48 replies to this topic

[Starman1]

Before you buy an XF, read this:

https://www.cloudyni...-xf-85-mm-r2737

[Sarkikos]

Is the Zhumell Z 18mm the same eyepiece as the Sky Rover UFF 18mm?  (Maybe "no.")

 

Is the Orion UFF 15mm the same eyepieces as the Sky Rover UFF 15mm?  (Probably "yes.")

 

Aren't these UFF different from the "Planetary" eyepieces?

 

I want to avoid some possible confusion between these two basic eyepiece designs.  Or are they the same?   

 

Mike

Edited by Sarkikos, 15 May 2025 - 12:59 PM.

[Olimad]

Is the Zhumell Z 18mm the same eyepiece as the Sky Rover UFF 18mm?  (Maybe "no.")

NO, as you said.

Is the Orion UFF 15mm the same eyepieces as the Sky Rover UFF 15mm?  (Probably "yes.")

YES, as you said.

Aren't these UFF different from the "Planetary" eyepieces?

UFF all made by KUO

Planetary LER, all made by Long Perng.

 

I want to avoid some possible confusion between these two basic eyepiece designs.  Or are they the same?   

 

Mike

Edited by Olimad, 15 May 2025 - 01:03 PM.

[Sarkikos]

 

Is the Zhumell Z 18mm the same eyepiece as the Sky Rover UFF 18mm?  (Maybe "no.")

NO, as you said.

Is the Orion UFF 15mm the same eyepieces as the Sky Rover UFF 15mm?  (Probably "yes.")

YES, as you said.

Aren't these UFF different from the "Planetary" eyepieces?

UFF all made by KUO

Planetary LER, all made by Long Perng.

 

I want to avoid some possible confusion between these two basic eyepiece designs.  Or are they the same?   

 

Mike

 

Thanks. 

 

So, the UFF and "Planetaries" are different designs?   That would be probable since they are made by different companies.  On the other hand, one could be copying the design of the other.

 

Mike

[Olimad]

UFF 18 is given to have 8 elements in 5 groups, 65° and 20mm eye relief.

 

Planetary LER 18 is given to have 7 5 elements in 4 3 groups (thanks dmgriff), 55° and 20mm eye relief.

Edited by Olimad, 15 May 2025 - 01:30 PM.

[dmgriff]

UFF 18 is given to have 8 elements in 5 groups, 65° and 20mm eye relief.

 

Planetary LER 18 is given to have 7 elements in 4 groups, 55° and 20mm eye relief.

The Celestron Ultima Edge and APM UFF (and clones) are the same.

8/5 configuration.

 

The Long Perng 55 LER, Orion EdgeOn, Zhumell Z, Stellalyra LER Planetary, etc. are the same.

The LER 18mm is 5 element 3 groups, the remainder of the series is 7/4

Edited by dmgriff, 15 May 2025 - 01:30 PM.

[Starman1]

Thanks. 

 

So, the UFF and "Planetaries" are different designs?   That would be probable since they are made by different companies.  On the other hand, one could be copying the design of the other.

 

Mike

The UFF15mm-30mm were designed by the US astronomer Mark Ackermann for APM in Germany, made by KUO in China.

KUO later added a 10.5mm from another set, but it wasn't part of the designed series.

Now, they are and have been offered under many labels, like Celestron, Meade, Svbony, and many more.  Apparent fields are 65° from 15-24mm and 70° at 30mm.

 

The 55° "Planetary" eyepieces were introduced many years ago by William Optics, and are made by Long Perng in Taiwan.

They have since been sold under several labels, including Zhumell, Altair Astro, Bintel, Founder Optics, Omegon and several others.

These are very different eyepieces than the UFFs, so don't confuse the two.

Edited by Starman1, 15 May 2025 - 01:44 PM.

[MrsM75]

 

 

Perhaps I will research the Pentax XF, 

 

The Pentax XF might not work well with a fast Refractor scope. But in all fairness to the Pentax XF read this review too

 

https://www.cloudyni...pentax-xf-r1393

 

12mm Radian and 12mm Pentax XF

 

Radian is the line before Delite, and this tedious review seem like it favor Pentax.

[Starman1]

The Pentax XF might not work well with a fast Refractor scope. But in all fairness to the Pentax XF read this review too

 

https://www.cloudyni...pentax-xf-r1393

 

12mm Radian and 12mm Pentax XF

 

Radian is the line before Delite, and this tedious review seem like it favor Pentax.

He liked the 12 XF a bit more than the 12 Radian.

Note that the Radian series was discontinued in favor of the Delite Series.

 

The review to which I linked compared the 8.5mm XF with the 8mm Astrotech Paradigm.

