Ruud

Congratulations, a field of 200 m at 1 km is something like 11.4°. That is wonderfully wide! Low power binoculars have interesting properties for amateur astronomers. Their bright and wide fields make them excellent for rich field observing. And of course, low power means you won't need a tripod to get shake free views. I have experience with 4x22, 17° field binoculars. Their exit pupil is 5.5 mm (22 divided by 4), which makes them bright enough to make targets like the Orion Nebula or the Andromeda galaxy stand out well. They offer impressive views of the constellations, and the the Milky Way is remarkable in them. Low power ensures that individual eyepiece focussing is hardly an inconvenience. Lower magnification comes with a greater the depth of field, which actually is a great benefits for nature observers. Unless your target is really nearby, it will look sharp, like everything else all the way to the horizon. Especially young children, whose eyes can accommodate over many diopters, will rarely need to adjust the focus of a low power pair of binoculars. My 4x22 Kasai seem to have the same eyepieces as yours. Mine are from an inexpensive line made by Kunming United Optics. I guess your 6x30s come from the same factory. Enjoy them!

What a handsome piece of gear!

Okay. Ten points, out of ten.

This is an interesting phase. I wonder: before you reassemble everything you probably want to blow any dust out. Do you suppose using a bulb blower (like the Giotto Rocket Blower) would be safe for the mirror coatings? Good luck with the rest of the project and thank you for documenting it so well.

Altogether it is an amazing idea and the concept is proven. Congratulations!

I do hope it works as planned!

Hi, I made them in Geogebra. It's a freeware tool used in maths education.

32 mm Plössls have a long eye relief and may take some time to get used to, especially when the exit pupil is close in size to the user's pupil. Kidney beaning, however, should not happen with TeleVue or any other Plössls as they tend to have well behaved exit pupils. (Kidney beaning comes from spherical aberration of the exit pupil. Until the first generation Naglers this was a rare phenomenon.) Could it be blackouts that you're seeing? I have a 32mm GSO Plössl. Had some blackouts at first, but got used to the eyepiece, and the blackouts disappeared. I think you too may get used to your 32mm Plössl. Here is how blackouts occur. With long eye relief, steady eye placement becomes difficult. The movements of the eye cause blackouts in which the image disappears from one side to the other. When the image is partially illuminated, it is as if a curtain is drawn over one side of the image Here is how kidney beans occur With kidney beaning a kidney shaped shadow forms between the centre and the edge of the field, while both centre and edge remain fully illuminated. Kidney beans arise from even subtle eye movements, especially with larger exit pupils. When the eye movements get larger, blackouts will also occur. Below, a kidney bean occurs as one of the red rays can not enter the eye, yet the more extreme off-centre green ray still can. (The brain inverts what's on the retina, hence the shadow appears below the centre.) Fortunately, spherical aberration of the exit pupil is, to a large extent, a thing of the past.

Wow, John, that is a beautiful telescope!

I love Stuart Gary. He is an outstanding science journalist. He clearly specialises in astronomy and often the guests on his show, professional astronomers, mistake him for a colleague. I've been listening to him for many years. I was very distraught when the ABC cancelled Starstuff, his radio show, which had been Australia's highest rated science show for many years. The show was sacrificed to 'horizontal programming'. Fortunately many people emailed the ABC asking them to reconsider, which led them to continue with Starstuff as a podcast only. The show was also broadcast on radio in the USA. Stuart did the research, production and presentation, the ABC lent him their facilities to make the show. End 2015 the podcast was discontinued because the ABC had stopped supporting it. Again, a great number of people emailed them to let now how much they regretted this. This time Stuart decided to continue with the podcast by himself. The ABC would not let him use the name Starstuff (even though the term was coined by Sagan), so Stuart chose a new name for the podcast: SpaceTime. I listen to every episode of SpaceTime using iTunes. That's two episodes per week!! SpaceTime, like Starstuff before it, is the best astsronomy podcast out there. I also enjoy the Jodcast, an astronomy podcast made by students of Manchester University, and the Weekly Space Hangout by Fraser Cain on YouTube.

The video shows the problem well and your accent is very intelligible. I think Brian is right. Good luck, and be careful as Brian says.

It looks great, Jim. I believe you when you say those legs are solid as concrete! I'm curious. How do you put the scope on top?

It certainly looks solid. I hope it works well. One of the advantages of this adaptation is that you will be able to use a proper star diagonal. I think that the erecting prism in the C70 may be this little telescope's weakest link. I'll cross my fingers for that functionality you don't want to lose!

I have this little scope. I use it with a 32mm GSO Plössl and for a finder I use the tube of a pen, like this: Thanks for the thread. I'll bookmark it!

Many thanks, Martin, the atlas is huge. Enormous. Overwhelming!

I really like this tip by L8-Nite: http://stargazerslounge.com/topic/254918-custom-made-eyepiece-case/#entry2781119 It teaches how you can use empty spray cans to make holes of the right size in foam. Wonderful, simple and effective! I suppose you have to make sure that the cans are really empty before you do this. Thanks to everyone who shows their eyepiece cases here. I visit regularly to have a look at them. Wouldn't want to miss any!

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.

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.

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.

a few more wheels on it and you'd think it is a locomotive. What a thing!

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!

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.