Which eyepiece?

[AstroNebulee]

Hi

I have a clestron cometron 76x300mm scope and have a barlow x2, 20 mm and 10 mm eyepiece, what other size EP would you recommend for viewing the moon.

[DaveL59]

are those the OEM eyepieces Lee and how are you finding them?

Surprised they went with 20 & 10 plus barlow as the 20+barlow would be a 10. With my little NatGeo 76/350 it came with junk H20 and seriously junk SR4 so at least maybe you got something better in the kit you have. I updated that scope with a low cost plossl pair off a seller on the bay, to a 25mm and 6.5mm which included a green moon filter and tho they're non-standard filter thread they work very nicely in this little scope. I don't recall using the 6.5mm barlowed but then these days I don't really use this scope much at all.

With the EP's you have you effectively get 20/10/5mm with barlow and at 5mm.

I think the limit for your scope will be its max magnification which I guess is really limited to x150 ish so going for shorter focal lengths will probably not gain much, since the small mirror would result in dark views and loss of detail. A wider view at lower mag at 25mm should work ok, not sure if a 32mm would but of course you can transfer that to another scope as(if) you upgrade later. With the barlow that'd give 25/12.5mm or 32/16mm which fill the gaps a little.

I guess a pertinent question would be - what are you hoping to see? more magnification on targets like the moon? or clusters and deeper sky objects?

[AstroNebulee]

HI Dave

 

The 20 and 10 mm EP came with the scope , i bought the Barlow in my inexperience.  Mainly id like to get good detail of the moon and planets really.  So you think a 25mm EP would be good?

[AstroNebulee]

When i put the barlow on the 20mm ep the focus wont go any further to get a clear view as its blurred when viewing the moon but i guess when viewing further away objects would pull into focus

[Waddensky]

40 minutes ago, LeeHore7 said:

The 20 and 10 mm EP came with the scope , i bought the Barlow in my inexperience.  Mainly id like to get good detail of the moon and planets really.  So you think a 25mm EP would be good?

If you want to see better details on the planets and the Moon, you'll need more magnification (and thus a shorter focal length eyepiece). The FirstScope is more of a widefield telescope due to the short focal length and (if I recall correctly) spherical primary mirror. Your 10 mm eyepiece combined with the 2x barlow gives a magnification of 60x, I think that's about it unfortunately.

A larger dobson, a 150/1200 for example, will have a higher resolution, larger focal length and a parabolic primary mirror that will all help to achieve higher magnifications. But that would require an investment in a new scope.

But I'm sure you'll be able to see more detail with you current setup once you've built up experience. It's often overlooked, but you'll develop a sharp eye for detail and the ability to detect very faint objects if you use your scope regularly. I've been observing with a 76 mm scope for years and in the end I was able to see details and split double stars I could only dream of when I was just beginning.

[DaveL59]

1 hour ago, LeeHore7 said:

When i put the barlow on the 20mm ep the focus wont go any further to get a clear view as its blurred when viewing the moon but i guess when viewing further away objects would pull into focus

which barlow did you get as it doesn't sound like it suits your scope?

In terms of more detailed view then as above you'd need more mag which that barlow "should" give you if you could find focus with it. the 20+Barlow should give the same mag as the 10mm on its own, but with a little more eye relief. The 10+barlow would give you an effective 5mm and so more mag but without losing the eye relief vs a 5mm eyepiece. This might be enough for what you want to have at this time.

The 32mm or 25mm would give less mag but a wider field of view which might be nice when panning around the sky at constellations etc but perhaps isn't what you need right now.

Going back to the barlow, I think you'd maybe need something like the Orion shorty barlow, but lets see what you have first. If the lens end on the barlow you have unscrews from the barrel, does it fit onto the eyepiece barrel and reach focus that way? More fiddly in the dark but saves buying another in the short term  

[AstroNebulee]

8 minutes ago, Waddensky said:

If you want to see better details on the planets and the Moon, you'll need more magnification (and thus a shorter focal length eyepiece). The FirstScope is more of a widefield telescope due to the short focal length and (if I recall correctly) spherical primary mirror. Your 10 mm eyepiece combined with the 2x barlow gives a magnification of 60x, I think that's about it unfortunately.

