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#1
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21CT55 is Alive and Well
My "Frankenstein" 21CT55 is now off life support and performs as good as original. The screen width is still too wide and has some video foldover that has to be tracked down and fixed. Also the chroma section is showing some color drift near the bottom of the screen occasionally. With 115vac mains, I am running B++ at 396v, boost at 790v, ultor at 27kv. Horiz system current measures 170ma at the fuse, therefore the HOT cathode is the same or less. Please lets not rehash this issue, OK!
I've been playing the "Wizard of Oz" DVD. Am very impressed with the near saturated (Lolly-Pop) screen colors. The screen looks much better than my digital cameras can capture. Seems the CTC2B video system and the 21FBP22A crt have greater brightness dynamic range then the camera's. If I run the camera's brightness down to get good pure whites (tablecloth, blouses etc) without blooming, I loose all low level dark detail in the shadows. The CRT has no problems with these scenes. I find this very disturbing and wish some VK members would drop by for direct viewing. Anyway, this ".....death" thread is no longer relevant and I intend to go back to my original "RCA 21CT55 #8802897 is Alive!" thread. I feel good about this...........Tom Last edited by Tomcomm; 03-26-2011 at 10:40 AM. |
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#2
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The limited dynamic range is something that plagues most digital cameras. I have done several exposures of the same scene, overexposing for shadow detail in one, underexposing for highlights in the other, and so on, and piecing the results together in photoshop. This happens a lot when trying to scan in old slides as well, particularly Kodachrome.
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#3
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Digital Camera Dynamic Range
My camera is an old 4mpix Canon S40, Judy's is a newer 7mpix Olympus SP-550UZ. They both have dynamic range considerably less than the 21CT55/21FBP22A screen display. I wouldn't want to resort to the heroics of Photo-shop enhancement to demonstrate this ancient CTV. Maybe it's a insurmountable problem. I shoot with ISO of 200 and 1/30 sec. usually F5.6.
The resolution is set for 1024 X 768 native so I don't have to scale it down for posting. Morie is not a big problem. Any suggestions..............Tom |
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