[Macksta]

Hi,


Ive been thinking about purchasing an iscan pro to output a progressive video signal from non HD digital tv material to my Sony 1292.


However one guy at a hifi shop I talked to said it was pointless buying such a cheap doubler as the iscanpro and using it with such a good projector. Basically he seemed to be saying that if I wanted improved results with my Sony 1292, Id have to buy a doubler worth 4 to 5 grand. This surprised me somewhat as I thought the iscanpro was a good doubler whatever u used it with.


Does anyone have any thoughts on this?


Dylan

 

[Ray Cendroski]

Dylan,


You did good coming here for a more objective opinion. I've been using an Iscan on my 9 inch projector for about a year and a half, and in my opinion, it is one of those rare products that I have been totally satisfied with.


I had a fellow AVS member (who owns a 1292) stop by for a demo one night. We played dvd's for about two hours. He left here at 8:30pm, drove home for 2 hours, and by 10:45 pm had a request in the AVS classified section looking for a used Iscan.


Ray

 

[Chris Williams]

On the other hand...


I found the iScan to be inadequate for my 1252 (an 8"). I own one, and only use it on my smaller VGA monitors any more.


It's limited to 640 x 480. Any 8" or 9" projector can be tweeked to a level where the iScan's 480 lines of vertical resolution are just not enough. Put 480 lines on a 16:9 screen - say one 48" high (for the sake of simplicity). That means 10 lines per inch. Any 9" CRT will (or at least can) produce a scanline less than 1/10th of an inch thick.


I'm using a HTPC now and the 600 lines I'm running it at are a lot better match to it. If I had a 9", I'd run it at 768 minimum.

 

[wm]

You'll also get more light output from those 9" crts if you go to a higher scan rate. Don't know specs for a 1292, but a G90 running at 31.5 khz (480p) on a 96" wide screen puts out less than 9 ft lamberts reflected (1.3 gain Stewart). Same projector running at 63 khz (960p) puts out 12.5 ft lamberts on the same screen. That's a very significant difference in image brightness!


Wm

 

[Ray Cendroski]

Sure, all of that is true, but he wants to line double an external video signal.


I have a HTPC in addition to the Iscan, and my Geforce2 card can take an external video signal input.


I've found that for external analog signals from tv's, vcr's, and laser disks, the signal thru the HTPC can come close to the Iscan at 480p, but trying to upscale beyond that just turns it into crap.


Ray

 

[Macksta]

Ray,


the external video signal is digital tv though... not analogue



Does that make a difference?

 

[Ray Cendroski]

Dylan,


The signal may be coming from a digital tv converter box, but the component video output signal from the box is still an analog signal.


I need to be careful here, because I don't have any experience with component video, or tv converter boxes.


Maybe one of our more learned members can check in.


Ray

 

[deronmoped]

I have used a I-scan with DVD'S and found it to work great, very easy set up and about the best bang for the buck out there. After using it for a while I wanted to try a HTPC, so mine is for sale and there are some others that always come up in the ads. here. Try one, you can be up in running as soon as you get it. If you do not like it, you can sell it and get your money back.


Deron

 

[DMan]

Quote:

However one guy at a hifi shop I talked to said it was pointless buying such a cheap doubler as the iscanpro and using it with such a good projector. Basically he seemed to be saying that if I wanted improved results with my Sony 1292, Id have to buy a doubler worth 4 to 5 grand. This surprised me somewhat as I thought the iscanpro was a good doubler whatever u used it with.

Well, I must say that the guy at the Hi-Fi store is pretty much correct (maybe a little high on his pricing). While the iScan Pro is a fantastic line doubler, a line doubler will only output 480p. Your 9" CRT projector will still exhibit line structure (scan lines) at only 480p. What you need to use is either a HTPC, or a video processor (scaler) that can output 720p or 960p for a 9" CRT projector. You can look into video processors like the TAW Rock, Faroudja NR, Crystal Image or Quadscan that output in these higher resolutions.


