CurtPalme.com Home Theater Forum

[jeffslife]

My pj is off level by 1/16 of an inch( 1.524 mm ) could this be why I am having trouble getting the T/L and B/R corners
to dial in?

[virusc]

electrical or optical?
How far off?
Are you running to the near outer edge of the tube face?
Is the screen square with the projector too? This will cause the same issue as the projector being off

[Curt Palme]

Not a chance Jeff. These CRT projectors are meant for all sorts of angles, and heck, even off axis projection if you're doing a stack. 1/15" will not throw anything like that off. You gotta post pix of what you're seeing, post a pix of your test grid so we can see what's going on.

[Curt Palme]

Not a chance Jeff. These CRT projectors are meant for all sorts of angles, and heck, even off axis projection if you're doing a stack. 1/15" will not throw anything like that off. You gotta post pix of what you're seeing, post a pix of your test grid so we can see what's going on.

[jeffslife]

ok here goes

[jeffslife]

I know the pic sucks, I took it with my BB.
I had red and blue outside of both corners
after redoing registration. Following the manual I went on to zone and corrected
most of it. But I know from previous posts how everyone feels about that.
I spent 3 hours trying to adjust it out with key and pin and got it
as good as I could before moving on to zone.

[jeffslife]

I know this sounds crazy but it was much worse last night.

[Curt Palme]

That's actually pretty good.

Looks like the bottom of the pix is pulled in a bit, can't you correct that with the green keystone control left and right?

[Curt Palme]

That's actually pretty good.

Looks like the bottom of the pix is pulled in a bit, can't you correct that with the green keystone control left and right?

[jeffslife]

I'll try and post the results tonite Gotta leave soon.
What is the best way to tell if the green is SQUARE
I am going by sight mostly, As my screen is big and the
edges are covered in black velvet it is hard to pick up an edge
to check squarenwss.

[jeffslife]

Reading my last question I know how dumb it sounds but
my screen is about 18 inches off the wall and if you put
anything up against it (like a square) it pushes in slightly
and everything changes.It is extremly difficult it check
the straightness of lines and get accurate measurements
for anything.All I have been doing is getting it as close as
I can And try to correct it with electronics. Not the best way
I'm sure.But I am at a loss on a better way.

[dvh99]

improve horizontal linearity first before doing convergence.
again use a testpattern disc and not the internal patterns.

[jeffslife]

VIRUSC, to anwser you questions as best I can
Yes the screen is parallel to the pj.
No the raster is not close to the tube edge.
I had red and blue about an inch outside those to corners
I dont know how to tell electrical from optical
I'm pretty dumb about this stuff and I am still
learning the terminology.

[garyfritz]

T/L and B/R corners... are you sure your Scheimpflug is done well? I.e. is this an electrical focus or optical focus issue??

You can stretch a thread across the screen -- maybe pin it to the borders? -- to get a straight line without touching the screen.

[jeffslife]

DVH99,
I downloaded a test pattern and burned it to disc off avs
but could not download the pdf to tell me how to use it.

GARY, the thread is a GREAT idea I will try that tonight
THANKS!

[AFryia]

[jeffslife]

AFRYIA,
I used key and pin balance.
Per the manual's directions.

[jeffslife]

picked up a bubble protractor angle is 8 degrees if that matters.

[dturco]

Jeff to check your screen build a TEE from a couple of 2x4 and use as a dog leg to hold the screen off of the wall.

Is your 8 degrees on top of the P/J's natural 15 degrees? or 23 in total? If 23 your nearing the edge of adjustment. I don't think 23 degrees is maxed but close.

[jeffslife]

DTURCO,
Even though the screen is 18 inches off the wall it is mounted to the wall with a crazy combo of
components that allow me to adjust it in any angle or direction to eliminate twist and ensure parallelism
and squareness to the pj. The screen itself is true to the pj. Its the image on the screen I am having a
problem measuring.It is stretched over a 2X4 frame and any pressure on it from the front distorts the
whole image making it extremely difficult to measure anything.

I dont know about the NATURAL 15 degrees. I didnt see anything about that in the manual.
What I did was place a bubble level on the machined edge on the left side and it showed
8 degrees. The pj is ceiling mounted and the back tilts downward. (8 degrees as far as I know)
So am I AT 23 ?
I really dont know for sure.
thanks

[dturco]

Jeff have you looked at this?

http://www.curtpalme.com/docs/SonyG70_Install.pdf

Also if the back of the G-70 is lower than the front your fighting the natural way the machine was designed. It was designed to be level on the ceiling or front pointing doward slightly.

So yes if your G-70 is firing towards the ceiling {back lower then front} you keystone will be harder to deal with.

Edit: I read up a little. Somewhere on like page 14 it shows the angles of range. Your within the adjustment range of the G-70 even though your fighting the neutral balance of the design.

[VideoGrabber]

Jeff,
> The pj is ceiling mounted and the back tilts downward. (8 degrees as far as I know) So am I AT 23 ? <

Nope. If the back is tilted down, then you subtract those 8-deg from the nominal 15 from the lens-to-chassis tilt. Leaving 7-deg. That will actually minimize keystoning adjustments needed, but will cause grief unless you compensate for it (it'll throw your lens-flapping off).