Waiting for Lacerta UWAN 4mm

[Bivanus]

For planetary my EP workhorses is a 9mm NT6 with and without a 1.5x Barlow. Works good , but I've got comfortable enough with my scopes to want more. Been looking around for a solution in the 3.5-4mm range , drooled at the Takahashi TOE , looked deep into the wallet and decided against it , and went for a second hand as-new Lacerta UWAN 4mm. Should've been here already , alas , monday is D day. Any thoughts about this EP from people having used it? I found references here and there but quite old , the general consensus was towards it beeing an ok Nagler clone, but not many details about how it actually performs.        

[John]

I had the flat topped version for a while (as per the photo below). I think the optics in the new style bodies are the same. I found it a very good high power eyepiece. Better than I expected in fact. The very wide and well corrected field of view helped me because my scopes are on undriven alt-azimuth mounts. The eye relief is stated as 12mm but may be a little less than that in practice because of the inflexible eyecup on the type that I used. I don't wear glasses when observing so I had no problem seeing the whole field of view. Overall a nice eyepiece I thought. I used it in a 12 inch F/5.3 dobsonian and also in my 102mm and 120mm ED refractors which ranged from F/6.5 to F/7.5 back then.

[Mr Spock]

How does that compare to the 4mm Nirvana I use? I'm pretty pleased with the planetary performance of that though I did get the Nirvanas for double star observing. On the moon the 4mm is impressively sharp and contrasty with both the 100mm f7.4 apo and 12" f5 Dob.

I think they are better looking too 

[Louis D]

All the rebrands of the current KUO 4mm UWA should perform similarly.  For example, it's also sold in the US under the Astro-Tech name by CN's sponsor.  Aside from cosmetics, I would think the optics are identical.

I did find this blurb which appears to be a factory-style release statement since Sky Rover is KUO's factory brand:

Compared with the old UWA eyepiece, the new version has mainly made the following improvements:
1. The optical system has been slightly adjusted;
2. The design of metalworking part has been changed. The main body is slender in shape, and the cannula made of stainless steel has better texture.
3. Silicone folding eye cup is adopted, which makes observation more comfortable.

SKY ROVER’s second generation UWA series ultra wide-angle eyepieces, with high-grade optics and impeccable appearance, are products that astronomy enthusiasts are keen on. Its success lies not only in providing an ultra-wide angle view of 82 degrees, but also in its reasonable price. Especially suitable for observing planets and deep space targets, and also suitable for observing ground targets.

So, it's possible the current KUO UWAs are slightly better optically than the original flat top style, assuming the "slightly adjusted optical system" improved rather than degraded the performance.  Notice they didn't explicitly say "slightly improved", so there is wiggle room as to what they did to the optical design.  Perhaps it was slightly adjusted to make it cheaper or easier to produce at the same image quality level.

[John]

Well, if the OP's Lacerta UWAN is the same as the Nirvana's pictured above they should be "slightly improved" over the one that I had and have those better ergonomics as well. Win, win 🙂

I now use Pentax XW's (5mm and 3.5mm) and a Nagler 2-4mm zoom to cover that focal length.

 

[Mr Spock]

I have a 4mm TOE for lunar and there isn't much between that and the 4mm Nirvana 

[Mr Spock]

The only 'pup' in the range is the 16mm. Field curvature is pretty bad on that one 

[John]

15 minutes ago, Mr Spock said:

I have a 4mm TOE for lunar and there isn't much between that and the 4mm Nirvana 

I tried the TOE 4mm for a while but could not see any benefits from it that the Nagler zoom and XW's don't show. Nice eyepiece though. 

 

Edited July 29, 2023 by John

[Bivanus]

I saw the 4mm TOE, yes indeed bit narrow but the eye liked it...The Life realities  however said 'not now mate' Nevertheless, me being just a tad ahem... strong-willed...and also the opportunity appearing, I went for the SH. The pictures are from the seller, due to the summer being a super bussy season in delivery it missed the Friday delivery spot, anoying but that's that. Looks kinda identical to the Nirvana me thinks.

[Don Pensack]

It is identical.  The maker, KunMing United Optics, makes this eyepiece under at least 8 or 9 different private labels.

[Bivanus]

Yuhuuu! Waiting no more, it's here ! Looks good, nice solid feeling , well machined, can't wait to put it out to the planets.

