Review of the Baader Morpheus Eyepieces

[John]

That may very well have been a consideration.  However, I think they were also trying to achieve an AFOV that is also easy to "view at a glance".  So they were being careful not to make the view so large, that it now really requires scanning around, something you read about often with the 82 and 100 varieties.  So by keeping the AFOV within that glance-range allows it to retain a certain level of engagement, which is nice.  In my eyepiece journeys that is why I settled on the XWs vs the T6s or ES82s -- they had a naturalness about them when you used them and felt effortless whereas with the larger AFOVs there is a degree of effort involved in using them.  One of the surprises for me with the Morpheus was their ability to retain this character that the XWs have.  So while the technology for eyepieces allows larger AFOVs, and one day we will probably see 120 degrees and perhaps a little larger, we have to realize that these uber-large AFOVs really go beyond what is physiologically comfortable and natural, so while cool it also detracts IMO from the natural experience we are used to.  So I think they were also concerned about keeping the AFOV restrained as well to maintain a comfortable and natural experience.

Interesting stuff Bill but I feel this must vary from person to person.

I've never experienced any discomfort or unnatural feelings viewing through 82 or 100 degree eyepieces. I have some XW's and Radians and they are great but the field of view of the Ethos eyepiece seems entirely natural and attainable for me without any facial or occular gymnastics.

You clearly have a different personal experience to using eyepieces to me so now, quite understandably, make your eyepiece selections accordingly. You and I are just 2 examples of the human species though so neither of us can claim the definitive version of what others will like. We can do no more than express and explain our own preferences.

Personally I feel viewing the Universe through as wide a "window" as possible is the most natural way to experience it. I've not travelled in space as yet so I've no first hand experience of that environment to compare it with though

It's great that fine eyepieces are available for a wide variety of viewing preferences and Baader have clearly produced an excellent wide angle eyepiece in the Morpheus 

[michael.h.f.wilkinson]

I think very much depends on eye relief. I find the 82° FOV of the Type 4 and longer Type 5 Nagler EPs quite easy too, but the eye relief some other UWA (and Ethos) EPs makes them uncomfortable. The 70° of the XWs is fine, but the 68° of the 20mm MaxVision wasn't, in contrast to the 24mm MaxVision, with its longer eye relief. I do need rather more than others, because I have to wear glasses while observing. The long eye relief of the new Morpheus EPs sounds very promising, much better than the new Vixen SSWs. I will happily trade 6° of AFOV for 7mm extra eye relief in this case.

[John]

If you have to wear glasses to observe that will have an impact on the specifications that feel comfortable and natural to you, of course.

You will also struggle with low glass, shorter focal length designs such as orthos, plossls etc.

[rockystar]

Think I might have just decided on my next set of eyepiece. Thanks Bill, great review.

[Ruud]

Possibly, the field stops Baader mentions are the diameters of the field lenses, rather than the actual effective field stop diameters. 

Of the 6.5 mm Morpheus, Baader says the field stop is 8.75 mm, but I calculate 8.62 mm, and my calculated field stops always come out slightly too high. 

For this Morpheus I get an unexpected 0.13 mm too low. Actually, for all of the Morphs I get results that are too low.

Because of this I first expected that the Morpheus would have unusually low rectilinear distortion, but the 6.5 mm doesn't. Rectilinear distortion is quite distinct, about what you would expect in an eyepiece as wide as 76°. (Rectilinear distortion, by the way, is not a shortcoming of an eyepiece. It is far more important that angular magnification distortion is absent, and is saw no trace of that.)

By Wednesday the sky should clear up again. I’ll do a star drift test then, to see what the effective field stop diameter really is.

[YKSE]

Ruud,

Can you show your formula for calculation field stops? How do you estimate how much Rectilinear in an eyepice? I mean in term of measurement, not the calculated geometrical distortion.

[Ruud]

Ruud,

Can you show your formula for calculation field stops? How do you estimate how much Rectilinear in an eyepice? I mean in term of measurement, not the calculated geometrical distortion.

