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10 minutes ago, Astro_Nic said:

Thanks, I will take a look.

Now trying to get an idea of eyepieces and binoviewers / barlows / comma correction etc....seems a mine field for a beginner!  Cheers

 

I use three eyepieces. That's it. In my SCT, with long focal length, I use only two. I never ever feel the need for more, but the ones I have are top quality.

Olly

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With my Orion Optics 12 inch F/5.3 dobsonian (focal length 1600mm) I find that I use eyepieces of the following focal lengths the most:

21mm (76x)

13mm (123x)

8mm (200x

6mm (267x)

4.7mm (340x)

I prefer eyepieces with a very wide angle of view (100 degrees) to maximise drift times of targets in the undriven scope, plus I just like the hyper-wide views :smiley:

I don't use binoviewers with the scope - if I did I would need to change to eyepieces with smaller fields of view because the hyper-wides would be too fat !

I don't use a coma corrector with my scope but if you go for something that is F/5 or faster (eg: F/4.5) and opt for wide field eyepieces then you may well need to so that coma generated by the scopes mirror does not mar your lovely wide views.

 

Edited by John
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Yeah I probably need more basic help.....what makes will work with f4.6.....what are good FL of the eyepieces.....what eye relief do I need (not clear what that is!).....what field of view would be best - people have said 'large', but what is large?  Do I need 100 degree or is 80 degree large....etc.....  Thanks everyone!

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3 minutes ago, John said:

With my Orion Optics 12 inch F/5.3 dobsonian (focal length 1600mm) I find that I use eyepieces of the following focal lengths the most:

21mm (76x)

13mm (123x)

8mm (200x

6mm (267x)

4.7mm (340x)

I prefer eyepieces with a very wide angle of view (100 degrees) to maximise drift times of targets in the undriven scope, plus I just like the hyper-wide views :smiley:

I don't use binoviewers with the scope - if I did I would need to change to eyepieces with smaller fields of view because the hyper-wides would be too fat !

I don't use a coma corrector with my scope but if you go for something that is F/5 or faster (eg: F/4.5) and opt for wide field eyepieces then you may well need to so that coma generated by the scopes mirror does not mar your lovely wide views.

 

Thanks John

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4 minutes ago, John said:

With my Orion Optics 12 inch F/5.3 dobsonian (focal length 1600mm) I find that I use eyepieces of the following focal lengths the most:

21mm (76x)

13mm (123x)

8mm (200x

6mm (267x)

4.7mm (340x)

I prefer eyepieces with a very wide angle of view (100 degrees) to maximise drift times of targets in the undriven scope, plus I just like the hyper-wide views :smiley:

I don't use binoviewers with the scope - if I did I would need to change to eyepieces with smaller fields of view because the hyper-wides would be too fat !

I don't use a coma corrector with my scope but if you go for something that is F/5 or faster (eg: F/4.5) and opt for wide field eyepieces then you may well need to so that coma generated by the scopes mirror does not mar your lovely wide views.

 

If I were to start with two eye pieces, which ones would you recommend?  If I get quality eyepieces I won't be able to get 5!  

Would you recommend a x2 Barlow as well?

 

Cheers

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Do you wear glasses and, if so, are you likely to need to wear them when observing ?

This will affect the spec of the eyepieces you consider.

I tend to think of "normal" eyepiece fields of view being in the 50-60 degree range, wide angle 65-72 degrees, ultra-wide 76-82 degrees and hyper-wide 90 degrees plus.

 

 

 

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For the same reasons as others, I'd suggest that to start with you buy second-hand.  Even though I could afford new I did just that, and if you can see my signature you'll see that I've got both 8 inch and 10 inch OOUK Dobsonians.  Both are VX models with 1/10th wave optics.  The reason I've got 2 sizes is that I wanted a 10 inch, but it took ages to find one.  In the meantime I found an 8 inch, that is much more common.  

10 inches is the most I can handle, and some days I can't even manage that, but I'm somewhat disabled.  I suspect that as you're young and fit you'd be able to cope with a 12 inch.  The 14 inch is much heavier and bulkier though, especially if  like the OOUK VX it's a closed tube design.  Don't neglect the bulk, as a bulkier scope is more difficult to carry even if it weighs the same.  Additionally, the standard OOUK 12 inch is an f/4 so will fit into most cars, including across the back seat.

An additional factor is that the bigger the scope, the longer it takes to cool down before the image is sharp.  You may need up to a couple of hours with a 14 inch Dob.

