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Discussion Starter · #1 ·
I bought a used G10 about 1.5 years ago, and have been enjoying it ever since. The lamp counter said 250 when I got it, but who knows how many hours were really on it. I'm somewhere in the 600s now.


Lately I'm beginning to think that I need a bit more brightness. Most likely due to watching football in the dark. Without any other frame of reference, I have no idea what I am missing, but I'd rather not plunk down $600 bucks to see if I get an marked improvement.


Was wondering if some kind soul with a G10 or G1000 and Dilard, could do a quick test for me. The contrast measurement test displays a unitless brightness level when it is finished. If someone with a relatively new bulb could run this test with the sensor at about 5ft away from the lens, we could compare numbers and see if I'm in the ballpark. Last time I calibrated, I think my brightness was somewhere around 100, but I'll have try it again.



Thanks,


jp
 

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I just calibrated my G-10 with a 500 watt atlas bulb with 800 hours on it. From about 4.5 feet with the panamorph and 20M filter on it I get a brightness of 395 and a CR of 950. The readings will vary depending on how far away you are and if you have a lense in front too. But 100 for brightness sounds low to me. I don't recall having any numbers that low. I think 150 i the lowest I have seen on my projector. Hopefully someone else can verify the numbers.
 

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Discussion Starter · #4 ·
Hmm. You've got a Panomorph, and I have an ISCOII. So, disregarding light loss through the lens, the following should all be equivalent.


Panomorph @ 4.5ft

395


no addon lens @ 4.5ft

296 (395 / 1.33)


ISCOII @ 4.5ft

223 (296 / 1.33)



I'm also using a 20M filter, so at a brightness of 100 it appears that my bulb is putting out less than half of what yours is. Maybe even less since the ISCO is supposed to be better at % transmission of light than the Pano.


Thanks alot for the info. Hopefully some other kind soul can provide another brightness value to verify this.


Have you had any issues with the extra heat generated by the 500W bulb, or did you do the voltage modification to tame it a little bit?


-jp
 

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No heat issues withthe 500 watt atlas and I did not do any internal adjustments with the power supply. Just plugged it in and that is it. However @ 800 hours it is having a hard time to light like it was over 1200 hours on my JVC lamp. The amount of light has dropped off a bit but still a good picture brightness. In fact, I think my contrast is a bit better.
 

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jp


maybe I am missing something...


Both will have transmission losses, but the panamorph compresses the height of the image, and the ISCO spreads teh image out sideways.


I am thinking that your ISCO might have been throwing a larger image at that same distance, which wqould make its reading lower, even if your bulb were the same brightness.


Adjusting both the setups to the same image size might make a better comparison than measuring at a set distance?


Best Regards,

Doug
 

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Discussion Starter · #7 ·
Doug,


I just reread my posts, and yes I did miss something quite important. My math only works for a given throw ratio (zoom setting). The problem is, when calibrating with Dilard, the sensor doesn't get setup at the screen, but at around 5ft from the lens. So even if image sizes are the same, I still need to know where the reading was taken.


So, if anyone out there wants to help out, please provide, your brightness reading, distance between sensor and lens, throw distance, and screen width.


-jp
 
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