Video Projectors

A forum to share ideas and opinions on the equipment and technical aspects of film, video and AV making.
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Ken Wilson

Video Projectors

Post by Ken Wilson »

I may have mentioned this before either here or in FVM, but does anyone else
find it extremely annoying and frustrating when all video projectors seem
to be set up differently? I have tweaked my tv/monitor connected to the computer
set up so that it looks the same as our main tv. Colour corrections and brightness
are thus adjusted so that it all looks as even as possible. Given that video
generally has very poor tolerance (compared to film) for exposure variations
and (say) one stop over-exposure can look awful on tape, it is all a careful
balancing act to make the latest movie look it`s best. It is therefore annoying
when at shows, the projector being used has a colour cast or is too bright---
a common fault.
As I have used black and white video several times, colour casts, usually
green or magenta, make it look terrible. I was asked at one of our recent
shows, why I had not made one film pure black and white.
It did not go down too well when I told them that the colour cast was from
THEIR projector. In fact, there was a deathly hush!
Video has lots of advantages to film and I am enthusiastic about the possibilities
with it, but a lack of a "standard" is one of the drawbacks. Film did always
pretty much LOOK the same on whatever projector it was shown on; though sound
speed was another matter.

Ken, in a quest for perfection.
Dave Watterson

Re: Video Projectors

Post by Dave Watterson »

As BBC engineers will tell you, Ken, there ARE standards for colour projectors.
The problem is that people rarely take the trouble to set them up properly.
Most of us accept a very wide range of colour distortions on tv and projected
video.

Your home system is all balanced so that all the displays look alike ...
which is fine so long as they are all correct! You might have balanced them
all to a pinkish shade which your eyes don't recognise ... though I don't
believe a fine film maker like you has anything other than a fine colour
sense.

What we need is a DVD image of the 625-line test card!

An available alternative is the DVD "Avia Guide to Home Theater".

The DVD output is, in effect, the same as that which used to be generated
by very expensive signal generators, so it is very precise. The DVD has
detailed instructions on how to use its vast range of test patterns to set
up your system perfectly. The instructions are of the American "chummy" variety
but nonetheless comprehensive. The disc also covers setting up your surround
sound system too.

I just checked and it costs 37 dollars 38cents at amazon.com ... amazon.co.uk
do not list it. Think of it as a sophisticated electronic tool and the cost
seems fair.

Now all we have to do is encourage clubs and festival organisers to use such
tools to set up their machines. It needs to be checked whenever the projector
is used in a different venue because emergency lights and even wall colours
can tinge the image. Luckily many modern video projectors have memories
so you can store the perfect set-up for "hall A", "hall B" etc.

The brightness issue is a real problem. After years of trying to fill decent
size screens with underpowered 8mm projectors most of us rejoice in the oomph
now available. The truth is that many modern video projectors ought to be
used on a "gray" screen - i,e, one which reflects just 80% of the light or
thereby. Much depends on the ambient light levels in the venue.

Sympathies, Ken, because it must be amazingly frustrating to have to watch
work you have laboured over appearing distorted on someone else's unadjusted
projector.

Dave McLight Watterson
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