4mm shootout: Nirvana 4 vs Svbony 3-8 Zoom

[Ags]

I took delivery of a Nirvana 4 mm today to complement my Svbony 3-8 Zoom as the high magnification options in my ~f6 telescopes. Surprisingly the skies were a bit hazy but good enough to view planets, so I thought I would try these two eyepieces head to head on Jupiter and Saturn. The scope of choice tonight (so nice to have a choice of telescopes!) is an f5.5 Long Perng 90 mm Apo(ish). 4 mm eyepieces give 125x magnification in this scope, which is a touch high for Jupiter but fine for Saturn.

Jupiter was first. On axis, the Svbony gave sharply delineated views of the big planet, while the Nirvana didn't seem to reach perfect focus no matter how I tweaked the fine focuser. However, the color of Io was much more apparent in the Nirvana. Moving the planet to the edge of the field, the Nirvana view held up well, but the Svbony view degraded - Jupiter went soft and distorted, and Io grew a little finger of light reaching back to the center of the FOV. I noted the Nirvana view of Jupiter was significantly bigger than the Svbony set to 4 mm. Perhaps the Nirvana is more like a 3.5 mm focal length.

Saturn showed the same differences - the planet was sharp in the Svbony at 4 mm (and at 3 mm) while the Nirvana couldn't reach the same sharpness.

So a bit disappointing, I had hoped for more from the Nirvana. It will be interesting to see on a less hazy night, and also compare performance on the Moon - the good off-axis performance of the Nirvana might work well there. I think however I may give the Nirvana 13 I was planning on getting a miss. The Svbony 3-8 is staying in the focuser for the rest of planet season.

Edited October 10, 2023 by Ags

[Mr Spock]

Interesting. I find the Nirvana 4mm only a shade short of the 4mm TOE.

[Ags]

1 minute ago, Mr Spock said:

Interesting. I find the Nirvana 4mm only a shade short of the 4mm TOE.

I'm not remotely seeing that, but I remember the Nirvana 16 which I didn't much like was a spectacular lunar eyepiece, so hoping the 4 mm will come through on Luna.

[Zermelo]

Very interesting. I felt the Svbony generally outperformed the 4mm Nirvana when I compared them across a number of sessions. I also find my 16mm Nirvana does better than the 4mm, though I know others think the reverse. Can you recall using your 16mm for comparison?

[Ags]

Edge performance of the 16 mm was abominable. It is one of the few eyepieces I have had that actually made me angry.

[Mr Spock]

I don't use the 16mm - it's horrible.

[Mr Spock]

The only one I use on the moon is the 7mm. It gives x217 with the 12". I did use the 4mm Nirvana for x380 but prefer the TOE.

For planets I usually use the TOEs in the Tak, and orthos + x2.5 Powermate in the 12".  The Nirvanas are used for doubles where the 82° makes it easier to frame things.

[Ags]

I would be using the 4 mm in my C6 (with f6.3 reducer) for about 230x so similar to the 7 mm on your 12" dob.

I think the Svbony zoom is a better choice for doubles as it can go wider and reach a higher mag.

[Louis D]

1 hour ago, Ags said:

I noted the Nirvana view of Jupiter was significantly bigger than the Svbony set to 4 mm. Perhaps the Nirvana is more like a 3.5 mm focal length.

I photographically measured the Svbony to have a 4.3mm central focal length shrinking to 3.1mm at the edge.  I have no idea about the Nirvana, but Ernest measured it at 4.0mm for the Meade PWA version.

[ScouseSpaceCadet]

Reading the varying opinions is interesting... I sold my Nirvana 4mm as it was a bit soft. The Vixen SLV 4mm is my high power choice.

The Nirvana 16mm on the other hand is one of my most used eyepieces. Nice for lunar with the Mak 127 and great at deep sky with the refractors.

The Nirvana 7mm combined with the f7 and f7.8 refractors is a good lunar eyepiece too. 

[John]

I had one of the older "flat top" style Nirvana 4mm's a few years back and it seemed a pretty good high power eyepiece I thought. The current body style is probably better than the flat top one though. Maybe there is some optical quality variation unit to unit with this one ?

Way back I had the 16mm UWAN (same as the Nirvana's) and decided to change to a 16mm T5 Nagler (at some cost) but could not really see much performance difference in the F/5.9 and F/6.5 scopes that I had back then. I recall thinking that the additional £'s might have been better spent back then.

I was loaned a 28mm Nirvana (again flat top type) by FLO to compare with the Pentax XW 30mm and Nagler 31mm many years back. I think that was the first eyepiece comparison that I ever did for SGL, 14 years ago 😲:

That's all the Nirvana / UWAN experiences that I have to offer.

Edited October 11, 2023 by John

[Ags]

I am not doubting that some or even most people get a good one, but the one I'm looking through is flatly unacceptable for detailed planetary viewing. It's not even close. I think there are good Nirvanas out there, but buy new so you can return your sample if it fails to perform.

[John]

3 hours ago, Ags said:

I am not doubting that some or even most people get a good one, but the one I'm looking through is flatly unacceptable for detailed planetary viewing. It's not even close. I think there are good Nirvanas out there, but buy new so you can return your sample if it fails to perform.

You called it as you saw it with the eyepiece you had. You can't do any more than that 👍

Edited October 11, 2023 by John

[Ags]

I will stick to Explore Scientific widefields and SLVs from now on I think.

