Help with scanner tuning

[2tall]

Hi everybody. It's been awhile since I've been on the forum. A little history. My first projector build was with the PT20 scanner set with Itrust showcard and a 400mw RGB China "brick". I am running Spaghetti on a winXP laptop with an Ishow DAC. Everything worked fine after some troubleshooting. THEN....I broke a mirror! So I replaced the mirror and had to retune the scanners. Here is where the problems start. I found a tutorial here on the forum and loaded up the ILDA test pattern. No matter what I do the test pattern always displays with the square INSIDE the circle. I managed to get very close to the displayed image. Since I mainly do beam shows this was not a big issue. I decided to hook everything up for the 4th of July. Fireworks and lasers just seem to go together. To my surprise the images displayed was full of dots. I know/assume this is a tuning issue. So my big question is should I retune to have the CIRCLE inside the square no matter what's on my computer screen? Mind you I have downloaded the test pattern numerous times but it always displays with the square inside the circle. I really need to know this as I am starting a new build somewhere around 1 watt analog RGB. This is nothing pro just home entertainment and knowledge. Thanks for any and all help and suggestions.

[colouredmirrorball]

IIRC the iShow DAC does some on-board interpolation so you can't use it to tune your scanners (the test frames need to be scanned as-is without any optimisation). Maybe Gary found a way around this. In any case make sure all optimisation settings are disabled in Spaghetti.
My suggestion is to ditch iShow (certainly for a 1 W RGB!)

[swamidog]

Hi everybody. It's been awhile since I've been on the forum. A little history. My first projector build was with the PT20 scanner set with Itrust showcard and a 400mw RGB China "brick". I am running Spaghetti on a winXP laptop with an Ishow DAC. Everything worked fine after some troubleshooting. THEN....I broke a mirror! So I replaced the mirror and had to retune the scanners. Here is where the problems start. I found a tutorial here on the forum and loaded up the ILDA test pattern. No matter what I do the test pattern always displays with the square INSIDE the circle. I managed to get very close to the displayed image. Since I mainly do beam shows this was not a big issue. I decided to hook everything up for the 4th of July. Fireworks and lasers just seem to go together. To my surprise the images displayed was full of dots. I know/assume this is a tuning issue. So my big question is should I retune to have the CIRCLE inside the square no matter what's on my computer screen? Mind you I have downloaded the test pattern numerous times but it always displays with the square inside the circle. I really need to know this as I am starting a new build somewhere around 1 watt analog RGB. This is nothing pro just home entertainment and knowledge. Thanks for any and all help and suggestions.

some pictures would be super helpful.

[buffo]

I am running Spaghetti on a winXP laptop with an Ishow DAC.

As coloredmirrorball mentioned, you can't tune your scanners properly using the Ishow software. It tries to optimize the frames before sending them to the DAC, and this breaks part of the ILDA test pattern. (Specifically, the center circle.)

No matter what I do the test pattern always displays with the square INSIDE the circle.

Yup. Ishow is down-sampling the points that make up that circle, which is why it appears smaller.

If you read through my tutorial, you'll see that the circle is actually made up of 12 points that are evenly spaced OUTSIDE the square. The scanners have no hope of ever reaching those points, and that's by design. The circle is designed to test the scanners when they are under continuous, maximum acceleration. That can only happen if they never get to where they're supposed to be going. (This is explained near the end of the tutorial.)

To my surprise the images displayed was full of dots. I know/assume this is a tuning issue.

That could be caused by quite a few problems, and tuning would not be one of the first things I would check.

Bad tuning can give you squiggles, tails, rounded corners, and other artifacts. Lots of dots sounds like a blanking issue, or possibly a phenomenon known as "jellybeaning", assuming you have at least one DPSS laser in the projector.

should I retune to have the CIRCLE inside the square no matter what's on my computer screen?

What you see on your computer screen is irrelevant. You want the circle to be touching the square in the image displayed by the laser projector. However, since you are using Ishow, you probably won't be able to tune your scanners properly due to the built-in frame optimization. (Unless someone has figured out a way to disable that somehow.?.)

I have downloaded the test pattern numerous times but it always displays with the square inside the circle.

As stated above, the circle is not a circle, but a series of 12 dots (they form a dodecagon) that are located well outside the square. (Well, technically it's 36 dots, since the shape is scanned 3 times in a row.) The thing to remember is that the image on your computer monitor is NOT what you want the laser-scanned image to look like. Look at the pictures in the tutorial linked above to see what the scanned image should look like.

Worst case, come to SELEM and bring your projector. We can connect it to another controller and tune the scanners properly for you.

Adam

[2tall]

Hey thanks for the quick response. I found out(the hard way)that the new version of Spaghetti no longer runs on win XP and I could not find a win 7 driver for the Ishow DAC. So it looks at the least I need to upgrade the DAC. I have looked at the RIYA lite but can't seem to find out who sells it. As far as tuning with what I have I guess I'll just get it as close as I can and live with it. Maybe one day I'll be able to get something like Quickshow lol. Thx again.

[2tall]

I'll see what I can do but don't hold your breath.

[2tall]

Thx for the response. I've only been at this for a couple of years on a limited basis. I have learned a lot but really just scratching the surface. The only reason I keep Ishow on my laptop is for the frames and the DAC driver. I only run Spaghetti. This may sound like a dumb question but should I remove the Ishow software and just keep the DAC driver?

[Bradfo69]

You're onlyin Georgia.... SELEM is basically about 16 hours a day for nearly 5 days, so, there is lots of opportunity. You WANT to find a way...

[JasonB]

2tall, I recommend getting the RIYA Lite DAC from JohnYaya's website; it pairs well with Spaghetti. fyi I also have an Ethernet Dream and LSX, and the RIYA performs just as well (for my setup, anyways; I'm not a pro and don't push my equipment to limit [yet]).

-Jason

[swamidog]

2tall, I recommend getting the RIYA Lite DAC from JohnYaya's website; it pairs well with Spaghetti. fyi I also have an Ethernet Dream and LSX, and the RIYA performs just as well (for my setup, anyways; I'm not a pro and don't push my equipment to limit [yet]).

-Jason

the riya lite dac is a great bargain. i still prefer etherdreams, but if money is tight, the riya is an excellent way to go.