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First Light 250 Dobsonian


cv01jw

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I was excited at the clear skies last night and managed to get an hour to give the dob its first light.  The scope is new to me and is double the aperture of my next largest scope and so I was hoping for some cracking views.

The first half hour was a bit of a let down as I realised how unprepared I was for manual star hopping.  After a faff with stellarium on my phone I picked a couple of easy targets and set about learning how to use the finderscope without breaking my neck - note to self - take a star atlas out next time!

First up was a simple one, line up on Polaris and check collimation.  It was, to my eyes, bang on, so I worked along the plough to Mizar, splitting it easily from Alcor - my first double star split :)  I used it to see what the FOV would be like with the three EP's I have at present - a set of Baader BCO's in 6, 10 and 18mm lengths.  All three were great to my eyes.

Next up I moved on to M13 - something I have only seen through binoculars.  This was a challenge for me to find but was worth it.  In the 18mm EP it was lovely, fuzzy centre obviously lit from inside, with a good number of individual stars visible as you move outwards.  Stepping up to the 10mm it was about perfect - filled the central 50-60% of the EP and looked magnificent.  I spent what felt like ages just staring at it.  I tried with the 6mm and it (just) fit in the EP but didn't look quite as crisp as the through the 10mm, so I went back down again and looked some more.

As a final check I put my 26mm plossl EP in and was surprised how good the view was - I was expected all sorts of aberrations around the edge but to me it appeared sharp over pretty much the whole view.  Considering this was a kit EP with my Mak, I am happy it provides my 'Widefield' EP for now.

As I was packing things away Mars popped up over the fence, but despite several attempts to move the scope to a higher position I couldn't quite see it - that would have been a great end to the evening.

I am now really looking forward to getting out again, remembering to take my atlas out with me, and get some practice at star hopping in.  Also looking forward to my two Denk EP's arriving in the post.

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I have a selection of things to sit on depending on how vertical (or not) the tube is - a chair, small stool and smaller still stool.  The most difficult bit was lining up Polaris as the scope is near vertical - so I was stooped over and twisted to look up through the finder.

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For me it's the biggest practical  'grab n go'. I would like a really big scope too, but wouldn't part with the 250.  I can make out the Veil neb with an Oiii from my back garden, which is about as light polluted as you can get.

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