Nirvana 16mm & 10mm Review

[Mr Spock]

The Nirvana is an inexpensive 82° eyepiece and I was keen to see how they would perform. The two I purchased were the 16mm and 10mm, as shown below.

Immediate impression is of decent build quality, small and light - 166g for the 16mm and 171g for the 10mm. Coatings are green in colour. They have a soft rubber eyecup which is comfortable in use. There is a tapered undercut which didn't snag or cause problems with a compression ring. The range is close to par focal and I found in practise there was little refocusing between the 16mm and 10mm. Eye relief is fine, though I suspect they won't be suitable for people who need glasses. Eye positioning is not critical and this makes them comfortable to use.

More important, and the reason for purchase, is the price. The 16mm is £89. When you compare this to the equivalent 16mm Nagler at £398 you can see we have a much more affordable option. Having used Naglers they are maybe a fraction better, not almost four and a half times better!

All tests were conducted using a Starfield 102mm f7 fpl-53 refractor which I know to be well corrected and free of false colour.

Star test. For this I used ε Lyr as it was well positioned.
16mm: Immediate impression was of a sharp image and comfortable eye position with no apparent darkening or blackouts/kidney beaning. Colours were natural with no false colour seen. The eyepiece had no difficulty picking up fainter stars and the background was quite dark. Some field curvature was visible with about the last 10% needing refocusing. Stars in this last 10% were also never really in focus due to astigmatism. In context when looking at central objects none of this was really noticeable. These issues were not repeated when combined with a Televue x2.5 Powermate, which seems to have a knack of cleaning up aberrations.
10mm: Similar to the 16mm in most respects. However, there was very little field curvature and stars were sharp right to the edge - quite remarkable at the price. I had a really enjoyable doubles session using these two eyepieces and the Powermate.

Jupiter. For this I compared the 10mm with Powermate to the 4mm SLV and 4mm Circle-T Orthoscopic; all these give x179.
I have to say, there was very little in it. All three showed the same amount of belt detail. The Nirvana didn't have any glare or false colour issues and the colour of Jupiter seemed natural and not tinted in any way. I found the Nirvana's eye positioning again very comfortable in use. For some reason though, out of the three, I preferred the view through the Ortho - perhaps it was a little more subtle in presentation. It's not something I can explain but is something I've noticed before with orthos - they just look right! In context I'd be happy with any of the three for planetary observing.

Solar. For this I used a Lunt wedge and Baader Continuum filter. Comparison was with a 17mm LVW, the closest I have to the 16mm Nirvana.
Sunspots were sharp, very sharp, with surface granulation visible. There was very little difference between the Nirvana and LVW. When moved to the edge the field curvature was more noticeable than it was with stars with the sunspots needing refocusing; they were sharp when focused though. Not really an eyepiece I'd think about for solar though - it's not what I bought it for.

Finally a couple of test images. Apologies for the quality, my iPhone XR doesn't really do this very well and I'm not very good at positioning or holding it steady.  It does give some indication of the field curvature though. However, in context, the distortion on view isn't really any worse than other eyepiece designs.

16mm

10mm

As you can see, they aren't that bad; quite acceptable really with reasonable distortion and good sharpness throughout. Any blurriness is due to my shaky hands - the actual view through the eyepieces were razor sharp.

Conclusion.
At the price these really are a bargain. They lose almost nothing on top brands. What's not to like? They are 82°, sharp, small and compact, decent build quality and a delight to use. I found them so impressive and comfortable in use that I've ordered the 7mm and 4mm. Hopefully they will arrive next week.

[Knighty2112]

Good review. For those less fortunate to be able to get the likes of a Nagler EP etc these sound like a very good option. Thanks for posting.   

[JeremyS]

Helpful review 👍🏻

[callisto]

I have the 7mm and like you said a very pleasing view 

[Highburymark]

Nice review - they look like excellent value. Lots of pincushion distortion but then TV Panoptics are no different, and it’s not a major problem for most astronomy applications. 

[Don Pensack]

8 hours ago, Mr Spock said:

The Nirvana is an inexpensive 82° eyepiece and I was keen to see how they would perform. The two I purchased were the 16mm and 10mm, as shown below.

Immediate impression is of decent build quality, small and light - 166g for the 16mm and 171g for the 10mm. Coatings are green in colour. They have a soft rubber eyecup which is comfortable in use. There is a tapered undercut which didn't snag or cause problems with a compression ring. The range is close to par focal and I found in practise there was little refocusing between the 16mm and 10mm. Eye relief is fine, though I suspect they won't be suitable for people who need glasses. Eye positioning is not critical and this makes them comfortable to use.

More important, and the reason for purchase, is the price. The 16mm is £89. When you compare this to the equivalent 16mm Nagler at £398 you can see we have a much more affordable option. Having used Naglers they are maybe a fraction better, not almost four and a half times better!

All tests were conducted using a Starfield 102mm f7 fpl-53 refractor which I know to be well corrected and free of false colour.

Star test. For this I used ε Lyr as it was well positioned.
16mm: Immediate impression was of a sharp image and comfortable eye position with no apparent darkening or blackouts/kidney beaning. Colours were natural with no false colour seen. The eyepiece had no difficulty picking up fainter stars and the background was quite dark. Some field curvature was visible with about the last 10% needing refocusing. Stars in this last 10% were also never really in focus due to astigmatism. In context when looking at central objects none of this was really noticeable. These issues were not repeated when combined with a Televue x2.5 Powermate, which seems to have a knack of cleaning up aberrations.
10mm: Similar to the 16mm in most respects. However, there was very little field curvature and stars were sharp right to the edge - quite remarkable at the price. I had a really enjoyable doubles session using these two eyepieces and the Powermate.

