N468AC - wing mount camera test video...

n468ac · #1 06-03-2007, 06:22 PM

http://www.checca.net/n468acVideos.htm

Video is short ... camera turned off at 10 mins

... also it looks as the camera picked up some type of vibration during flight, will have to work on that.

n5lp · #2 06-03-2007, 06:48 PM

Quote:

Originally Posted by n468ac

http://www.checca.net/n468acVideos.htm

Video is short ... camera turned off at 10 mins

... also it looks as the camera picked up some type of vibration during flight, will have to work on that.

Hello Allen,

That ripply stuff is something Paul Dye had trouble with too. He was thinking it was maybe from a too flexible mounting. I don't remember seeing it on his latest video, so maybe that was it. His wasn't as bad as yours.

Might be a good idea to level the camera with a level because the out-of-kilter is distracting.

I know the video was short but I think it would be better to edit out all the taxiing, it isn't really interesting.

n468ac · #3 06-03-2007, 07:07 PM

(christopher_talking) Thanks for the comments ... i agree the taxing is nothing special, but left it in so i can compare the ground movment vs flying, in later videos.

The camera is about 1" round and very hard to see if it's level. I'm going to try and add a rubber mount between the camera and the frame i'm using.

Ironflight · #4 06-03-2007, 07:23 PM

Good first time out Christopher - better than my first couple!

A couple of rungs on the learning curve:

1) Try Lithium batteries - they have a higher voltage out of the box and when I started using them, the early camera shut-off problem went away. (I think that Alkalines are marginal, and the camera is marginal on 3.0 volts, so all it takes is one voltage sag, and you're done.)

2) Make the mount as rigid as possible to the wing. I had several layers of Velcro between the mount, a wedge, and the camera, and got the same waviness. I "firmed up" the attachment by adding some safety wire twisted nice and tight, and got much better results.

As far as leveling, I just took a little more care, stepped back to make sure it looked straight, and it was. If you can level a picture frame by eye......

Can't wait to see your future efforts!

Paul

videobobk · #5 06-03-2007, 07:35 PM

It is really hard to tell what caused the "waving" in the video. Let us know what you learn. Now, not ALL vibration is bad! I do very few commercial videos (I do videos for missionaries) but did one for the Harley Owners Group (HOG) back in 2003. I built a complicated mount that mounted a camera about 3' behind and 2' to the right of a Harley. It picked up quite a bit of the H-D engine shake and I prepared to start all over, but they LOVED it! Seems Harley riders expect it. I'm sure it saved me massive headaches trying to damp the vibes out.

Bob Kelly

aadamson · #6 06-03-2007, 08:11 PM

The waveiness is the frame rate vs how the camera digitized it's image. It looks like its a pretty slow frame rate and I'll be a fairly slow scan rate. So what happens is that the vibration shifts the image on the imager before a full frame has been scanned and saved. In essence the image moves before the full frame is grabbed. Only thing to do to fix it is to take the vibration away some how or crank up the frame capture rate.

GrayHawk · #7 06-03-2007, 08:15 PM

This is not meant to be critical or negative on your efforts, as any flight video is better than no video; which is where I'm at (until I get some fab & wiring done).

I am just going to suggest that some of the artifacts seen with this type camera (prop lines, 'waving', etc.) may be due to the cmos imaging sensor used (rolling shutter) and/or the compression algorithm used.

There I said it.. Feel free to beat up on me.

Gray (CCD imager for me and as any bits as I can afford until the last minute) Hawk

Tim Goddard · #8 06-04-2007, 06:25 AM

I have been reading about you guys with your cameras, where do I get mine?

Ironflight · #9 06-04-2007, 07:32 AM

Quote:

Originally Posted by Tim Goddard

I have been reading about you guys with your cameras, where do I get mine?

http://www2.oregonscientific.com/sho...cid=77&pid=709

have fun!

n468ac · #10 06-04-2007, 10:33 AM

First thanks everyone for the comments ... I do like them both positive and negative.

Ironflight - I?d edited out the 32 mins of me trying to get the camera level and just left the last look / engine startup in the final video. The battery idea is a good one and I will have to try it.

I think I will try to point the camera at the landing gear next try and see if that makes any difference and work on adding a stiffener to the middle of the mount. My thinking is the camera will be mounted along the main spar and my have a harder contact point.