Epson TW10 (Home 10)

[Rik Wang]

There is obviously some magic number of horizontal pixels the projector wants to receive, but what is it? The 640x480 timing you supplied uses 848 total pixels, which is what I used for 720x480, and why it sync'd. But 848 is obviously not THE magic number.

Try this:
720x480=720,32,56,32,480,48,2,11,34083,7

[intinig]

I'll let you know about this one. Meanwhile what do you think of an 848x480 with total number equal to the 720p I posted earlier?

[intinig]

I tried the resolution you gave me, but it's overscanned . Then I tried reducing 8px at time the horizontal total number but it kept overscanning as soon the projector went "on tracking" (please correct me if this term is wrong).

So I thought the horizontal total wasn't the way to go. What mattered me was that it kept saying 640x480 in the info window of the projector. Maybe it was the vertical resolution that mattered so I increased the vertical total until I hit 750 (720p total number) and boom, the image completely changed.

Now it was much much smaller, a little rectangle in the center of the screen, and the info window in the projector menu said 960x720. It was obviously rendering our 720x480 in a 960x720 window and then scaling it down to 854x480.

This one still isn't usable but I hope I gave you good directions to find the ultimate solution

[intinig]

After another two days spent playing with powerstrip, the only plausible conclusion is that it's impossible to bypass tw10's internal scaler.

The TW10 has only 3 accepter video modes: 640x480, 800x600 and 960x720. Every resolution is scaled up or down to match these three and then it is scaled to fit the 854x480 matrix

I e-mail epson asking for more info, but until they tell me otherwise I fear it isn't possible a 1:1 mapping on the TW10.

[Rik Wang]

If you can get a Linux modeline from Epson for the native, one-to-one pixel mapping resolution, that's all you need. They only provide the total number of lines needed (525), but don't say if that is native or scaled...

[intinig]

Hi again Rik. So you say it is actually possible to do a 1:1 mapping on the  tw10 and that I don't have to give up?

[intinig]

Rik, if Epson won't give me the linux modeline, is there a way to find it through experimentation?

[Rik Wang]

Well, there has to be a perfect 1:1 pixel mapping - this is the resolution all others are scaled to. Its listed as 854x480 for active resolution, but they do not say what the total values are, and the totals are what really matter.

[intinig]

This is the first answer I got from Epson, looks really like an automated one

Thank you for taking the time to contact Epson.  It is my pleasure to
respond to your inquiry.

Unfortunately there is no way to get around the way the projector will
project the image on the screen.

If you require further assistance with this particular issue, please ensure
all of our previous correspondence is contained in your reply, so we can
better track the history of this issue.

If you have a different technical support issue, please submit another
E-form via our website (http://www.epson.com), and we will respond in a
timely manner.  Thank you again for contacting Epson.

My question was this one:

Is there a way to give the projector a pixel perfect (854x480) resolution?

Looks like it isn''t possible. No matter how many horizontal pixels I give
it,
it always use a 640x480 resolutions and scales down horizontally.

If I increase the vertical res instead it switches to another number of
lines
and accepts wider resolutions.

The problem is that I actually want to bypass the projector''s internal
scaler
and I still can''t find a way to do it?

Can you help me?

BTW what I think it does is checking against vertical res and then scaling to the nearest one among the resolution it supports. And for 480 lines it scales to 640x480. Do you think this is possible?

[Rik Wang]

Yes - I think that's exactly what happens.

[intinig]

That means it could be impossible to map 1:1, no matter what, right?

[Rik Wang]

Well no - I think there must be a magic horizontal and vertical total that the Epson wants. Even if the scaler intercedes, it would scale this signal to itself (so to speak).

But if Epson won't tell you what the numbers are, the only way to get it is by experimentation.

[Anonymous]

Rik you don't know how your last message made me feel better
I was cursing at Epson since their last response. I'm waiting for another reply to my e-mail then I will start experimenting like mad.

[intinig]

Epson latest email:

The projector has the built in resolution which cannot be changed.  If you
connect the unit to a computer, you can adjust the computer resolution but
then the projector and computer may not be in sync which can result in an
improper projection.  Unfortunately, there is no way around this.

And my reply:

I know the builtin resolution cannot be changed. What I want to know is the total number of pixels (not active, but the sum of active + front porch + back porch + sync porch) for horizontal and vertical to use so that

1) The pc and projector are in sync
2) The internal scaler doesn't scale

This should exist because this is the resolution the projector checks against before scaling. I would like to know this info because I have complete control over my computer output and I can change every frequency to match what the projector needs.

[intinig]

Last (hopefully) Epson e-mail:

To know the total amount of pixels you must do the following

Take the projectors resolution 854x480 and multiply it by three (409920x3).
>From there you will get the total pixels. In addition I have some other
information that may be important.

1. Effective scanning frequency ( your computer must fall in this range)

Horizontal - 15KHz to 92KHz
Verticle - 50Hz to 85Hz

Pixel Clock - 13.5MHz to 162MHz

This is all the information we have available. The rest is information that
we are not privy to. Hope this helps resolve your issue.

I think they won't give me any other info, and I hope this is enough to understand what to do