[jimmyk01]

I've been interested in the world of front projection for quite awhile and I am now ready to take the plunge. Through all of the info posted here as well as other research I am 99% sure I will be getting the Benq 8700. I have a couple of questions though concerning this projector and was hoping that someone on this forum could answer. First, I've read where the projectior will have a resolution of only 1024x768 when using the DVI input. Is this true and if so how big of a negative is this? Second, I've also read that whites are crushed when using component input. Can this be fixed through alignment or is this something else that has to be accepted?

 

[vincanity]

I'm also interested in this projector and had the same question about it. I recall discussion on this a while back, but the search routine doesn't seem to be able to bring it up for me.


My DVD player is a HTPC. I plan on outputting 1280x720 through DVI. If the BenQ cannot accept this computer resolution, I'll have to cross it off my list.


I know it accepts 720p through DVI from the Bravo. I'm not sure why it wouldn't accept 1280x720 through DVI from a computer (if that is the case).

 

[Daniel Hutnicki]

To be honest, I dont know what the answer is, however I think that the dvi connection will take just about any resolution except maybe 480i. The question is when the internal scaler will kick in

 

[jschefdog]

I am researching this PJ as well. See this thread where some people indicate that they are successfully running 1280x720 into DVI from both DVD players and HTPCs.


Also, the Widescreen Review article says:
Quote:

The computer input uses a DVI-I connector and accepts 480p, 720p, and 1080i. The DVI input works well with both RGB-Video levels (16 to 235) and RGB-PC levels (0 to 255).... The DVI input worked well on both DVI-D and analog RGBHV signals. There was zero overscan, and 720p was “pixel perfect.â€

 

[Krobar]

I have been doing extensive work with the Benq and an external scaler recently. 1280*720 is supported but NOT when set to Through mode. This means you take an image quality hit because the internal scaler cannot be disabled in conjunction with native resolution and hence 1:1 mapping is not possible.


The projector will detect 1280*720 in "thro" (Internal Scaling disabled) mode but will display it at 4:3 ratio (960*720). "Thro" mode does not work as advertised and since I wanted to use an external scaler with this PJ i'm not happy. Hopefully Benq can fix this with a firmware update but that might just be wishful thinking.


And as for this:

"and 720p was “pixel perfect.â€"

I know alot of people cant get the Benq working in "Thro" mode and dont know of one person who has it working. This means WSR either had an updated firmware for the Benq, an unreleased firmware for the Momitsu DVD player or they wrongly assumed it was pixel perfect.

 

[jschefdog]

Quote:

Originally posted by Krobar I have been doing extensive work with the Benq and an external scaler recently. 1280*720 is supported but NOT when set to Through mode. This means you take an image quality hit because the internal scaler cannot be disabled in conjunction with native resolution and hence 1:1 mapping is not possible.

Thanks for posting this info. If it doesn't work with Thro mode, what mode does it work with? How bad is the image quality hit? Is the firmware user upgradable?

 

[StevenH]

I have emails & calls in to BenQ regarding this issue - none of which have been returned. I had hoped for better pre-sale customer support from them.


I would like to feed the pj 1280x720 from a PC via DVI and also from a HiDef Tivo via DVI at 720p and 1080i.


So, I guess what I'm curious about is the following:


1. If a 1280x720 signal is sent to the PE8700 via the DVI input and ANA is selected what happens? Is there any down/up scaling involved?


2. Same as (1) but THRO pushed


3. If a 1024x768 signal is sent to the PE8700 via the DVI input and ANA is selected what happens? Is there any down/up scaling involved?


4. Same as (3) but THRO pushed


Steven

 

[vincanity]

Quote:

Originally posted by StevenH I have emails & calls in to BenQ regarding this issue - none of which have been returned. I had hoped for better pre-sale customer support from them.

I have sent e-mail enquiries into BenQ Canada on three seperate occasions with various questions. Never got a response other than an automated response from BenQ.com (as a pose to BenQ.ca) saying that someone will respond shortly.


I also tried BenQ Canada's pre-sales phone number a few times at different times in the day for the last couple of days. No one picks up and I always get sent back to the automated telephone system. I guess they're not to keen on building customer confidence.


You wouldn't think it would be so difficult gettings a company's attention to alert them to the fact that you want to spend thousands of dollars on their products.


I don't think I want to find out about their after sales service/response. I'll pass on BenQ.


Plus it doesn't sound like you can do native 1280x720 with a HTPC through DVI.