For eyepieces I just look at straight lines to estimate rectilinear distortion (RD). Some have a lot for their afov (panoptics, my Nagler 4.8), others seem to have very little (Delos). RD in eyepieces is always of the pincushion type. I've read that correcting for pincushion distortion increases astigmatism which would explain why so many eyepiece designs allow for it.

Measuring RD is difficult because angular magnification distortion (AMD) can be present as well. With AMD, the magnification (focal length) of the eyepiece varies from the centre to the edge of the field. If AMD is of the barrel type, the image looks like it is pasted on the outside of a sphere, and if the AMD is of the pincushion type the image looks pasted on the inside of a sphere.

Measuring distortion for camera lenses is easy. To undistort images from camera lenses you can use Adobe Camera Raw (expensive and not always successful) or Hugin panorama stitcher (free and it always works). The settings of the parameters in both programs would give you a reproducible measurement of the distortions present in the original images. There's a guy at ESA who uses Huging for just that purpose.

My formula to calculate field stops is empirical. I just tried lots of variations with tangents. Here's a screenshot with some comments, and below it is the worksheet itself, if you want to try it:

ScopeCalculator11 .xls  (Please see post number 46 for corrected version of this spreadsheet)

By the way, I read that the afovs of some of the Delos are smaller than 72°, and that the afovs of the Hyperions are larger than 68°.

Now, if the avofs of the Morpheus are slightly bigger than the stated 76°, my field stop errors are as I've come to expect them from the worksheet. In my 500 mm fl telescope it takes a star at the equator just 240 seconds to travel across a 8.75 mm field stop. I'll need no more 15 minutes of clear sky and I can do the drift test three times. 

[YKSE]

Nice to know that using camera for measurement, do you know how the quantify the measurement? any link to this measurement?

As to RD and AMD, my understanding is slightly different than yours, with AMD, the straight lines will keep straight across the field of view, but the spaceing between the lines gets narrower and narrower closer to the edge. While with RD, there're two types of RD, pincushion distortion where straight lines close to edge look like )(, and barrel distortion, where straight lines close to edge look like ().

RD and AMD are part of Geometrical Distortions (GD), Chris Lord has more detailed discussions about distortions here, what I can understand is that GD depends only on FOV, the wider FOV, the more GD, you can trade between RD and AMD, but you can't reduce the total Geometrical Distortions.

The fact that most astronomical eyepieces choose to correct AMD, is because AMD will cause close double stars smear together close to the edge, not because of astigmatism, also there are no straight lines in night sky to show this distortion, while in daytime use, AMD is more preferred because we have too many familiar staight lines in the view. You can increase GD (AMD or RD) to correct astigmatism (some Nikon eyepieces has more AMD than calculated total GD for correcting astigmatism), or you can increase field curvature to correct astigmatism (like some Pentax eyepiece).

[bomberbaz]

only strange thing I can see about these is the spacing, 9 - 12.5 = 3.5mm / 12.5 - 14 =1.5mm. A little perplexing but I am guessing they have done thier homework here. I am interested but un-committed just yet.

[BillP]

Yes...those are rather close.  But for C14 scopes those two give good planetary mags of 254x and 284x.

[Ruud]

Hi,

I've repaired my formula and now I get amazingly exact results. Baader certainly provides the effective field stop diameters, rather than the dimensions of the front lenses.

Here's a screenshot of the field stop results I get with the new formula, compared with the values Baader gives.

See how the field stop of the 4.5 mm is calculated with a precision of 0.01mm?

Attached you find a short pdf document which explains the two formulas I used: one to calculate pincushion distortion (the Morpheus have 15.1% of it), and another to calculate field stops.

Both formulas are very easy! Have a go and read the pdf. It will take no more than a minute or two.

The pdf: FS SGL.pdf

Meanwhile I'm very happy with the 6.5 mm. I've even decided that I have an eyepiece gap in the 17.5 mm range.

Bye!

Edited September 17, 2015 by Ruud

[Mike73]

Very interesting Ruud.

My 9mm should be arriving today and I'm really looking forward to trying it!

[michael.h.f.wilkinson]

Very interesting Ruud.

My 9mm should be arriving today and I'm really looking forward to trying it!

Looking forward to your report!

[Mike73]

Looking forward to your report!

