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Signal to Noise

Reposted from Cloudy Nights this introduction to SNR by Craig Stark of Stark Labs and PHD fame this will be of passing interest tour astrophotography fraternity

Signal to Noise: Understanding it, Measuring it, and Improving it (Part 1) You've probably heard it before and if you continue to read my columns here, you'll hear it a hundred more times -- astrophotography is all about signal-to-noise ratios (SNR). But, what does that mean and can such a blanket statement be true? I mean, really. It's all about SNR?   What about aperture? What about...

How to make a Helical Crayford Focuser

This is a simple article I wrote a while ago and rather than re-edit it completely I just added an update

Somewhere on the web I found something called a Helical Crayford. It looked so easy to build and as I wanted a very low profile focuser I decided to build one although these pictures show a long eyepiece tube for clarity. The best part is that with a selection of different length tubes you can always get an eyepiece to focus irrespective of its foibles. I was amazed how easy it...

Build Your Own Backyard Observatory

I spent many hours debating whether to buy a purpose built observatory or to make my own and finally decided to go for a Skyshed pod. The advertising looked good and I did like the idea of having my own dome however delays in getting the thing became too frustrating so I went back to the build my own plan. I chose a standard garden shed 2.92 X 3.00 mm  which importantly had a gable roof...

Telescope - Starting Out

You may think about astronomy for awhile and then one morning you wake to the idea of scope ownership and what a great idea it is, but!!!  There is a whole heap of things to be considered before you take that step towards purchase of your optical device. Firstly, is it a knee jerk reaction – have you recently viewed the galaxy (or a very small portion of it) in a friends ‘super’...

Filters

Some Notes on Filters

Introduction: Essentially a filter is an optical device that blocks undesirable wavelengths of light and therefore only allowing light of desirable wavelengths for a given target, therefore "enhancing" that target. However a filter does not increase available light: it decreases the total light passing through the light path of your telescope and eyepiece configuration. A filter is not a...

Cleaning your Optical Components

This article is for reflector type telescopes as I have and am only comfortable servicing my Dobsonian. With lens's if it is only dust on the lens surface itself try blowing lightly on the lens, if no joy a camera blower brush is the next step blowing across the face of the lens the same way you would with a camera lens. If the mark still persists, try cleaning the lens with a damp lint free...

Polar Alignment without Polaris

An updated tutorial by Vince Legge

I am referring throughout to the use of a German Equatorial Mount (GEM). You will need a magnetic compass, one that you can read down to 1° increments, a device for measuring angles, and a little basic handyman skill but we’ll get to that as we work through the technique. Also you will need to determine the Latitude and Magnetic Declination of your location. These can be found here...

Tuning up a Synta Crayford focuser

Most of the earlier standard 2” Crayford focusers as fitted to Skywatcher/Orion and other Synta made scopes have a particular machining fault. Here’s an easy fix. The example pictured is from a refractor, but the same applies to reflectors. If you have one of these its worth taking a close look at it. If you look at Pic 1 note the area indicated by the screwdriver and you will see that...

Marking Out and Setting Up Azimuth/Altitude Inscriptions On Dobsonian Type Telescopes

Also a Quick and Easy Way Of Setting Your Telescope To North

Hey guys, Nic here. As promised, finally got my act together, and have put this little piece to paper (as it were). No stuffing around straight into it the process is pretty painless and not time consuming nor does it need a great deal of technical skill, but to help you out I will go through it stage by stage. For ease I will use the measurements that I worked out for my Telescope (an 8”...

A Budget Home Observing Platform and Pier

I guess for most of us the ultimate dream is to have that big observatory in the back yard. Unfortunately though, too often it is just that; a dream that likely will never be fulfilled. There are more basic ways to make home observing simple and easy, though, on a surprisingly small budget. I moved house recently and finally decided that it was time to set up a permanent observing area in the...

Finding The South Celestial Pole (SCP)

I suppose we have always taken the south of the planet or where we are on it at any given time for granted. Let’s face it – 180o is south, we all know that! But, that is not much good to an equatorial telescope mount. They need to be on celestial south and that at this time is in the constellation of ‘Octans’ about 1o from a 5.5 magnitude star  called ‘Sigma Octanis’. A very...

Basics of Astrophotography

I have been photographing the night skies for many years, and is something I LOVE doing. My results are dependent on the camera, the lens and the darkness and quality of the night sky. If you have the right equipment, then it is a relatively easy process to get started, and start experimenting with the settings, to improve the final outcome. I am certainly NOT an expert, and go only by my own...

The Basics of Eyepieces

I would like to start by saying that I am far from an expert on the subject of eyepieces, I would also like to state that I have no affiliation with any eyepiece manufacturer or reseller. The views expressed in this article were written based on readily available information and on my own experiences, and therefore is merely my opinion. Some of the following information is very basic, but we...