (it's the same set of inputs) and must be manually told what you are feeding yet in my experience I can unplug the color difference component cables from the DVD player and plug in the RGBHV from a computer monitor breakout cable and change no settings at all and it works.