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Its arrived! 300p

Theninjagecko

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Theninjagecko

Theninjagecko

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First, oh my god its big. Took some putting together. Mirror comes in its own box.

Line the tube up best i could With the cell but 2 skrews wouldnt go in, managed to get all in in the end but 1. Thing the guy who drilled the tube holes must have had one eye lol. Comes with a right angled finder! Bonus!

Anyway man handle her outside as its clear but very windy. Straight to double cluster with the 25mm. Oh my god! Even without colimation its stunning! Not liking these tension handle things... Just doesnt feel right. Do i tighten and loosen or just tighten and use?

I think i saw m37 glob... Was absolutly stunning with a bright orange star smack in the center. Hyades didnt all fit in the 25, surprised asbi thought it would.

Quick blast on mars, hard to trac as the az was ver lose and it was windy, i think i could see a moon? Or a star very neary by?

Very window now. Az needs tightening so packed her up and came in.

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alfingido

alfingido

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If its like my Flextube 300P, one of the tension handles should have a roller bearing on it. Use this one to adjust tension and loosen the other one. Once you have the tension right it should hold balance and move pretty easily.

I have never got the smooth alt movements everybody else speaks of using a high power ep, I push gently then it jumps past where i wanted it, then back again, etc, sort of see saw viewing!

But, the views are stunning!

Allan

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acey

acey

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I have the flextube version and love it. Like you I started by having the az too loose. I find that's what right for me is when I have the base empty, if I give it a spin it comes to rest almost as soon as I let go of it. In other words stiffer than you might expect.

I'm not a fan of the tension handles - they're just another part to lose in a dark field some night, or forget to bring. I've heard reports of the screw scockets coming loose through overtightening so I never screw mine too tight - just enough to stop the scope from tipping under its own volition.

For collimation I use a laser on the secondary then a cheshire for the primary. Never takes me more than a couple of minutes. Then re-align the finder. I do this every time I use the scope. But on a solid tube the secondary won't need adjusting often. Two simple mods I did straight off: replace the secondary collimation screws with Bob's Knobs, and insert a milk carton washer in the secondary holder as described here:

http://stargazerslounge.com/equipment-discussion/79004-cure-jumpy-secondary-syndrome.html

This makes secondary collimation a breeze - but it's more of an issue for the flextube than the solid tube.

I also made a camping-mat dewshield - the secondary holders round the top of the tube are useful fixing points - and a cardboard dewshield for the finder. I consider these essential, otherwise things are apt to dew quickly.

Pretty much all my eyepieces are TeleVue Plossls - superb, and I've been using them on all my scopes for years. If you want very wide field then you need to pay a lot more to get the same level of performance. For the time being I'd suggest you stick with the supplied Plossls which are decent enough.

The 12-inch is superb for deep-sky viewing, especially from a dark site. Have fun with yours!

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pvaz

pvaz

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My dob is very tight on both alt and az. I like slow and precise movements when I'm tracking at high mag or changing EPs. The 2" EP is always hard to fit in the focuser, in the dark, and if the telescope is loose it will move easily.

I rarely have any problems with dew for under 2 hours sessions. But then again, the weather in the UK is known to be very humid, so you may need it.

On accessories I would advise:

Telrad or similar finder.

If you are into DSOs a very low mag wide field EP, around 30mm, and an intermediate one around 15mm.

And maybe one 7mm planetary EP if you like observing planets and the moon.

As on the brand/model, you should ask guys with bigger and faster dobs to see what they have and how they perform.

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Theninjagecko

Theninjagecko

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I'm tempted by one of these... It's focal length is 1500mm. how big is the field of view? What length of eyepieces are you using?

Thanks

Alan

With the 25mm i could just about get the double cluster in, but i couldnt fit all the pleiades in. It came with a 25 and a 10mm, I brought a 2x Barlow on its own.

