Newbie- Scope Advice please!

[Roy Challen]

As scarp15 says, buying second hand is fine. Everything in my current set up is second hand except the maxvisions and even one of them was discounted. It brings items that may have been out of your budget into being affordable meaning you don't have to go with your second choice.

I actually enjoy buying s/h now, it's also a way of occasionally meeting a member of our community face to face.

[niallk]

I'd snap that up and spend the difference on some carefully chosen (ie, not the the largest you can find!) eyepieces and a Cheshire Collimator.

If you don't get on with it? Well, you can sell it for £195 delivered. It wouldn't be an expensive mistake and can give some very good views indeed.

Russell

Great advice here: my 250px came alive with good eyepieces - slowly acquired over the years - birthdays/Xmas etc. More spent on accessories than the orig scope

[astromackem]

Great advice here: my 250px came alive with good eyepieces - slowly acquired over the years - birthdays/Xmas etc. More spent on accessories than the orig scope

Tell me more about eyepieces please? What happens and why does it make the image better? What type would I need to fit a Dob? People always mention Barlows (2x 3x...)

Cheers

[Physopto]

Hi,

The eyepiece depends upon what you want to see. I don't have a DOB, but say a 20 mm will give a good view of one thing, whereas it may be better to go wider field with a 40mm. If you want to see detail in a planet such as Jupiter you may need a 10mm. You may even find that a 2x Barlow is required in conjunction with the 10mm. The problem is that the seeing will be the deciding factor in many cases. Also each scope has a maximum magnification that it is capable of. Eye pieces will have to be matched to the scope you are using. Also there are many different types of eyepiece. There are wide field (100)deg, then intermediate types (70-80)deg. There are massive differences in quality between makes and even by the same manufacturer. You pays for quality. When you actually decide on the type of scope you want and buy it then you will need to match the size and types you want.

You will get plenty of advice here but nothing beats looking through the scope with the eyepiece you are thinking of. Here is where clubs come into their own. The members will give you the chance to see through theirs at star parties of member evenings.

Derek

[astromackem]

Hi,

The eyepiece depends upon what you want to see. I don't have a DOB, but say a 20 mm will give a good view of one thing, whereas it may be better to go wider field with a 40mm. If you want to see detail in a planet such as Jupiter you may need a 10mm. You may even find that a 2x Barlow is required in conjunction with the 10mm. The problem is that the seeing will be the deciding factor in many cases. Also each scope has a maximum magnification that it is capable of. Eye pieces will have to be matched to the scope you are using. Also there are many different types of eyepiece. There are wide field (100)deg, then intermediate types (70-80)deg. There are massive differences in quality between makes and even by the same manufacturer. You pays for quality. When you actually decide on the type of scope you want and buy it then you will need to match the size and types you want.

You will get plenty of advice here but nothing beats looking through the scope with the eyepiece you are thinking of. Here is where clubs come into their own. The members will give you the chance to see through theirs at star parties of member evenings.

Derek

Most of that went over my head haha! 10mm? and a Barlow? Im lost.

[Physopto]

Go to this web site and have good read. It will hopefully explain better than I can.

Derek

Understanding Magnification - Starizona's Telescope Basics

starizona.com/acb/basics/equip_magnification.aspx

Magnification is the most misunderstood aspect of telescopes, but not only by beginners........

[astromackem]

Go to this web site and have good read. It will hopefully explain better than I can.

Derek

Understanding Magnification - Starizona's Telescope Basics

starizona.com/acb/basics/equip_magnification.aspx

Magnification is the most misunderstood aspect of telescopes, but not only by beginners........

Thanks for that..great information.

So from that I guess other lenses are used to bring the scope upto the maximum for the arpeture?

[happy-kat]

You choose an eyepiece for what you want to view with the telescope you are using and how good the seeing conditions are. Hence why in time users may have a number of eyepieces of varying size and field of view to pick from.

[astromackem]

You choose an eyepiece for what you want to view with the telescope you are using and how good the seeing conditions are. Hence why in time users may have a number of eyepieces of varying size and field of view to pick from.

So as a start, would you have say 3 at low, medium and high maybe?

[Roy Challen]

So as a start, would you have say 3 at low, medium and high maybe?

That's a good way of starting, say between 24-30mm for low, 14-18mm for medium, 8-11 for high. Then you can fill any gaps you think you may have later on. Magnification depends on scope focal length hence the ranges.