Jupiter. For this I compared the 10mm with Powermate to the 4mm SLV and 4mm Circle-T Orthoscopic; all these give x179.
I have to say, there was very little in it. All three showed the same amount of belt detail. The Nirvana didn't have any glare or false colour issues and the colour of Jupiter seemed natural and not tinted in any way. I found the Nirvana's eye positioning again very comfortable in use. For some reason though, out of the three, I preferred the view through the Ortho - perhaps it was a little more subtle in presentation. It's not something I can explain but is something I've noticed before with orthos - they just look right! In context I'd be happy with any of the three for planetary observing.

Solar. For this I used a Lunt wedge and Baader Continuum filter. Comparison was with a 17mm LVW, the closest I have to the 16mm Nirvana.
Sunspots were sharp, very sharp, with surface granulation visible. There was very little difference between the Nirvana and LVW. When moved to the edge the field curvature was more noticeable than it was with stars with the sunspots needing refocusing; they were sharp when focused though. Not really an eyepiece I'd think about for solar though - it's not what I bought it for.

Finally a couple of test images. Apologies for the quality, my iPhone XR doesn't really do this very well and I'm not very good at positioning or holding it steady.  It does give some indication of the field curvature though. However, in context, the distortion on view isn't really any worse than other eyepiece designs.

16mm

10mm

As you can see, they aren't that bad; quite acceptable really with reasonable distortion and good sharpness throughout. Any blurriness is due to my shaky hands - the actual view through the eyepieces were razor sharp.

Conclusion.
At the price these really are a bargain. They lose almost nothing on top brands. What's not to like? They are 82°, sharp, small and compact, decent build quality and a delight to use. I found them so impressive and comfortable in use that I've ordered the 7mm and 4mm. Hopefully they will arrive next week.

That isn't field curvature you photographed, it's pincushion distortion.

Field curvature is when the outer edge comes to focus at a different place than the center of the field, which is a different issue than distortion.

[Mr Spock]

23 minutes ago, Don Pensack said:

That isn't field curvature you photographed, it's pincushion distortion.

 

8 hours ago, Mr Spock said:

the distortion on view

 

8 hours ago, Mr Spock said:

reasonable distortion

I think what I said is quite clear. I have also adequately described the field curvature and how it needs to be refocused, which is just starting to be visible in the 16mm image.

[Louis D]

13 hours ago, Mr Spock said:

Finally a couple of test images. Apologies for the quality, my iPhone XR doesn't really do this very well and I'm not very good at positioning or holding it steady.  It does give some indication of the field curvature though. However, in context, the distortion on view isn't really any worse than other eyepiece designs.

I think it was this group of sentences that might make it sound like field curvature is being described as distortion.  In my experience, it is nearly impossible to photograph field curvature with a cell phone camera due to the wide angle lens having enormous amounts of depth of field, bringing everything into focus at once.  In your images, I'm not seeing any defocus due to field curvature at the edges.  In fact, focus sharpness looks pretty good to the edge.  Perhaps if you posted a full resolution edge crop showing the defocus, it would be clearer.  You were clearly were using the term field curvature correctly and without confusion elsewhere as you replied.

Here's my classic example of field curvature being tamed by a wide angle camera phone.  Notice how good the 30mm Agena UWA looks to the edge.  As seen by my fixed focus eyes, it was a blurry mess out there in the last 30% without refocusing.  I verified how good this eyepiece could be by overcorrecting the scope's field flattening by extending the separation between the TSFLAT2 and the eyepiece.  The 30mm Agena UWA looked pretty darned good with very low amounts of edge astigmatism.

[bosun21]

Thanks for your detailed review of these Nirvanas, and as you say at a very reasonable price.

[Mr Spock]

8 hours ago, Louis D said:

Perhaps if you posted a full resolution edge crop showing the defocus

By angling the phone, I've managed to reach the edge of the 16mm...

You can see it's sharp up to about 70° then the last bit goes out of focus.

 

[bingevader]

I have the 7mm and 4mm and think they are rather smashing.

[Don Pensack]

I wonder what the actual focal lengths are.

Stellarvue sells the 7mm as 8mm and sells the 16mm as 15mm.

I wonder if the measured focal lengths are in between.

[MetroiD]

I used to own the Nirvana 16mm and I was very surprised by how much better than the Meade UWA 14mm it performed in my f/4.9 10" scope. Contrast in particular was noticeably better which I would not have expected considering the eyepiece's price (and, respectively, the potential to be faced with subpar coatings). In my book, the Nirvana EPs are great quality for the money with the 16mm in particular one of the best wide field 1.25" EPs on the market. 

Edited October 7, 2022 by MetroiD

[Louis D]

Which Meade UWA 14mm were you using?  There was the vintage 4000 version (actually 2, smoothie which I have and recessed eye lens with rubber grips) which I've found has terrible stray light control and outdated coatings, and the newer 5000 version which may have been either JOC (ES/Bresser) or some other manufacturer (pre/post ~2013).  Side-by-side, I found the 14mm Morpheus better than the 4000 version in all respects.  It wasn't even close.

[MetroiD]

@Louis D, I was comparing my 16mm Nirvana UWAN with the Meade 5000 UWA 14mm, i.e. the "new" version. At one point, I owned the 5.5mm, 8.8mm, 14mm and 24mm iterations in this line, all of the 5000 type. I must have kept the 14mm for about a week, that's how unimpressed I was with this EP. The 16mm Nirvana had definitely set the bar pretty high.

As a sidenote - I've replaced all of the above EPs with a line-up of Morphei with the odd addition to the family here and there.