The bigger the Dobsonian, the more it depreciates.  This particularly applies to the more upmarket makes.  For instance, you should be able to find a second-hand 10 inch OOUK Dob for perhaps £500, leaving more funds for other items.  They'll be plenty of these such as eyepieces, a coma corrector, a binoviewer, and maybe an equatorial platform.

This is what I did, and in particular it left funds for a high quality 72mm f/6 refractor.  Many of us, even if we just stick to visual, end up with a light bucket Dobsonian plus a grab 'n go refractor, that because of its shorter focal length has a much wider field of view.  Such a scope is also great for holidays, plus for observing the sun in h-alpha.  For the latter I use a Quark and, as the focal length is less than 450mm I can see the whole disc plus prominences.

Finally, almost all experienced astrophotographers will recommend a small/medium refractor of about this size rather than a reflector.  So it would be more useful for future possible astrophotography than a big Dobsonian.  By far the most important component for astrophotography though is the mount, and this alone can cost more than all the rest of the scope.

Edited by Second Time Around
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If you order a new dobsonian from Orion Optics at least you will have plenty of time to research accessories for it before it arrives :grin:

 

 

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22 hours ago, Second Time Around said:

For the same reasons as others, I'd suggest that to start with you buy second-hand.  Even though I could afford new I did just that, and if you can see my signature you'll see that I've got both 8 inch and 10 inch OOUK Dobsonians.  Both are VX models with 1/10th wave optics.  The reason I've got 2 sizes is that I wanted a 10 inch, but it took ages to find one.  In the meantime I found an 8 inch, that is much more common.  

10 inches is the most I can handle, and some days I can't even manage that, but I'm somewhat disabled.  I suspect that as you're young and fit you'd be able to cope with a 12 inch.  The 14 inch is much heavier and bulkier though, especially if  like the OOUK VX it's a closed tube design.  Don't neglect the bulk, as a bulkier scope is more difficult to carry even if it weighs the same.  Additionally, the standard OOUK 12 inch is an f/4 so will fit into most cars, including across the back seat.

An additional factor is that the bigger the scope, the longer it takes to cool down before the image is sharp.  You may need up to a couple of hours with a 14 inch Dob.

The bigger the Dobsonian, the more it depreciates.  This particularly applies to the more upmarket makes.  For instance, you should be able to find a second-hand 10 inch OOUK for perhaps £500, leaving more funds for other items.  They'll be plenty of these such as eyepieces, a coma corrector, a binoviewer, and maybe an equatorial platform.

This is what I did, and in particular it left funds for a high quality 72mm f/6 refractor.  Many of us, even if we just stick to visual, end up with a light bucket Dobsonian plus a grab 'n go refractor, that because of its shorter focal length has a much wider field of view.  Such a scope is also great for holidays, plus for observing the sun in h-alpha.  For the latter I use a Quark and, as the focal length is less than 450mm I can see the whole disc plus prominences.

Finally, almost all experienced astrophotographers will recommend a small/medium refractor of about this size rather than a reflector.  So it would be more useful for future possible astrophotography than a big Dobsonian.  By far the most important component for astrophotography though is the mount, and this alone can cost more than all the rest of the scope.

There's a 12 inch OOUK tube assembly on UK Astronomy Buy/Sell.  Go to https://www.astrobuysell.com/uk/propview.php?view=177296

It includes a Losmondy plate for an equatorial mount, but instead I'd suggest you buy a Dobsonian mount from OOUK as a 12 inch equatorial is a beast!.  These OOUK Dobs are really excellent.

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Hello @Astro_Nic and welcome to SGL.

You have a good budget but I would suggest you start with a modest 12” Dobsonian to gauge how things work in the real world before shelling  out a lot of money.

My suggestion would be this scope……

https://www.firstlightoptics.com/stellalyra-telescopes/stellalyra-12-f5-dobsonian.html

Plus a couple of good eyepieces, the 22 and 9 from this range would be very good…… but there are lots of others.

https://www.firstlightoptics.com/tele-vue-eyepieces/tele-vue-nagler-82-degree-eyepieces.html

Also large mirrors like this take a long time to cool down when you take them out so you will have to factor in thermal management time.

And the optics will occasionally need to be aligned to each other (collimation) for best optical results - it’s easy when you have done it a few times and there are lots of guides on the net. 

Edited by dweller25
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