CurtPalme.com Home Theater Forum

wassup30 · Joined: 14 Jun 2017 Posts: 30

So I've gotten my Sony G90 to (I'm guessing) about 70% of the picture quality you can get out of these things and can't help but wonder what it would look like if someone who knew what they were doing came along (for a price of course) and calibrated this bad boy.

Does anyone still do this?

jbmeyer13 · Joined: 03 Dec 2010 Posts: 1135

**kal** · Posted: Thu Jun 15, 2017 4:47 pm Post subject:

Mention your location too as there may be others willing to help. DIY with our guide is also an option to consider:

http://www.curtpalme.com/forum/viewtopic.php?t=35322

Welcome to the forum and good luck!

Kal

wassup30 · Joined: 14 Jun 2017 Posts: 30

I'm located in Winnipeg, Manitoba, Canada. I've gone thru the guide and Sony service manuals but can't quite get the projector to focus correctly.

**kal** · Posted: Thu Jun 15, 2017 5:17 pm Post subject:

Ah! If you're having focus issues that's not really what most would call calibration. Focus is part of initial setup which includes things like physical positioning, geometry, focus, convergence, etc.

Once you get that dialed in you use a specialized smeter and calibration software to do greyscale/gamma/colour. This is the link I provided above. (Before someone else mentions it, yes, defocusing blue is usually done for better greyscale tracking but that's still something I'd consider separate from the initial projector setup and is probably not what you're referring to).

So I take it you're looking for help with all of the above?

Kal

wassup30 · Joined: 14 Jun 2017 Posts: 30

yup help with everything pretty much. I mean I have converged it and am watching movies on there but I feel like it's no where near what it could be.

**kal** · Posted: Thu Jun 15, 2017 5:25 pm Post subject:

Got it - so you're looking for help from the ground up. Hopefully some others can chime in.

Is the projector ceiling mounted? On a mount with which you can slide the projector closer/farther from the screen? Usually the first thing someone wants to do is move the projector closer to the screen as the manufacturer installation guides are sub-optimal. How much tube wear is there? What are the hours?

Kal

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Do you know how to get into the expert and service modes? I'm guessing yes, since you can converge it.

The basic process for getting best focus, or at least the way I do it, is to start with the green tube,
cutoff red and blue, hit MG focus, bring up a grid pattern, and defocus green so that the grid pattern is blurry.
Switch to the dot pattern.

When you defocus, the direction you move focus in determines if the dots will become rings, or if they will become
round blobs with a bright center.

Turn the contrast up to make the shape of the dots clear to the eye.
Work your way down from the 2P to the 6P adjustments, with the idea being that the dots need to be made
into clearly defined round blobs with a bright center at one extreme of focus, and at the other, clearly defined
round rings.

Go through the 2P to 6P adjustments at least twice, in order, just to be sure you got it right, and then, switch to the
E pattern and adjust the focus adjustment on the top of the list for sharpest central focus. Adjust mechanical focus here,
too, if you have not already done so.

Repeat the process in every convergence zone so all the corners are sharp.

Now switch back to the grid pattern and now you will check the scheimpflug adjustment. Go back into MG focus,
and make a note of your focus value. Defocus and look at the width of the grid lines, both horizontally and vertically.
If they are not of uniform width, you may need to adjust scheimpflug (the two hex bolts above each lens) using the wrench
that is stored under the lens hood. Adjust both horizontal and vertical scheimpflug so that the grid lines are of equal width, top to bottom and side to side. Readjust focus to its sharpest value when done.

I've found that looking at the defocused width of the grid lines is the most reliable, and easiest, way to determine if
scheimpflug is adjusted correctly. It's easier when the image is out of focus than when it's sharply focused.

Repeat the process for the red and blue tubes.

Remember to bring the contrast down when you don't NEED it to be that bright to see the shape of the dots in the dot test pattern.

wassup30 · Joined: 14 Jun 2017 Posts: 30

wassup30 · Joined: 14 Jun 2017 Posts: 30

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Depending on whether or not the old Dallas chip was copied over to the new one, the timer hours may not have been reset.

When I do a Dallas chip replacement, I have the old chip copied to a new one. This preserves ALL settings, serial number, hours timers, everything.

I do not know if Curt also does that.

Use whatever mode gives you the most control. Set that projector up as far as it CAN be set up. All adjustments in every zone. Only then do you really get the full impact of its picture quality.

wassup30 · Joined: 14 Jun 2017 Posts: 30

**kal** · Posted: Mon Jun 19, 2017 9:17 pm Post subject:

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

What is the distance, across the floor, from the face of the green lens to the screen?

What is the width of your screen?

Normally a G90 has HD10F lenses on it. Are these your lenses?

jeffslife · Joined: 17 Apr 2010 Posts: 4181 Location: ohio usa

Call Craig Rounds. What he can make a pj do is nothing short of amazing. Its been a few years now since Craig calibrated mine all I have done since is a couple quick zone touch ups. I watch mine every day. Worth every cent. It looks like film. I haven't seen a digital that looks like film yet. As an added bonus you get to meet Craig. A great guy.

wassup30 · Joined: 14 Jun 2017 Posts: 30

wassup30 · Joined: 14 Jun 2017 Posts: 30

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Yeah, your setup is good, distance to screen width is pretty much what the book says.

I run a 10 foot distance for an 8 foot screen. (120 distance across the floor, 96" wide screen) and this does a good
job of filling the tube face. You have a little longer throw but the difference is only a few inches and that just means your corner focus should be slightly sharper. Corner focus suffers the closer you get to the edge of the tube face.

wassup30 · Joined: 14 Jun 2017 Posts: 30

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Probably a keystone limit. The closer to the screen the projector is, the more geometry adjustments are needed.