Preferred focal length spacing for your eyepiece collection?

[Rob_UK_SE]

Hello all,

I am toying with the idea of filling in some gaps within my current eyepiece collection. For some time I have tried to simplify things by owning fewer eyepieces that would, in theory, spend more time in the focuser. The current focal lengths are 21mm, 13mm, 8mm and 6mm plus a Nagler zoom (for higher power in a refractor). The scopes used are a 12” f5 dob and a 130mm f7 APO.

 

Living relatively near to the coast, the atmospheric conditions can be quite unpredictable which has resulted in me wondering... should I ‘fine tune’ things a bit to achieve more optimum views? Excluding the 6mm, the 21/13/8 trio follows a spacing of 1.6, but -perhaps- I am trying to cover too much ground with just these focal lengths and two scopes. Have others (that have adopted 100 degree eyepieces) also ended up reducing their originally planned eyepiece spacing due to this?

In summary, I am considering purchasing a 10mm Pentax XW to both try out this much praised Pentax range as well as to start filling in the current gaps.

Is this unnecessary madness, a case of ‘eyepiece addiction’ or have others ultimately found it useful to have closer focal lengths? Is there a general consensus on a ‘goldilocks’ (not to short/large) eyepiece spacing when you use more than one scope?

 

Thanks.

Rob

[John]

My "100"'s are 21mm - 13mm - 8mm - 6mm.

These 4 focal lengths are my "staple" set with my 12 inch F/5.3 dob. I have a 1.25" set which I use with my refractors and that has more focal lengths in it so I guess you can make do with less eyepieces if you use 100's.

My refractor set includes a 10mm Pentax XW but I only very rarely use it with the dob. I do use the 5mm and 3.5mm XW's with the dob when I want really high magnifications. I do find closer spacing of the short focal lengths useful to get some more choices at higher powers.

I did have a 17mm Ethos for a while but found myself often skipping that focal length and going straight to 13mm. I currently have a 17mm ES 92 degrees in that slot because its very good but a lot less expensive than an Ethos 17 so I don't feel so guilty if it does not get much use.

I really ought to amalgamate these two eyepiece sets into a single one to serve all my scopes but I suppose I am still to some extent an eyepiece addict. Not the best person to talk you out of expanding your collection, really

 

 

 

 

 

 

[Don Pensack]

1 hour ago, Rob_UK_SE said:

Hello all,

I am toying with the idea of filling in some gaps within my current eyepiece collection. For some time I have tried to simplify things by owning fewer eyepieces that would, in theory, spend more time in the focuser. The current focal lengths are 21mm, 13mm, 8mm and 6mm plus a Nagler zoom (for higher power in a refractor). The scopes used are a 12” f5 dob and a 130mm f7 APO.

 

Living relatively near to the coast, the atmospheric conditions can be quite unpredictable which has resulted in me wondering... should I ‘fine tune’ things a bit to achieve more optimum views? Excluding the 6mm, the 21/13/8 trio follows a spacing of 1.6, but -perhaps- I am trying to cover too much ground with just these focal lengths and two scopes. Have others (that have adopted 100 degree eyepieces) also ended up reducing their originally planned eyepiece spacing due to this?

In summary, I am considering purchasing a 10mm Pentax XW to both try out this much praised Pentax range as well as to start filling in the current gaps.

Is this unnecessary madness, a case of ‘eyepiece addiction’ or have others ultimately found it useful to have closer focal lengths? Is there a general consensus on a ‘goldilocks’ (not to short/large) eyepiece spacing when you use more than one scope?

 

Thanks.

Rob

if you arrange your eyepieces to have constant jumps in magnification, i.e. 60x/120x/180x/240x etc., they grow closer in % as the magnification goes up.

If you are trying to beat the seeing conditions, then those jumps will allow you to creep up on the highest magnification you can use.

The thing is, the jumps should probably be smaller for the 130mm than for the 305mm.  A 60x jump is probably fine for the 12", where magnifications up to 300x will be used all the time.

But on the 130mm, it's not likely you'll use magnifications over 200x much and jumps of 40x make more sense.

So you need to see if the eyepieces you have will provide the jumps you need.

In the 12", you are lacking a 10mm Ethos (assuming you want to stay with 100° eyepieces), which I found essential in between the 13mm and 8mm in my 12.5" dob.

