Do I need a Nagler 31mm or similar

[Mark at Beaufort]

My main observing is DSOs and I have a good range of EPs which include a Myriad 20mm 100 degree and an ES68 24mm. I recently had the opportunity to use a Nagler 31mm on a 16" Dob and the view of the Veil was brilliant.

I am looking at members who may have a 20/21 100 degree EP and a Nagler 31mm and I wonder how often they use the Nagler and whether they feel its completely necessary.

Part of my consideration is exit pupil. My 12" Dob with the Nagler will give me an exit pupil of 6.22 and a true field of 1.673. My Myriad 100 degree gives me 4.01 and 1.316.

I know that Explore Scientific do a 30mm 82 degree which is nearly half the cost of the Nagler and Opticstar in Sale have a clone version at £260 - https://www.opticstar.com/Opticstar-Ultra-Wide-Angle-XL-Eyepieces.html

I welcome opinions.

[scarp15]

Hi Mark, when I take my 14" dob on dark sky trips, I start with a Nagler 31mm and in conjunction with a 21mm Ethos they form a dominant combination, sometimes along with a 41mm Panoptic. Mostly I have the paracorr in, therefore an exit pupil of 5.09mm for the 31 and 3.96mm for the 21. However the Panoptic 41mm increases to 7.73mm exit pupil and the 31mm Nagler, on occasions when the paracorr is not in use gains 6.8mm, each are wonderful for wide field views and contrast is fine. The sky brightness measures between 21.3 and 21.6 mag, which is a factor.    

[Don Pensack]

Depends.

Just looking for a larger exit pupil?  A very cost-effective way would be the 30mm APM Ultra Flat Field or one of it's rebadged brothers.

Looking for a larger true field?  Then you want a larger field stop eyepiece, like the 31mm Nagler or 30mm ES 82°.

Of course, the second option also gives you the first.

[Mark at Beaufort]

36 minutes ago, scarp15 said:

Hi Mark, when I take my 14" dob on dark sky trips, I start with a Nagler 31mm and in conjunction with a 21mm Ethos they form a dominant combination, sometimes along with a 41mm Panoptic. Mostly I have the paracorr in, therefore an exit pupil of 5.09mm for the 31 and 3.96mm for the 21. However the Panoptic 41mm increases to 7.73mm exit pupil and the 31mm Nagler, on occasions when the paracorr is not in use gains 6.8mm, each are wonderful for wide field views and contrast is fine. The sky brightness measures between 21.3 and 21.6 mag, which is a factor.    

Thanks Iain that is useful information. As I stated previously I recently used the new StellaLyra 16" Dob and the exit pupil was 6.88 so perhaps I should not worry especially reading your reply because the view was fantastic

I know in my 6" Newt I could  fill both parts of the Veil which I fancy trying .

Now it's just a matter whether I buy the 31mm Nagler or the cheaper ES.

[Mark at Beaufort]

6 minutes ago, Don Pensack said:

Depends.

Just looking for a larger exit pupil?  A very cost-effective way would be the 30mm APM Ultra Flat Field or one of it's rebadged brothers.

Looking for a larger true field?  Then you want a larger field stop eyepiece, like the 31mm Nagler or 30mm ES 82°.

Of course, the second option also gives you the first.

Thanks Don I just read the reviews on the APM 30mm which was very good. However I think I want the extra large field but not sure about the opinions on the ES and the edge quality although some state the new version is better.

[Mr Spock]

Views with the 16" StellaLyra are amazing, with the Witch's Broom being especially memorable. There's nothing wrong with replicating that combination with a 12", it will work.

I'll be limiting myself to 22mm with my 12" due to sky brightness. I'm hoping an old Lumicon OIII will help a bit with that. We'll see.

[jetstream]

5 hours ago, Mark at Beaufort said:

I am looking at members who may have a 20/21 100 degree EP and a Nagler 31mm and I wonder how often they use the Nagler and whether they feel its completely necessary.

I have the 20mm APM 100 and it is the mainstay in my 15" f4.8 with and without the PCII. The 30mm ES 82mm here is not used much at all these days- I find the Ethos like contrast of the 20mm APM overshadows the 30mm ES. The 20mm is also the mainstay in my 24" f4.1, with and without the PCII.