 

In this case, the eyepieces compared are different eyepieces, of different focal lengths, in different scopes.

I've used the XFs and the Paradigms, and I do not feel the XFs are worth twice the price.

For the Moon, the XFs had too much ghosting and light scatter for my taste.

I did not use both series on the same night, so there is some doubt about whether the Paradigm is actually better in that regard.

 

If you are buying used, the Pentax XF will still be more than a Paradigm.  If eye relief is critical, the Pentax has more, so there is that.

[MrsM75]

The thing with the Paradigm is it only 13mm eye relief, for a 60 degrees fov that is quite tight eye relieft. Because the Luminos it 82 degrees fov and it 13mm eye relief too.

 

I like the Pentax XF it because even it 60 deg, it has 18 degrees fov. So easier on the eye for sure.

 

I find the 12mm Pentax XF sharper than the Vixen SLV 12mm, Mars was sharp to the edge with the Pentax XF, the Vixen as Mars get into the edge it get a bit blurry.

 

I use a 90mm Mak last night, I can test it on my other Maks, but it be the same due to the long focal ratio.

Edited by MrsM75, 15 May 2025 - 03:59 PM.

[MrsM75]

I find it odd that people jump in recommended the Paradigm without even remember that it 13mm eye relief. But I digress. I guess people eyes just work differently. 

 

I can't buy the Paradigm regardless of how good reputation it is, 13mm eye relief for 60 degrees fov is very tight. Even a 50 degrees Plossol has more eye relief than that at the 20mm Plossol (15mm eye relief) and 25mm Plossol (19.5 mm eye relief).

[vtornado]

With small exit pupils, I don't have to wear my glasses and 13mm of eye relief is enough for me.  My glasses go on around 4mm of exit pupil, if I want the best view I can get.  I have around .7 diopters of astigmatism.

 

With the 18mm eyepiece alluded to here, in an f/5 scope the exit pupil is 3.6.  I don't spend a lot of time in the 20-30mm range because of my terrible light pollution.  Usually I use a 32mm 70 AFOV as a finder eyepiece, then i switch to a shorter focal length to frame the target.  If I'm looking at really large things like the beehive cluster, The 32mm 70 stays in the focuser, and I flip on my glasses to clean up my astigmatism.

 

When I set up a scope for star parties, I use longer eye relief eyepieces so everyone can view with their glasses on without refocusing.

Edited by vtornado, 15 May 2025 - 04:32 PM.

[dmgriff]

My pair of Zhumell Z LER Planetary arrived yesterday afternoon. 2 or 3 day delivery in US. 

 

They have a nice slightly hefty build. I put one in a AT60ED f/6 refractor and did a quick terrestrial visual check. Clean image of some neighbors leaves, wires, tree trunks, at 20x with some edge distortion. With a ST80 f/5 at 22x I noticed more edge distortion. I put the pair in my Burgess Model 24 bvs with my Vixen VMC 110L f/9.4 modified cassegrain and at 57.5x the leaves were sharp to the edge.   

 

The pair in my Burgess BV and VMC110L, ready for a lunar test at native 57.5x, and 115x, 172.5x with 2x/3x telecentrics. I will have a Baader Contrast Booster or Moon and Skyglow in the BV nosepiece.

 

Edited by dmgriff, 16 May 2025 - 02:46 PM.

[star acres]

I have a 12.5 and a 3. They are my favorite eyepieces.

[Olimad]

In Ernest Bench test, the 3 mm is one of the few eyepieces reaching the yellow color (meaning diffraction Limited at F4 and F10). 

[MrsM75]

 

My pair of Zhumell Z LER Planetary arrived yesterday afternoon. 2 or 3 day delivery in US. 

 

They have a nice slightly hefty build. I put one in a AT60ED f/6 refractor and did a quick terrestrial visual check. Clean image of some neighbors leaves, wires, tree trunks, at 20x with some edge distortion. With a ST80 f/5 at 22x I noticed more edge distortion. I put the pair in my Burgess Model 24 bvs with my Vixen VMC 110L f/9.4 modified cassegrain and at 57.5x the leaves were sharp to the edge.   

 

The pair in my Burgess BV and VMC110L, ready for a lunar test at native 57.5x, and 115x, 172.5x with 2x/3x telecentrics. I will have a Baader Contrast Booster or Moon and Skyglow in the BV nosepiece.

 

 

Glad it arrived safe and sound. It a $39 eyepiece so I know it won't work on Fast f/ratio scopes. But with my Maks it work, I'm happy with it, I bought one (no Bino here). 

 

I did link you the return page/form of Celestron site in the page 1, but I personally would keep one, because at $39 price point, all you can get is Plossol.

