Advice please..

[cumbrian stargazer]

Hi all,as you can see by number of posts i am new to all this.I have the skywatcher 8"dob and the two lens that came with her,10mm and 25mm,could do with a little help on which barlow to choose and any other lens i should consider ? also advice on a pair of binos would be great,thanks in advance for your help,Neil 

[tuckstar]

Any 10x50 bins will show you some nice widefield views. As with all kit the more you spend the better the quality.

As for eyepieces, I would look to upgrade your existing set before worrying about a barlow. I'm not a fan of barlows for visual. Too much glass. If you can, join a local club and see what people have. An eyepiece could be the best on the market and still not be suited to your eyes. I have heard great reviews of the celestron xcel range, but when I tried them I couldn' get on with the eye relief. Horses for courses. That said people seem to regularly recommend the bst range. I'd recommend the Baader hyperions for your scope. Second hand you can pick them up for around £50.

[alanjgreen]

Cumbrian stargazer,

if your scope is new then don't buy anything now!

use what you have for the first couple of months and get to grips with the scope.

you will soon learn what you want to improve on and that will help you buy stuff you actually need.

no point buying stuff only to have to sell it shortly after.

buying a Barlow is not necessarily a great idea. It could double the power of your 25 to make it a 12.5. You already have a 10 so the 12.5 would be almost the same.

if you double the 10mm to a 5mm then this may be too much for your scope.

read up on how to calculate magnification for your scope

scope focal length/magnification = eyepiece focal length

1200/10=120 (a 10mm eyepiece in a 1200mm focal length scope gives x100 magnification)

what you need is a nice spread of magnifications so you can match the target size and the uk atmospheric conditions on any given night.

a nice spread is a spread with gaps of x50 (gaps of less than x50 do not show much difference at the eyepiece)

so a set of eyepieces giving x50, x100, x150, x200 and x250 would be a great set

 

next eye relief, if you wear glasses then you need eyepieces with stated eye relief of more than 15mm (distance from top lens to eyeball is called eye relief)

finally, field of view. If your dob is manual nudge like mine then you need eyepieces with stated field of view greater than 70 degrees. This means you see a wider sky in the eyepiece and the target will stay in view for longer and mean less nudging of the scope by you is required. At high powers, objects will fly across the field of view (FOV).

read up on the above and try with the equipment you have.

spend your money in a couple of months when you will know more about what you want  

clear skies, Alan

if you are desperate to buy something, then buy the book "turn left at Orion" , this will help you find more targets and shows pics of what you can expect to see... best book I ever bought when I was new!

https://www.amazon.co.uk/Turn-Left-Orion-Hundreds-Telescope/dp/0521153972/ref=sr_1_1?s=books&ie=UTF8&qid=1514545549&sr=1-1&keywords=turn+left+at+orion

[scarp15]

Hi, a 6mm will provide 200x, 1.0mm exit pupil, a useful focal length for high power. 20mm 60x 3.3mm exit pupil for medium / low power perhaps. Wide, ultra wide field eyepieces are desirable with nudging a dob. Brand options could include Explore Scientific, dependant on budget, used TeleVue Delos i.e. at 6mm, 8mm (150x), 10mm (120x) a consideration. Also consider a quality filter such as an OIII. I do not use a barlow, I like to use varied focal length eyepieces, as Alan has stated, retaining good eye relief and extended field of view. Binoculars could include 10x50, I use 16x70 as personal preference.  

[rwilkey]

As with others, I would recommend waiting for a few months and get used to using the scope with the eyepieces that came with it, unless you do this you will not appreciate any improvements later.  I would NOT recommend the Baader Hyperions as they do not work so well in 'fast' focal ratios like yours, they will get a bit soft at the edges so steer clear of these.  The BST StarGuiders are good options for your scope, but as I say, leave it for awhile.  Clear Skies!

[ronl]

Robin recommended the BST Starguiders s good few years ago, to me, and I love them,

they are really good value for money, the twist up eyecups make them a joy to use, I find

them very comfortable, take your time, and get familiarised with your kit before you buy,

then you will have an idea to what focal lengths you need. Good luck.

Clear Sky's.

 

[cumbrian stargazer]

Thank you all for your advice,as pointed out i will wait on the eyepieces until i am more comfortable with the scope but look at the above mentioned book and binos. Take care Neil

[ronin]

Binoculars - 8x42's. They are the most popular in the birding fraturnity and they are so because they do everything pretty well. I have Bushnell's but any good set will do you. Don't go mad on an expensive pair unless you want them specifically and likely for something else such as serious birding. My approiach is that with binoculars you look around you do not so much look at.

Eyepieces, I tend to think most will consider additional eyepiece fairly quick. Part of looking at the skies is to get the best enjoyment you can from it and the supplied items are not great so not so much enjoyment.

Ignoring the pair you have then consider 30mm, 20mm, 12mm and maybe one shorter at 8mm. I have used some of the BST focal lengths here are they are popular. I have a set and a half of them. They are £50 each however, equally so is a good plossl these days - Vixen NPL's.

Vixens go in 5mm steps more or less, so 30, 20, 10, 8 (yes I know 8mm is not 5 away). If BST's then 25mm, 18mm, 12mm, 8mm. You could possibly leave the 18mm out for a while. I do not use a barlow. If you got the 25mm, 12mm and 8mm and a barlow you do not gain much. The 12mm is the 25mm barlowed and the 8mm barlowed may be too much. So in a way only the 12mm barlowed produces anything. May as wekll just buy a 6mnm eyepiece.

You could go buy the GSO = Revelation plossl's. They are less cost and generally fairly good. But the BST's will last you a lifetime. If you waear glasses then plossl's have drawbacks.

[Timebandit]

 

 

Hi and welcome to SGL .

If you feel like the eyepieces that have come with the scope are the weakest link in the optical chain then my advice is to change them.

Most stock eyepieces that come with the scope are usually put in with the kit as a cheap way to get you going on the scope. They will not be the best quality or the widest field ect.

The usually step up in quality of an eyepiece over stock of many members is something like a BST starguiders, fov of 60d and eye relief of around 18mm and optically good. In your position I would buy one and compare it to your existing stock eyepieces. If you can see a marked difference then you are on the right track. At around £50 new or £35 used then a BST is a worthwhile upgrade in many users eyes.

As for Barlow, personal preference is I am not a big fan of a Barlow. But if you do wish to go down this route. Then you will need to buy a quality one IMO like a powermate,as otherwise you run the risk of an inferior one degrading the image. A Barlow should only introduce magnification, if it degrades the image then it's not worth adding to the optical chain IMO