What would be a good planetary eyepeice for 72mm f6?

[stafford_stargazer]

On 14/02/2023 at 14:49, badhex said:

From personal experience with a ZS73 F5.9, I found the 5mm BST to be around the comfortable limit a lot of the time. I never enjoyed using the 3.2mm with it. 

Although it doesn't really count as planetary for those looking for a 'pure' /limited glass experience, the Morpheus 4.5mm also works well with that scope. 

If you do want to go with minimal glass, BCO 6mm, or 10mm with a high quality barlow also works well as @jetstream says. In fact, the 10mm BCO plus barlow gives you additional ER which is helpful, as it can be very tight with orthos on a scope like that. 

Which Barlow would you recommend without spending on a televue powermate which alot of people say are superb?

Thanks Gary 

 

[RT65CB-SWL]

Following on from the TeleVue DeLite’s mentioned earlier, I would suggest the predecessor… Radian’s. I have a 6 and 8mm.

When it comes to zoom e/p’s I have a choice between the TeleVue Nagler 3-6mm zoom and the Svbony SV215 3-8mm zoom.

[badhex]

6 hours ago, stafford_stargazer said:

Which Barlow would you recommend without spending on a televue powermate which alot of people say are superb?

Thanks Gary 

The Powermates are indeed excellent, but they are actually a slightly different design to a standard barlow, and would be less help here because they generally maintain the same eye relief of whatever EP you are using. A barlow will push the exit pupil further out towards your eye, meaning more eye relief which is helpful in this situation. 

TeleVue do a Barlow which is quite a bit less than the Powermates, but a more wallet friendly option would be the GSO 2.5x Barlow which is very good quality and very reasonably priced. I have used this very same barlow in combination with my BCO 10mm and ZS73 to good effect, and is definitely more comfortable than using the BCO 10mm + Powermate 2.5x + ZS73

The only problem is I can't see to find it in stock anywhere for you. I think TS-Optics have a rebadged version, otherwise have a dig about on the Internet for "GSO 2.5x Barlow", sometimes listed as ED or semi-apo. You could call a few suppliers to see if they can get hold of it, I got the below picture from 365astronomy.com who have it listed but not in stock. 

Edited February 17 by badhex
Missed half a paragraph off

[badhex]

On 14/02/2023 at 15:49, badhex said:

From personal experience with a ZS73 F5.9, I found the 5mm BST to be around the comfortable limit a lot of the time. I never enjoyed using the 3.2mm with it. 

Two additional points on this btw: One reason I mentioned the 5mm BST often being "the comfortable limit" is not because I think the scope can't handle higher magnification (it definitely can) but more because sky conditions are often the limiting factor.

Second reason is that I've never got on with the BST 3.2mm in my two main use scopes (ZS73 F5.9 and TS102 F7) for some reason, but that's possibly just personal preference. 

[Louis D]

1 hour ago, badhex said:

Second reason is that I've never got on with the BST 3.2mm in my two main use scopes (ZS73 F5.9 and TS102 F7) for some reason, but that's possibly just personal preference. 

Experienced observer Jon Isaacs over on CN also has issues with the 3.2mm BST off axis.  He prefers the 5mm BST Barlowed.  The 3.2mm Paradigm (BST Starguider) is the only one I don't have and have never looked through, but the 5mm that I do have is quite good.

If you've got the budget, the 3.5mm Pentax XW is basically flawless.  However, it's a rare night even here in Texas that it shows any more detail on an object than my 5.2mm Pentax XL, so I don't tend to use it much.  Perhaps if I had an f/4 Dob it might see more use.

[badhex]

10 minutes ago, Louis D said:

Experienced observer Jon Isaacs over on CN also has issues with the 3.2mm BST off axis.  He prefers the 5mm BST Barlowed.  The 3.2mm Paradigm (BST Starguider) is the only one I don't have and have never looked through, but the 5mm that I do have is quite good.

If you've got the budget, the 3.5mm Pentax XW is basically flawless.  However, it's a rare night even here in Texas that it shows any more detail on an object than my 5.2mm Pentax XL, so I don't tend to use it much.  Perhaps if I had an f/4 Dob it might see more use.

Thanks @Louis D it's good to hear that I'm not on my own! I also like the 5mm and would still use it had I not replaced it with a 4.5mm Morpheus. I also tend to find I don't need more than that on most nights. 

[Ags]

I have been pondering this for my small refractors, and the solution I am currently saving for is the Svbony 3-8 zoom.