Category: Astro knowledge
Astro knowledge / General / Observing Reports
Chinese zodiac
Chinese Year of the Rat this year (my “sign”, you guess which multiple of 12 I am). I’ve decided that the “rat” constellation must be Aries, since the “Ox” is clearly Taurus. […]
Astro knowledge / General / Observing Reports
better to be lucky than good
So I’m on 2 trips, lasting 2 weeks each, in the next 6 weeks. As you know by now, the astrophotography part of the month is only 2 weeks long (from 3 […]
ATM dreams
I also collected all of the ATM photos into one place. I need to crop and resize, but I’ll have a decent record of the process. I’ve really enjoyed it. It makes […]
HOWTO – calibrate a laser collimator
I bought an Orion laser collimator, but suspected that it was out of collimation, so I tried to adjust it, and got it *really* out of collimation, so I needed to realign […]
Pumpkin field flattener / reducer?
I’m trying to decide if the curved field on the AT66ED is going to bug me or not. I think that it is. But the field flattener unit is also a focal […]
Astro knowledge / General / Observing Reports
Chinese zodiac
If you get a chance, take a look at the sky tonight (June 26, 2008). Jupiter is in about the same position it was when I was born (it takes 12 years […]
birthday images 3 – aspect ratio and book thoughts
I’ve been thinking about printing out a book of my astrophotos. 8×10 and 16×20 are both 4:5 (1:1.25) sizes. So while the native resolution of the D70 is 3008×2000, the max 4:5 […]
birthday images 2 – resolution
This article is talking about magazine quality, 300dpi printing. It suggests that 6mp is good for 8×10, and about 4x the resolution is needed for 16×20. however, Kodak says 1600×1200 is sufficient […]
Re: Pointing Model vs. Polar Alignment
Art Morton wrote: > > On Jun 9, 2008, at 9:13 AM, Jimbo S. Harris wrote: > >> Art Morton wrote: >>> I also have to find out how to handle that […]
Gemini slew speeds
To do a CCD Polar Alignment, you need to run the mount east at 1x sidereal (the motor runs “backwards” at 1x sidereal), then run the mount west at 1x sidereal (the […]
RECENT UPDATE
Polar Alignment Calculations
Here’s a page that derives Polar Alignment Calculations. (update 5/2020: the original site is gone, so I found the text on Wayback and am inserting it below. This is by the original […]
Gear / Observatory / Telescope
Special Guest Star takes the mount at Hilltop O
The Astro Jedi needed somewhere to store his light sab—- I mean, bucket, and I was only too happy to accommodate him. I have decided that I need to come to a […]
General / Maintenance / Observatory
Dome shutter is motorized again!
I finally decided to bite the bullet and fix the shutter motor. Things went sideways last winter, and I’ve been opening the shutter manually (and tying it shut with rope, so we […]
Trixie 2017 – tube mods
I finally got around to cutting the MTA-UTA tubes to length; the only eyepiece that would come to focus with the focuser spacer in place is the Televue 55mm Plossl. If I […]
MOST COMMENTED
Observatory
Observatory 2.0 – Time has come today!
General / Maintenance
First Light, a deeper look
Mount / Observatory / Telescope
Observatory 2.0 – Result!
Observatory
Observatory 2.0 – The Pier goes in
Gear / General / Maintenance
Martin Farmer Wormblock installation notes
Deep Sky / Long Exposure Photography
NGC2244, The Rosette Nebula
Deep Sky / Long Exposure Photography
Another beautiful night.