Technology

[Geoffrey Spencer]

About a decade ago,some of us(at South Bucks), had to fight for recognition that digital technology was a practical U3A necessity.
That fight was won, without note of the effects of the speed of technical change.
This matter now needs serious consideration, beginning with a reminder of when, and at what cost, we bought projectors, to compare with what is on the market now.
I lead with my chin to ensure that any adverse reaction finds me.
At our last Opera meeting,about 30 of us saw a performance, all apparently staged by candlelight. I came home, put on the same performance, (miraculously?} full of light and colour.
At all Arts showings, the speaker has to say that his laptop shows what he wants, but the big screen does not.
Why should anyone spend time preparing these travesties?
I have just updated the DVD recorder on which I have created about 500 discs over a decade. Not spelling out the detail, I think this purchase is THIRTY times a better buy than the old.
I see that Tesco Direct,{page 723}, sell an HDMI projector for £500. Don't we deserve one?
                                Geoff

[David P]

I agree that the results from our projectors are usually disappointing.  My experience with the Panasonic is that the results are usually acceptable (if not strictly accurate) but the Optoma (the fixed one in the Pottery Room) is a pig to get anywhere near right.  There are several reasons for this.

First, I'm afraid, the users:
- fiddle with the controls, usually making the situation worse for the next group of users
- when offered instruction sessions on the use of the equipment fail to turn up
- after the Optoma had been properly calibrated, manage to crash the laptop, thus losing that calibration.

Second, technical reasons:
- it is not possible to achieve a set-up where both the laptop screen and the projector are correct at the same time (unless you use a very expensive laptop with dual graphics cards)
- light leakage round the blinds in the Pottery Room (not sure about the Owen Room) severely reduces the contrast and apparent brightness of the screen
- the only way to ensure accurate reproduction is to use a proper calibration device to calibrate the computer/projector/screen combination together, and the to leave all adjustments fixed.

The problem is that all equipment varies.  A particular RGB value output to one projector will produce a slightly different colour from the same value sent to another.  Furthermore, the variations are not linear.  A calibration device accurately measures the actual colours output and produces a colour profile (a look up table) for the computer to correct the output values so that the correct colours are reproduced.

I borrowed a calibration device a couple of months ago and used it to calibrate the new laptop and Optoma.  The results were pretty good and consistent from one image to another.  Unfortunately, as I've said, that profile was lost when the laptop crashed and had to be rebuilt (and some groups continue to use the old laptop anyway).  I shall try to borrow the device again (can't promise when) and repeat the exercise on both projectors.  

All the above refers to the use of a laptop.  As far as I know there is no way of calibrating a projector with a DVD player, other than doing it by eye, which is never very accurate and tends to be inconsistent.

As for a new projector, all the above still applies though I would guess that newer models tend to be better 'out of the box'.  I'm not sure that HDMI would make a difference  (are you perhaps thinking of HD?).  

My guess (I could be wrong) is that your facilities at Beaconsfield have been properly calibrated, the adjustments are out of reach of the users and the hall is properly dark - makes a big difference.

Hope this starts to explain things.

Cheers,

[Geoffrey Spencer]

I have only just seen David's reply to my deliberate provocation.
I marvel at his dedication and patience against such odds.
All his endeavour is directed to producing good pictures and sound, and he deserves more reward than he gets, certainly at the Pottery Room
The undemanding tolerance of U3A members has always kept the brakes on technological advance.
We are fortunate at the Beacon Opera, but not through chance.  We had to find and pay for a proper theatre, where only the saintly Trevor handles the screen and projector, and I would never play the disc from a multi-purposed laptop.
I have sympathy with the Pottery presenters, which was why I raised the issue. If only the laptop OR the big screen can deliver proper pictures, the choice is obvious
(I must turn to compiling a disc for Chiltern Arts).            Geoff