26 replies to this topic

[Cheshire Cat]

Hello folks.

 

Would you have a look at this spread of eyepieces (all of which just work and which I don’t plan on changing) and see if I need anything else.

 

Thanks in advance 

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[SeattleScott]

The only sizable magnification gap is 32 to 13. At lower magnification, I feel like FOV gap is a bigger issue than magnification gap. Without knowing the AFOVs, I can’t tell what the FOV gap is. If the 32 is a Plossl and the 13 is a hyperwide, there isn’t much of a FOV gap at all.

Some would argue for a 17-18mm in order to get the “magical” 2mm exit pupil, which some DSO look best at. Personally I’m not particularly sold on that approach, but you could look at something in that range if you want to cover your bases. There are some really good options available, TV, Baader, Nikon in particular. The new Pentax 16.5XW could be close enough. But this is more of a luxury than a necessity.

[carver2011]

I would add an 18.2mm Televue Delite to your group. A great eyepiece, with good eye relief. At a fair price.
Ed

[Cheshire Cat]

The eyepieces are a Naglar zoom, a 32 mm plossl with a 7, 9 and 13 mm Delite in the middle. The plossl has an eye guard extender, it feels like a 32 mm Delite. Everything just works

[SeattleScott]

The eyepieces are a Naglar zoom, a 32 mm plossl with a 7, 9 and 13 mm Delite in the middle. The plossl has an eye guard extender, it feels like a 32 mm Delite. Everything just works

Ok, so there is a bit of FOV gap. There could be an argument for the 18.2 Delite. I guess it depends on how often the 13 is too narrow, and the 32 is too little magnification. I could see it being a specialty eyepiece for big showpiece targets like Double Cluster and Orion Nebula. Targets small enough to take more magnification than the 32, but too big to fit in the 13 Delite. There aren’t many targets this size, but there are some showcase ones.

Basically an 18.2 Delite could be beneficial for targets bigger than 0.9 degrees (or needing more than 0.9 degrees to provide some framing) up to 1.3 degrees. So you could look at targets around that size. Double Cluster is 1.1 degrees, Orion Nebula about 1 degree at a dark site, etc. Beehive cluster probably too big, would still need the 32 Plossl.

Really, the biggest game changer here would be a 2” eyepiece. Right now you are hitting about 1.8 degrees at lowest power. Not enough to fit the whole Pleiades cluster. With the right eyepiece, you could hit three degrees wide. Faster starhopping, ability to fit larger targets, and more immersiveness when just cruising the summer Milky Way. This would be a much bigger impact than getting a $300 eyepiece for a couple of targets. But presumably you are staying 1.25” for a reason.

Edited by SeattleScott, 23 February 2025 - 03:44 PM.

[PKDfan]

I'm with SeattleScott on this Cheshire Cat !

A 18.2 Delite would be a wise investment. A ~2.3mm exit pupil ~48X and just over 1 1/4 degrees true field. A 16.5XW is an awesome choice also, right at the 2mm exit pupil and just over 50X.

A very nice eyepiece choice selection ! Well done !


CSS
Lance

[SeattleScott]

I'm with SeattleScott on this Cheshire Cat !

A 18.2 Delite would be a wise investment. A ~2.3mm exit pupil ~48X and just over 1 1/4 degrees true field. A 16.5XW is an awesome choice also, right at the 2mm exit pupil and just over 50X.

A very nice eyepiece choice selection ! Well done !


CSS
Lance

I suggested the Pentax before I knew his kit was only 1.25". If there is a desire to stay 1.25" only, then the Pentax would be out. Now if there was an interest in expanding the kit to include 2" format, the Pentax could be in play as a bridge between a lowest power, 2" and the Delites.

 

The Delite still works obviously.

[T1R2]

Im a OCD purest...gotta have exactly 10 eps, this ain't gonna cut it...lol, you need 2 more a 25 and a 20, nor do I care or think that they are "too close" together because there are objects of every size out there, and there is something that will fit perfectly in those two eps. 

