What will give me the best, crisp image on a monitor?

[RoyS]

Hi All,

 

This is not to do with production video but a PC setup in my home and wondered if you could help me..

 

I have recently invested in a 24" LCD capable of running 1920x1080. My video card is a dual head Radeon outputting on two SVGA tails from a hybrid connector in a Y arrangement.

 

The PC is a few meters from the screens and therefore the cables need to be around 5m and this is accomplished by using a standard 1.5m + 3.5m M-F extension.. I have this arrangement for both screens.

 

My problem is that the new big screen is not as crisp as it could be. e.g. If I plug it into a laptop it's very sharp. Also if I put the PC on the desk and connect the 1.5m directly to the Y cable its OK but not quiet A1.

 

So my question is this: Should I

 

A: Invest in a higher quality 5m SVGA cable

B: Invest in a new video card that has DVI & SVGA outputs, using the SVGA for the new TFT and the SVGA for the old 1280x1024 TFT..

 

(having the PC living on the desk is not an option...)

 

Many thanks in anticipation of your thoughts...

 

Cheers

[David Lee]

You want to be outputting the native resolution of your screen so probably easiest is to upgrade your graphics card to something capable of 1920 x 1080 over a dvi connection with a good quality cable.

[RoyS]

Thanks David for your reply.

 

I'm currently running each monitor at its native res but with VGA cabling. Is DVI more capable of the crisper image I'm after?

For £30-40 I could pickup a card with VGA & DVI dual screen (extended desktop) capabilities + a 5m DVI cable.

I was looking at Novatech and came across this card: http://goo.gl/WYSUZ and this cable: http://goo.gl/SCsDr

 

What are your thoughts?

[David Lee]

Sorry, thought you were running your new monitor at svga res. A dvi connection should help as it cuts out the digital to analogue and back again conversion. Also, VGA cable isnt always that good at transmitting those resolutions.

 

Choosing a graphics card is always about what you want to do with it. As long as you don't play graphics heavy games or want to run large screen displays you could probably pick up a low cost card. No idea about the novatech ones.

[revbobuk]

DVI (being a digital signal - at least, DVI-D is) is less prone to deterioration with length and cable quality than VGA / analog video. Having said that, 5m is not far, and a decent cable should not show signal deterioration over that distance. Borrow a decent VGA cable, just to make sure that isn't the issue.

 

Having said all that, I would personally go with DVI for a large monitor, as VGA tends to blur at these resolutions, even though they aren't close to the theoretical limits of the VGA standard, which can go much further.

 

Analog VGA tends to degrade more gradually with increasing cable length, so it's a good choice for longer feeds - although converting to Cat5 tends to be an even better choice.

[Nick Mawer]

Hi Revbobuk - I think your statement above needs some qualification - due to the "Cliff Effect" if you push a DVI-D signal too far (much beyond 15m without re-clocking and depending on the resolution) you will get no picture at all, where with an equivalent analogue signal you will get a perfectly serviceable image. However I agree with you that I would go with DVI-D for this situation as you would get a crisper image at 5m with DVI-D.

 

On the subject of native resolutions raised above, there are some very good utilities from companies such as entechtaiwan.com and madrau.com (PC and Mac respectively) that will allow you to check the native or preferred resolution on your displays. I think that the issue here could be the y-cable, and a graphics card with two independently configureable output resolutions would be a much better bet to work with displays that almost certainly have different resolutions and are therfore relying on internal scaling to produce an image.