[I went from 140x to 228x in one jump and it was often too large a jump.  The in-between of the 10mm at 183x was perfect.]

You're also missing a really low power eyepiece, like a 30-31mm.  Perhaps your light pollution doesn't allow for that, but that low power would be wonderful on the Veil Nebula, North America nebula, Praesepe cluster,

Perseus double cluster, M31, etc.  I ecommend the APM 30mm UltraFlatField or its Altair UltraFlat twin.

 

 

Edited August 20, 2020 by Don Pensack

[Barry-W-Fenner]

Excellent question Rob, I will be watching this thread with interest. I to have been thinking of reducing my set for my 8 & 12" dob.

I had a full set of BST eye pieces and frequently found myself swapping out eye pieces  and trying to get the optimum power. I have since purchased the 6.5 and 14mm Morpheus eye pieces and have so far had two sessions with just these two eye pieces, I found I spent far less time messing around wondering what was the correct mag and just enjoyed time at the focuser.

I would like the 9mm Morpheus as they perform wonderfully. Then I am considering thinning out my combined set of morphs, BSTs and my 30mm 2" aero Ed

Less is more I hope.

Regards

baz

Edited August 20, 2020 by Barry-W-Fenner

[Rob_UK_SE]

Thank you for these suggestions.

John, it’s interesting to read that you tend to stick with your Ethos set for the 12” dob. I was assuming that your XWs might have some benefits in the dob too (in terms of light transmission, scatter control, object framing etc.)? I have certainly been very pleased with the Ethos quartet and don’t plan to part with them - especially for DSOs. I think we are all, to some extent, eyepiece addicts on this forum!

Don, I have checked the magnification steps, based on your suggestion, and can see that the biggest gap does indeed appear to be between the 13mm and 8mm Ethos. In the 12” the spacing is 73x between these two; it is 43x in the 130mm APO. Given the current UK price for Ethos I can’t -regrettably- stretch to a 10mm now, but could go for an XW, Morpheus or similar. Reflecting on this focal length a little more, in the 12” it would result in 152x (2mm exit pupil) and 92x in the 130mm APO (1.4mm exit pupil). I think both of these magnifications and exit pupils would be useful. 

The views of both parts of the Veil (in the 12”) are lovely, but it does struggle -even with the 21mm Ethos- to frame the eastern part properly. When using the 21mm in the 130mm APO the exit pupil is down to 3mm which may well account for the dim view which isn’t nearly as immersive. One of my biggest regrets in this hobby was selling my 31mm Nagler, but it is now too expensive to be replaced for only occasional use. Further to your suggestion and linked to the 10mm, perhaps a 30mm XW or APM UF is indeed needed too? With an exit pupil of 6mm it could still be useful (at dark sites) with the dob.

Baz, your point is one I have wrestled with for quite a while in this hobby - wanting to spend more time observing than auditioning eyepieces.
 

Decisions, decisions...

[Stardaze]

I'll follow this too as I've decided to go the same route with my dob (30, 20, 13, 8, 6).  I'd rather have 3 excellent EP's than 6 average ones. My dob is 10" so the jumps aren't quite as large as you have there though.

[Paz]

You've already got a great set of eyepieces but if your looking for more I agree with 10mm being a good choice. I had a set of 17.3, 12, 8, 6, 4.5, 3.5 Delos and was very happy but gradually realised I was missing out at 10mm, that being a sweet spot for my 14" dobsonian, so I got a 10mm. I don't have the 14mm Delos but that is not a length I was missing for the dob. I do miss having something at 14mm on the C8 but I'm trying to be mentally strong and not buy any more eyepieces.

[John]

I have toyed with the idea of the 10mm Ethos. It is reputed to be one of the best in that range. My frequency of feeling the need for something between the 13mm and 8mm is low though so it's difficult to justify a £600 investment on top of the 10mm Pentax XW

I'm obviously not quite 100% addicted !

 

 

[Stardaze]

20 hours ago, John said:

I have toyed with the idea of the 10mm Ethos. It is reputed to be one of the best in that range. My frequency of feeling the need for something between the 13mm and 8mm is low though so it's difficult to justify a £600 investment on top of the 10mm Pentax XW

I'm obviously not quite 100% addicted !

