RCA 21CT55 #8802897 is Dead

[Tomcomm]

Here are some later screen pics of the Ferris Day Off. The stitches are before and after FBX swap. Some are after vs Sony. With the exception of too much width, picture quality re facial color graduation and non-combfiltered fine detail, typical of my 21CT55 aka Frankenstein, has been restored. Following advice of this thread, I purchased at great expense DVD of Wizard of Oz and Blu-ray of Gone with the Wind ($10 and $12 respectively. I am now ready for the Lollipop Color of the original Technicolor. I hope I'm not disappointed………………Tom,

[stromberg6]

Looking real good Tom! Look forward to lolipop color screen shots on the old gem. 1938 "Robin Hood" is another good one for Technicolor, and I use it often with the 4.
Kevin

[Steve D.]

It's alive, Its alive! Tom you should change the title of this thread. Your 21-CT-55 is most certainly resuscitated.

-Steve D.

[zenithfan1]

Please pardon my language but that thing looks goddamn awesome! You really should change the name of the thread! That chick sitting on the bricks drinkin' coffee looks hot! (that's my type) The detail on the CTC 2B has much better detail too! It puts the Sony to shame!! Oh yeah, did I mention that chick's hot

[Tomcomm]

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

[leadlike]

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.

[Tomcomm]

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

[old_tv_nut]

Part of the problem is that cameras (digital or film) that produce pleasing pictures of natural scenes have a contrast boost in the mid tones, with a gradual S-curve compression of highlights and lowlights,compared to the original scene. TV systems have this contrast boost as well. The result when photographing the screen is a double contrast boost. The raw capture of a digital camera actually has enough dynamic range, so if you can capture in raw mode and reduce the contrast in Photoshop, you may get decent results.

There is one other problem that can occur (less so on color CRTs than monochrome) - if the CRT is resolving scanning lines with dark spaces in between, this means that the average level in an area (which the eye can see quite well) is made up of bright lines and dark spaces. Both film and digital cameras have a hard time accomodating that dynamic range. The actual video variation of the bright lines ends up compressed into the highlight region of the digital sensor or film when the average is correct. For best gray scale, the focus (either CRT or camera) needs to be just not so sharp that lines with spaces are visible. Some film recording systems used a vertical spot wobble at a high frequency to just make the bright lines touch each other. Your use of reduced resolution may help by averaging nearby pixels, but it may not be a cure if some of those pixels are overexposed and some are seeing black. An alternative is to underexpose the average, then blur the lines together precisely in Photoshop (by reducing resolution), and then boost the average back to normal. This problem is similar to taking pictures of stars at night. The system really can't handle the dynamic range, but a tiny bit of defocussing changes the brightness modulation somewhat into an area modulation (brighter stars light up bigger blobs of pixels) and gives the right final impression.

So, something to try:
Shoot at highest resolution, with exposure compensated down by at least one stop;
Then reduce the resolution to average the bright and dark adjacent pixels;
Finally, increase the levels to the correct average.

[ohohyodafarted]

Tom,

This is absolutely astounding!!! It goes to show that there are people here on VK that have a level of technical expertise that goes above and beyone anything that many of us "re-cap and refinish" restorers like myself, could possibly ever approach.

You have accomplished something that only very few on this forum could have even attempted.

Congratulations, you have my sincere admiration and respect for what you have accomplished!

[Tomcomm]

My screen shots are good, but when I view the actual screens of the 21CT55 and my comb-filtered Sonys I realize my two cameras don't do them justice. Leadike and Wayne have offered possible solutions to increase brightness dynamic range of the shots, Since I don't have Photoshop I've decided to try Wayne's suggestion of processing RAW format on both cameras. This seems daunting but worth the effort. As for Bob's reply, I am most humble. I consider him the primer restorer, both in cabinetry, electronics and CRT rebuild technology. All his projects are museum pieces, including his recent 21CT55, which gives me brief pangs of guilt for what I did to mine in '64. I'll attempt to make it up with some outstanding, RAW based screen shots from my " vertical chassis table model" 21CT55 conversion....Tom

[leadlike]

A cheaper software alternative to Photoshop is the freeware Gimp, which has a lot of pro features. Gimp works very well, it's main flaw (to me, anyway) is that the workflow is a bit clunky. That could be me just being too stuck in my ways with Photoshop, though.

[Tomcomm]

Always wondered how to get BIG pics posted on this forum:




Well that works but its no bigger than the regular VK forum, only 511 X 400 pixals. maybe thats the max size of Picture Trail's URLs...........Tom. So how did Bob G get his full page??

[miniman82]

He probably hosts them off-site.

[Phil Nelson]

It depends on how you link. Say that you have a picture stored on some other website. If you paste that URL into your message, you get a link that people can click to view the photo:

http://antiqueradio.org/art/Discovery.gif

If you enclose that URL in [IMG] [/IMG] tags, the photo shows up here in its native size, which may be big or small:



That's what results when you insert a photo using the Insert Image button at the top of the message editing box.

Displaying a super-giant photo in a message isn't a great idea. People with smaller screen resolution then have to scroll back and forth to read any text in messages on that page. For a very large photo, use the first method and give people a clickable link.

Phil Nelson

[Tomcomm]

Didn't work...........