|
|
This topic comprises 7 pages: 1 2 3 4 5 6 7
|
|
Author
|
Topic: I get to see a carbon arc setup!
|
|
|
|
|
Monte L Fullmer
Film God
Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004
|
posted 07-07-2006 04:25 AM
2500w Xenons ususally run in the range of 80 to 95 amps with 27 to 32 volts.
The carbon arc equivalent would be the 9mm positive with the 8mm negative. Unfortunately, carbon arcs take more voltage to operate within the above DC current range - being into the mid 30's to low 40 volt range.
The efficency factor of a xenon bulb terribly outweighs the operation of carbon arcs in cost to operate in as well the cost of the rods themselves - be it in the past, or the present day.
The duration factor of a common 14inch rod (copper coated, non-rotation type of the 9mm positive above mentioned) would last approx. one hour run per rod.
Each box held 50 rods - both positive and negative rods .Thus, a box of positive rods would last 50 hrs with the one hour burn per rod. The negative rods would last three times as much and the negative rods were only 9 inches long.
There were 5 boxes in a case of carbons, or 250 rods. So, you do the math :
One case of positives would last 250 hrs (approx). Case cost (towards the end the golden age of carbon arcs) would hit the price around $175.00. - for the 9mm variety.
Now, you take that 250hrs per case on a duration of your 2500w xenon bulbs (which usually hits between the 650 to 750 dollar range), which a bulb can last a good 3000 plus hrs (if the cooling is good and good rectification), You'd come up with and avg, of 16 cases of positives to get your 3000 hour run with that one bulb.
Then,you take that 16 x 175.00 per each case of positives to equivalent the maximum that you would want to push a 2500w bulb, you have just spent on an average of $2800 bucks for the same amount of hours of light that just one $675.00 bulb cost and illumination.
(Now, wer're not even including power to run carbon arc - which was the basic reason in itself of the changeout from carbon arc to xenon....tons more effiency in power conservation with xenon..)
-Monte
| IP: Logged
|
|
|
|
|
|
|
|
Frank Angel
Film God
Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999
|
posted 07-08-2006 03:18 PM
I once read an article way back in the late 60's, maybe early 70s, comparing carbons and xenon in the very early days when they first started twining single screens. I believe it was either in Boxoffice or possibly International Projectionist, and along with stating all the characteristics of both in terms of light quality, spectral uniformity, etc., they had a graph which showed the operational cost-per-hour of each with the two plotted across a few years' time. I remember it showed that when xenon was first introduced, its operational cost was much higher per hour than carbons. The first couple of generations of xenon bulbs were much more expensive than they are today while carbons were much, much cheaper. Luckily for me, when I got my job in 1972, my first task was to convince them that we needed to install 70mm in a 2500 seat theatre (they only let me put in 35mm) and at that time I bought a huge cabinet full of carbons as part of the "package." I finally ran out of them only about 10 years ago. It wasn't any wisdom on my part....I had no idea carbons would skyrocket once xenons took hold, but there I was sitting on the gold of carbon futures!
According to the article, carbons back then were actually much cheaper to run than xenon. Somewhere around 1976 or so, the lines on the graph crossed and carbons became more and more expensive. Then, of course, even today, with carbons being much more expensive, the very first time that $1000 xenon explodes and takes the reflector out and you have to replace it, that pretty much screws up the whole xenon cost-to-operate equation big time. ![[Eek!]](eek.gif)
My contention is, that had the exhibition industry not been like drooling, lusting, ravenous dogs tearing at a piece of raw meat in rushing back then to convert any theatre they owned into a twin or triplex just so they could get a single projectionist to run multiple screens instead of one projectionist to run a single screen, I think R&D by lamphouse manufacturers would naturally have continued to improve on carbon arc technology so they could last as long as a feature length movie and with more servo feedback to control stability with little or no human intervention. Had that happened, xenon would not have its single most driving advantage: that of allowing automation, which in turn allowed multiplex operation.
Sure, new carbon technology might still have required to change rods after each show, but if you could teach an usher to thread a projector, you could teach him how to stick a rod in a holder. Refined, high-tech carbon arc lamphouses would could easily have been made to accomodate automation, if the industry wasn't so quick to want to run 30 screens and still pay a single salary.
| IP: Logged
|
|
|
|
Frank Angel
Film God
Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999
|
posted 07-09-2006 06:46 PM
Well, I am flattered that you would like to hear my work. I mostly have done local work and only occasionally over the years. I've done a few regionals, but that was years ago. The only recent national spot I worked on was for Geico (Geico before the gekko) but never got a copy of it. Believe me, the five lines I spoke in the :30 spot weren't all that, unless you like a Brooklyn accent, which was what they needed, so I was a shoe-in.
Recently I just narrated a 5 min promo: Brooklyn Center Gala of Stars. I think that might be going up on the website -- if not, I can have them put an .avi up in a private page so you can see (hear) it. It's boring.
But what is really cool, I will try to get my hands on a promo I did for a production of the opera, Der Freischütz, which I flubbed royally. But the great thing about it is that the producer who, like me, had never heard of the composer and didn't catch the mispronunciation. We did a series of 6 different cuts; in each one I gleefully call the composer Carl Maria von Web-er instead of Carl Maria von Vay-ber. The best thing is, it actually aired that way, gross mispronounciation big as life. I'll see if I can find it and up-load it.
In the meantime, if you are really hell-bent on hearing how well or how poorly (your call) I mask the Brooklyn accent when doing voice-overs, you can call the theatre -- I am the voice menu. Listen to the calendar of events 718-951-4600 prompt 5. But that's all uninteresting stuff. I am most proud of the Von Weber flub that got aired on the classical music station (at the time) WNCN. Seems everyone was asleep, either that or everyone stops listening when they hear Carl Maria. Everyone is going, "Whoe...the guy's name is Maria?!" ![[Big Grin]](biggrin.gif)
| IP: Logged
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
All times are Central (GMT -6:00)
|
This topic comprises 7 pages: 1 2 3 4 5 6 7
|
Powered by Infopop Corporation
UBB.classicTM
6.3.1.2
The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion
and agrees to release the authors from any and all liability.
|
Home
![[Wink]](wink.gif)
Printer-friendly view of this topic