XW14 v Morpheus 14 v Delos 14

[globular]

I'm looking at 14mm EPs for use in my 8" Edge HD SCT F/10.5.

I need long eye relief for glasses use and so the choice seems to be between Pentax XW 14, Morpheus 14 or Delos 14.
New prices for these are £190, £189, £330 - so nothing between the XW and Morpheus and a lot more for the Delos.

Reading comments on other threads:

• XW 14 suffers FC but otherwise is very good optically.  I'd have thought in my scope FC would not be an issue..? So I'd get a near perfect view in my scope?
• Morpheus 14 suffers from some astigmatism at the edge of field in particular. People seem to prefer this aberration over the FC in the XW. But in my scope won't this be worse than the XW?  I like the idea of the slightly wider FOV, but not if the extra field has noticeable aberrations in it....?
• Delos 14 - is it worth the extra? Do I avoid both FC and astigmatism with this EP? Or may be in my "forgiving" scope it doesn't matter which I choose?

It would be great to hear from 14mm users - especially in a similar telescope to mine.

[dweller25]

A new XW for £190 - that’s a good price 🙂

Edited October 28, 2020 by dweller25

[markse68]

I think that was a special offer price from 365 doing a stock clearance? They’ve just gone up a bit maybe because of covid but flo has the XWs  at £260 now i think

Mark

[globular]

So do I buy the XW while I can 'get it cheap'? Or would one of the other ones be better?

[Barry-W-Fenner]

I can't comment on the XW or Delos. I own a 14mm Morpheus and am very pleased with it. Star clusters are very clear and colourful with a nice dark contrast. The 37mm lens gives a brilliant wide field of view. I have gone back to 60 degree eye pieces after using the Morph and find the view quite restricted. The Morph also has a very generous amountof eye relief. I don't think you will find many eye pieces  that are as high end as the Morpheus range at this price point.

I own 3 of the range and inteend to get more 😃

[Louis D]

The 14mm Morpheus has very slight field curvature and astigmatism in the outer 15% of the field, so pretty easy to ignore.

The 14mm Pentax XL (XW predecessor) is sharp to the edge once refocused, but has noticeable field curvature.  However, I didn't notice it until I got presbyopia and had to start wearing bifocals.  So, as far as field curvature goes, it depends on your eyes' focus accommodation ability.  Young eyes will probably be fine with the Pentax XW, but not so much with older eyes.  I replaced my Pentax XL with the Morpheus.  Also, 78 degrees vs 65 degrees is an enormous difference.  However, I still think the Pentax XL is very slightly sharper overall.  Contrast and stray light control is about the same.

I've never looked through a 14mm Delos, but the 10mm Delos I do own is spectacularly sharp and flat of field.  The 14mm Delos focus a fair bit below its shoulder, so be aware of this if you have limited focuser in-travel.

I would probably recommend the Morpheus of the three.

Here's my images through eyepieces at around 14mm for reference:

Edited October 28, 2020 by Louis D

[globular]

Thanks @Louis D.

How do I interpret your images?  It looks to me that the Morpheus has more curvature than the XL. But when combined with the curvature of the scope being used I imagine things change... and may be the extra curvature in the lens cancels more of the opposite curvature in (some) scopes?  But isn't the Edge HD supposed to be relatively flat compared to other scopes?  So the Morpheus might look more curved in my scope than the XL / XW? .... May be I'm getting this all wrong? 

[IB20]

I've heard great things about the Morpheus range and I think they might be where I head after my BSTs.  I do like those ruler tests, always amazes me how sharp the BSTs look on axis. 

[globular]

On FOV:
Using manufacturers published field stop to calculate AFOV I get Morpheus at 77, XW at 72 and Delos at 71. 
And in my scope that's TFOV of 0.51^o, 0.47^o and 0.47^o respectively.

So Morpheus is 8.5% larger - but Louis says the last 15% suffers a bit - so maybe the sharp area of the XW and Delos are a little larger than the Morpheus?  Albeit smaller overall.

I really wish I could try before I buy 😢

[Jiggy 67]

What @Barry-W-Fenner said......It’s important to note that the Morpheus eye relief is around 20mm (I think) but can be increased with the supplied spacer ring which I’ve done with all mine. I’ve got the full range and, like Barry, I’m very pleased with them

[globular]

Thanks @Jiggy 67 (and @Barry-W-Fenner).
All three are on my shortlist because of the good eye relief.  Published figures have the Morpheus at 18.5, XW at 20 and Delos at 20.  So in theory the Morpheus (in it's 14mm variant) is the tightest of the three - but I've read reports that they all work pretty well with glasses.

Edited October 28, 2020 by globular

[Louis D]

36 minutes ago, globular said:

Thanks @Louis D.

How do I interpret your images?  It looks to me that the Morpheus has more curvature than the XL. But when combined with the curvature of the scope being used I imagine things change... and may be the extra curvature in the lens cancels more of the opposite curvature in (some) scopes?  But isn't the Edge HD supposed to be relatively flat compared to other scopes?  So the Morpheus might look more curved in my scope than the XL / XW? .... May be I'm getting this all wrong? 

You're not going to be able to see field curvature in these images because the camera's lens has more than enough depth of focus to bring all of the field into focus.  Unsharpness at the edge is mostly due to astigmatism in these images.

Most scopes that I am aware have a field curvature that accentuates the field curvature in the 14mm and 20mm Pentax eyepieces.

The Edge HD would do best with flat field eyepieces as you suggest.  The Morpheus will still look flatter of field than the XL/XW eyepieces, but not as flat as the Delos.