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George Jones

George Jones

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I'm tempted by one of these... It's focal length is 1500mm. how big is the field of view? What length of eyepieces are you using?

Thanks

Alan

I'll take a guess that the 25mm eyepiece has a field of view of about 50 degrees. When used with the scope, its field of view will be about

(50 degrees)/(mag) = (50 degrees)/(60x) = 0.83 degrees.

[edit]Which is about one-and-two-thirds full moons.[/edit]

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Theninjagecko

Theninjagecko

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I'll take a guess that the 25mm eyepiece has a field of view of about 50 degrees. When used with the scope, its field of view will be about

(50 degrees)/(mag) = (50 degrees)/(60x) = 0.83 degrees.

[edit]Which is about one-and-two-thirds full moons.[/edit]

Wonder why i couldn't fit all the Pleiades's in? :\

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John

John

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Thats a great scope !

When I was at the SGL4 star party a chap called Alex was camped next door to me and during the lovely clear night we had he kindly let me share his 12" Skywatcher dob. The views were fantastic that night - we were using my Naglers and Ethos eyepieces which gave some fabulous views. The highlights for me were seeing the spiral arms of Messier 51 and spotting a magnitude 13.5 supernova in another faint Ursa Major galaxy - superb stuff :rolleyes:

A 12" scope has so much potential :)

John

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George Jones

George Jones

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The picture

http://www.naic.edu/~gibson/pleiades/ukschmidt/pleiades_ukschmidt.gif

has a width of about 1.5 degrees, or about three full moons.

The brings up an interesting phenomenon. Because the Moon is so bright, it leaves an image in our mind as being larger than it actually is. Sitting here in the day at work and trying to picture the Pleiades and the Moon, I can convince myself that the Moon completely covers the Pleiades.

But this isn't true! My mind has tricked me! See

APOD: 2005 April 14 - April's Moon and the Pleiades.

And the Hyades cluster is much bigger, eleven full moons across.

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pvaz

pvaz

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They are wider so it's easier for manufacturers to make low mag widefield EPs with that format. You also get a wider lens to look through witch makes it more enjoyable.

For example a 1,25" plossl EP around 30mm will be physically limited to a thin FOV (around 40º).

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George Jones

George Jones

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Whats the benefit of 2 inch eyepieces? I was looking at the 2 inch 38mm skywatcher panaview on FLO.

Skywatcher - Skywatcher PanaView 2" eyepieces

This 38mm eyepiece has a field of view of 70 degrees, and, in your scope, a magnification of 39.5x. When used with your scope, the field of view will be

(70 degrees)/(39.5x) = 1.77 degrees = 3.5 full moons,

or more than double the field of view I think that you get with the 25mm.

This assumes no vignetting, and I am unsure of when this occurs for various scope/eyepiece combinations. Vignetting is something about which I have worry, but I think you're okay. Other people here can address this much better than can I.

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pvaz

pvaz

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As George pointed out, the quality of the EP matters. The widest the field, the more imperfection you may get in the edge.

For example I bought the agena SWAs EPs. I get 70º at a price you can't beat but I wouldn't recommend them for your scope. Mine haves a focal ratio of f/5.9 so they kind of do fine. Perfect view for about 70 to 80% of the FOV center. On the 10-15% of the edges I see some mild signs of coma (elongated stars) that would probably be exaggerated on you scope, since it's f/5.

Fast scopes (f/5 and lower) demand good quality EPs.

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TheThing

TheThing

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Just a quick point, but with a solid tube dob, you shouldn't really have any need for dew protection. In all my years of owing and using Newts, I've never had any dew problems at all, not even on the finder.

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Theninjagecko

Theninjagecko

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Thanks for all the info guys i really appreciate it. "thething" I get bad dew here, I remember my 8 inch secondary dewing up, and my old 127 mak would be useless without a shield. I need a good clear windless night to test it out fully :rolleyes:

I might go for the skywatcher panaview :)

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