The search continues.

 

[Jeraden]

I hate when this same question comes up repeatedly. Benq claims it only does 1024x768. THIS IS NOT TRUE. It does 1280x720 perfectly fine, as long as you are using an ATI card. Perhaps they say its not supported because it doesn't work through Nvidia cards, at least I couldn't get it to work with mine and a couple others couldn't either.


Forget about THRO mode, it doesn't matter. Just stick it in anamorphic or letterbox and you'll get 1:1 mapping. There is no stretching or lost pixels or anything. I don't understand why this keeps getting brought up. It's a non-issue. Who cares if THRO mode doesn't display it correctly, use one of the other modes that do.


There is nothing to worry about. There are a zillion threads on here about people getting 1280x720 fine. Nobody has ever not been able to do it with an ATI card. The problem is, there is some review out there at some high-profile projector site that claims 1024x768 is the highest res, so people keep getting paranoid about it.

 

[jschefdog]

Thanks to everyone who replied. We seem to be getting contradictory responses. Widescreen review says you can get "Pixel Perfect" mapping. Krobar says you can't avoid the internal scaler except for THRO mode and that affects image quality. Jeraden says you can get 1 to 1 mapping in Anomorphic mode.


It sounds like you can definitely feed a 1280x720 signal to DVI in Anamorphic mode and get a properly sized image with no black bars, overscan, or lost pixels. The only debate seems to be whether or not is it going through the internal scaler and thereby degrading the image in some way. I think there are test patterns that can be used to verify whether or not a PJ is providing true 1 to 1 pixel pass through, or is processing the signal in the internal scaler. I remember an article in SGHT on this topic. I may have it at home, I will have to look for it. I assume that Widescreen Review used some type of test to verify "Pixel Perfect". They seem to know what they're doing.


I did find this thread in the HTPC forum which may be of some help. It contains links to some bitmap files that can be loaded into a PC to test the pixel mapping. Maybe someone who has the PE8700 and a HTPC can try these and put this question to rest once and for all.

 

[paris401]

ok.. here is a stupid question from a 'newbie'


i just bought a 7205. the receiver will be a harmon k. 7200, a phillips 963 dvd. i have a new dell computer model 8300, with the best video card .


why would i hook up the computer to the pj ?? i do not plan on using the pj for games, only for dvd's and hd-sports (about 50/50)


am i missing something..


thanks in advance

 

[Jeraden]

Some people like to do a bunch of other things with their PC, like turning it into a PVR, using it for music, high-def cards, ripping DVDs and storing them on HD for easier playback, etc.


For just DVDs, its probably a bit of overkill, but you can get the best picture via a PC outputing over DVI and using a software DVD player with FFDShow for some extra fine-tuning of the picture. Thats really all I'm using my HTPC for right now. I don't know anything about the 963, but you probably aren't going to get optimal image quality with it. Your best bet would probably be a Momitsu V880 dvd player, which will scale the image up to your projectors native resolution and output over DVI. It will make quite a noticeable improvement. Using a PC, you can make it even better.


I don't think many people really play games on their projector. I'm sure there are some, but personally I don't think its a very good atmosphere for gaming.

 

[Krobar]

Quote:

Originally posted by Jeraden I hate when this same question comes up repeatedly. Benq claims it only does 1024x768. THIS IS NOT TRUE. It does 1280x720 perfectly fine, as long as you are using an ATI card. Perhaps they say its not supported because it doesn't work through Nvidia cards, at least I couldn't get it to work with mine and a couple others couldn't either. Forget about THRO mode, it doesn't matter. Just stick it in anamorphic or letterbox and you'll get 1:1 mapping. There is no stretching or lost pixels or anything. I don't understand why this keeps getting brought up. It's a non-issue. Who cares if THRO mode doesn't display it correctly, use one of the other modes that do. There is nothing to worry about. There are a zillion threads on here about people getting 1280x720 fine. Nobody has ever not been able to do it with an ATI card. The problem is, there is some review out there at some high-profile projector site that claims 1024x768 is the highest res, so people keep getting paranoid about it.

1280*720 will always work in anamprohpic mode (Nvidia, ATI or most scaling DVD players). You can see line crawl with test patterns though and hence it is NOT 1:1 MAPPING, this has been confirmed by Benq. The projector is running at native res but the OPlus internal scaler is enabled and cetering and messing with the input. People think that 1:1 mapping and native res are the same, they are not. The Letterbox mode zooms the picture and anyone can see it hence is not running 1:1.

