Don Pensack

Are you standing to observe? Long eye relief eyepieces, no glasses used, and standing are 3 things that don't go together if ease of use is contemplated. Either raising the eyecup or sitting, or both will make the use of the eyepiece easier.

He tested individual eyepieces. Typically, field stops vary perhaps +/-0.05mm or less, meaning the apparent fields will differ insubstantially (maybe 0.05°?) from eyepiece sample to eyepiece sample. For sure, whether an eyepiece is 76° or 78° won't make any difference in the field. There are a lot of other factors that most would rate more important. The Morpheus eyepieces wouldn't have become popular if they had been dogs, optically, so a couple degrees doesn't really matter. It's the same with zooms, too. They never actually measure what the advertising claims, but the differences are small, and unimportant. Only large differences may matter to someone, like one that has a 30° low power field versus another with a 42° low power field. Say you're a company that produces a line of eyepieces and they vary from 70° to 74°. You might just advertise them all at 72°, knowing that only a few people will ever measure them to find out that variation exists. That doesn't invalidate a measurement that shows something different than the advertising claim. It's incumbent, perhaps, on the reviewer, to note that it is a relatively unimportant variation. Knowing the measurements is one thing; how they perform in your scope is another, and one doesn't always follow from the other.

You can get the 43mm spacer as a separate item as well. Baader sells them separately. Perhaps some dealers do, too.

Alternative facts. Where have I hear that before? LOL. However, like weight, apparent field is just one measurement of many on an eyepiece, and each of us weighs the importance of each characteristic of the eyepiece for our own purposes. It might be weight, or eye relief, or apparent field, or field stop. But seeing measurements for hundreds, if not thousands of eyepieces over the last 60 years, it is worth noting that apparent field and eye relief are usually approximate and rarely exact. Does that matter? Probably not. It just means that things are rarely exact, and many things are rounded off, and advertising isn't the same as physical measurements. It's just all part of the astronomy world.

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.