A larger dobson, a 150/1200 for example, will have a higher resolution, larger focal length and a parabolic primary mirror that will all help to achieve higher magnifications. But that would require an investment in a new scope.

But I'm sure you'll be able to see more detail with you current setup once you've built up experience. It's often overlooked, but you'll develop a sharp eye for detail and the ability to detect very faint objects if you use your scope regularly. I've been observing with a 76 mm scope for years and in the end I was able to see details and split double stars I could only dream of when I was just beginning.

Thank you for your reply and comments which are taken on board.  What kind of upgrade to this do you recommenced eg aperture size would a 114, 127, 130 be any good, my budget is tight mybe upto £150-180

 

[AstroNebulee]

13 minutes ago, DaveL59 said:

which barlow did you get as it doesn't sound like it suits your scope?

In terms of more detailed view then as above you'd need more mag which that barlow "should" give you if you could find focus with it. the 20+Barlow should give the same mag as the 10mm on its own, but with a little more eye relief. The 10+barlow would give you an effective 5mm and so more mag but without losing the eye relief vs a 5mm eyepiece. This might be enough for what you want to have at this time.

The 32mm or 25mm would give less mag but a wider field of view which might be nice when panning around the sky at constellations etc but perhaps isn't what you need right now.

Going back to the barlow, I think you'd maybe need something like the Orion shorty barlow, but lets see what you have first. If the lens end on the barlow you have unscrews from the barrel, does it fit onto the eyepiece barrel and reach focus that way? More fiddly in the dark but saves buying another in the short term  

Hi Dave

Thank you for your reply. I have to say what kind and thoughtful members are on here and don't take the mickey or judge beginner users.  The barlow lens i have is just a bog standard normal one and not branded (my inexperience again buying this and not expensive so cheap meant crap) Sadly the lens from the barlow i have doesnt screw on correctly to my 20mm or 10mm ep so i think I'll need a new barlow lens.  Do you think the celestron branded one or the orion shorty be best for my celestron 76x300mm scope and what is a reasonable price youd pay for them. Sorry for being this inexperienced but thank you for your comments.

[DaveL59]

if you'd like to make a jump would you stick with a reflector?

I'd suggest if so that 130 or 150 would be a reasonable jump as that's a lot more light capture than the 76. Anything below 130 and you'd largely be wasting the funds, you'll hardly notice much going to a 114 for example. I have a TAL-1 (110) and SW130 and you'd be pushed to notice much difference, tho the TAL's do punch above their weight. 

Something like a SW heritage 130 flextube may suit since you're using a table-top DOB type scope and seem comfortable with that. You may want to rig a shroud around the open part of the tube though to block stray light. It's a scope lots here recommend and its easily portable and gives good views, should suit well for taking pics through the eyepiece as you've also been trying  

 

[DaveL59]

29 minutes ago, LeeHore7 said:

Hi Dave

Thank you for your reply. I have to say what kind and thoughtful members are on here and don't take the mickey or judge beginner users.  The barlow lens i have is just a bog standard normal one and not branded (my inexperience again buying this and not expensive so cheap meant crap) Sadly the lens from the barlow i have doesnt screw on correctly to my 20mm or 10mm ep so i think I'll need a new barlow lens.  Do you think the celestron branded one or the orion shorty be best for my celestron 76x300mm scope and what is a reasonable price youd pay for them. Sorry for being this inexperienced but thank you for your comments.

no probs Lee, we all started as beginners after all and I'm not that expert myself lol. I can't say re the celestron barlow but I'd guess the short omni would work. The gear I mainly have is TAL so I've TAL barlows you see, tho the Barlow that came with the SW130 I have works well in my 76/350 so I'd expect both the others mentioned would work too. The Orion gets a lot of recommendations hence mentioning that one specifically. As to price, hard to say, if you're lucky to find a good one used then 60% of new price is fair. Harrisons list the Omni at £25 but out of stock, so its not an expensive one, going up the range may be better if you're staying with the hobby and looking at later upgrades.