 

 

Out of interest John, what are supposedly the best of the range? I have a feeling when I have a complete set (not all Ethos, APM 100 deg too) I may swap the APM 13 out for an Ethos, if I find a good one at the right money secondhand. But that's a way off yet.. 

[Rob_UK_SE]

the 13mm Ethos is certainly my most used and the one I find easiest to take in the entire 100 degree field of view.

I have directly compared it to the 13mm APM and found that they were very close indeed. For me, at least, the benefits of the Ethos were the eye cup (I found the APM one slightly less comfortable and needed to fold it down), slightly improved transmission and contrast as well as stars being sharp across the full 100 degrees. I would say the APM is a good 80-90% of the Ethos. If I ever had to replace it, I would probably buy the APM and be very content.

I have made many changes to my eyepiece case/s over the years, but the 13mm has always been a constant.

The images below are from 2012, 2016 and 2019 (before I got the 6mm Ethos from FLO). The 13mm Ethos has survived all major changes... so far.

[John]

1 hour ago, Stardaze said:

Out of interest John, what are supposedly the best of the range? I have a feeling when I have a complete set (not all Ethos, APM 100 deg too) I may swap the APM 13 out for an Ethos, if I find a good one at the right money secondhand. But that's a way off yet.. 

Not sure. I like all the ones I've owned / currently own. The 10mm is the only one that I have not owned or used - perhaps that's the best one !

If Don Pensack sees this thread his opinion would be valuable I think.

 

[SiriusB]

I'd suggest it rather depends on the  fl. of your scope(s)

having 1mm increments is not all that useful on 500mm fl, maybe a lot more so on 2000mm?

I've found it helpful having  a wide range of fl's to match the seeing/transparency conditions.

But be warned it can degenerate into spending more time swapping ep's than actual observing!

Usually  over time most people end up with a few ' favourites' though.

I've a rule of thumb, any scope i've owned 2"-12.5" thus far. about 50x mag is ALWAYs handy.

If you're looking for an excuse to buy more ep's~ don't~ just buy. 😁

Can always sell on if not needed.

[Stardaze]

1 hour ago, Rob_UK_SE said:

the 13mm Ethos is certainly my most used and the one I find easiest to take in the entire 100 degree field of view.

I have directly compared it to the 13mm APM and found that they were very close indeed. For me, at least, the benefits of the Ethos were the eye cup (I found the APM one slightly less comfortable and needed to fold it down), slightly improved transmission and contrast as well as stars being sharp across the full 100 degrees. I would say the APM is a good 80-90% of the Ethos. If I ever had to replace it, I would probably buy the APM and be very content.

I have made many changes to my eyepiece case/s over the years, but the 13mm has always been a constant.

The images below are from 2012, 2016 and 2019 (before I got the 6mm Ethos from FLO). The 13mm Ethos has survived all major changes... so far.

Looks like you’ve simplified your set perfectly. It’s a slippery slope I foresee..

what size nanuk case is the bottom image. I have a 910 and already need a foam replacement 

Edited August 21, 2020 by Stardaze

[niallk]

You've a fine set

Mine is also ratiometric: follows approx 1.7x for base set.  The 10mm is the "anchor" giving approx 200x, and around which the rest were picked:

31/17 ; 17/10; 10/6

The afov of the 31 is 82°, and the others all 100°.

I indulged by adding an 8mm too, for nights of less good seeing, and on nights of excellent seeing (I can wish...!) combining with a 2x PowerMate gives the option to approximately continue on down from the 6mm with 6/4, or continue down from the 8mm with 8/5, 5/3.  Bit of a luxury, but gets a lot of use!

Edited August 21, 2020 by niallk

[Don Pensack]

On 20/08/2020 at 11:00, Rob_UK_SE said:

Thank you for these suggestions.

John, it’s interesting to read that you tend to stick with your Ethos set for the 12” dob. I was assuming that your XWs might have some benefits in the dob too (in terms of light transmission, scatter control, object framing etc.)? I have certainly been very pleased with the Ethos quartet and don’t plan to part with them - especially for DSOs. I think we are all, to some extent, eyepiece addicts on this forum!

Don, I have checked the magnification steps, based on your suggestion, and can see that the biggest gap does indeed appear to be between the 13mm and 8mm Ethos. In the 12” the spacing is 73x between these two; it is 43x in the 130mm APO. Given the current UK price for Ethos I can’t -regrettably- stretch to a 10mm now, but could go for an XW, Morpheus or similar. Reflecting on this focal length a little more, in the 12” it would result in 152x (2mm exit pupil) and 92x in the 130mm APO (1.4mm exit pupil). I think both of these magnifications and exit pupils would be useful. 

