Don Pensack

The apparent fields of the Morpheus line are: 17.5--72° 14, 12.5, 9, 4.5--78° 6.5--79° These are measured using lab instruments by Ernest Maratovich and listed on his website here: http://astro-talks.ru/forum/viewtopic.php?f=32&t=1483#p41976 As to why Baader would not show the exact measurements, I cannot say. Probably for the same reason TeleVue doesn't show their Nagler line varies from 78° to 84° Actual measurements of most lines show the apparent fields vary over around a 4-5° range. And it really doesn't matter much in the field, does it?

I use a 17.5mm Morpheus myself. Almost every line of eyepieces varies in its apparent field over the series. Why would you consider it a criticism if you make positive comments about an eyepiece and someone else mentions its test bench measurements? Most people won't care, but some will. That doesn't mean the people who own and love the eyepiece (I certainly do) will somehow need to get rid of it. There is no harm in knowing the facts about an eyepiece.

You said, in an earlier post; "I bought my first Ultima Edge, 15mm, because I wanted an eyepiece exactly half way between my Morph 17.5 - 12.5 mm eps. thus I skipped the 14mm and then bought several more Edges after that." I only mentioned that either 14mm or 15mm would have been half-way between because 14.5mm is half way between. It wasn't a criticism, merely pointing out that 14mm would have been fine as an in-between, just as 15mm is. There are only a small number of eyepieces that have ever come in a 14.5mm focal length. Experimentation is how you learn about eyepieces. Buying and trying is how you learn what you like. I must be in favor of that because I've owned over 360 different eyepieces over the years. It sounds like you've done your fair share of that as well.

Measured apparent fields: 30mm UFF 70° 17.5mm Morpheus 72° 12.5mm Morpheus 78°

Effective eye relief from rubber eyecup up on the Pentax 23mm is 12mm. On the 22mm Nagler, it's 16mm. Most glasses wearers could use the latter. Very few glasses wearers could use the former.

One clarification: the measured field stop in the 17.5mm Morpheus is 21.75mm and the apparent field 72°. That's a case where the eyepiece that was actually released, 3 years after the other focal lengths, was different than what was planned.

It's what you observe. If you want to see details in a small planetary under 1' in size in an f/5 scope, you might use a 3-4mm eyepiece. If you want to see a large galaxy like M33, you might want a 20-24mm eyepiece in the same scope. If you want to see M15 fully resolved, you might want a 6-8mm eyepiece. The Perseus Double cluster, a good 30mm. NGC 4565 with contrast, a 10-12.5mm eyepiece I could go on with a longer list. With an 1830mm focal length, I would be hard-pressed to whittle the eyepiece count down to 5. i'd miss some often-used magnifications. 8 would be a bit easier. At this point, though, if no coma corrector existed, I'd sell the newtonian and go back to using an 8" SCT. I'd miss the aperture, however.

Exactly halfway between, magnification-wise, is a 14.58mm focal length. That makes either 14mm or 15mm acceptable as an in between.

Except for the 30mm UFF/Edge, which is world-class. It's in a different category than the other UFFs.

A #12 is a longpass filter. The Baader Contrast Booster is very different. Here is the spectrum on my own personal CB filter:

The advantage of the CB on Mars is that the minus violet filtration also eliminates a lot of atmospheric light scatter and doesn't appreciably change the color balance on Mars. So it yields a sharper image and augments surface detail. The last apparition, it was shocking how good the image of mars was.

In a 9.25" scope, a jump of 56x is not a large jump unless the seeing supports 335x and not 391x. Over the years I've done this, I don't really find seeing supports 335x and not 391x, though. On the nights where 335x is clean, clear, and sharp, so will 391x be. In my 12.5", if seeing supports >300x, it usually supports 500x. If it doesn't support 300x, 200x might be the maximum sharp magnification, not 260x. So I would argue that a 56x increase at that power is probably fine, maybe a bit small, actually. That being said, there is a rational reason to make the % jumps at high powers be smaller than at lower powers. One way to do that is to choose eyepieces that yield an even step in magnification, like 50x. That will automatically produce smaller % changes at high powers. Even % changes usually results in low powers too close together and high powers too far apart.

Given the results from the Fringe killer, this scope didn't have the most severe CA I've seen in doublet refractors. But looking at the bottom edge of the coupler on the right, only the contrast booster eliminated the violet. Of course the Moon & Sky Glow filter did not eliminate any violet--it has no violet filtration at all. It tends to create a "cold" image of Jupiter as well, which is one of the reasons it enhances the banding, like a #82 light blue, only without the red filtration of the blue filter.

