Hooking up a BNC video to a PC?

[96Firebird]

Not really sure if this is the right area for this, but feel free to move to a more appropriate forum if need be.

We have a fairly old SEM (scanning electron microscope) that has a BNC video output on the back. I am looking to hook up this video output to a PC (I'm guessing via TV tuner card) in order to capture some images from the SEM. We have confirmed the output still works with an old CCTV monitor. What is the best way to go forward with this? I was thinking of just getting a BNC --> RCA cable, and then a standard TV tuner card to take the video and get it to the computer. I'm not familiar with BNC video types, so if this won't work, please let me know. Any other advice to get this to work?

 

[piasabird]

Well I have seen these data drop line devices like this one. It converts video from BNC to Cat-5 You should be able to convert cat-5 video to HDMI or composite video and import it. We use to use something like this on our mainframe monitors. I have also seen HDMI converters like this because you can transmit the video up to about 100 meters or whatever the max is for the type of CAT-5 you are using. Of course I have never tried this.

 

[mfenn]

Just a single cable? If so, that's electrically the same as composite video. You can just get a BNC to RCA adapter and feed that to any tuner card with a composite input.

 

[Paperdoc]

There are two questions here. One: how to make a cable that will allow a physical connection between a BNC output and a common RCA ("phono") input - shouldn't be hard. Two: is the electrical signal available on the BNC output the "standard" NTSC Composite Video used on TV-like systems. The answer to that second question is probably yes. You can test by feeding that signal into any TV or monitor with a Composite Video input; in fact, if you are sure that the old CCTV monitor you used was set up for that signal type, you've already done that test and have your answer. Alternatively, if you don't have such a monitor around, virtually any old VCR machine will have a Composite Video input on it, and you can then route that signal out to any TV.

You may not need a full TV tuner card. Just a video capture card that has an NTSC Composite Video input on it will do the job. Or maybe even a simple external Video Capture device that connects to your computer's USB port, and accepts Composite Video input (often also stereo sound and S-Video).

You should be aware of the resolution limits of a Composite Video signal. Its quality is typical of computer screen resolutions of about 640 x 480, or maybe 720 x 540. You certainly won't get anything exceeding 1024 x 768.

 

[dave_the_nerd]

http://www.newegg.com/Product/Produc...82E16815116068

?

 

[mfenn]

http://www.newegg.com/Product/Produc...82E16815116068

?

That would theoretically work, but it seems like the product (or at least its description) hasn't been refreshed in a while.

"Video from any analog source can be captured as either still frame video images or motion video. The ImpactVCB comes with a VFW capture driver (Video for Windows)for Windows 95 and Windows NT, and a WDM driver for use with WindowsXP, Windows98SE, Windows Me and Windows 2000. Typical capture rates range from 15 to 30 fps depending on system configuration."

 

[wirednuts]

bnc connector is just the physical type. it still uses composite video as the signal, so its exactly the same as any rca composite signal. mcm electronics carries BNC-to-RCA couplers, just buy those. we use them at work everyday and never had a problem.

and yes, many tv tuners are composite capture devices too. or you can buy a card that just does capture and nothing else (should be cheaper). or, if you have a discrete video card there is a chance it has analog video input too, but most of those were around in the early 2000's

i think there is even cheap RCA-to-USB adapters that make things too easy. its just composite video, its become the baseline compatible signal across nearly anything made that handles video. there isnt a lot of variation in the technology anymore.