 

[Krobar]

Quote:

Originally posted by StevenH I have emails & calls in to BenQ regarding this issue - none of which have been returned. I had hoped for better pre-sale customer support from them. I would like to feed the pj 1280x720 from a PC via DVI and also from a HiDef Tivo via DVI at 720p and 1080i. So, I guess what I'm curious about is the following: 1. If a 1280x720 signal is sent to the PE8700 via the DVI input and ANA is selected what happens? Is there any down/up scaling involved? 2. Same as (1) but THRO pushed 3. If a 1024x768 signal is sent to the PE8700 via the DVI input and ANA is selected what happens? Is there any down/up scaling involved? 4. Same as (3) but THRO pushed Steven

1) Full Panel used, a nice picture but not 1:1 mapping.


2) Compressed to 4:3 not useable.


3) Stretched to full panel, and slight vertical dowscaling. Fills the screen,


4) 4:3 format, down scaled vertical res to 960, further proof that Thro mode is not behaving as it should.


I will hopefully be speaking to Benqs top guy (In the USA anywayz) on this subject on Tuesday. I will report back any findings in this thread. I also have a list of resolutions and timings supported by the Benq and have tried all three 720P ones, Thro mode still misbehaves.


Firmware is user upgradeable.

 

[Jeraden]

I've toggled between letterbox and anamorphic and can detect no change in the picture via 1280x720 dvi. I usually just leave it in anamorphic though. I threw a variety of test patterns at it a long time ago, and I can't see any evidence of it not being 1:1. Do you have a test pattern that clearly shows that its not 1:1?


When I had the panasonic l300u, on that one you couldn't get 1:1 mapping, and it was clearly evident whenever text was on the screen. I've never seen the slightest evidence of any kind of scaling on the 8700 and I have 200 hours on the unit now.


And as far as BenQ confirming anything, I don't really place much faith in any thing they say since they claim you can't do 1280x720 at all through dvi.

 

[jschefdog]

I found the SGHT article on "Pixel Perfection" written by Patrick Megenity in the Dec 2001 issue. The attached ZIP file contains a bitmap which is a 1x1 checkerboard pattern of black and white pixels. If you set this bitmap as your desktop wallpaper (Position center) and don't see any sort of interference bands or random noise, then supposedly you have achieved Pixel Perfect display. You could probably open it in Paint as well, or any graphics viewer which displays the image at full size.


The article was written before DVI and talks about how to adjust the pixel clock and phase control on the analog VGA input to match your HTPCs output and eliminate the interference bands and noise. I don't have a digital PJ yet, but tried it on my LCD monitor using the VGA input. It did indeed show interference patterns until I did some tweaking. After that it looked like a sharp checkerboard of black and white pixels.

 

1280_720 pixel perfect test pattern.zip 7.5517578125k . file

 

[Krobar]

I dont use an HTPC so that pattern will be difficult for me. I have actually achieved Widescreen 1:1 mapping in Thro mode at 480P. Normally when you feed the Benq 480 it reports DVI(525P) and displays it in 4:3. With the correct timings it reports DVI(525P-R) and displays in widescreen. I believe the Benq isnt 1:1 mapping because it isnt as sharp as clear as the 525P-R setting and if you add say 20 pixels to the height or width of the image it incorporates them all and does not crop any (It down scales while still reporting 1280*720*Refresh-D).

 

[jschefdog]

Quote:

Originally posted by Krobar I have been doing extensive work with the Benq and an external scaler recently... You can see line crawl with test patterns though and hence it is NOT 1:1 MAPPING, this has been confirmed by Ben... I dont use an HTPC so that pattern will be difficult for me...

Is it possible that the problems you are seeing are coming from the external scaler? Can you provide some details on your hardware and test methods? Does your PE8700 have the latest firmware?


I'm wondering if this problem is unique to your setup. In all the research I have done, this is the only report I've found of an issue with feeding 1280x720 to the DVI input on the PE8700.

 

[jdiehl]

Quote:

Originally posted by Jeraden I don't think many people really play games on their projector. I'm sure there are some, but personally I don't think its a very good atmosphere for gaming.

Can I ask what you are basing that opinion on?

 

[Krobar]

I dont think the issues are with the scaler it can achieve 1:1 mapping on my TFT screen at 1024*768. My Benq is running V1.04. Im gonna wait and see if I can get any info from Benq tomorrow and will post more details then.