The Morpheus seem to tick all the boxes for what I like in a EP and Bill's review where he compares them to the mighty XW was enough to sway me to try one, if I like the 9mm I'II probably go for the other focal lengths.

[michael.h.f.wilkinson]

The Morpheus seem to tick all the boxes for what I like in a EP and Bill's review where he compares them to the mighty XW was enough to sway me to try one, if I like the 9mm I'II probably go for the other focal lengths.

As I said before, I am looking at the 14mm first, but the 9mm might be nice next to the XW10 to tune magnification to seeing more subtly in the C8

[Saganite]

Very interesting Ruud.

My 9mm should be arriving today and I'm really looking forward to trying it!

I too am interested in the 9mm and the 14mm, so very much look forward to your view of the 9mm .

STEVE

[Mike73]

Well I've just tried the new 9mm Morpheus and I'm very impressed!

It seems to have more ER than the stated 21mm, there really isn't any pressing your eye into the eye cup, come to think of it your eye doesn't get anywhere near the eye cup. I found this tricky at first but it soon became very comfortable.

Something that was also very obvious and I think Bill also mentioned was you really don't see very much of the eyepiece housing when looking through. its almost like you see a black ring of the field stop and thats it! Its hard to explain, I haven't looked through any eyepiece which has given the same effect.

My only negative point was that the changeable eyecups come off too easily. You take the cap off then try and roll the rubber eyecup out and it pops off, this happened maybe 50% of the time I used it. 

I'II probably be able to add more in the morning but I've seen enough to know that I'm going to get one (or maybe two) other focal lengths, the tough part now is to decide which ones!

[Ruud]

Hi Mike,

About the rubber eyecup: I too prefer it when an eyecup slightly touches my brow. Even on the 6.5 mm with its 18.5 mm eye relief, the wingless eyecup won't reach high enough for that. The winged one is even lower.

Prying up the wingless eyecup is a bit tricky at first, but after a while mine has become easier to flip up without coming off. The part that folds down seems to have relaxed a bit and no longer sits as tight around its bottom when it is down. In the beginning I also had trouble folding it down (parts of it would fold in, rather than down). That too has stopped.

It has to do with the huge eye lens, I think. The Morpheus has an even bigger eye lens than the Delos. The Delos have their rubber eyecups firmly stuck in place. The rubber is much thicker as well. On my 12mm Delos (my earlier one) the rubber is coarser, duller looking, lighter in colour and much less flexible than on my 8mm (my later one). But the soft, shiny, black rubber on the 8mm, although much more comfortable, is very sticky for dust. I keep them both folded down and only use the adjustable metal sleeve the Delos have. I might get one of the softer Delos eyecups for my 12mm, as the current one is way too hard for comfort. 

The winged eyecup of the Morpheus was easy to lift up all along. Just gently lift it by its wing. Gently, because as you say both eye guards come off with little force. I use the wingless eyecup only, by the way, as it serves to warn me when I get closer to the glass. 

Of coarse, if you keep having trouble raising the wingless eyecup, you might consider fixing it in place with thin double sided tape.

One day, pretty soon I imagine, Baader will come up with a line of replacement eyecups of different heights for the Morpheus eyepieces. Probably with matching end caps, if the currents ones won't fit. If that takes too long I may buy myself an inner tube of the right diameter, and make my own eyecup.  

Praise Be, for Baader's Morpheus. 

Edited September 19, 2015 by Ruud

[michael.h.f.wilkinson]

Sounding better and better.

[Mike73]

Hi Ruud

Yep the rubber eyecup is the only thing I can fault the Morpheus with so far but I really think Baader messed up big time with it. Its not as if it only happens when you pull it, the eyecup comes off with very little effort your then left trying to get it back on in the dark.

Its almost as if they have used the wrong diameter eyecup!?

I'II have a little play with it today and try and fix it, like you say it shouldn't be too hard with some tape or something.

The 76˚ seems perfect for me, I feel the same as Bill when it comes to 100˚ EP's in that I found myself having to look around the corners to get the whole view (I understand the personal thing though ) but for sketching its great to see the whole FoV in just one quick look.

I'm looking forward to trying the Morpheus again at my dark site in a couple other focal length's.