I've used a iScan Plus in the past on my 7" CRT projector and it was decent, but when I upgraded to a scaler I now run my DVDs at 1280x720p and the image is much brighter and sharper than the 480p output.

 

[Geordie]

Macksta doesn't give the information but I think he's from Australia, in which case we are talking 576p not 480p. That could change the above opinions a bit, perhaps. It certainly adds a little bit of a positive to the iScan argument.


Side note: the ozzies that have recently popped up here on the forum should talk in US dollars for opinions and comparisons to be meaningful. You'll get the wrong advice if you don't.

 

[Gatherer]

I had the pleasure today of seeing a iscan pro using a 1292 and the picture difference was exceptional also tried it on a 1272 and it improved the display out of site the screen was 2.5mtr standing 3 mtr approx away no scan lines


BYW Im from down under and greeting to all

 

[Mark Glover]

Quote:

Originally posted by wm You'll also get more light output from those 9" crts if you go to a higher scan rate. Don't know specs for a 1292, but a G90 running at 31.5 khz (480p) on a 96" wide screen puts out less than 9 ft lamberts reflected (1.3 gain Stewart). Same projector running at 63 khz (960p) puts out 12.5 ft lamberts on the same screen. That's a very significant difference in image brightness! Wm

Wm, I find your reply about light output very interesting and I think it warrants further discussion as another reason why you need to use a doubler or scaler with these high quality CRT PJ's. Don't know if we should discuss it in the CRT Area or the Video Processor Area.


-Lets discuss it here and start a new thread if others want to contribute.


Each projector has it's own max VIDEO resolution in lines (like say 1000 VIDEO lines res.) waiting to be used. This can be verified by having an NTSC test pattern generator @ 525(480i) NTSC odd/even lines fed into the composite or S-VHS VIDEO input and you can read on the test pattern generated the VIDEO resolution this PJ can resolve.


The odd/even lines of the NTSC signal will be highly visable on most projectors using the VIDEO inputs with the viewer seeing the black horizontal lines at this scan rate 525(480i) and the resultant light output.


Is there a formula to use to calculate the light output acheivable at each scan rate or do you have to use a light meter?

 

[Cobra]

The big problem with a well setup 1292 is that it shows up all the problems/limitations of your source.


Is it worth your while to upgrade to a HDTV box like DG-TEC that has RGB(VGA connector) output. It outputs 1080i or 1152i, not sure though if it upscales 576i(SDTV) to these resolutions, by the looks of the manual it does. Actually what you need is to buy a scaler than can handle 1080i so that you can get 1080p out of it. Wonder what that looks like on a 1292.


I haven't had enough time with my 1292 to work out the sweet spot resolution but I know that it is big, these things love high resolutions so glad that I'm using a HTPC for dvd.


Haven't seen an Iscan Pro or other line doublers connected to 1292 to compare but would expect that 576p will look good, but higher resolutions will look better.

 

[Curt Palme]

Properly set up, the 1292 shoud still show scanning lines clearly, so to get rid of them, you need a tripler or quadrupler or HTPC to make the most out of the projector. I wenrt from a DVDO to a Quadscan, and the difference is as dramatic as going from a regular video signal to a doubler in the first place.


On a scale of 10, the video signal is a 1, a doubler a 5, and a quad a 9.5 (there's always room for improvement).


Curt

 

[bkwong73]

Hi All,


If I had a great nine inch projector like the Sony 1292 I would definitely get a better scaler than the good Iscan pro.


I had a Quadscan with my Nec xg75 and it looked okay. But I recently upgraded to a Faroudja NR scaler and the difference was dramatic.


With a nine inch Crt you should try to find a good used Faroudja 400 quadrupler or maybe look into a good used Faroudja NR scaler. This combination should give you stunning results but it will cost you a bit more.


Just my 2cents, Brian