"Shadowed" IMAQ Images

[Tek]

I recently installed the IMAQ-1405 and tested it by running several example VI's, mainly LL Snap.VI.  The images were taken from a VCR tape, and the connections between the IMAQ and the VCR seem secure, and, but the images were not very clear.  It was almost as if the image was a "double exposure" of the same picture...all of the figures had a displaced shadow.  Is this something you have known to have occured previously?  Is there a fix?  Could I have a faulty IMAQ card?  Do you have any other suggestions?  Thanks.

-Tek

[MarcoPolo5]

Make sure that you have your 1405 setup to acquire the propper signal the VCR is outputting (NTSC for USA and Japan standard and PAL for European standard) - you can select this under MAX (Measurement and Automation Explorer) by right-clicking on Channel 0 of the IMAQ Board. Also - check in MAX to see that the offsets are set properly - for NTSC the acquisition window is 640x480 and the offsets are 119 Left and 19 Top by default.

Most VCR's don't record some of the timing signals that cameras output. These synchronization signals indicate the start of a frame and the start of each line of the image. It's very possible this will cause an "unclear" image.

You might want to check out this example prog:

http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B45EACE3DE5256A4E034080020E74861&p_...

If these suggestions don't fix the problem, attach an image that displays the symptoms you are talking about so I can get a better idea of what might be going on.

[Tek]

I could not find where in MAX to select NTSC (when I click on the device, I get a device description for the IMAQ 1405, but I don't see a channel list).  Also I did not see where to set the offsets.  I did check out the link you sent, but I don't think that is the problem I am having.  I have attached a screen shot of an image I aquired using the HL Snap.vi.  Thank you for your time.

-Tek

[Tek]

Looks like I spoke too soon.  I did find Channel 0 and made the setting changes you suggested.  Everything works properly now.  I really appreciate your help.

-Tek