Edited May 7, 2020 by DaveL59

[Waddensky]

41 minutes ago, LeeHore7 said:

Thank you for your reply and comments which are taken on board.  What kind of upgrade to this do you recommenced eg aperture size would a 114, 127, 130 be any good, my budget is tight mybe upto £150-180

 

The Sky-Watcher Heritage Dave is suggesting is a great upgrade. It's a tabledob just like the FirstScope. A 150mm dobson, the Sky-Watcher Skyliner 6" for example, would also be a decent upgrade but it's outside your budget (if I roughly convert EUR to GBP). It's also quite a large scope, keep that in mind if you need to trave to a dark site.

Edited May 7, 2020 by Waddensky

[DaveL59]

oh if you do decide to go for the heritage, don't go buying a barlow for the current scope yet  

Doesn't look like the 130 comes with one but on the FLO page they've a recomended one which should work with no issues.

https://www.firstlightoptics.com/beginner-telescopes/skywatcher-heritage-130p-flextube.html

[AstroNebulee]

31 minutes ago, DaveL59 said:

if you'd like to make a jump would you stick with a reflector?

I'd suggest if so that 130 or 150 would be a reasonable jump as that's a lot more light capture than the 76. Anything below 130 and you'd largely be wasting the funds, you'll hardly notice much going to a 114 for example. I have a TAL-1 (110) and SW130 and you'd be pushed to notice much difference, tho the TAL's do punch above their weight. 

Something like a SW heritage 130 flextube may suit since you're using a table-top DOB type scope and seem comfortable with that. You may want to rig a shroud around the open part of the tube though to block stray light. It's a scope lots here recommend and its easily portable and gives good views, should suit well for taking pics through the eyepiece as you've also been trying  

 

Thanks Dave, great advice taken on board.  I have seen the SW heritage 130 flexitube before and wasn't sure about the missing shroud but will research it on the on the internet more and around £142.  Yes I'm comfortable with the table top dob style scopes so far. On the issue of the barlow lens Iv'e seen an orion one for £31 on amazon

https://www.amazon.co.uk/Orion-08711-Shorty-1-25-Inch-Barlow/dp/B0000XMWQW/ref=sr_1_1?dchild=1&keywords=orion+shorty&qid=1588871210&s=electronics&sr=1-1

 

[DaveL59]

seems not too bad a price, the FLO listing shows an astro essentials one for £25 tho so could order that with the 130 and get it all at once, with the usual clouds included of course  

As to a shroud, you can maybe make one up yourself rather than buying something custom and more expensive, I'm sure others here have done so and could advise on that.

[AstroNebulee]

HI Dave and Waddensky, Thank you again, i will not invest in the barlow if i choose the sw heritage130, but will do more research. Thanks guys!

[AstroNebulee]

Hi

I've given the sw heritage 130 some serious thought and added to my wish list as I have a birthday coming up in a few months time so maybe, but definitely will be my next scope. I've ordered the Celestron 93640 1.25 Inch Universal Barlow and T-Adaptor and a nikon t ring adapter as my dad said I could use his nikon dslr to take photos with so will stay with what I have for now and get into it more, if that makes sense. 

[cletrac1922]

Lee

First of all welcome from Land Down Under

For lunar viewing, would not go past a 25mm, as will then fit in the entire moon, lower magnification will tend to show one section

With my 10" flex Dob, with planets and other DSO, I use a 17mm

Find the 17mm and 15mm ideal when out doing presentations in scout groups, K-7, primary schools, as gives good eye relief for young eyes

Have a 2 X barlow, which have used on a few rare occasions, mainly trying to split double star Alpha Centauri with my ED80

John

[DaveL59]

that's mighty nice of him Lee, hopefully it'll be able to reach focus in your scope and you can get some nice afocal images if the clouds let us have a peek at the night sky again. Be prepared for a learning curve doing this though, but plenty here to advise when you need it  I've yet to get around to buying a DSLR, plan was to get a full-frame Minolta as I still have my old film SLR and lenses, but then they got bought by Sony and when the full-frame came out the price was eye-watering! So still on the fence on which way to go on that really.

For the barlow, sounds like a decision made, looks quite like the one I got with the SW130 scope I have and is quite usable. You can unscrew the barlow element off the end and fit that onto the end of an eyepiece too, which I think would give around x1.4 which can be handy. It'll be one you can use on the upgrade when you do go for the 130 and useful to have to extend the range of mag, tho maybe not the best for imaging, others will be able to advise better on that.