[Bivanus]

First light tonight , Saturn and Jupiter , with the 72ED on the new AZT6. Crisp and sharp views, no issues with eye placement - to me seems similar to the Nagler T6 9mm. What surprises me is that I was expecting to have more issues with focusing due to the short travel of the 72ED focuser. Nope, the EP has a long neck and one can adjust the positioning upper or lower . Also , lighter than expected , I was able to keep the torsion low on the mount and position it really well. 

Good view of the rings of Saturn including the Cassini division much to the delight of my wife and Jupiter showed us four bands . Used an Optolong UHC filter to try and squize a bit more contrast , it worked but the colors got kinda funky with a bluish hue.

Overall , I do believe this is a very very good value for money EP that will get a lot of use in my kit.

[Mr Spock]

I'm pleased you like it. Definitely an 'under the radar' eyepiece and much better than the price suggests. I've previously owned a 7mm T6 Nagler and I believe the 7mm Nirvana to be better. On the moon for example the 7mm Nagler had odd colour shading effects from SAEP which the Nirvana doesn't have. A third of the price too 

[bosun21]

I used to own the full range of Nirvanas and found them to be very good eyepieces apart from the 16mm. Great value for money as well. I have now moved them on as i found that I am more comfortable with the 76 degrees provided by the Morpheus eyepieces. Some folk enjoy the wider field whereas others don’t. I fall into the later category.

[Bivanus]

After toying a bit more with it , I can say that compared to the Nag 9mm + Barlow 2X combination, which would be the equivalent of a 4.5mm, I found it more comfortable, for my eyes it is a pleasant eyepiece that does not tire and whose optimal position is easy to find and keep.

I did detect a slight kidhey-bean phenomenon outside the optimal position, but thin, without affecting the central area where the planet was. A bigger black ball in my book is the eyecup that leaves a lot to be desired , it is too soft and too shallow, it is similar in size to the Nags but not in texture.

[Bivanus]

Question: does anyone knows or has the ability to measure the thread on the eyecup side of the Lacerta UWAN eyepieces?  I would like to try a bit of non-prime astrophotography however an adapter would be needed and the thread data seems to be elusive.

[Mandy D]

24 minutes ago, Bivanus said:

Question: does anyone knows or has the ability to measure the thread on the eyecup side of the Lacerta UWAN eyepieces?  I would like to try a bit of non-prime astrophotography however an adapter would be needed and the thread data seems to be elusive.

Although it does not answer your question directly, this link may help you identify the thread:

https://agenaastro.com/articles/guides/astronomy-threads-explained.html

[Bivanus]

@Mandy D Thank you, it's a good read. In another life thread measurements & fitting were an almost daily activity. The calipers I used back than remained back with the job so now I don't have the means 😭

[Louis D]

Are these threads under the eyecup?  Most of these threads tend to be either M37 or M43, depending on the width of the eyecup.  The 30mm UFF is different from most others because it has such a large eye lens.  I think it has an M45 thread.  Measure the width of the threads with a ruler, and see if it is closer to 37mm or 43mm to figure out which it is.

[Don Pensack]

It looks to be a hair under 33mm.  I got 32.9mm at the top of the threads on the 4mm.

The thread looks to be a fine thread, too, maybe 0.5mm

Why it is threaded, I don't know, since the eyepiece has too little eye relief for camera attachment, or for use with a DioptRx.

If you attach a camera, the lens will be outside the exit pupil and yield a smaller apparent field than the eyepiece.

This is NOT an eyepiece designed for projection imaging.

[Bivanus]

@Don Pensack: Indeed , I've received an e-mail from Teleskop-Austria which is as far as I know Lacerta's on-line shop , kindly informing me there is no adapter available because mainly the reasons you talk about. I suppose they put it there just to hold the rubber , and since the tooling is already available at the factory , a thread is simpler to make than other profiles. 

[Don Pensack]

One really short focal length eyepiece that IS adaptable to projection photography is the Baader Morpheus 4.5mm, which has a 43mm thread under the eyecup and for which camera adapters are available.

[Louis D]

There are various 33mm diameter 0.5mm thread pitch step rings out there.  You might be able to jobber several step rings together to get to a usable thread size for an adapter.  However, it may add too much distance to be of any use for pupil matching as Don has pointed out.

[Merak]

I'm looking at getting the OVL Nirvana badged version of this eyepiece.   Is the planetary views through the eyepiece satisfactory?

Cheers.

[cajen2]

Another under-the-radar option at this sort of f/l is the StellaLyra (= Long Perng) 4mm 80° LER/UWA. I've just got one and it's very good: long eye relief, wide AFOV and sharp / flat from edge to edge. The only downside is that it's huge - definitely a holy hand grenade job!