Film-Tech Forum ARCHIVE: Centering Lens on Barco

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Posted by Carsten Kurz (Member # 5396) on 11-11-2017, 07:37 AM:

Is there an easy way to center a lens on a Barco (DP2K-6E)? We set this machine up in various locations, and in order to have the best electronic adjustment range for L/R and T/B, I would like to start physical machine adjustment while the lens is centered.
I know I could try to do a full movement run through all directions and count/measure the lens position, then create a 'lens centered' lens file - but is there an easier, more direct way I missed in Communicator?

- Carsten

Posted by Marco Giustini (Member # 4544) on 11-11-2017, 11:15 AM:

Not that I am aware of.

Another way to confirm the lens is centered is to zoom in and out with a crosshatch: the cross must not shift left/right when you operate the zoom.

Posted by Dave Macaulay (Member # 813) on 11-11-2017, 01:29 PM:

Project a pattern and look at the light on the front element of the lens, it will be centred when the lens shift is centred. You can use a piece of paper against the lens barrel and a dark pattern like red if you can't tell from looking at the glass.

Posted by Sean McKinnon (Member # 612) on 11-12-2017, 05:58 PM:

My opinion is it is a good idea to perform the lens home function when you remove and replace the lens so that you are sure the lens hasn't been damaged and you know the mechanical limits are recorded properly.

Posted by Steve Guttag (Member # 268) on 11-12-2017, 06:22 PM:

Sean, the home/return is something completely different entirely.

If the installer does a home/return on installation, the projector has effectively learned where 0,0 is for position, focus, and zoom. Thus, if the lens has been handled in any manner (causing gears to no longer be biased as they were or the lens mount shoved one way or another), rehoming/return should bring everything back to the day-1 setting. Anytime the lens is handled, it should be done. I have found that it is best to not only do it when you first put the lens in, but when you find what positions are going to be for your theatre, to do it again so that the numbers are most accurate where you will be setting the lens.

To the best of my knowledge, Barco has no "center" mode and the techniques listed above will get one in the ballpark. I've tended to use the one by just looking at the front of the lens with a full-white (unmasked) and put the rectangle in the middle.

Posted by Leo Enticknap (Member # 534) on 11-12-2017, 09:42 PM:

That's the way I do it, too - look for the reflection of the white test pattern in the front element of the lens, and then operate the motorized lens shift as necessary to get it in the middle.

Incidentally, at the Barco "101" Series 2 installation training school, you are instructed to do a home and return as a mandatory procedure immediately after every time you insert and latch a lens. It's on the installation checklist in the booklet handed out to the class, and you'll lose a mark if you forget to do it in the test.

Posted by Sean McKinnon (Member # 612) on 11-15-2017, 05:41 PM:

Your right Steve I was unclear in my post. My understanding is that the lens home and return will bring the lens from where it is to the limit switches and then return back to where it was so you are absolutely correct in that it does not center the lens. What it does do is properly record the position and number of steps available and records a known reference point. I am Sorry for any confusion! [Eek!]

Posted by Svjetlana Oppen (Member # 9624) on 12-19-2017, 01:21 PM:

Hi, does anyone know default login on Barco Web Communicator? I have to switch the lens and perform lens homing but the company that sold us the projector is not responding to this question. Any help or advice would be appreciated.

Posted by Dave Macaulay (Member # 813) on 12-21-2017, 10:00 PM:

Svetlana - who are you calling? This is not "a secret" and we will answer any requests from customers.
Forum rules prohibit posting passwords here.

Check your messages.