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Got a RC-760!!!

Posted: Sun Jul 26, 2015 9:30 am
by precertvideo
Just received a Canon RC-760 from eBay. Seller had listed lenses separately so good job I spotted them. £225 for body, 6mm, 13~52mm & 50~150mm [Just got to find a 11~66mm now!]

The charger is 120 volt, presumably from the US which is a NTSC country, hence this;

It came with a few video floppies so I thought I'd try my player unit for the first time - Canon RV-321B UK model (PAL country) but all I get is organized static as if there is something on the disc but no chance of seeing it. This leads me to ask is this likely to be PAL/NTSC incompatibility which is something I never thought of before with still video cameras but I guess the clue is in the VIDEO name.

At least one of my cameras is marked NTSC, but the RC-760 isn't marked at all maybe as it does not contain a player (think some Mavicas do.)


Re: Got a RC-760!!!

Posted: Mon Jul 27, 2015 12:36 pm
by Stan Disbrow

Welcome to the wonderful world of television standards. Which used to be three, now there are dozens.

PAL is Phased Alternating Line, and is 25 frames per second sent as two sets of fields at 50 vertical fields per second. The fields will be all the odd numbered lines followed by all the even lines. There are 625 lines total. Horizontal sync is 15625 Hz.

NTSC is National Television Standards Committee and is 30 frames per second sent as two sets of fields at 60 vertical fields per second with 525 lines total. Horizontal sync is 15735 Hz. This is what we now call 480i in the modern High Definition era.

Notice that not all the lines, 625 or 525, are used for the actual video picture. This is why the 525 line NTSC is called out as 480 these days. The number of lines which actually carry video information. And the making up of a frame from alternating fields is also known as interlacing. Hence the 'i' vs. the 'p' (progressive, meaning the lines all follow each other) in the modern parlance. As in how you can set a modern DVD player to show a SD disc as 480p instead of 480i.

Anyway, back to the old standards. The 50 and 60 fields per second rate is derived from the AC power line frequency used where the standards come from. Power companies make sure their frequency is dead-on. So, by using a field rate which matches, there is the clock for synchronizing the signal.

Playing a 60 fps video disc signal on a 50 fps player will result in a bunch of noise which, as you note, shows some amount of organization. As will having the wrong display attached even if the disc and player match. Most modern displays have enough circuits to be able to resync to what is fed them, fortunately.

Oh, and the third old standard was SECAM, which was the French standard. The vertical and horizontal frequencies were the same for SECAM and PAL, but the colorburst frequencies were different. So, crossing them up shows a picture in B+W with some noise from the color information not being quite the same.

Also, there are three variants of PAL. PAL, PAL-N and PAL-M. PAL and PAL-N are almost the same but the colorburst and audio channel frequencies differ. PAL-M changes to 60 fields per second to make conversion of US video easier. So, you might be close with your PAL player if it can do PAL-M instead of PAL.


Re: Got a RC-760!!!

Posted: Sat Aug 01, 2015 7:08 am
by precertvideo
Thanks as always for your knowledge. I managed to get a Sony MVC-7000 working which has a built in player (NTSC) and a very twitchy eject switch. The MVC-5000 is only a recorder even though it has a video out.

The camera must have been used in a media college of some sort, lots of students & AV equipment, all looking very dated now of course so I'd guess they were taken in the early 1990s. Out of about 20 discs I couldn't guess where in the world they were taken, no discernible signs at all.

In one shot there is the distinctive rear shape of a DCS-100 so must be after 1991 (and they must have had some money!) They had a Kodak Professional banner up.

I was viewing them on a 42" plasma and the quality was really very good, great color & very good resolution. Easily equal to a still frame SVHS or shot-on-video DVD.


Re: Got a RC-760!!!

Posted: Sat Aug 15, 2015 8:22 pm
by NikonWeb
Nice. Enjoy!