Eyepiece/ Barlow for AR-80 640mm acro.

[Don Pensack]

No 5 year old should use a telescope unsupervised.

Unless the 5 year old is 5 going on 12, the scope would be destroyed in no time, by falling over and maybe on the child!

Mom or Dad will need to be present at the scope with the child at all times.

 

[Adam J]

19 minutes ago, Don Pensack said:

No 5 year old should use a telescope unsupervised.

Unless the 5 year old is 5 going on 12, the scope would be destroyed in no time, by falling over and maybe on the child!

Mom or Dad will need to be present at the scope with the child at all times.

 

Thanks, but it does not take my master's degree in physics to have worked that out for myself. 

[Adam J]

5 hours ago, Mark at Beaufort said:

I have a SvBony 90mm 5.5 Acho which I rate very well. I usually use a SvBony 7-21 zoom which works very well. To be honest I have never used my Televue Ethos 6mm EP  on this set up and my 3-6mm Nagler zoom has been used but it's been a long time ago and I cannot remember how it performed.

So for the money the SvBony frac and the EP are great value and I would recommend them for anybody never mind a 5 year old although I appreciate the owner has bought the scope. If I was thinking of changing the EP I would consider a zoom to Adam J.

Honestly, thinking about cancelling it and for one of these instead. 

https://www.firstlightoptics.com/sky-watcher-az-pronto/sky-watcher-skymax-102s-az-pronto.html

Or this

https://www.firstlightoptics.com/sky-watcher-az-pronto/sky-watcher-evostar-90-660-az-pronto.html

 

[vlaiv]

2 minutes ago, Adam J said:

Honestly, thinking about cancelling it and for one of these instead. 

https://www.firstlightoptics.com/sky-watcher-az-pronto/sky-watcher-skymax-102s-az-pronto.html

Or this

https://www.firstlightoptics.com/sky-watcher-az-pronto/sky-watcher-evostar-90-660-az-pronto.html

 

Both very fine choices and deciding factor should be based on planetary/lunar vs wide field priority.

Mak can also be used on DSO. Most people say that they feel boxed in with Mak102, as if it only provides very narrow field of view, but I don't think that is necessarily true.

It has only 100mm longer FL than most often recommended beginner (and in reality lifetime) scope - 200p dob. Former has 1300mm while later has 1200mm - not much of a difference, so FOV is almost the same with same eyepieces. I don't hear many dob owners complaining that they feel boxed in even when not using 2" eyepieces (I know I was certainly happy with 200p dob and 32mm plossl).

Only thing that Mak won't do well is of course wide field views, but it will do lunar and planetary very well with decently priced eyepieces (~10mm plossl/ortho is still usable as far as eye relief and will provide one with x130 on Mak).

 

[Don Pensack]

4 hours ago, vlaiv said:

Both very fine choices and deciding factor should be based on planetary/lunar vs wide field priority.

Mak can also be used on DSO. Most people say that they feel boxed in with Mak102, as if it only provides very narrow field of view, but I don't think that is necessarily true.

It has only 100mm longer FL than most often recommended beginner (and in reality lifetime) scope - 200p dob. Former has 1300mm while later has 1200mm - not much of a difference, so FOV is almost the same with same eyepieces. I don't hear many dob owners complaining that they feel boxed in even when not using 2" eyepieces (I know I was certainly happy with 200p dob and 32mm plossl).

Only thing that Mak won't do well is of course wide field views, but it will do lunar and planetary very well with decently priced eyepieces (~10mm plossl/ortho is still usable as far as eye relief and will provide one with x130 on Mak).

 

And the Mak is a lot shorter, so less of a wind sail for the mount, and less variation in eyepiece height from horizon to zenith, making it more practical for a shorter observer.

[Adam J]

2 hours ago, Don Pensack said:

And the Mak is a lot shorter, so less of a wind sail for the mount, and less variation in eyepiece height from horizon to zenith, making it more practical for a shorter observer.

Yes one of many reasons I don't want a dob, not practical for a child. Even the table top ones are not great as they just end up leaning on the table and seeing nothing. 

[RT65CB-SWL]

My TeleVue Ranger is 70mm obj. - 480mm f/l - f6.85 and use either a 1.8 TeleVue Barlow or a x2.88 Klee barlow. So you have to be pretty quick with maths, (of which I am not), to work out the total magnifications are, if asked by 'joe public' at a star party, if not written down or saved on a mobile phone and/or tablet, etc.

Another option maybe a 'Magni-Max'. These are/were made by AstroEngineering and are x1.6 (now available at x1.5) and screws into the thread of a 1.25" nosepeice of an eyepiece or star diagonal. They also released a x0.6 focal reducer (now available at x0.5). Both maybe available elsewhere, or under different brand names, as I think AstroEngineering has entered a 'black hole'.

Edited September 19, 2022 by Philip R

[Second Time Around]

I'd recommend a dual 1.5x/2x Barlow. These dual 1.5x/2x Barlows allow the black lens cell to be unscrewed from the body of the Barlow and then screwed into the filter thread at the bottom of an eyepiece to give approx 1.5x.

Thus you'd treble the number of magnifications you'd have.

I've got this one https://www.firstlightoptics.com/barlows/astro-essentials-125-2x-barlow-with-t-thread.html

Cost is only £25.