[astromackem]

That's a good way of starting, say between 24-30mm for low, 14-18mm for medium, 8-11 for high. Then you can fill any gaps you think you may have later on. Magnification depends on scope focal length hence the ranges.

Cheers. Then what would the Barlow be for?

[pipnina]

Cheers. Then what would the Barlow be for?

A barlow could be useful for doubling the number of eyepeices you have. For example:

You have a 30mm, 20mm and a 10mm EP selection.

If your scope's focal length is, say 1000mm, that gives you 33, 50 and 100 times magnification with your eyepeices.

However, with a barlow (assuming a 2.0x) , you can not only chose those magnifications, but these also:

66x

100x (a little pointless because of the 10mm)

200x (This would be too high without a larger telescope or better than average seeing conditions)

I use my 2x barlow to go between my 25mm (36x on my scope) and 10mm (90x on my scope). It lands at a comfortable 72x.

[Roy Challen]

Oh yes, forgot the Barlow. Increases magnification by the factor indicated, so try to avoid duplication eg. As pipnina says if you have a 2x Barlow and a 20mm ep no need to buy a 10mm.

Some people find them useful, some find them necessary, personally I don't really get on with them. I would rather have the correct ep for the mag I want to view at. However, it does save on buying lots of EPs, and a good one can be quite unobtrusive optically (apart from doing its job of course).

One more thing - select your initial ep upgrades with usable, not maximum, magnification in mind. Too many beginners buy EPs hoping for good views at well over 200x mag, but generally in the UK we are limited to around this figure except on very rare nights. As an example, my highest possible mag with my set up is 200, but more likely I'll view Jupiter at 90-125 and have very steady sharp views which are more enjoyable than a blurry mess!

[astromackem]

Thanks everyone for this brilliant advice. Never thought I would get so interested in eyepieces

[pipnina]

Oh yes, forgot the Barlow. Increases magnification by the factor indicated, so try to avoid duplication eg. As pipnina says if you have a 2x Barlow and a 20mm ep no need to buy a 10mm.

Some people find them useful, some find them necessary, personally I don't really get on with them. I would rather have the correct ep for the mag I want to view at. However, it does save on buying lots of EPs, and a good one can be quite unobtrusive optically (apart from doing its job of course).

One more thing - select your initial ep upgrades with usable, not maximum, magnification in mind. Too many beginners buy EPs hoping for good views at well over 200x mag, but generally in the UK we are limited to around this figure except on very rare nights. As an example, my highest possible mag with my set up is 200, but more likely I'll view Jupiter at 90-125 and have very steady sharp views which are more enjoyable than a blurry mess!

Lower mags tend to be useful for windy nights as well (I found this out yesterday, I was observing venus at 180x (there isn't much detail on that planet to blur out XD).

But the 15 mph winds made it look... interesting on my wobbly mount.

[astromackem]

Well.. i've splashed out. What have I done!?

The 10% sale on Astroboot was too much to resist. Got the Skyliner 8" Dob second hand for £175.

Good deal?

[niallk]

Congrats Best of luck!!

I know you mentioned GOTO before:- a Telrad (or equivalent - not expensive) and Sky Safari app in night vision mode is very very useful for finding things imho

[pipnina]

Well.. i've splashed out. What have I done!?

The 10% sale on Astroboot was too much to resist. Got the Skyliner 8" Dob second hand for £175.

Good deal?

Decide whether it's a good deal once you have it!

But just my gut feeling: You've probably saved £100! Be happy!

[Physopto]

Hope it is all you expect. You should have many happy nights exploring the stars. It just takes a lot of time and dedicated web surfing to start getting information you will need.

Regards,

Derek

[John]

The price was a good one for a nice condition used scope. As long as you read the condition description carefully and are happy with whats described you should be fine with the scope.

[astromackem]

The price was a good one for a nice condition used scope. As long as you read the condition description carefully and are happy with whats described you should be fine with the scope.

Well the description said the only thing wrong with it was "a few creases in the tube which have no affect on the operation of the scope" otherwise in as new condition.

So I'm hoping it fine.. if not I've got 7 days to get a refund.

[John]

Well the description said the only thing wrong with it was "a few creases in the tube which have no affect on the operation of the scope" otherwise in as new condition.

So I'm hoping it fine.. if not I've got 7 days to get a refund.

Should be OK then. A few shallow dents / creases in the tube won't affect the performance of the scope. It does affect the used value though so the price was fair.