Lunt/APM HDC- XWA 13 mm 100°/110° v OVL MWA 100°/110° Eyepieces

[DRT]

I have recently bought various focal lengths of these eyepieces branded Lunt, APM and Myriad.

Are they all optically identical, or is this a design that allows various brands to select varying quality of optics to go into the same sexy package?

[DRT]

This is the Lunt 9mm and APM 13mm & 20mm...

This is the OVL Myriad 3.5mm

[Ricochet]

1 hour ago, DRT said:

I have recently bought various focal lengths of these eyepieces branded Lunt, APM and Myriad.

Are they all optically identical, or is this a design that allows various brands to select varying quality of optics to go into the same sexy package?

The Lunt and APM versions will be identical, why different batches were labelled differently I don't know. If I remember correctly the only claimed optical difference to the Myriad is in the coatings applied, but I'll have to leave it to you to determine if you can actually tell the difference. 

[John]

I've only used the Myriad and the William Optics XWA's and those were certainly identical.

Apart from the small cosmetic differences, whether the coatings or other small optical details are different in the Lunt / APM's is going to be difficult to tell without lengthy back to back comparisons and maybe even taking them apart I guess ?

You are well placed to do the comparisons Derek

Not suggesting you should take them apart though !

[DRT]

It's going to be difficult to give a direct answer on this as I only have one brand of each focal length. 

I will certainly report back on what I find, but at the moment I'm thinking £166 for the 5mm Myriad (4.7mm apparently) looks better than 240 Euro for the Lunt equivalent

Edited June 19, 2018 by DRT

[John]

For a quality eyepiece with that optical complexity, £166 quid is pretty amazing !

[Timebandit]

 

As John says its going to be difficult to say for certain unless more testing and possible pulling them apart for comparison?

But there has been such instances before. The Williams optics Uwan and SW Nirvana were supposedly the same eyepiece internally and externally , but with a different brand name on it. In such cases then you can save a considerable amount of cash if you are canny enough to know about the twin syndrome ?

 

 

 

[Mike_S]

I have these too and going to order the 13mm soon for the complete set. What Barlow would you reccommend with them? APM Lunt sell one. 

[John]

2 minutes ago, MSammon said:

I have these too and going to order the 13mm soon for the complete set. What Barlow would you reccommend with them? APM Lunt sell one. 

They are huge eyepieces - are you sure you want to use a barlow ?:

 

[Mike_S]

Oh I see. I’m still waiting for a used Pentax XW7mm that will do instead. Kicking myself I didnt snap one up when I bought my 5mm as they were selling a 7mm as well. 

[Piero]

Personally, I wouldn't use those eyepieces with a barlow. They tend to be too heavy and tall.

Aside from optics, in my opinion the eye rubber design of the Lunt APM is much better than its counterparts. I actually prefer that design to those installed in the TV eyepieces I tried.

[Mike_S]

11 hours ago, Piero said:

Personally, I wouldn't use those eyepieces with a barlow. They tend to be too heavy and tall.

Aside from optics, in my opinion the eye rubber design of the Lunt APM is much better than its counterparts. I actually prefer that design to those installed in the TV eyepieces I tried.

Thanks that’s good to know. What do you use inbetween the 5 and 9mm?

[Piero]

1 hour ago, MSammon said:

Thanks that’s good to know. What do you use inbetween the 5 and 9mm?

No problem.

With my 2" eyepiece set, I use Docter 12.5mm + Baader VIP barlow (about 6mm), Zeiss zoom 25.1mm-6.7mm, or same zoom + VIP barlow (about 12.5mm-3.4mm).

With my 1.25" eyepiece set, I use Nikon zoom MC1 21mm-9mm + Baader 2.25x barlow (about 10.5mm-4.5mm). 

 

Edited June 11, 2019 by Piero

[niallk]

13 hours ago, Piero said:

Personally, I wouldn't use those eyepieces with a barlow. They tend to be too heavy and tall.

Dont forget the Paracorr...

Congrats on the EPs - great set!  Clear skies.

I only use my PM rarely, and only for my 10mm and below... never for my 17E or N31T5.

[Piero]

24 minutes ago, niallk said:

Dont forget the Paracorr...

Congrats on the EPs - great set!  Clear skies.

I only use my PM rarely, and only for my 10mm and below... never for my 17E or N31T5.

Lol!

That's longer than my TV-60!

[Louis D]

I think the Paracorr is supposed to go first since you need to maintain a constant distance between the primary and the corrector lens (ala the SIPS version).  I can't reach focus with a barlow or telecentric magnifier when using my GSO CC, so I remove the CC since slowing down the light cone greatly reduces coma anyway.