Extended eye relief can cause blackouts when the eye drifts inside the exit pupil, too close to the eyepiece. This occurs on axis as well as off axis if the eye drifts in and out or side to side. That is not what "kidney bean" blackouts are caused by. They are caused by spherical aberration of the exit pupil, or SAEP, which is when the exit pupil is curved and eye relief is not the same in the center as it is at the edges. It is possible for a simple eyepiece to have too long an eye relief AND SAEP, but anything that eclipses light in the field is simply called blackouts, and "kidney bean" blackouts have a special cause. Here is a better, illustrated, explanation: http://www.handprint.com/ASTRO/ae4.html#SAEP and, a more technical explanation go down the page to see a full explanation of SAEP: https://www.telescope-optics.net/eyepiece_aberration_2.htm

After years of using all kinds of planetary filters, I was advised to try the Baader Contrast Booster on Mars. It was sharper and revealed more surface details than any colored filter or planetary filter. It was magic. I tried it on Jupiter and Saturn but found the yellowish tint a bit too intense (though it worked to bring out details). Upon recommendation, I tried the Neodymium oxide filter without the minus violet, the Baader Moon & Sky Glow filter, on Jupiter and it was amazing, and it brought out tons of details not seen with any other filter. Saturn, I think, benefits from a #8 light yellow to bring out details in the rings (though we're quickly losing ring detail as we head toward the edge-on rings in 2025), though my best views have always been without a filter. So I think a pair of the Baader filters are useful for Jupiter and Mars, but on Saturn, especially now that it is getting dimmer with the rings closing, using a filter for enhanced details is becoming dubious.

Great idea.

You might also find this interesting: https://www.cloudynights.com/topic/860739-adjusting-collimation-on-a-cheap-mirror-diagonal/?p=12448264

Well, something is fishy, because no eyepiece made in the universe puts its spot in a 4 microradian circle. Milliradians, yes. And you can see the translation here, also using Google Translate: https://www.cloudynights.com/topic/883440-new-takahashi-eyepieces-announced/?p=12829217

That is a mistranslation. The Takahashi illustration says 0.004 rad, which is 4 milliradians, not micro.

Not if you own and use a good Barlow lens. Not if the scope you use is small and 4 or 5 eyepieces gives you a decently spaced set from its lowest to highest power. Not if the objects you view only require magnifications at one end of the magnification range. If all I viewed with my 4" refractor were planets and Moon, 3 eyepieces would be sufficient. But if you have a large dob and view everything from large Sharpless nebulae to small 5" planetaries, 10 eyepieces might not be enough.

It is identical. The maker, KunMing United Optics, makes this eyepiece under at least 8 or 9 different private labels.

The problem comes when someone gives a review of an eyepiece in an f/8 refractor and only cares about the sharpness in the center 1/3 of the field. The person who has an f/4 dob and is looking for sharpness from edge to edge who reads that review has not read a review relevant to his scope or requirements. And perhaps the reviewer hasn't looked through hundreds of eyepieces and doesn't have the experience to really review the eyepiece. Merely stating that it was good doesn't carry any weight, in that case. So some form of a review that contains measurements, even if it is above the heads of most readers of the review, is really essential. We just don't get that 95% of the time. I want to see at LEAST the following in a review. We won't get it, though, because there is too little profit in eyepieces to pay for the necessary testing and too little interest in knowing the results of such testing.: 1. spherical aberration_________________________________________________________ 2. coma_____________________________________________________________________ 3. astigmatism________________________________________________________________ 4. field curvature______________________________________________________________ 5. distortion--type and amount___________________________________________________ 6. chromatic aberration--axial and lateral___________________________________________ 7. apparent field_______________________________________________________________ 8. eye relief___________________________________________________________________ 9. light scatter control--field and star outside field (glare)______________________________________________________________________ 10. SAEP_______________________________________________________________________ 11. CAEP_______________________________________________________________________ 12. Tint or spectrum of transmission________________________________________________________________________ 13. Vignetting___________________________________________________________________ 14. Transmission_________________________________________________________________ 15. thermal issues________________________________________________________________ 16. field stop focus_______________________________________________________________ 17. impression of contrast_________________________________________________________ 18. EOFB_______________________________________________________________________ 19. Sharpness on axis/50%/edge____________________________________________________ 20. Presentation of field: close, medium, distant________________________________________ 21. Presentation of field: concave (bowl), flat, convex (globe)_____________________________ Other comments about eyepiece_______________________________________________________________________________________________

If you look at Ernest Maratovich's tests of many eyepieces, you'll see that many many eyepieces yield edge of field apparent stellar sizes in excess of 10'. http://astro-talks.ru/forum/viewtopic.php?f=32&t=1483#p41976 start with the 4th post on that thread.

And if the lower circle was a lot smaller than the upper circle, wouldn't the spot sizes be larger instead of smaller? That's one reason I think they meant milliradians in the bottom row, not microradians.

That would make the circle 0.01375', or 0.825", and the spot size a small fraction of that I think they made an error. That would make the star image essentially diffraction limited near the edge of the field. I've seen that in several eyepieces at f/10, but none with a 4 element construction.