The views of both parts of the Veil (in the 12”) are lovely, but it does struggle -even with the 21mm Ethos- to frame the eastern part properly. When using the 21mm in the 130mm APO the exit pupil is down to 3mm which may well account for the dim view which isn’t nearly as immersive. One of my biggest regrets in this hobby was selling my 31mm Nagler, but it is now too expensive to be replaced for only occasional use. Further to your suggestion and linked to the 10mm, perhaps a 30mm XW or APM UF is indeed needed too? With an exit pupil of 6mm it could still be useful (at dark sites) with the dob.

Baz, your point is one I have wrestled with for quite a while in this hobby - wanting to spend more time observing than auditioning eyepieces.
 

Decisions, decisions...

I recommend the 30mm APM UFF for a lower power with a somewhat wider field than the 21mm Ethos.  The 30mm's field is ~5% wider.

It's not quite as wide a true field as the 31mm Nagler, but then, is way less than half the cost.

Between the 10mm Delos and the 10mm XW, I would pick the Delos.  I found it sharper than the XW AND the Ethos (though, of course, the field of the Ethos is a lot wider).

The Delos 10mm measures a 73° field and is stunningly sharp--I've looked through orthos with softer star images.

Look at the specs here:

http://astro-talks.ru/forum/viewtopic.php?f=32&t=1483#p41976

 

[Don Pensack]

1 hour ago, John said:

Not sure. I like all the ones I've owned / currently own. The 10mm is the only one that I have not owned or used - perhaps that's the best one !

If Don Pensack sees this thread his opinion would be valuable I think.

 

My favorites in the Ethos eyepieces were the 17mm, 10mm, 8mm, 6mm, 3.7mm, though they were all a bit different.

I never really took to the 21mm, and ended up preferring my old favorite 22mm Nagler.

The 13 was very very sharp, but I never felt it had the contrast of the 17mm or 10mm.

The 4.7mm isn't as sharp as the 6mm or 3.7mm in my 12.5", though I couldn't tell you why.  Perfect focus at 400x is often tough,

but why, on the same night, the 3.7mm was sharper at 500x indicates the internal configuration might be a little different.

Some day I'll do a comparo of 4.5-5mm ultrawides as I've done at several other focal lengths, though I think the 5mm Nagler will win--that eyepiece even tests better than the others. 

Anyway, Ethos:

17mm--excellent contrast, sharp stars, great step down from 30-31mm.  Could be a low power eyepiece for me most of the time.

10mm--excellent contrast, a very sharp view, very low aberrations of any kind.  perfect magnification for most DSOs in my scope.  Perhaps my most used eyepiece.

8mm--easiest exit pupil of the series to acquire and hold--like the 11mm Apollo, just an easy eyepiece to use.  I use this one a LOT.

6mm--Is this an ortho?  Fantastic contrast and sharpness.  Close to having no flaws at all.  Stunning.  Beats all the other focal lengths in superb seeing.

3.7mm--not used that often, but rendered moons of Uranus and Neptune as tiny pinpoints and even allowed me to see a white stripe on Uranus.

Used a month ago on Mars with a Baader Contrast Booster--OMG.  Mars at 500x--incredible.  My go-to planetary nebula, smallish planets, eyepiece.

[scarp15]

The 10mm Delos, as others have already mentioned, will fit in snugly with your other focal lengths and not become too compromised in TFOV. Something wide field at lower power, as also previously mentioned, than your 21E if you have access to dark skies will be purposeful. 

[Rob_UK_SE]

10 hours ago, Stardaze said:

Looks like you’ve simplified your set perfectly. It’s a slippery slope I foresee..

what size nanuk case is the bottom image. I have a 910 and already need a foam replacement 

The larger case is a Peli 1500. The internal measurements are: 435mm (length), 292mm (width) and 155mm (depth). The other case is a Peli 1300 which is now being used for a Telrad and collimator. 

[Rob_UK_SE]

9 hours ago, Don Pensack said:

I recommend the 30mm APM UFF for a lower power with a somewhat wider field than the 21mm Ethos.  The 30mm's field is ~5% wider.

