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SkyWatcher 100P Dobsonian

Posted: Mon Nov 30, 2015 2:17 pm
by rwilkinson
We've recently acquired a SkyWatcher 100P on a mini-Dobsonian base (another AstroBoot bargain!), to take along on schools visits and other outreach events:
The "Little Bolton Telescope"
LBT.jpg (192.99 KiB) Viewed 3417 times
It's a just a compact 4" Newtonian, but performs well when the mini-Dob base is set up on a convenient perch (much better than using a lightweight "whackery" tripod!).

It has a 400mm focal-length, which gives a decent field-of-view and quite a bright image: the full Moon was literally dazzling (maybe I should have used the pop-out centre of the tube-cap to provide a field-stop?). And once my eye had recovered, I could easily pick out the M31 galaxy from my back garden in the centre of town.

Using a 20mm eyepeice, the coma-distortion of the f/4 mirror is noticeable, but at least you can see all of The Pleiades cluster at once. Then swapping to a 10mm ocular, I got a good view of the double-star Albireo and could just about resolve The Trapezium in Orion.

Although the primary mirror is fixed, the secondary is carried on a 3-vane spider and is fully-adjustable.

Re: SkyWatcher 100P Dobsonian

Posted: Mon Nov 30, 2015 5:25 pm
by bbones
Following a visit to see Ross about a Laser collimator, I took the opportunity to take the scope home and hopefully get a few clear breaks in the cloud, pushing my luck a bit.

I did however get an opportunity to view the moon and because it was raining at the time this was done from inside the conservatory looking through the glass door, not the best of viewing conditions. However I'm please to report that the view of the moon was better than I expected the craters, Mares and the shadows across the terminator where clearly visible and due to the nature of the dobsonian type mount moving to the target was easy and also easy to track the moon on its journey around the earth. Hopefully I will get some clear sky's to check it out further

This was an ideal purchase for the Schools and Outreach events showing what can be achieved with a cost effective telescope and mount.