[niallk]

My EP set in my 15" f4.5 + PC2 is based around 17E-10E-6E.  My first 100° EP was an ES 20mm ... and I never use it - I prefer the 17E.  I did also augment the line-up with a N31T5, but tbh it gets far less use than my 17E.  There are a few targets where I do look for max tfov - and it's a very nice luxury to have it, rather than a 'necessity', imho.

If I'd gone for the 21-13-8 type progression, I expect that I wouldn't have added the N31T5.

[Mark at Beaufort]

I am grateful for the many excellent replies. The cost of the Nagler 31 is very high and although I might use it a bit on balance it won't get used as much as my 20mm Myraid. So I will hold off at the moment.

 

 

[Mr Spock]

If you want to spent lots of money there's always the 21mm Ethos  Similar fov to the 31mm Nagler.

[Mark at Beaufort]

Just now, Mr Spock said:

If you want to spent lots of money there's always the 21mm Ethos  Similar fov to the 31mm Nagler.

Thanks Michael I had a 21mm Ethos and sold it together with the 13mm and 8mm Ethos. I missed the extra wide field so bought the 20mm Myraid which is nearly as good. As mentioned I am going to hold off for the time being but if a used one appears in the classifieds at a reasonable cost I might change my mind.

[Stu]

3 minutes ago, Mark at Beaufort said:

Thanks Michael I had a 21mm Ethos and sold it together with the 13mm and 8mm Ethos. I missed the extra wide field so bought the 20mm Myraid which is nearly as good. As mentioned I am going to hold off for the time being but if a used one appears in the classifieds at a reasonable cost I might change my mind.

Mark, if you get yourself a nice 4” f7 ish refractor then you’ve got even more excuse for a 31mm Nagler. That’s probably where I use mine most, for those lovely wide field views.

[Mr Spock]

ES does a 25mm 100° - costs as much as my 12" Dob! 

[Voyager 3]

Mark,

https://www.cloudynights.com/topic/810970-astrotech-28mm-uwa/#entry11730857

How about waiting for a few reports? 

https://www.teleskop-express.de/shop/product_info.php/info/p2757_TS-Optics-2----28-mm-Ultraweitwinkel-Okular---82--Feld.htmlMark

This is the TS version of the same eyepiece. 

But maaaaybe a bit close in FOV to the 20mm 100°.

 

[Don Pensack]

18 hours ago, Mr Spock said:

If you want to spent lots of money there's always the 21mm Ethos  Similar fov to the 31mm Nagler.

36.2mm field stop compared to 42mm.

The Nagler has a true field 16% wider.

If the magnification in the 31mm is too low for most purposes though, you're right--the 21 would get more use.

[Don Pensack]

15 hours ago, Voyager 3 said:

Mark,

https://www.cloudynights.com/topic/810970-astrotech-28mm-uwa/#entry11730857

How about waiting for a few reports? 

https://www.teleskop-express.de/shop/product_info.php/info/p2757_TS-Optics-2----28-mm-Ultraweitwinkel-Okular---82--Feld.htmlMark

This is the TS version of the same eyepiece. 

But maaaaybe a bit close in FOV to the 20mm 100°.

 

It's been around several years.  Just look for reports on the William Optics UWAN 28mm.

[Voyager 3]

8 hours ago, Don Pensack said:

It's been around several years.  Just look for reports on the William Optics UWAN 28mm.

Agreed . Except that the reader has to ignore the comments on the eyecup problems.

[Paz]

On 22/02/2022 at 23:14, Stu said:

Mark, if you get yourself a nice 4” f7 ish refractor then you’ve got even more excuse for a 31mm Nagler. That’s probably where I use mine most, for those lovely wide field views.

I use a 31mm Nagler often in my dobsonian for the maximum true field of view. I use a 22mm Nagler when I want to darken the background more or magnify/frame a smaller object better. I probably use the 22mm slightly more often due to light polluted skies. 

I've recently ordered a 2" diagonal so I can use my 2" Naglers in my small scopes which until now I have only used with 1.25" eyepieces. I'm looking forward to this arriving.

[Don Pensack]

On 23/02/2022 at 17:28, Voyager 3 said:

Agreed . Except that the reader has to ignore the comments on the eyecup problems.

There are now reports appearing on CloudyNights and apparently it is very good, so another good eyepiece in the mix.

By the way, I just posted the 2022 Eyepiece Buyer's Guide there.