3.5 mm nagler eyepiece, any good?

[Stargazer_00]

I didn't even notice the date blimey

[gravityguy]

That would be my Ascension 32mm 2" eyepiece, there are plenty of clones of these online & I did a thread about mine Ascension Eyepiece.

Hey Tich, the ep I was referring to was Simon's T5 nagler. It was the absolute dogs danglies. Your ascension 32mm was also pretty damn good but I have to say the nagler blew my mind. Not something I can afford though right now, however the ascension is a definite possibility. Thanks for the use last week tich, very much appreciated

Has something gone a bit wrong here, what have the last two posts to do with a 3.5mm Nagler?

Sorry my fault I have just re-read the thread, someone was way out with their magnification, I agree 400 plus is far too much.

Alan.

i started it again as the last post said that I newb probably wouldn't notice the difference between a standard ep and something like a nagler so I just wanted to say that even being a newbie I could tell a huge difference

[BGazing]

let's resurrect this bit, in a different setting. i use 4.7 es 82 with my borg 71fl when travelling light. 4.7 gives about 85x, so it is neither here nor there. on the lower end i have 8.8 82 deg. thinking about buying a second-hand 3.5 nagler to either replace or complement 4.7 es and would appreciate any comments. i am not too keen on 4.7 eye relief and placement, quite possibly the only of my eyepieces where i can never quite get the eye in the right spot.

[John]

The thread that won't die !

The 3.5mm Pentax XW is superb and has 20mm of eye relief. They cost less than Nagler T6's new and are even better performers if you don't mind a reduction of 12 degrees of FoV. I moved from the Nagler 3.5 to the XW.

 

 

 

[BGazing]

well, 12 degrees comes in handy when you are on a photo tripod. and nagler is a bit lighter than pentax, right?

 

[John]

11 minutes ago, BGazing said:

well, 12 degrees comes in handy when you are on a photo tripod. and nagler is a bit lighter than pentax, right?

 

Yes to both. My scopes are all on undriven, alt-az mounts as well. The Nagler T6 range is remarkably compact and light for the panoramic views that they provide. I had a full set of them for quite a while and really enjoyed them.

 

 

[John]

Another option would be the Vixen SSW 3.5mm. Small, light and with an 83 degree apparent field.

[BGazing]

kinda feel that with the little borg having par weight among eyepieces is the key...vixen looks interesting, thanx for the tip. i reckon that at that price range they are pretty much all equally good. or should be.

given that the little frac has considerable fc, would it be exacerbated by vixens/pentaxes/naglers? i reckon only long fl pentaxes are adding to the fc, correct?

[Ricochet]

1 hour ago, BGazing said:

only long fl pentaxes are adding to the fc, correct?

Correct, see the discussion here: http://www.cloudynights.com/topic/25103-pentax-xw-astigmatism-and-field-curvature/

I've recently bought a 14mm XW and in my 1200fl dob (so pretty flat field) the combined curvature is such that it's not great for open clusters but in my 390fl spotting scope (must somehow be even flatter field) I don't notice it (unless that is something to do with the reduced magnification and/or lack of secondary shadow). Unfortunately, the purchase came with many clouds and so I've only had two half hour sessions to try to assess it. 

[BGazing]

well those short fl pentaxes appear to have trukloads of curvature, but in the opposite direction of the most fc patterns...does it mean they appear flat because two curvatures cancel each other out? apologies for my poor grasp of optics in this case.

[John]

1 hour ago, BGazing said:

well those short fl pentaxes appear to have trukloads of curvature, but in the opposite direction of the most fc patterns...does it mean they appear flat because two curvatures cancel each other out? apologies for my poor grasp of optics in this case.

I have the 10, 7, 5 and 3.5mm Pentax XW's. I use them in refractors from 102mm F/6.5 to 130mm F/9.2 and in my F/5.3 300mm dobsonian. If they have faults I can't see them - they are very fine eyepieces to my eye.

 

 

 

[Timebandit]

29 minutes ago, John said:

I have the 10, 7, 5 and 3.5mm Pentax XW's. I use them in refractors from 102mm F/6.5 to 130mm F/9.2 and in my F/5.3 300mm dobsonian. If they have faults I can't see them - they are very fine eyepieces to my eye.

 

 

 

 

Totally agree with John. I have the Pentax 3.5mm 5xw , 7xw 10xw . These have Ortho like tack sharpness of views, but with around 70d fov and 20mm eyerelief. I use these in the 120ed apo equinox refractor and the OOuk 14" dob at f/4.6 with 1/10pv. I find these eyepieces excellent at these focal lengths.

IMO these eyepieces are some of the best around and have no regrets in owning these as they are "keepers"?

[Ricochet]

1 hour ago, BGazing said:

well those short fl pentaxes appear to have trukloads of curvature, but in the opposite direction of the most fc patterns...does it mean they appear flat because two curvatures cancel each other out? apologies for my poor grasp of optics in this case.

If they are in opposite directions then, yes, they will cancel out to some extent. I'm not sure but I guess to get the field curvature in the same units as the graphs we want 1/radius of curvature, which for a refractor is approximately 1/(fl/3) = 3/fl. If that is correct, then for a 400mm fl scope the field curvature is 7.5m^-1. As to how big a field curvature number is acceptable/noticable I've got no idea other than to say that applying the same methodology my dob would have fc of 0.82m^-1 and that plus the fc of the 14mm is noticeable. 

