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SW 250PX Dobson 1st observing report/mini review


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This is my first observing report with my new SW 250mm the old homemade 250mm I had now retired off and broken up for parts.(all sold).It was 14yrs old and served well but having got back into astronomy at the start of the year I hankered after some new eqpt. and another 250mm dob was the best buy for my needs.

Last night I had a very fruitful 2 hour session mainly with with the SW 250PX and a 21mm eyepiece with deep sky filter attached.

Telrad now attached to the dob for even faster finding of DSO objects.

I did not get set up until 11pm,only a 5 min job with the dob B) as high wispy cloud and only average seeing had me in two minds to get the scope out at all. I was just planning to have a scan around with the 15x70 bins for a 1/2 hour.

In the end it was a good choice as every 15 mins or so gradually improved the seeing conditions but by no means very good to excellent for DSO's.

I started off in Leo picking out NGC's 2903,a very bright galaxy and surprisingly not listed by Messier.Moved onto NGC 3190 and its companion but failed to see a further two galaxies in this grouping.

Thought I would have more succes with M95,96 105 in Leo but seeing conditions or my lack of patience hunting them down made me give up after only 5 mins and decide to move onto the Leo triplet.Both showed well and NGC 3628 could be seen with averted vision,unlike a few weeks ago where it was clearly visible in excellent seeing.

Spent about 15mins on Saturn which was now in a good positon from my garden.Dark banding showed well and

Cassini division easy on the planet. Titan was picked out along with three additional moons.At x240 Saturn showed some impressive when the atmosphere briefly settled.

It was now time for the main reason for setting up,the Coma-Virgo cluster, and now seeing had improved greatly.Spent about 20mins galaxy hpopping with the best view of the night centred around the M84-M86 grouping.I picked out 5 galaxies in one eyepiece view centred around M84-86,better seeing conditions will show 8 galaxies with a 8"-10" scope at x 50-60 with a deep sky filter.

I then spent a few mins. on each of the brighter Messiers,using higher mag x240 without the filter M3, was the only globular I decided on in this session and concentrated on galaxies M81 & M82,M51, M64 (the black eye feature was easily seen) all showed some great detail.By now conditions were good and about mag 5 stars could be made out overhead.Finished off with an old favourite I hadn't viewed for a few years M104 the Sombrero galaxy,at the time still a little low in the sky but it still showed its distinctive shape at x240.

Wished I could have spent longer but by 1am I packed up,unfortunately viewing this lot in a short time takes it out of my neck/back these days :grin:.

I may get back into sketching at the eyepiece again ,a much slower pace to enjoy the objects and move around the sky.

I've posted some old sketches in my SGL album from the days of using the old 250mm dob but I believe its way behind in what the SW250 is capable of,at a guess I would say the SW 250mm "appears" to be almost 1.5"-2" ahead in the views and light gathering ability to what the homemade scope/mirror was cabable of even when the homemade mirror was at its best new.

Focusing with the SW is a lot easier with the crayford,everything snaps into focus quickly and the collimation hold very well on the SW,tonight I did not even check it,once a star test looked good I just got on to vewing.

The SW 250 does have an excellent mirror and when perfectly collimated its hard to beat as an allround scope for one person set up visual viewing.Really pleased with this purchase.:)

Clear Skies All


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Sound like a productive night. The PX is a great bit of kit at a great price. I'll never forget my 1st light with mine. I was extremely lucky to have bought the scope just in time for the clearest night in months. The jump from 5" to 10" had me smiling all night :)

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Nice report Jon

I was very pleased with my 250px purchased too. What also impressed me was it's ability to split tight doubles. It performs fantastically in this area for a reflector and very good collimation holds for months on end.


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Thanks Guys,

The SW250mm is a true gem,as for splitting tight doubles I have yet to have a good go at it but a few weeks ago I had 6 stars showing in the Trapezium and that was a first for me.:)



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Nice report. I also recently got NGC 2903 and it is one of my favourites. From a dark site the bar shows up clearly, and even with my C8 I got distinct hints of spiral structure. The Sombrero is also great, but difficult because it is rather low in the sky. Well done getting it! I really must try to get it this spring.



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