From: Milton Aupperle <maupperl@gmail.com>

Date: May 23, 2015 9:39:55 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] IR Cut Filter Necessary?

Hi Kevin;

Thanks for the info. it sounds like that Hub / Repeater should be able to handle the distance and power requirements just fine.

If your just previewing video live, then 8 bit (256 shades) is usually more than adequate for a monitor. If your processing the images or movies and looking for subtle details (i.e. nebulas, cloud patterns on Venus, faint prominences etc.) then 16 bit likely helps a lot. If you want to try an experiment, try dropping the bit depth to 8 bit and see if that solves the start up issue and is good enough quality for your needs.

The issue might be that there is barely enough per packet bandwidth to run them at the same time in 16 bit. If you check the CAP_Date_Time_L.txt file that Astro IIDC creates when you record a movie or grab a frame, the first 8 lines in the file indicate the cameras current setup. For my Grasshopper it might looks like this for a recorded movie:

=================== File:20130520_052311_U.mov #frames 101

Monochrome Camera = Model:'Grasshopper2 GS2-FW-14S5M' SerialNumber: 0xA94B07

IIDC Format:7 Mode: 0 ClrCode: 5 MaxFps: 27.12 MaxPacketSize: 9720 

Camera Display Format: 1384 x 1036 16 bit

CCD Image Left: 0

CCD Image Top: 0

CCD Image Width: 1384

CCD Image: Height 1036

If you can post those first 8 lines in your own CAP text file for those cameras, I'll have a look at the camera specs and see what the packet size is.

HTH..

Milton Aupperle

On 2015-05-23, at 3:30 PM, Kevin in Fort Davis fsm79734@gmail.com [Astro_IIDC] <Astro_IIDC@yahoogroups.com> wrote:

Thanks for those great suggestions, Milton.  The FW800 hub I'm currently using is this one:

http://www.amazon.com/NitroAV-8-Port-FireWire-Professional-Repeater/dp/B00506K4NC

and its power supply is rated at 12V/3A.  When I first started having the FW bandwidth issue (everything worked fine for nearly two years before this problem developed), I tried swapping in the exact Kramer hub that you mentioned, with the same result. I've also replaced all the cabling end to end.

I have not tried running the cameras at 1624x1224 8bit.  Will the image quality not suffer at 8 bit?  I will try that as soon as it stops pouring rain.

I will ask PGR if their USB3 cameras can run at USB2 speeds and what the minimum frame rate is.  Unless I've missed it, they only specify a "frame rate" which is presumably the fastest frame rate.

-Kevin