[Ruud]

Yes Mike, the rubber eye guards definitely need a bit of extra work. And although mine stopped coming off when I flip it up, it still isn't high enough for the eye relief. Fortunately I'm very much in love with the eyepiece itself. 

---

I also have something else: my apologies and a retraction:

I notice that 9 people have downloaded my earlier attempt at an Excel worksbook for useful eyepiece calculations. That is regrettable because it contains an obvious error in the calculation of the field stops.

My bad! I'm really sorry.

Here is a corrected version of the worksbook:   ScopeCalculator18.xls

It is still a project in development though. I plan to add a feature or two in the near future.  But at least this version (18) gives correct results when you assume that angular magnification distortion is absent and only rectilinear distortion is present.

[RAC]

I would like to here from anyone how has tried one of these with a fast scope(f3-f4) with a Paracorr.

[Astro_Baby]

Great review - I can only imagine the work and time that went into it.

Mel

[SpaceWalker]

So... any new field reports? I'd especially be interested to hear how the 6.5mm and 12.5mm work in faster scopes since I have f/6 Dob. We've already got mixed reports on the 12.5mm  Morpheus (do you like FC? I don't for this price), but those were just pre-production samples.

[Ruud]

So far I used the 6.5 mm mostly in my F/5 refractor of 500 mm focal length. In that telescope the eyepiece gives 77x magnification and an exit pupil of 1.2 mm. The focal plane of the refractor is flat. It's a 4" so the resolving power is slightly over 1 arcsecond. 

From my notes:

In the late afternoon on the day I bought it, I tested the eyepiece on terrestrial targets. There's a church steeple about a kilometre away, which is covered in grey shingles. They looked fine, showing the same slight colour differences as I can see through my Delos. The view was sharp across the entire field.

There were bright sunny spells which I used to test for kidney bean shadows. The result was good: eye placement becomes slightly more critical for my bright-light pupil, but the eyepiece remains comfortable to use. For me, it is suitable for daytime use. 

The contrast between the bright white paintwork on a window frame and the dark interior behind it (a scene some 50 metres away) did seem to show chromatic aberration. But that was due to the telescope itself: I see the window from an angle and, due to a shallow depth of field, not the whole frame was properly focussed. When the Genesis is not properly focussed it is not colour free. Toward the edge of the view straight edges definitely show pincushion distortion.

For these daytime tests I had removed the 1.25" adapter from my diagonal and used the eyepiece as a 2". That works and it makes the whole a bit lighter. Still, it makes the telescope back-heavy by increasing the torque on the altitude axis. This is because without the 1.25" adapter, the eyepiece sinks much deeper into the diagonal, so it needs  a lot more back-travel of the focuser. So much that any parfocallity with my other eyepieces is lost. I don’t think I’ll use it as a 2".

I later took a look at the night sky, for an hour or two between the showers.

I tried to find lateral chromatic aberration using Vega and Deneb, but found none. Sharpness across the view was excellent. The focal plane of the eyepiece looks completely flat to my eye: it did not matter on which star in the field I focussed, all the others became just as sharp.

At 77x, both double stars of epsilon lyrae were cleanly split and each pair was separated by a thin, black gap. The ring nebula showed well and had a dark centre. Albireo looked very beautiful with its orange and blue star. Especially the orange star appeared very saturated. The double double cluster in Perseus filled the view with pinpoint stars. I saw no trace of astigmatism.

77x is too much for the Andromeda galaxy, which is just too big, but the cores of both M31 and M32 fit nicely in the field. I saw no EOFB.

A few days later we had a clear night again and I tried the eyepiece on a gibbous Moon with my 6" F/10 1500mm FL Nexstar SE. Magnification was 231x and the exit pupil 0.7mm. The seeing was good and the view was very crisp and contrasty. The seeing got even better so I put my 1.8x barlow between the SCT and the eyepiece to try it at 415x with an exit pupil of 0.4mm. I saw even more detail then, but the view was no longer very crisp. I think I spent 4 hour studying the Moon's terminator. The Pleiades were dazzling at 231x.

At F/5 the 6.5 mm performs very well. Much like a Delos.

I wish the weather was better.