[Jiggy 67]

The spacer will increase that figure by 2 or3 mm

[Louis D]

I've measured the 14mm Pentax XL and Morpheus to both have 18mm of usable eye relief.  My 7mm and 3.5mm Pentax XWs also have a measured 18mm of usable eye relief.

My 10mm Delos has 21mm of measured, usable eye relief.

Edited October 28, 2020 by Louis D

[Louis D]

To revisit the difficulty of capturing field curvature with a small camera lens, here's an extreme example of the camera lens's ability to flatten an otherwise very curved field.  The 30mm WideScan clone below (Agena UWA second from right/bottom) has vast amounts of field curvature.  So much so that most folks describe it as entering light/warp speed.  But, it looks pretty good here, having only mild astigmatism:

[Barry-W-Fenner]

Some very informative eye piece info from @Louis D
as usual 👍

[John]

30 minutes ago, Jiggy 67 said:

What @Barry-W-Fenner said......It’s important to note that the Morpheus eye relief is around 20mm (I think) but can be increased with the supplied spacer ring which I’ve done with all mine. I’ve got the full range and, like Barry, I’m very pleased with them

I'm wondering how the spacer increases the eye relief unless it is an optical device of some type ?. A barlow lens will increase eye relief but that is an optical device of course.

I can see that it will raise the position of the eye cup though. Maybe some folks find the eye cup a little too close to the eye lens without the spacer ?. There is a similar situation with the Tele Vue 32mm plossl which is somewhat easier to use for the non-glasses wearer with the TV Eye cup Extender in place. I figure that the spacer ring supplied with the Morpheus works in a similar way ?

I have the 14mm Delos by the way but I don't have an SCT. I find that the longer focal leghth Delos and XW's are very similar in performance and ease of use. I've not used a Morpheus.

 

 

Edited October 28, 2020 by John

[globular]

My wife and I will both be using the EP... one wears glasses and the other doesn't.  So I guess it would be important to be easy to use for both of us... adding a spacer for non glasses use and removing it for glasses use would be rather annoying.

Trouble is everyone is different and we won't really know until after we've bought one of them.

Maybe this favours the XW a little.... where the spacing is adjustable by screwing the cups in or out.
And scores against the Morpheus - unless folded up and folded down works for us 
How do the Delos cups adjust?

[John]

The Delos uses a system where the whole top section of the eyepiece slides in and out and is locked in place by twisting the top and bottom of the eyepiece in opposite directions.

I have both Delos and XW's and I reckon the XW's are a bit easier to adjust quickly. There is not a lot in it but the Delos is a 2-handed operation whereas the XW's can be done with one.

 

Edited October 28, 2020 by John

[Jiggy 67]

19 minutes ago, John said:

I'm wondering how the spacer increases the eye relief unless it is an optical device of some type

Maybe it’s my understanding of eye relief which is lacking, I assumed that by increasing the distance between eye and outer most lens that would increase the eye relief but I bow to your better knowledge John 😀

[Louis D]

56 minutes ago, Jiggy 67 said:

What @Barry-W-Fenner said......It’s important to note that the Morpheus eye relief is around 20mm (I think) but can be increased with the supplied spacer ring which I’ve done with all mine. I’ve got the full range and, like Barry, I’m very pleased with them

Make that decreased eye relief with the supplied spacer ring.  One came with my 9mm Morpheus.  It's nothing more than an M43 spacer ring (think empty filter ring).  It works the same as the Tele Vue eye cup extender, only it attaches differently.

12 minutes ago, John said:

The Delos uses a system where the whole top section of the eyepiece slides in and out and is locked in place by twisting the top and bottom of the eyepiece in opposite directions.

Actually a bit more complex than that.  It's the top and bottom of the upper/outer barrel of the eyepiece.  The lowest part of the eyepiece that resides in the focuser plays no part in the adjustment.  Thus, it is a two handed operation compared to what can be a single handed operation for the Pentax XW as you stated.

Edited October 28, 2020 by Louis D

[Louis D]

5 minutes ago, Jiggy 67 said:

Maybe it’s my understanding of eye relief which is lacking, I assumed that by increasing the distance between eye and outer most lens that would increase the eye relief but I bow to your better knowledge John 😀

Eye relief is the fixed distance behind/above the eyepiece's eye lens where the image forms.  All the rays should converge to a fairly tight circle/point at that distance.  You need to put the lens of your eye at that distance to take in the image.  Adding a spacer ring merely pushes your eye back a bit.

[John]

7 minutes ago, Louis D said:

Actually a bit more complex than that.  It's the top and bottom of the upper/outer barrel of the eyepiece.  The lowest part of the eyepiece that resides in the focuser plays no part in the adjustment.  Thus, it is a two handed operation compared to what can be a single handed operation for the Pentax XW as you stated.

Sloppy description of the operation by me !

I did try and find a video to illustrate but could not find one quickly.

It's not a difficult operation but I would not want to have to do it repeatedly during a session. Even with the XW's it would be a chore to have to adjust the eye cup position by more than a small amount each time a different observer uses the scope.

Obvious solution: a set of Delos for him and a set of XW's for her

 

Edited October 28, 2020 by John

[globular]

@Jiggy 67 Each EP has a fixed position at which the maximum / optimal exit pupil is formed.

Everyone's face and eye sockets are different... then there is with and without glasses..... and some people like to rest on something and other like to hover.... etc etc.

EP eyecups are adjustible and/or spacers are used to help a wide variety of users as possible place their eye at the optimal viewing distance.

 

[globular]

3 minutes ago, John said:

Obvious solution: a set of Delos for him and a set of XW's for her

Agreed.  I'll send you my wife's mobile number so you can explain to her why this is necessary. 🤣