Scopes

I use my set-up mainly for astrophotography. The main imaging scope is a 8" Meade LX90 which I bought nearly-new on eBay in 2005. With the benefit of hindsight I perhaps should have gone for an LX200 as it is better geared for astrophotography. Anyway, I'm still very happy with the LX90 and I'm starting to generate reasonable results. Although its focal length is 2000mm I usually image deep-sky targets with a focal reducer, either f/5 or f/3.3. For lunar and planetary imaging a Barlow lens usually boost to f/20 or f/30.

You can also see a guidescope piggy-backed on the LX90. Another second-hand bargain, I bought the Skywatcher ST-80 on UK Astro Buy & Sell. It has a focal length of 800mm, pretty good when I'm using the LX90 at f/3.3.

 Cameras

I started in deep-sky photography with a Meade DSI-C one-shot camera but have since moved up to a Starlight Xpress SXV-M7C one-shot camera, which is a cooled, very low noise CCD. The DSI-C is now very actively used as my guide camera, attached to the ST-80. Both cameras are attached to my laptop via USB cables. On each I've used active USB extenders to boost the range beyond the 5m range limitation on USB cables, giving plenty of spare cable to avoid tangles.

For lunar and planetary imaging I use what thousands of other imagers use - the Philips ToUcam Pro, a simple webcam. It comes with a lens which you need to replace with an adaptor which screws into the webcam one end, and attaches to the eyepiece tube of the scope at the other end.

Click on thumbnail to annotate the picture

 Mount

For serious imaging you need to have a polar-aligned mount. The LX90 comes as standard as a fork-mounted alt-azimuth mount, which means it moves left-to-right (azimuth) and up-and-down (altitude). If you take an image with this type of mount, although the LX90 will track the object you are imaging, the rotation of the sky will mean you get field rotation - the stars at the edge of the picture will not be point sources but trails.

Hence imagers need to upgrade to a wedge-mounted arrangement which allows you to polar align the scope so that it rotates with the sky. You can go over-board on wedges, spending around £300-£500 on very solid and finely-adjustable works of art. For now I'm making do with the standard Meade wedge (another eBay purchase).

Finally you need a tripod or pier. The standard Meade field tripod is very sturdy and would probably be fit for purpose. But in my modestly-sized observatory the tripod's legs would get in the way and I'd regularly kick it out of alignment. So I invested in the super-solid AC421 pier from Astro-Engineering. The pier is solidly bolted to 1 tonne of concrete and provides a very solid base.

 Accessories

There are probably a few other things worth mentioning.

Firstly, power: I have mains electric in the observatory which powers the laptop, scope, dew heater, etc. Most equipment runs off 12V power, so there are a range of adaptors, all of which are kept moisture free in a plastic box on the PC workstation.

Secondly, the laptop. Only a cheap second-hand (yes, eBay) IBM thinkpad. It controls everything: scope, CCDs, guiding, etc. It is connected to the internet via a Belkin USB receiver and this enables me to remotely-control everything from the warmth of the house on the main family PC using Remote PC Client. It's cheap and reliable but the only drawback is too few USB ports and USB 1. I have a hub to boost the number of ports but it still suffers from the slower USB 1 speed (which results in slower download times).

They're the main accessories - others which are worth noting include a heated car seat strapped to my observatory chair. Fantastic! Also, I have a small dehumidifier to ensure that moisture is under control.

 


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