Focussing - Videokarma.org TV - Video

lnx64 · #1 03-21-2012, 11:02 PM

I started feeling my CRT wasn't in focus since switching over to the hybrid chassis, and rightfully so. I never did adjust the flyback for this CRT, and have no idea if the other TV it came out of even had the same CRT.

Well, when focussing, I went by my old trick, put on a dark grey raster, and focus until the scanlines are as sharp as they can look.

When done, I put the TV back together, and put on my SEGA Genesis, and was rather a-mazed at how well this thing looked.

http://img.photobucket.com/albums/v3...n/IMG_0202.jpg

Now, I remember someone telling me a long time ago, that making the focus as perfect as possible is not good for the health of the CRT or the flyback. I can't imagine this be true as it's just a focus. If it was the screen control then yes I'd understand, but not the focus..

I'm still amazed at how well it turned out. And here I thought the hybrid chassis was just "softer" but it actually can be better than the completely SS chassis.

Don Lindsly · #2 03-22-2012, 11:35 AM

Either there was more to the story or someone was misinformed. The set is designed to produce a fully focused picture.

lnx64 · #3 03-22-2012, 01:46 PM

That's what I thought. It wouldn't make sense otherwise.

lnx64 · #4 03-22-2012, 07:19 PM

Wow this almost looks like it's S-Video quality. It has some dot crawl so you know it's not, but for RF, this is damn good in my book..

http://img.photobucket.com/albums/v3...n/IMG_0208.jpg

old_tv_nut · #5 03-22-2012, 09:33 PM

That focus is good, but unfortunately it looks like there is quite a bit of line pairing also. Does this chassis have a vertical hold control? You could try tweaking it to see if the line pairing improves.

lnx64 · #6 03-22-2012, 10:02 PM

Quote:

Originally Posted by old_tv_nut

That focus is good, but unfortunately it looks like there is quite a bit of line pairing also. Does this chassis have a vertical hold control? You could try tweaking it to see if the line pairing improves.

It does have a vertical hold.

Line pairing, I'm new to this term. Maybe this explains this post?
http://www.videokarma.org/showthread.php?t=253775

lnx64 · #7 03-22-2012, 10:04 PM

On the original picture, of the SEGA game, it only has even fields played 60 times a second, there is no odd fields, so that one essentially is progressive scan, so it will have big scanlines.

As for the second picture of the cartoon network, that was regular interlaced.

ChrisW6ATV · #8 03-23-2012, 12:27 AM

Quote:

Originally Posted by lnx64

On the original picture, of the SEGA game, it only has even fields played 60 times a second, there is no odd fields, so that one essentially is progressive scan, so it will have big scanlines.

I never knew for sure which video-game console was the first to have interlaced video output. I know the Sony Playstation 2 does; so, the Sega Genesis does not, based on your description.

lnx64 · #9 03-23-2012, 12:40 AM

Correct, the Sega Genesis mainly did 240p progressive. It did have interlacing capabilities, but only one video game ever used it, Sonic 2 for it's 2-player mode.. PS1 uses 480i for it's boot screen and some games (like some versions of Tekkan).. PS2 is always interlaced unless a game says to not do it...

Oddly enough my SEGA does have a TV test pattern cartridge for it.. Not very useful though as it's chroma output stinks horribly.