Jump to content

Recommended Posts

Hi Folks,

I am new to the hobby of RC wireless photography and I bought a system that uses the KT&C (http://www.ktnc.co.kr) KPC-650CHQ camera. I am having trouble with the camera when I point towards the sun; the CCD seems to get saturated and the feed goes black until I turn away from the sun. A video demonstrating this problem appears on Vimeo @ http://www.vimeo.com/720528

I consider this a big drawback and I can't understand why such a camera would be marketed to the RC photography (FPV) market. I am wondering if I received a flawed camera or if something else is causing the problem. I know this is a very light sensitive camera but should I really expect such performance? Please share your experiences.

Thank you,

Chester

Share this post


Link to post
Share on other sites

From what I can see, it is not a camera issue. There seems to be some local interference or other RF link issue, compounded by slow video re-sync by the recording device.

If you are using a whip/dipole on the Rx, then it might be wise to try a patch on it. Plus, try another field that is farther from buildings and other interference prone areas.

Share this post


Link to post
Share on other sites
From what I can see, it is not a camera issue. There seems to be some local interference or other RF link issue, compounded by slow video re-sync by the recording device.

If you are using a whip/dipole on the Rx, then it might be wise to try a patch on it. Plus, try another field that is farther from buildings and other interference prone areas.

I have attached some pictures describing my setup because it may be related to the semi-poor quality video. I realize that I have trouble beyond the black spots but the black spots were the most troublesome. Did you notice how they occur only and always as I face the sun? It seems a pretty high correlation but I may need to do some further troubleshooting to determine causation.

I am using a whip, as you predicted, and I believe a patch would help. I don't know about the slow video re-sync because I don't understand what it means (now). However, I am using a rather high quality Sony Handycam DCR-DVD403 NTSC to record. I have the Tx mounted to the fiberglass stick of the trusty Slow Stick with some hot glue and a zip tie. This setup might transfer too much vibration. Plus it's mounted downwind of the prop. And the whip antenna crosses the control Rx antenna. I plan to go Easystar which should remedy these issues. I will also try another field.

Thank you for the suggestions.

post-2801-1203946183_thumb.jpg

post-2801-1203946311_thumb.jpg

post-2801-1203946379_thumb.jpg

post-2801-1203946418_thumb.jpg

Share this post


Link to post
Share on other sites
Did you notice how they occur only and always as I face the sun? It seems a pretty high correlation but I may need to do some further troubleshooting to determine causation.

I see that when the model is flying in certain orientations and at certain parts of that field, the interference hits you. To me, it is either antenna orientation issues or something in the area is interfering with your RF link. That is why I suggest you try a Patch on the Rx and fly at a different place, far away from buildings and other structures, before making any decisions about the camera.

If the problem is due to the sun, then just bench test the camera. Plug your camera directly into the DCR (omit the RF link) and record different light intensities. If the exact problem that is seen in the demonstration tape appears with bright lights, then it is either the camera or the DCR.

The video interruptions seen in your video are not a new phenomenon. The common cause is local RF interference or a poor antenna setup. It would be very unusual if your issue is caused by the camera, but nothing is impossible. So, suspect everything.

I don't know about the slow video re-sync because I don't understand what it means (now).

There are places in the demonstration tape where your video drops out and turns black or goes weird. These short interruptions tape a moment for your DCR to re-synchronize to the video signal. Your DCR seems to take a few video frames to get back in sync. That causes the short interruptions to look slightly worse. It's nothing to worry about, but the effect is there.

Your photos show that the Tx antenna crosses very closely to the metal tail tube, A/V wiring, and tail pushrods on the model. I suggest you swing the antenna downward so that it is below the model, away from the metallic parts.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×