From: Milton Aupperle <milton@outcastsoft.com>

Date: April 13, 2008 10:00:27 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Lines of Saturn

Hi Phil;

A 5 meter FireWire cable could be the problem too.

FireWire 400 is technically only only rated for 1.5 meters without a repeater, although if it's very good quality cable (well insulated) and has Ferrite beads on it, it may be okay that long. FireWire 800 is rated out to 100 meters at FW400 speeds (I might be wrong on the speed though -  would need to re-read the spec).

My longest cable here is 3 meters and it has ferrite beads on it. I use a hub repeater if I need more.

The other thing is making sure the cable is not picking up EM noise from some power source or powered device.

When I worked for Vitana / PixelLink, we had an awful time getting some cameras passed for CE EM emissions because of cable issues. Once we swapped out the standard cable for a "Granite" one with Ferrite beads we passes with flying colors.

Possibly the reason you didn't see the noise at longer exposures or 2x2 mode is because it shifts over time and gets blended in.

HTH..

Milton Aupperle

On 13-Apr-08, at 8:41 PM, Phil Houston wrote:

Hi Milton,

The pattern is just detectable in single frames of some movies.  I use the MacBook firewire port to power the camera (no external p.s).  The cable is 15 ft. long.  Tomorrow I'll test it indoors and switch cables.  I am glad that you didn't mention the possibility that my camera was failing. ;-)

Your images do show the same effect, although not as pronounced. 

Interesting that the lines were absent in longer exposures as well as in 2x2 binned captures.

Thanks for your help,

Phil