[Ben the Ignorant]

I've been using the former version of this 4mm/82° for many months:

http://www.teleskop-express.de/shop/product_info.php/info/p8989_TS-Optics-Optics-1-25--Ultra-Weitwinkel-Okular-UWAN-4mm--82--Gesichtsfeld.html

The newer one seems to be the same optics in a waterproof housing. After I bought it I immediately tried it my scopes: 80mm f/7.5 achro, 80mm f/6 apo, 127mm f/10 Schmidt-Cass, 300mm f/5 dob; the result was excellent in all of them, especially the f/6 apo despite its relatively steep light cone. Apart fom edge sharpness, the most critical feature in a wide-angle eyepiece, which is excellent, anti-reflection treatment, blackening, weight, eye comfort, and smoothness of the mobile eyecup, all are very good.

Only my 4.7mm Explore has a tiny, very slight advantage in definition, center and edge, but it also costs 40% more, so value for the 4mm is excellent.

[BGazing]

56 minutes ago, Ben the Ignorant said:

I've been using the former version of this 4mm/82° for many months:

http://www.teleskop-express.de/shop/product_info.php/info/p8989_TS-Optics-Optics-1-25--Ultra-Weitwinkel-Okular-UWAN-4mm--82--Gesichtsfeld.html

The newer one seems to be the same optics in a waterproof housing. After I bought it I immediately tried it my scopes: 80mm f/7.5 achro, 80mm f/6 apo, 127mm f/10 Schmidt-Cass, 300mm f/5 dob; the result was excellent in all of them, especially the f/6 apo despite its relatively steep light cone. Apart fom edge sharpness, the most critical feature in a wide-angle eyepiece, which is excellent, anti-reflection treatment, blackening, weight, eye comfort, and smoothness of the mobile eyecup, all are very good.

Only my 4.7mm Explore has a tiny, very slight advantage in definition, center and edge, but it also costs 40% more, so value for the 4mm is excellent.

what's the ER like on that one? ES 4.7mm feels like a 12mm plossl in that aspect...

[John]

10 minutes ago, BGazing said:

what's the ER like on that one? ES 4.7mm feels like a 12mm plossl in that aspect...

The 4mm UWAN / Nirvana / TS Ultra Wides have 12mm of eye relief. Same as as the Nagler T6's. I had the UWAN 4mm for quite a while as a high power eyepiece and it's pretty good.

12mm can still feel tight if you are used to 20mm but is comfortable if you are used to plossls / orthos.

 

[Highburymark]

I've been looking for a high power, light, widefield EP for my Takahashi for a while, and have considered many options. But in the end only one eyepiece met all needs - the venerable Nagler 3.5, so picked one up this afternoon at Astrofest (20% discount on all Televue gear). Couldn't resist the 11mm either for a lightweight set. Hopefully will be able to report back soon on impressions of the 3.5.

[BGazing]

42 minutes ago, John said:

The 4mm UWAN / Nirvana / TS Ultra Wides have 12mm of eye relief. Same as as the Nagler T6's. I had the UWAN 4mm for quite a while as a high power eyepiece and it's pretty good.

12mm can still feel tight if you are used to 20mm but is comfortable if you are used to plossls / orthos.

 

That is the stated ER for 4.7. However, it feels like a 8mm relief, i.e. the equivalent of a short fl plossl. Must be the recessed lens.

[Ben the Ignorant]

I can see the complete field when my skin is two millimeters above the eyecup; the distance between my eye and the eyelens is too difficult too measure but that's how the older 4mm feels, the newer one has a different eyecup.

[BGazing]

51 minutes ago, Ben the Ignorant said:

I can see the complete field when my skin is two millimeters above the eyecup; the distance between my eye and the eyelens is too difficult too measure but that's how the older 4mm feels, the newer one has a different eyecup.

Different as in....more relaxed?

[Helen]

4 hours ago, Highburymark said:

I've been looking for a high power, light, widefield EP for my Takahashi for a while, and have considered many options. But in the end only one eyepiece met all needs - the venerable Nagler 3.5, so picked one up this afternoon at Astrofest (20% discount on all Televue gear). Couldn't resist the 11mm either for a lightweight set. Hopefully will be able to report back soon on impressions of the 3.5.

Off to Astrofest tomorrow and also looking for a high power eyepiece for the Tak 100!  I've been musing about a Myriad or the Nirvana 4mm As I really like the UWAN, but I think the Nagler may be smaller.   Who was doing the discount? and what was the final reduced price on the 3.5?

Thanks

Helen

[Ben the Ignorant]

1 hour ago, BGazing said:

Different as in....more relaxed?

I don't know, I haven't tried it. It's been issued only a few months ago.

[Highburymark]

1 hour ago, Helen said:

Off to Astrofest tomorrow and also looking for a high power eyepiece for the Tak 100!  I've been musing about a Myriad or the Nirvana 4mm As I really like the UWAN, but I think the Nagler may be smaller.   Who was doing the discount? and what was the final reduced price on the 3.5?

Thanks

Helen

Hi Helen - Televue products are 20% discounted  at Astrofest- head for the Widescreen Centre stand. The two Naglers I bought were reduced to around £250 each - still a lot of money but £100+ less than the current retail price for the two eps, which slightly reduced the pain of buying them. I noticed the Skywatcher distributor had some very good deals going too, but didn't have time to linger. Hope you find what you are looking for and at the right price.