[MrsM75]

In Ernest Bench test, the 3 mm is one of the few eyepieces reaching the yellow color (meaning diffraction Limited at F4 and F10). 

 

Is "diffraction Limited at F4 and F10" bad Sir? Sorry I not understand the technical stuff. 

 

I read in CN alot of members said the 14.5mm and the 3mm is the best of the line/series.

[Olimad]

When it is said that an eyepiece is diffraction-limited, it means that the eyepiece does not introduce significant optical aberrations (such as spherical aberration, astigmatism, coma, etc.). The lenses are well-aligned and properly collimated, and if any aberrations are present in the image, they are not caused by the eyepiece itself.

 

If the eyepiece is described as diffraction-limited at f/4, this means it maintains that high optical performance even with fast optical systems, delivering sharp, aberration-free views from the center of the field all the way to the edge.

 

So It is a good thing for an optical devices, to be diffraction Limited .

The 3mm is the only one of the line to have this stamp, (by Ernest).

 

Edit: 3mm is too short focal lengths for your Mak.

Edited by Olimad, 16 May 2025 - 09:42 PM.

[RichA]

Hi, I know the Zhumell Z line has discontinued but Celestron has the Zhumell Z 18mm eyepiece with 20mm eye relief for $39.98 New and Free shipping. It a made in Taiwain eyepiece too.

 

https://www.celestro...-18mm-eyepiece?

 

No, I have no connection with Celestron. It just due to the tariff, if you want a planetary eyepiece for $40 price, you should get it. I actually get myself one, it is New, and I got free shipping. Just want to share this.

 

Screenshot from Celestron site.

 

Good point there.  One reason I dislike eyepieces like the Delos is the large, exposed eye lens (does it even need to be that large?) that gets dirty easily and annoyingly.

[MrsM75]

 

 

So It is a good thing for an optical devices, to be diffraction Limited .

The 3mm is the only one of the line to have this stamp, (by Ernest).

 

Edit: 3mm is too short focal lengths for your Mak.

 

 

Hi Sir Olimad, yep. I have small Maks and 3mm is too high for my Maks. The highest magnifications my Maks can take is a 6mm eyepiece. 

 

ah the Orion 3mm HighPoint has it for $69.95 New, and $48 Used (customer return).

https://www.highpoin...netary-eyepiece

 

It does seem like people like this eyepiece.

 

[dmgriff]

Glad it arrived safe and sound. It a $39 eyepiece so I know it won't work on Fast f/ratio scopes. But with my Maks it work, I'm happy with it, I bought one (no Bino here). 

 

I did link you the return page/form of Celestron site in the page 1, but I personally would keep one, because at $39 price point, all you can get is Plossol.

 

No reason for me to return it. I have several eyepieces that do not perform well in fast scopes. But do well in slow scopes or with a barlow in fast scopes. 

 

Besides my Z LER 18mm, the Astronomics ATPF 25mm (40usd), among others, does not do that well in fast systems, but cleans up in slow ones. By definition a barlow or telecentric extends the focal length of the system and will clean up the edges in many cases.

 

Eyepieces in a regular prism binoviewer (such as mine) when used with most newtonian and refractor otas require a optical corrector or focal extender of some sort to reach focus. So I find both the above eps do well in slow or fast newtonians or refractors, operating at a reduced focal length, as 18mm becomes a effective 9mm with a 2x corrector or 6mm with a 3x. A nonlinear binoviewer does not require a optical corrector for focus.

 

The 18mm will be just fine for me.

Edited by dmgriff, 17 May 2025 - 02:19 PM.

[MrsM75]

No reason for me to return it. I have several eyepieces that do not perform well in fast scopes. But do well in slow scopes or with a barlow in fast scopes. 

 

 

 

The 18mm will be just fine for me.

 

Are you more of a planets person or DSO person Sir dmgriff? Since you have a pic of Jupiter I'm guessing planets. 

 

Well if all else fail in an eyepiece, then put it in a long focal scope and use it on DSO, lol.

 

I hope you can test it some time.

[MrsM75]

This is the Celestron Ultima Edge 15mm 65 deg, I got it from HighPoint, it brand under Orion Ultra Flat Field 65 deg 15mm, it an awesome eyepiece.

https://www.highpoin...e-15mm-eyepiece

If anyone want to get it you should, it $69.95 at HighPoint, while Celestron brand it $124

[star acres]

I have a 114/500 long Sky-watcher. I have no problem with the Zhumell 3 MM in a tiny telescope. I stare straight at the moon with no filters. I also do terrestrial as my mount is good for aiming and holding aim perfectly. My slipperiest subject is the hospital helicopter. It swoops in low and fast and I usually bead on the bubble back to the green light. If the pilot is eating a sandwich, I can see it.