[Whistlin Bob]

Interesting thread. I have the 4mm Nirvana. In my f6 200mm dob, with good seeing, it's ok but a touch soft on planets but spectacular on the moon, sharp right across the fov. Always find this slightly odd, but this has been repeated on several different nights. It's a keeper because of how it performs on the moon. 

[Ags]

21 minutes ago, Whistlin Bob said:

It's a keeper because of how it performs on the moon.

Good to know - I will try it on the Moon next (which after all was my main reason for getting the EP).

[runway77]

I would like to note that an eyepiece is only one part of the optical train. I would be a bit cautious with statements like an eyepiece is horrible, etc. I do have all the nirvana's and use them with a properly collimated newtonian with a coma corrector. I find the views outstanding for the price. Many factors can affect a perceived view, an eyepiece is really only one of them. 

[Mr Spock]

I remember someone else here describing the 4mm Nirvana as a 'sleeper'. It's interesting how we perceive different pieces of kit. If that weren't the case we'd all have the same scope and eyepiece.

Comparing views on Jupiter using a Tak FC100 with Tak prism diagonal, I find the 4mm Nirvana and 4mm TOE to have similar detail and sharpness. The wider field of view of the Nirvana is irrelevant on this subject. The only optical difference I found between the two was a festoon was a little darker and easier to see in the TOE; the belts were very similar in appearance. I think given the TOE is FOUR times the price of the Nirvana I could live with that difference if I couldn't afford the TOE.

If you want the very best out of your equipment then a premium price can't be avoided. I'm happy I'm getting the very best planetary performance a 4" has to offer.

The 7mm Nirvana with the 12" f5 Dob is excellent on the moon. I can't imagine a sharper more contrasty view. On test (old version) https://astro-talks.ru/forum/viewtopic.php?f=32&t=1248&sid=3852cbe9b93d0a8e7e1b59d99fe2cd1d the focal length is stated as 8mm. So when I get an opportunity I'll test this against my 8mm LVW which I know to have exceptional image quality.

[cajen2]

I need counselling.

Last night, the seeing was excellent at the SWAG party site and I looked at Jupiter (again!). He looked gorgeous through my 6.5mil Morpheus (110x mag), with pin-sharp moons and the most surface detail I've ever seen. The image was a bit small to make out more than a couple of the bands, so I switched to my Pentax XW 5mm (143x). A bigger image, but fewer of the subtlest details seen with the Morph.

So I've just shelled out £229 on a 4.5mm Morpheus. At these high mags, it strikes me that small f/l changes become important in my Starfield 102 frac. I'll now have:

6.5mm Morph (110x)

5mm Pentax XW (143x)

4.5mm Morph (159x)

4mm StellaLyra 80° (179x)

I can always sell one if I find I'm not using it. And this is all after congratulating myself on not needing any more EPs!

[Mr Spock]

I settled for (in the Tak) 4mm for x185 and 3.3mm for x224. I'd suggest the same for the Starfield; I don't see the need for low magnifications 

Perhaps dump the 5mm if you like the Morpheus range. 

[John]

At the shorter FL end I've ended up with a progression of

8mm, 7mm, 6mm, 5mm, 4.7mm, 3.5mm in fixed focal lengths plus 4mm-2mm with .5mm stops in the Nagler zoom plus 7mm, 6mm, 5mm and 4mm HD orthos for when I'm in the ortho mood.

You are not alone in having a crowded short end in the eyepiece case !

I've very often noticed with Jupiter that a lower magnification teases out the subtle planetary detail better than pressing on more power. Last night with my ED120 (and similarly with my Tak 100) 8mm / 7mm (113x / 129x) did a little better than 150x on the planet despite the image scale being smaller.

With Saturn 180x - 225x was very good. On Neptune it was "all hands to the pump" and 257x-300x to show a well defined but tiny pale blue "marble" and even at times glimpses of Triton around 10 arc seconds from the planetary disk.

Its so nice to have some good nights to be able to experiment "for real" and see what works best 🙂

 

 

Edited October 15, 2023 by John

[MalcolmM]

I have also fallen into the trap of having a large,  small FL range of eyepieces! I think it's inevitable as you try to get the best compromise between image detail and image size. I have the 3-6 Nagler Zoom but just prefer using fixed focal length eyepieces. 

Malcolm 

[Ags]

5 hours ago, runway77 said:

I would like to note that an eyepiece is only one part of the optical train. I would be a bit cautious with statements like an eyepiece is horrible, etc. I do have all the nirvana's and use them with a properly collimated newtonian with a coma corrector. I find the views outstanding for the price. Many factors can affect a perceived view, an eyepiece is really only one of them. 

Just to be clear, I was keeping the whole optical train the same except for the eyepiece. I have no reason to doubt that the numerous positive reports about the Nirvana 4 are genuine, so I assume I am just unlucky in the sample variation lottery.

[John]

Eyepiece preferences seem to be a very personal thing - what one person likes may well not suit another person at all. 

 

 

[Mr Spock]

I've just been doing some solar with the Tak. So, 7mm Nirvana v 8mm LVW v 18mm Ortho + x2.5 Powermate and 17mm LVW + x2.5 Powermate. What I can say is there is little in it. In moments of steady seeing they were all very similar.

2 hours ago, John said:

Eyepiece preferences seem to be a very personal thing - what one person likes may well not suit another person at all.

From the above test I preferred using the 8mm LVW