[Louis D]

On 19/06/2018 at 12:46, DRT said:

Are they all optically identical, or is this a design that allows various brands to select varying quality of optics to go into the same sexy package?

The Lunt/APM version claims to be weather/water proofed.  I don't recall the WO/Myriad versions making any such claims.  Other than the different eye cups, that is it as far as differences that I know of.

[niallk]

3 hours ago, Louis D said:

I think the Paracorr is supposed to go first since you need to maintain a constant distance between the primary and the corrector lens (ala the SIPS version).

Per the TV Paracorr2 instructions, the recommended 'stack order' is a function of the EP family & focal length.

In practice, I just remove the P2 when PM'ing my 10E/8E/6E.

...Its a stretch to the focusser knob 🤣🤣

[Piero]

Par Corr plus Barlow is a monster!

The mag is quite high anyway when you use a 10mm or 6mm on your 15".

[Littleguy80]

I have the APM/Lunt in 20, 13 and 9mm. I used my Baader VIP Barlow successfully with the 9 and 13mm on my 10” dob. I had to buy a 80mm extension tube and use both of those EPs in 1.25” mode to reach focus. The Barlow slides down the extension tube up to the eyepiece adapter. Even so it’s still quite a stack. It does give me a very nice 100 degree 6.5mm and 4.5mm EPs though  

[Littleguy80]

Some pictures. Long arms are recommended for reaching the focuser 😉 

Edited June 12, 2019 by Littleguy80

[Louis D]

14 hours ago, niallk said:

Per the TV Paracorr2 instructions, the recommended 'stack order' is a function of the EP family & focal length.

In practice, I just remove the P2 when PM'ing my 10E/8E/6E.

...Its a stretch to the focusser knob 🤣🤣

Couldn't find anything such as you describe in the Paracorr 2 instructions, but I did find this old Ask Al blurb from the Internet Wayback machine:

Richard Keppler asks about positioning the new 4x Powermate with a
Paracorr. Which goes first?

Unlike the 2x Big Barlow which must go ahead of the Paracorr, either way
is fine with the 4x Powermate and either way is approximately parfocal
for most eyepieces.

So I stand corrected.  I'll have to try using my barlow/PBI combo with my GSO CC sometime in both orders.  I think I've tried it in the past without success, though.

There's also this blurb:

Nick Black asks if there are any problems using a Big Barlow with a
Paracorr.

Not if you place the Big Barlow ahead of the Paracorr. In other words,
eyepieces should always go directly into the Paracorr when using a Big
Barlow. Since the 2" Big Barlow won't slip all the way into the
Paracorr, it does not reach its parfocal point and changes the Paracorr
correction.

As an aside, you can place Tele Vue 1.25" Barlows or Powermate into the
Paracorr because these are parfocal devices.

And by corollary, the SIPS version can only be used with parfocal barlows like the Powermate series that don't change the focus position of eyepieces.

 

[Piero]

12 hours ago, Littleguy80 said:

Some pictures. Long arms are recommended for reaching the focuser 😉 

🙄 If you...

- remove the extension tube

- put a 1.25" to 2" adapter into the focuser

- put the VIP barlow into this adapter (1.25" nosepiece)

- put eyepiece into the barlow

don't you reach focus?

 

I can see that you are using the VIP barlow in 2" mode and believe that that is the reason why you need the extension tube.

[Littleguy80]

23 minutes ago, Piero said:

🙄 If you...

- remove the extension tube

- put a 1.25" to 2" adapter into the focuser

- put the VIP barlow into this adapter (1.25" nosepiece)

- put eyepiece into the barlow

don't you reach focus?

 

I can see that you are using the VIP barlow in 2" mode and believe that that is the reason why you need the extension tube.

I did do a fair bit of experimenting prior to getting the extension tube. I’m not sure if I tried it like that or not if I’m honest. It does make sense that it would reach focus like that though. I’ll give it a try next time out. Thank you!

[Louis D]

2 hours ago, Piero said:

🙄 If you...

- remove the extension tube

- put a 1.25" to 2" adapter into the focuser

- put the VIP barlow into this adapter (1.25" nosepiece)

- put eyepiece into the barlow

don't you reach focus?

 

I can see that you are using the VIP barlow in 2" mode and believe that that is the reason why you need the extension tube.

He will need to rack the focuser pretty far out to account for the removal of the extension tube.  I'm not sure how long the 1.25" VIP barlow nosepiece is, as this might take up some of the difference.

When using barlows, I tend to not insert them all the way in.  I just insert them far enough in to be parfocal with the eyepiece by itself and then tighten the focuser's eyepiece holder on the barrel.  This saves having to crank the focuser outward quite a ways.  I've never had issues with barrel tilt with my focuser when doing this.  Of course, I'm generally using medium to long barrel barlows that allow for this.