From: "Tim" <tjp314@pacbell.net>

Date: April 26, 2005 12:21:29 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: Still in market for firewire webcam

Milton:

--- In Astro_IIDC@yahoogroups.com, Milton Aupperle <milton@o...> wrote:

Hi Tim;

On 26-Apr-05, at 11:10 AM, Tim wrote:

Can the

unibrain fire-i?  (there's one on ebay at the moment).

Nope. None of the inexpensive cameras can do more than 1 second.

Okay.  I'll either go that route and forego the longer exposures, or wait and buy one of the 

30-second capable cameras.

The cheapest on the market is the one that Alan uses - the DMK 21BF04 

monochrome can do up to 30 second exposures and they are $590USD. But 

that's all moot anyhow as unless your scope if perfectly equatorially 

aligned, your drive works perfectly with no problems / PEC or your 

guiding it, it's not going work well for capturing DSO's anyhow.

I've had reasonable success taking exposures up to two minutes long with my Starlight 

HX5 and a 4.5" f/5 Newt on a Super Polaris mount with the old Skysensor.  Yep, it must be 

accurately polar aligned, but that isn't hard to do with that mount.  Periodic error didn't 

crop up until over a minute exposure length, and even then didn't ruin every exposure.  I 

did no guiding.

But what am I saying?  This is for planetary imaging, first and foremost.  DSOs would be 

gravy, but not if it's expensive to do.  

The DSO's image I put up were manually guided using 2 copies of Astro 

IIDC, a Unibrain mono camera attached to a 600 mm telephoto lens as 

guider and the Flea FireWire camera on my MAK 127 mm scope with a MOOG 

focal reducer (focal length 450 mm). I then sat at the laptop and kept 

a faint guide star locked onto a particular point using the RA hand 

controller in one copy of Astro IIDC, while the main scope was 

capturing with another copy. Very tedious and one reason I'm trying to 

get RA (+/- DEC) control guiding in Astro IIDC 2.0.

This reminds me of a remark I made to some astronomy friends a while back, as I had just 

gotten my second webcam for telescope use.  I said "what I'd like to do is mount one 

webcam on the main scope, one in a guidescope, and one in the finder.  That way, I'll 

never have to look through an eyepiece again!"  ;oD

-Tim.