8mm Forum: GS1200 Brightness vers 1 and 2

This is topic GS1200 Brightness vers 1 and 2 in forum 8mm Forum at 8mm Forum.

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Posted by Paul Adsett (Member # 25) on September 10, 2019, 08:33 AM:

I have done a comparison of the screen illumination of my GS1200 version 1 versus the version 2 machines. I have no measurements, just based on observation of screen brightness using the same ESC lamp and the same Elmo f1.0 lens. Both machines have 2-blade shutters. I measured the running lamp voltage on both machines and the version 1 was 23.9 volts and the version 2 was 24.1 volts. Despite the slightly higher lamp voltage on the version 2 machine, IMO there is no doubt that the version 1 is significantly brighter and whiter than the later version 2. I know that the gate aperture of the version 1 machine is larger than the later version 2/3 but it is hard to believe that this makes such a noticeable difference in screen brightness.
So I actually prefer the version 1. It's quite a bit brighter plus it projects more of the actual super 8 frame area.

Posted by Maurice Leakey (Member # 916) on September 10, 2019, 10:22 AM:

Paul
How does a GS-1200 owner know what version he owns?
By serial number, perhaps?

Posted by Paul Adsett (Member # 25) on September 10, 2019, 11:02 AM:

Maurice, the version 1 has a forward facing loop below the gate, and the version 2 or 3 has a rear facing loop below the gate.
.

Posted by Pierre Mdihi (Member # 6808) on September 10, 2019, 01:39 PM:

Hi maurice,

Here a picture of a old model:

the loop former knob is pointing towards the front so it's a older model. If pointing towards the back its the newer model

Posted by Leon Norris (Member # 3151) on September 10, 2019, 02:26 PM:

My choice is the newer model! And that's because you can modifie it! You can't do that with the older version! Plus Elmo changed a few things. To me I did not see a difference in light! But if you want more light just file the aperture plate window with a diamond file! The bigger the window the more light you will get!plus the older model did not handle splices well. And the rewind is sluggish. It had the 2-3 volt motors. The newer model had the 5-6 volt motors! Plus the newer model can take the large arms that hold the 2400 ft reels! And you can speed up the rewind and takeup functions! You can't do that with the older models! I fully recommen the newer model! Much better!

Posted by Paul Adsett (Member # 25) on September 10, 2019, 07:17 PM:

Well Leon is the expert on the GS1200, and I totally agree with all the plus points of the newer version that he has listed. But I do like the better light output of the version 1 which I experience, at least on my particular machines.

Posted by Thomas Knappstein (Member # 6134) on October 05, 2019, 07:00 AM:

The Difference in Brightness between two or three GS 1200 Projectors I have found in the fixing of the Halogen Lamp in the Mirror. The Focus of this Lamps was not exactly the same over 10 Lamps. A Difference of 0,5mm you can see on the Screen in less brightnes.
So I have cut of an old Mirror and stick a 250W Halogen Lamp in wich I can move forward and back. So I can focus exactly the max. Brightness. I also need an external Transformer for this Lamp but I never will go back to the old fixed Cold Mirror Lamps.

Posted by Adrian Winchester (Member # 248) on October 05, 2019, 08:05 AM:

Paul - I'd have no wish to argue with your finding, but lamps can vary in quality and get dimmer with age, so you could possibly test your observation by switching the lamps round and checking the result seems the same.

I'm curious about version one showing more of the frame. Do you notice a small(?) difference on all sides of the frame. More height would certainly be good when viewing scope films.

Posted by Paul Adsett (Member # 25) on October 05, 2019, 10:54 AM:

Hi Adrian,
My comparison tests were done using the same lamp. I have no scientific measurements except that my version 1 machine just looks brighter.
The picture area difference is significant, at least on my machines. Predominantly it seems to be a height difference with the version 1 machine aperture sitting very close to the frame lines, wheres the version 2 seems to have more overlap to the frame lines. This can be a disadvantage as you have to make more framing adjustments. Perhaps the perceived brightness increase of the version 1 is related to the larger aperture. or as Thomas has eluded - the exact position of the lamp.

Posted by Osi Osgood (Member # 424) on October 09, 2019, 09:44 AM:

I have only messed with a few ELMO's and i don't know if this would help, but one time I would have sword when projecting film that the screen seemed ever so slightly dim ... not as bright as on other days.

I was thinking that, like some lamps, when they are about to expire, the lamp starts to "dim" a little.

After reel one I opened up the projector and noticed that, somehow, the projector lamp had gotten ever so slightly out of position. In other words, the lamp wasn't pointed perfectly "forward" (best word I can use), and so the full impact of the lamp wasn't being seen on screen. i let it cool down just a little, took that metal "holder" off the lamp, re-positioned it, put that metal brace back in place, lit her back up and behold, bright projection again.

I don't know if that helps, in this particular situation; but sometimes it can be just such a simple thing as that. [Smile]

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