15 pin D-sub connector V 5 BNC connector

highdef

OK, not much of a computer whizz kid. But was wondering if there is a marked improvement by using the 5 BNC connections for connecting the PC to a monitor rather than the standard monitor cable. The monitor is an Eizo 21" Flexscan CRT. Can't remember the model number as I'm on a different PC in work. I do a lot of video editing at a 1600 x 1200 resolution and was really just wondering if the BNC's would make a difference?

Stephen

Does your graphics card actually have those kind of outputs? One of those ATI all in wonders or something? Most consumer type cards only have VGA and/or DVI plus TV-out in my experience.

highdef

Graphics card is just a standard ATI Radeon 9200. The cable itself is 15 pin at PC end and 5 BNCs at the monitor end. I'd heard that the BNC connector is supposed to be superior but I'm not really sure. The 15 pin to 5 BNC cable I have been trying to get information about seem to be always labeled as high definition cables for CAD and graphics design type things. Graphics card can support much higher resolutions - I've had it set to 2048 x something and it displays fine on the monitor although everything is tiny when just browsing the www. Sure I'll know this evening when I swap over to this cable, if it is actually any better.

Lump

The BNC, splits the Luma values, and the RGB Values... Well just the B-Y R-Y values. I don't know why there's 5 BNC connectors though. If it's coming from a VGA at one end, no real point.

JOhn

highdef

Thanks John

I was also thinking why it would make a difference if one end was the standard vga type connector and the other BNC. Anyway, I'll connect it up this evening and see how it goes. There appears to be a slight fault with the current VGA connection. Sometimes flickers to a yellowy color every now and then. Maybe this connection will solve that. Got the monitor 2nd hand and was told by the previous owner of this fault - It only happens every so often so doesn't bother me anyway. Monitor was free anyway so who am I to complain!!

astrofool

BNC is slightly superior to the standard 15pin vga cable.

I think the other two are for horizontal and vertical hold Lump, a quick google will probably give the proper answer. Had one for my crt before I got a tft.

Lump

Eh.... The sync pulses are built into the picture.

Anyway google.

John

highdef

Have the monitor connected up via the BNCs now and pic seems fine. TGH, can't really notice any difference but haven't done anything where I need detail yet. The five connectors are red, green, blue, horizontal sync and vertical sync. My picture flickering to yellow every so often is gone too with this setup so I imagine I'll stay with the BNCs

Inspector Gadget

I think the advantage of using the BNCs is reduced crosstalk between the colour channels - if you're getting all of these feeds from a single DSUB then it's unlikely you're gaining anything from the use of the BNCs, except maybe that the red line is damaged in your VGA cable (I think it's red; two primary colours together make yellow, it's the other one that's gone, I think).

One thing - I think you lose the monitor identification and DPMS stuff if you go the BNC route as that information isn't exchanged with the monitor any more... (as far as I know)

Gadget

ZENER

The 5 BNC's are R G B H V ok, the flicking to yellow indicates a problem with BLUE or the B cable.

I used to have a fixed frequency 21" SONY monitor with 5 BNC's, it was from a CAD station originally. As gadget correctly pointed out above, the advantage was that as the cable used 5 mini coax cables instead of a multicore there was a slightly better picture at very high resolutions. It was done to stop ghosting or reflection of the signal.

I think LUMP is confusing SCART or RGB signals which contain the sync pulses on the GREEN signal.

ZEN

Lump

No, I'm confusing television pictures.

John

Inspector Gadget

ZENER wrote:

The 5 BNC's are R G B H V ok, the flicking to yellow indicates a problem with BLUE or the B cable.
ZEN

Cheers for the correction - yep, I was stupid enough to make the mistake that blue and green make yellow, instead of red and green (the same R/G/B signals are present in a standard VGA cable). Doh! :rolleyes:

Gadget