It's not quite as wide a true field as the 31mm Nagler, but then, is way less than half the cost.

Between the 10mm Delos and the 10mm XW, I would pick the Delos.  I found it sharper than the XW AND the Ethos (though, of course, the field of the Ethos is a lot wider).

The Delos 10mm measures a 73° field and is stunningly sharp--I've looked through orthos with softer star images.

Look at the specs here:

http://astro-talks.ru/forum/viewtopic.php?f=32&t=1483#p41976

 

Thank you, Don, for this helpful advice and also for your great insight into the Ethos range. I was surprised to hear of the differences between the 4.7mm and 3.7mm. I would very much like to observe through one (or both) of the Ethos SX for Uncle Al’s ‘Spacewalk Experience’ of the lunar module simulator. It sounds the 3.7mm is very much the one to have. Perhaps one day.

...hopefully I haven’t done the wrong thing!

I ended up placing two orders yesterday morning. One was for a 30mm XW (following Don’s suggestion to acquire this focal length again) and the other for a 10mm XW. Both should be arriving today.

I found a good price on the 30mm XW (£270), but couldn’t find the 30mm APM available anywhere in the UK - just from APM directly or from other suppliers in Germany. 365Astronomy may be having an eyepiece clear out as they are selling off some of the XWs, including the 10mm, for £210. I would have loved to have a full set of green and black (adding the 10mm Delos and 31mm Nagler again), but this is not possible at the moment.

[RickEm]

On 21/08/2020 at 18:52, Don Pensack said:

My favorites in the Ethos eyepieces were the 17mm, 10mm, 8mm, 6mm, 3.7mm, though they were all a bit different.

I never really took to the 21mm, and ended up preferring my old favorite 22mm Nagler.

The 13 was very very sharp, but I never felt it had the contrast of the 17mm or 10mm.

The 4.7mm isn't as sharp as the 6mm or 3.7mm in my 12.5", though I couldn't tell you why.  Perfect focus at 400x is often tough,

but why, on the same night, the 3.7mm was sharper at 500x indicates the internal configuration might be a little different.

Some day I'll do a comparo of 4.5-5mm ultrawides as I've done at several other focal lengths, though I think the 5mm Nagler will win--that eyepiece even tests better than the others. 

Anyway, Ethos:

17mm--excellent contrast, sharp stars, great step down from 30-31mm.  Could be a low power eyepiece for me most of the time.

10mm--excellent contrast, a very sharp view, very low aberrations of any kind.  perfect magnification for most DSOs in my scope.  Perhaps my most used eyepiece.

8mm--easiest exit pupil of the series to acquire and hold--like the 11mm Apollo, just an easy eyepiece to use.  I use this one a LOT.

6mm--Is this an ortho?  Fantastic contrast and sharpness.  Close to having no flaws at all.  Stunning.  Beats all the other focal lengths in superb seeing.

3.7mm--not used that often, but rendered moons of Uranus and Neptune as tiny pinpoints and even allowed me to see a white stripe on Uranus.

Used a month ago on Mars with a Baader Contrast Booster--OMG.  Mars at 500x--incredible.  My go-to planetary nebula, smallish planets, eyepiece.

Don, what didn’t you like about the 21mm Ethos?  It’s one of my favorites.

[John]

3 hours ago, RickEm said:

Don, what didn’t you like about the 21mm Ethos?  It’s one of my favorites.

Mine too

 

[Don Pensack]

I never took to the 21mm because it had a slightly poorer outer field correction in the 12.5" than the other Ethos focal lengths.

Axial sharpness was excellent, as was contrast but it was obvious to me why TeleVue didn't stretch the focal length past 21mm.

Even using my glasses to completely correct astigmatism (I see none at 31mm with the glasses on), the edge of the field displayed some visible astigmatism when running through

focus from one side to the other.

Granted, it is WAY out in the field, but the 17mm was simply sharp to the edge, as was the 13mm.

Compared to the 22mm Nagler, the Nagler seems to have a flatter field (not field curvature per se, but the presentation of the field to the eye), and a slightly easier exit pupil to acquire and hold.

I just find the 22mm more comfortable to use.

 

I find it ironic that in comparisons I've done of all the focal lengths in the ES 100° series and the APM XWA series, that the poorest edge correction in each of those lines is with the 20mm as well.

