Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Thinking about getting a biggish Dob...


Recommended Posts

doesnt have to be 3K. i picked up an excellent 16" mirror on ABS for £400. if you want more information just pm me

I'm ashamed to say I don't have a practical bone in my body - I can barely tie my own shoelaces so I'd be lost knowing what to do with a 16" mirror! Even collimating for the first time has me worried...but I guess I'm getting ahead of myself there - haven't even placed an order yet!

Link to comment
Share on other sites

  • Replies 39
  • Created
  • Last Reply
Yikes!! Looks like the missis is going to have to wait a while longer for the new kitchen...

Are there any useful threads on the forum on "How to explain to one's other half that one needs a 16" Dob and associated equipment"?

Link to comment
Share on other sites

The lighter the scope the more you will compromise on strength.

The ultra compact types do not have the rigidity of classic style truss Dobs. If it's to be your main scoe you want rigidity and strength first, portability second.

I would think very long and hard before putting money down on a lightweight design. Remember the Ultra compact design was designed primarily as an occasional use travel scooe not ones prime instrument.

I would recommend a classic style truss Dob of whatever size you can handle.

Link to comment
Share on other sites

Thanks Steve - since I've no experience of using either, I'd be really grateful if anyone who has been lucky enough to own, or at least look through, a good ultra compact and a good "standard" truss Dob, could give me an idea of what the differences "at the eyepiece" might be. I wouldn't class myself as a dedicated observer - my job and family commitments mean I'll never be able to get out as often as I might otherwise like - and I just "love the views", rather than aspiring to make any serious observations. I enjoy it a lot, though, and have done since I was six, and so I'm happy to spend the money to bring the glory of M13 that little bit (or hopefully, quite a lot) closer! In other words, if the impact of the "wow" I'll get with a 14" or 16" compact is significantly less than with a more conventional truss-tube Dob, then it would certainly impact my choice. Any thoughts and experiences gratefully received - I'd like to get this one right!

Link to comment
Share on other sites

Ok...I've decided...it'll be a Sumerian. It'll occasionally be bundled into the back of a car with some kids (not sure which will be in the boot and which in the back seats) and taken to the odd star party, so that settles it. Plus I like the look of the design. Richard - I'd be really interested to know how you get on with yours - do let me know.

Link to comment
Share on other sites

I have the Sumerian 10" travel scope. The truss is remarkably rigid. The flexure all comes from the top ring but, in my experience, it's not really that severe. The Canopus have a proper OTA, so that issue should be gone. I've got excellent planetary views out of my 10". The only thing I don't like is the lack of a proper mirror cell. The mirror sits on the nylon screws and collimation is a little annoying. It's still perfectly possible, just not as nice as a regular cell. The other issue is that it's harder to mount stuff on the scope and it's too light for a paracorr. Other than that, it's a great instrument.

Link to comment
Share on other sites

Ok...I've decided...it'll be a Sumerian. It'll occasionally be bundled into the back of a car with some kids (not sure which will be in the boot and which in the back seats) and taken to the odd star party, so that settles it. Plus I like the look of the design. Richard - I'd be really interested to know how you get on with yours - do let me know.

Will do.

Link to comment
Share on other sites

Thanks folks - it'll take a few months to get the money together, but already looking forward to my first views (probably this time next year!) through a big scope!

you wont need that 13mm ethos till next year so feel free to sell it too me :D

Link to comment
Share on other sites

I take it the deck is wooden? I'd have a look at how much it moves when you move plus the weight of even a lightweight biggish scope. You only need a small movement on the boards of a deck to cause huge movement at the eyepiece. I'm not trying to put you off or throw a spanner in the works it just may be something to be wary of.

My mate has an 8" CPC and no longer views off his deck as any movement he made made the scope wobble and move off target. His deck went round 3 sides of his house and someone walking on the sides caused vibration to his scope at the back.

Link to comment
Share on other sites

I take it the deck is wooden? I'd have a look at how much it moves when you move plus the weight of even a lightweight biggish scope. You only need a small movement on the boards of a deck to cause huge movement at the eyepiece. I'm not trying to put you off or throw a spanner in the works it just may be something to be wary of.

My mate has an 8" CPC and no longer views off his deck as any movement he made made the scope wobble and move off target. His deck went round 3 sides of his house and someone walking on the sides caused vibration to his scope at the back.

I used the wrong word there Digger1895 - it's really only a deck in the sense that it's a flat area in a very steeply sloping garden - it's actually a patio, i.e. stone slabs on a thick concrete base, so hopefully no issues (or at least fewer issues) with vibration, thank goodness.

Found twenty quid in my jeans pocket yesterday, so I'm already 0.5% of the way towards being able to buy the scope! Now then, how many other pairs of jeans have I got...

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.