From: Mark Gaffney <markgaffney@mac.com>

Date: March 30, 2009 12:14:15 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Re: New file uploaded to Astro_IIDC


Hi Milton, I finally brought everything inside! It was wet both inside & out of my 2 tarps & the tripod was in about an inch of running water! Sun damage is a worry here as well. In summer the temperature rarely goes below 35 centigrade & the scope must be cooking in the UV. The Telegizmous cover is supposed to give protection from this & I`m hoping when Celestron finally sort out the southern hemisphere bugs in "All Star" alignment I`ll have more options as to moving the scope. I did a rough PA the other night by (with everything pointed south by compass & latitude scale set to this latitude), 3 star aligning then slewing back to a bright star & centreing with the manual mount knobs. I`ve just obtained today a replacement cable for the RS- 232 to the HC base. It got a broken clip to make things interesting! With it I`ll have another go at re-installing GEM 4.15 & then "All Star". I`m told it may be viable if you manually find the stars then centre & align. Once it stops raining! Tomorrow I should get the T-thread to 1.25" tube adaptor from Mogg`s. It`s the final guider part! That`s an interesting design, the first shed-observatory in your link. I`ll look at the others tomorrow. I`m also at the moment interested in "Sky Tools" Pro for it`s ccd exposure calculator etc. Greg Crinklaw was asking if there`s a spectral sensitivity graph for the Flea 2 which I`ve just been obtaining. I`ve also moved my gear around tonight, so I can have one of my monitors on a picnic table closer to the scope (on a long VGA cable I have) to improve my focusing! Mark.

On 31/03/2009, at 3:21 AM, Milton Aupperle wrote:


Mark;


The Grasshopper I bough was $2961 USD. When I ordered it, the

canadian dollar was worth 3.7 cents more than the American dollar was

due to a very favorable surge in the exchange rate. Now it's reversed

again and the camera would cost anywhere from $3500 to $4,000 CDN today.


I really suggest you get comfortable with the Flea 2 your before

"graduating" to a new much more expensive camera (it was 2 years

before I moved up to a larger format camera) especially for DSO's.

Polar Alignment, guiding, selecting guide stars, image processing,

learning turbulence tells and other aspects  take time to master.

Doing DSO's with a mono camera with filter wheel has taken me almost

6 months to get used too and work out all the details for correct

exposures for each channel (i.,e. with the AstroDon E series filters,

I need exposure times of about 1.3 Red 1 Green 1.1 Blue to balance

RGB stars properly).


As to an observatory.


Why not create a small slanted top roll off shed so that at least

your scope is out of the rain?


http://www.david-higgins.com/Astronomy/construction.htm


http://www.mapug-astronomy.net/AstroDesigns/MAPUG/Obsrvtorys.htm


This month alone we've had nearly 1 meter of wet snow and luckily my

scope is still dry (another 25 cm on Saturday night), which is

roughly 3 times the amount of snow we normally get for March. I will

have to replace the BBQ Bag Cover I use this spring as after 4 years

the sun damage has made it become brittle and their are cracks in it.

I "double bag" my scope and have a thin transparent huge garbage bag

on the inside over the scope and mount as a final rain barrier. But

Alberta is a dry climate and unless i'ts raining cats and dogs, the

humidity is normally in the 30% range even in the summer.


Milton Aupperle


On 30-Mar-09, at 4:07 AM, Mark Gaffney wrote:


Hi Milton, It`s bucketing down rain here at present! Even in fairly

light rain a certain amount of moisture gets through the plastic tarps

to the scope. I don`t know how well the scope can cope with this in

the long run but it is a worry! The basic manually operated Home model

of the Sirius Observatory is $7000. I`d like at least to put the scope

on a new base hopefully prepared in size for the addition of the

Observatory if it happens. I was looking at a new Mac Mini later in

the year but you have put the germ of an idea there about the

Grasshopper. I think you said they were around $3000 USD? At least

making a cooler for one dosen`t seem the obstacle it once was! Maybe

the Telegizmous scope cover will provide a solution to my moisture

problems when obtained, probably in June. You`d have your problems

with ice & snow, where mine is torrential rain! Mark.

On 30/03/2009, at 3:46 PM, Milton Aupperle wrote:






------------------------------------


Yahoo! Groups Links