From: "sandybumgarner" <sandy@vbbn.com>

Date: September 26, 2005 10:15:57 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: M2 from Los Angeles - dew

Hi Alan,

Excellent advice all around!

Sandy

===

--- In Astro_IIDC@yahoogroups.com, Alan Friedman <alan@g...> wrote:

When I shoot Mars I usually set-up the evening before to let my 

scope 

cool completely. I leave it with caps on covered by a tarp and go 

to 

sleep, setting the alarm to get up for mars (somewhere between 

2:00 and 

3:30 at the moment.) Things may have gotten dewy outside but the 

optics 

will be dry. If I am going to be up all night I always set up a 

Kendrick dew system. But for a couple of hours of imaging near 

dawn I 

wrap a layer of foam around my dewshield - this is will delay the 

formation of dew quite effectively.

Dew is a drag. It deposits airborne contaminants on the corrector 

which 

requires more frequent cleaning. I almost never use a hair dryer. 

Blasting warm air at the optics will generally ruin the figure of 

the 

glass for the balance of the observing session. At the end of the 

imaging session I cover the scope and put it away in the case 

(which 

has been left closed) and let the scope return to ambient 

temperature 

slowly.

Best -

Alan

On Sep 25, 2005, at 6:53 PM, Milton Aupperle wrote:

Hi Tim;

Very nice shot for a first time out doing DSO's with Astro IIDC.

I think you'll be impressed with the increased sensitivity your 

going 

to get with Mars imaging, as the larger pixels give you about 

40% 

more light per pixel than the ApLux gathers. You can use less 

gain 

and/or run at higher frame rates, which will help improve S/N.

I can sympathize with the dew problems. When I was on holidays 

I 

tried imaging the day after it had finally stopped raining (3 

days 

worth). The scopes optics would "dew up" after 5 minutes and 

the only 

way to briefly clean them was with the hair dryer at max. 

However to 

make matter worse, when I checked the optics with a flash light 

for 

how dewed they were, a bazillion little gnats and moths would 

land on 

the optics and get stuck there. After 45 minutes of screwing 

around I 

finally packed it in for the night. After another day of sunny 

conditions all the dew was gone and the dessert like climate 

in 

Saskatchewan allows me to image all night with none of those 

problems 

at all.

TTYL..

Milton J. Aupperle

President

ASC - Aupperle Services and Contracting

Mac Software (Drivers, Components and Application) Specialist

#1005 - 815 14th Avenue. S.W.

Calgary Alberta Canada T2R0N5

1-(403)-229-9456

milton@o...

www.outcastsoft.com

On 25-Sep-05, at 10:17 AM, Tim wrote:

Folks:

I uploaded a file into the DSO area this morning.  It's a 

stack of 

ten 20" exposures taken with

my new Pt. Grey Flea camera (the camera is actuallly smaller 

than 

the Mogg 1 1/4" adapter

with the 0.6 FR lens).

I experimented for about 3 hours last night with various DSO 

objects.  I would have shot Mars

as well, but was set up in the back yard, and our house is 

40' 

tall, so it didn't rise above the

roof before I started to fade!  Too bad, too.  The seeing 

was 

pretty good, though the dew was

moderate.  I don't have a dew heater, so I had to use a blow 

dryer 

every 20 minutes or so.  I

thought the clouds would roll in by morning, but they didn't.

Anyway, I am amazed at the quality of the images from the 

Flea.  

Dark frame subtraction in

Astro IIDC works very well, too.  If anything, I found that 

taking 

these sample DSO images

with the flea was orders of magnitude easier than my "first 

night 

out" with my Meade DSI Pro.

And the image quality is much better, too.

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