[well, except the 25mm ES 100°, which is a "bridge too far" in my opinion]

I don't really expect perfection in an eyepiece, but I came to the 21mm Ethos after 12 years with the 22mm Nagler, and just never got comfortable with the 21mm Ethos.

In contrast, the 17mm was an example of everything an eyepiece should be.  It ended up being my most-used low power eyepiece. Because of the nature of the targets I observe,

which are usually small, my most-used eyepieces are in the 6-11mm (166-304x) range, so I use any eyepiece in the 15-30mm range primarily for the very largest targets at low power.

 

I certainly recommend the 21mm Ethos over those other two, and I used it for 10 years.  It was only when I found I needed glasses to observe that I went back to the 22mm Nagler.

Otherwise, I'd still be using it.  A 95% score is still an A grade.

 

 

 

[Stardaze]

2 hours ago, Don Pensack said:

I never took to the 21mm because it had a slightly poorer outer field correction in the 12.5" than the other Ethos focal lengths.

Axial sharpness was excellent, as was contrast but it was obvious to me why TeleVue didn't stretch the focal length past 21mm.

Even using my glasses to completely correct astigmatism (I see none at 31mm with the glasses on), the edge of the field displayed some visible astigmatism when running through

focus from one side to the other.

Granted, it is WAY out in the field, but the 17mm was simply sharp to the edge, as was the 13mm.

Compared to the 22mm Nagler, the Nagler seems to have a flatter field (not field curvature per se, but the presentation of the field to the eye), and a slightly easier exit pupil to acquire and hold.

I just find the 22mm more comfortable to use.

 

I find it ironic that in comparisons I've done of all the focal lengths in the ES 100° series and the APM XWA series, that the poorest edge correction in each of those lines is with the 20mm as well.

[well, except the 25mm ES 100°, which is a "bridge too far" in my opinion]

I don't really expect perfection in an eyepiece, but I came to the 21mm Ethos after 12 years with the 22mm Nagler, and just never got comfortable with the 21mm Ethos.

In contrast, the 17mm was an example of everything an eyepiece should be.  It ended up being my most-used low power eyepiece. Because of the nature of the targets I observe,

which are usually small, my most-used eyepieces are in the 6-11mm (166-304x) range, so I use any eyepiece in the 15-30mm range primarily for the very largest targets at low power.

 

I certainly recommend the 21mm Ethos over those other two, and I used it for 10 years.  It was only when I found I needed glasses to observe that I went back to the 22mm Nagler.

Otherwise, I'd still be using it.  A 95% score is still an A grade.

 

 

 

Interesting Don! Out of interest, having got the APM 20 and 13, how improved did you find the Ethos variants? 

[Rob_UK_SE]

A quick update...

Firstly, thank you all for sharing your insight with this. I ended up making the decision to close the gaps in my available focal lengths (expanding on the 21E, 13E, 8E and 6E quartet) and, in particular, have something else to complement the 21E for lower power / wide field views. Below is the updated case which now includes a 30mm XW and a 10mm XW. This will be my main case as it covers focal lengths from 30mm to 3mm.

 

After spending some initial hours with the XW eyepieces, I have found them to be extremely comfortable and very easy to use in terms of eye placement. I will evaluate their optical performance over a series of nights and don’t want to jump to conclusions, but I have certainly been pleased with the views, so far. For the reasons of comfort and accessibility primarily (so that my son can enjoy higher power views too), I have decided to expand my higher magnification set and complement my 3-6mm Nagler zoom with the XWs. I’m starting to see why you enjoy using these eyepieces with your refractors, John.

This arrived today. Can you see the emerging theme here... (another case might be required)😀

Ironically, my observing partner (who also reads through the posts on SGL) ended up purchasing your recommendation, Don, for the 30mm APM ultra flat. I had, regrettably, already ordered the 30mm XW before your recommendation. I will therefore look forward to a bit of a ‘shoot out’ between these two heavyweights: the 30mm XW and the 30mm ultra flat.  

Edited September 3, 2020 by Rob_UK_SE

[Louis D]

I went with a large and deep Pelican-style case so I could store my eyepieces upright.  It allows many more eyepieces in a single case.  One downside is I have to have the layout memorized since many eyepieces look the same from the top in the dark.  Another is it allows for the weight to creep as I've added more heavy eyepieces.  The case is over 20 pounds now.