Film-Tech Forum ARCHIVE: BARCO VIDEO PROJECTOR

This is topic BARCO VIDEO PROJECTOR in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Ian Bailey (Member # 1752) on 02-12-2004, 04:47 AM:

I have the chance to buy a Barco Reality 6500 video projector real cheap,not sure if it will suit my large auditorium with the lens it has.It has 4300 ansi-lumens light output and it has a 1.36-2;1 zoom lens.The large auditorium's screen is 29foot x 12 foot(C/S) and the throw is 56 feet,can anyone help.

Posted by John Anastasio (Member # 607) on 02-12-2004, 06:54 AM:

More information is needed here. Without knowing the other focal characteristics, just the zoom figure won't give you the size of the picture. Barco will specify a certain picture size over some distance, such as 96" at a 15' throw. Every Barco I've worked with that has a normal lens is designed for a distance no greater than around 20', but they do come with special lenses for longer throws, especially the high powered ones designed for theater use. Hopefully someone here on the forum has used the model you're asking about.

Posted by Bevan Wright (Member # 1884) on 02-12-2004, 07:12 AM:

For the various aspect ratios given your throw you will need the following lenses and will get 'approximately' the listed light levels...

Assuming you have side masking, projector is really putting out 4,300lm and your screen is 1.0 gain.

4:3
12x1.33= 16ft 56/16 = 3.5:1 lens.

4300/(12x16) = 22.39ft-l

16:9
12x1.77 = 21.32ft 56/21.32 = 2.63:1 lens

(4300/(12x21.32))x.75 = 12.6ft-l

1.85:1
12x1.85 = 22.2ft 56/22.2 = 2.52:1 lens

(4300/(12x22.2))x .72 = 11.62ft-l

You get the idea.

Typically the shorter focal length lenses (like the 1.36-2.0:1) are only 70% efficient in comparision to the 'standard' lenses (usually a 2.0-2.6:1 or similar). Also, real lumens are only 80% of 'marketing' lumens. For this brightness and vintage of projector (not sure how many hours it has on it) it should be <<$3k, IMO.

Posted by Ian Bailey (Member # 1752) on 02-12-2004, 09:17 AM:

Bevan-So I would need 2 different lens for 4:3 and 16:9 aspect ratios?This could prove an expensive toy to play with! One idea we had for the projector was to have Playstation competitions for the kids to help support local charities.

Posted by Bevan Wright (Member # 1884) on 02-12-2004, 02:10 PM:

Or get an anamorphic (which is likely to cost about the same). Not sure if the Barco has it but some LCDs let you store electronic zoom settings which is another option. Set your lens for 16:9 and digitally zoom (shrink) the image for 4:3 to ~576x766.