From: Milton Aupperle <milton@outcastsoft.com>

Date: August 8, 2008 10:52:33 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Re: First Light with PGR GRAS14S5M Camera-Filters????

Hi Tim;

On 8-Aug-08, at 10:31 AM, Tim wrote:

Wow!

Those pix are gorgeous!

For second night out I was rather impressed too.

So, how do you cool the camera?  Like with the Flea?

Yes.

I have picture of my "Mark II Rig" cooling rig in the "Other" folder. I can use it with the Flea or The Grasshopper and it uses springs to secure the heat sink / cooler to the camera now.. With more foam padding for insulation and wrapping the camera in saran wrap to prevent dewing of the foam / camera, I can drop it down to as low as 15° C below ambient now.

I think with a copper heat sink or one those new heat pipe CPU coolers, I can probably go another 5°C to 10°C down.

I've got a milling machine and a couple of lathes.  I've cogitated

about making a cooled enclosure for the whole camera, though sealing

it around the firewire port might provide something of an interesting

challenge...

What you I would do is attach the FW800 cable to the camera, run the cable through the hole, and then seal it in with silicone caulking.

However any enclosure will increase the camera weight a lot too.

For me, during the winter I likely will not need a cooler at all.

How does the Starlight Xpress camera that uses the Exview chip compare

pricewise to the Grasshopper?  (though it likely can't do the frame

rates, it's cooled).

They are about the same price now. I've seen the XPress come off in price by about $200 this month.

The issue with he XPress is that the USB interface isn't fast at all. You'll never get full frame read out in < 1 second or even close to the 15 fps that I get with FireWire 800. And I want to use this camera for Venus in the UV narrowband imaging and lunar too. At prime focus on the C8, it will take maybe 2 shots to do the entire lunar disk.

TTYL..

Milton J. Aupperle