Advice on eyepieces for 10" bresser dobsonian telescope

[Jakerm1995]

I purchased a bresser 10" dob recently and would like to start investigating which eyepieces I should purchase. It's specs are '254/1270 f/5'. It comes with a 25mm eyepiece. I have been looking at an Olivon 18mm with long eye relief for a good price, I am wondering if 18mm is a good eyepiece to go for after the 25mm that I already own? I would like to purchase a 10mm so I can have 3 eyepieces to choose from (10mm, 18mm and 25mm) do think I should get 18mm or 15mm for the scope I have? 

I am a complete noob with this subject so please excuse my lack of knowledge. 

Thanks for your input!!

[johninderby]

Would strongly recommend the Nirvana eyepieces. An absolute bargain.  In fact all three of the Nirvanas would make an ideal set for the Bresser 10” starting with the 16mm. Nearly as good as the Televue Naglers at a fraction of the price.

I use the 7mm and 16mm Nirvana in my Bresser 10” dob. Did have the 4mm as well but now replaced by a Televue Nagler 3-6 zoom.  

https://www.firstlightoptics.com/ovl-eyepieces/ovl-nirvana-es-uwa-82-ultrawide-eyepieces.html

Would also recommend a 30mm to 35mm 2” eyepiece such as the Skywatcher Aero or Panaview. Good eyepieces but not too expensive.

Edited June 1, 2020 by johninderby

[Pixies]

Hi. John knows his stuff with this scope. But you can also try this for background: 

 

[johninderby]

And for lower cost but still good eyepieces there are the BST Starguiders.

https://www.firstlightoptics.com/search/for/starguider/

Edited June 1, 2020 by johninderby

[johninderby]

BTW the Olivon is the same eyepiece as the BST Starguider but more expensive.

Edited June 1, 2020 by johninderby

[Jakerm1995]

Thanks for the info... What would you use the 16mm and 7mm for with your bresser 10"? 

[johninderby]

Would use the 4mm and 7mm for lunar and planetary and the 16mm as a general all round eyepiece. For wide field use a 30  to 35 mm 2” eyepiece would replace the 25mm that came with the scope.

The srock 25mm isn’t a bad eyepiece and is usable until you get a better wide field low power eyepiece. Unlike most other brands  Bresser puts in a decemt eyepiece instead of two really cheap ones.

Edited June 1, 2020 by johninderby

[Ricochet]

If you do end up buying Starguiders instead of/as well as the Nirvanas, the 5, 8 and 12mm are the ones you should consider. The longer ones will not be well corrected in an f5 scope.

[Stardaze]

I followed John's advice with the Nirvana 16 and can say that, for the money, it's superb. I'm a believer in buying something that you'll keep for a good time and so have personally opted for a mix of 82 degree EP's (Nirvana and Explore Scientific). I did have a couple of the Starguiders, but love the wider FOV, saves you nudging the dob every two seconds and it is more immersive IMO. For mine, the core EP's are 24 (bought secondhand on here), 16, 11 & 8.8 - covers the spectrum pretty much, but I will add a few other intermediary FL's when I can.  

[johninderby]

This looks like an update to the Nirvana 28mm 2” eyepiece with a different eyecup to the old version.

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p2757_Astro-Professional-28mm-UWA-82--2--High-Perfomrance-Eyepiece.html

Old style Nirvana 28mm

https://www.365astronomy.com/SkyWatcher-Nirvana-UWA-82-deg-28mm-2-inch-Eyepiece.html

[John]

9 minutes ago, johninderby said:

This looks like an update to the Nirvana 28mm 2” eyepiece with a different eyecup to the old version.

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p2757_Astro-Professional-28mm-UWA-82--2--High-Perfomrance-Eyepiece.html

Old style Nirvana 28mm

https://www.365astronomy.com/SkyWatcher-Nirvana-UWA-82-deg-28mm-2-inch-Eyepiece.html

That is a good re-design taking on the shape that Tele Vue have used on the 31mm Nagler. The Nirvana 28, when I tested it, was a very good eyepiece but the eye cup (face cup !) did take some getting used to !

 

 

[Jakerm1995]

On 01/06/2020 at 02:16, johninderby said:

Would strongly recommend the Nirvana eyepieces. An absolute bargain.  In fact all three of the Nirvanas would make an ideal set for the Bresser 10” starting with the 16mm. Nearly as good as the Televue Naglers at a fraction of the price.

I use the 7mm and 16mm Nirvana in my Bresser 10” dob. Did have the 4mm as well but now replaced by a Televue Nagler 3-6 zoom.  

https://www.firstlightoptics.com/ovl-eyepieces/ovl-nirvana-es-uwa-82-ultrawide-eyepieces.html

Would also recommend a 30mm to 35mm 2” eyepiece such as the Skywatcher Aero or Panaview. Good eyepieces but not too expensive.

I forgot to ask, what would you use the 30mm and 35mm 2" eyepieces for with the bresser 10" dob? 

[johninderby]

Useful for low power observing of DSOs. 

[Astro_Dad]

Hi, have recently bought a few eyepieces to go with my upcoming 10 inch Skywatcher 10 inch (f/4.7) including BST’s plus the 16mm and 4mm Nirvanas. Just reading more about them having been recommended elsewhere, but good to see the experts here validate the purchase decision on a similar instrument. Also have the 30mm Aero ED. I think the 250p is slightly faster than the Bresser and have heard lots about coma - assume not really an issue visually unless using say the 30mm or other low power for sky sweeping?

When it is suggested that the longer focal length Starguiders are not as well corrected for short focal ratio scopes, does that mean in terms of coma and/ or field curvature? 

Any idea how well the 7mm OVL compares to a good quality ortho?

Thanks,
AD

[Ricochet]

43 minutes ago, Astro_Dad said:

coma - assume not really an issue visually unless using say the 30mm or other low power for sky sweeping?

It will depend on how sensitive your eyes are to it and the apparent field of view of the eyepiece. The wider the apparent field, the more you will see coma towards the edges. 

45 minutes ago, Astro_Dad said:

When it is suggested that the longer focal length Starguiders are not as well corrected for short focal ratio scopes, does that mean in terms of coma and/ or field curvature? 

The 18 has a combination of field curvature and astigmatism(?), the 25mm has astigmatism. 

[Astro_Dad]

Thanks Ricochet - both probably better suited to longer focal length instruments then. I’ll do more research. 
If coma becomes a concern in the future, would you recommend a coma corrector and if so what would be a reasonable entry level one to test (if at all possible - the Paracorr looks to be the “standard” but is expensive relative to the cost of the scope). 
 

AD

[Louis D]

1 hour ago, Astro_Dad said:

If coma becomes a concern in the future, would you recommend a coma corrector and if so what would be a reasonable entry level one to test (if at all possible - the Paracorr looks to be the “standard” but is expensive relative to the cost of the scope).

I use a GSO/TPO/Revelation coma corrector with a 25mm spacer ring between the eyepiece holder and the optics section.  As long as your eyepieces focus within 5mm of their shoulder in that configuration, at least 90% of the coma will be corrected along with flattening the field slightly.  It appears to be currently unavailable in the UK in any branding.

[Astro_Dad]

21 minutes ago, Louis D said:

I use a GSO/TPO/Revelation coma corrector with a 25mm spacer ring between the eyepiece holder and the optics section.  As long as your eyepieces focus within 5mm of their shoulder in that configuration, at least 90% of the coma will be corrected along with flattening the field slightly.  It appears to be currently unavailable in the UK in any branding.

OK thanks Louis, will take a look.