[T1R2]

Ok, I can tell you from experience with a 800mm FL scope that an 18/60* is barley enough fov to frame the Double Cluster, M39 is a little tight from the edges of the cluster to the field stop, if that is ok for you then cool, it wasn't for me,it is a good exit pupil,  but I found I liked the view of the 20mm/ 70* for a little more room in the fov,  but the Meade 25mm HD60 is on AliExpress for $75 and would work nicely in that 880mm FL scope. 

[Jay_Reynolds_Freeman]

I suspect the TV-102 has a two-inch focuser; if so, that 32 mm Plossl won't give you as much field of view as the telescope can provide. I would in that case recommend an additional eyepiece, whose field lens comes as near to spanning the full width of the eyepiece barrel as is physically possible. There are several eyepieces of focal length 32 mm and more that will do that, but specific recommendations would depend on how wide the pupils of your eyes dilate and how dark the sky is at the places where you regularly observe. "Try before you buy" might be the best advice here.

[SeattleScott]

Well it sounds like you don’t do much low power viewing, so probably not a lot of use for it. As pointed out, while it would provide a nice contrast with the 32 Plossl on Caldwell 14, the framing would be snug and overall, if I had to choose one, I would want a lower power, wider view (like the 32 Plossl). Orion Nebula could still be great with it, but does that justify adding another eyepiece to the set? Basically, if you don’t feel like you need anything in that gap, you probably don’t.

Ok this might seem like heresy, but the Meade 18UHD is on closeout sale for something like $80. It isn’t as good at the edge as the Delite, but at nearly F9 it shouldn’t matter. Similar AFOV and eye relief. If you don’t want to drop nearly $300 on a rarely used focal length, this could be a way to have something in that gap when an opportunity arises, without spending serious money on something that will be rarely used. And you probably wouldn’t be able to tell much difference in the view compared to Delites in your slow scope.

[Cheshire Cat]

I expect the likelihood is, and since I have 3 Delites and the rest of my gear is Tele Vue, that I will buy a 18.2 mm. Probably more than likely actually.

Thanks chaps

Edited by Cheshire Cat, 24 February 2025 - 12:47 PM.

[mikeDnight]

 I'd suggest a 24mm UFF. It will play havoc with any OCD you may have as it isn't Televue, but it's more comfortable than the 24mm Panoptic. The reason I'm suggesting it is that it will provide a significantly darker sky background for DSO's and star fields, than your 32mm, and still give you a wide field of view. They don't cost the earth either.

Edited by mikeDnight, 25 February 2025 - 09:30 AM.

[SeattleScott]

 I'd suggest a 24mm UFF. It will play havoc with any OCD you may have as it isn't Televue, but its mire comfortable than the 24mm Panoptic. The reason I'm suggesting it is that it will provide a significantly darker sky background for DSO's and star fields, than your 32mm, and still give you a wide field of view. They don't cost the earth either.

I was thinking the same thing. Clearly there is a desire to stay 1.25" and a desire to have long ER, and a desire to stay TV. Which means the 32 TVP. 

 

A few months ago I swapped out a 30 Ultima for a 24mm Meade SWA for that greater image scale and darker background sky. The Ultima is a sharp, vintage Japanese eyepiece. But the extra magnification overruled any subtle advantage of the nice Japanese glass. The 24UFF would do similar with long ER. Is it Televue good? No, but it's F8.8, so it won't matter. Still, Cheshire Cat (shouldn't they have a SCT?) appears to be Televue only, so I expect no change.

 

That being said, for certain targets, the larger exit pupil of the 32mm is advantageous. Especially faint fuzzies. So there is some logic to sticking with the 32mm other than just it is TV. I don't know how much they observe faint fuzzies versus open clusters and bright showpiece targets like Andromeda and Orion Nebula. For open clusters and bright showpiece targets, I would rather have the magnification. For M81/M82 I might prefer the brighter exit pupil.

Edited by SeattleScott, 24 February 2025 - 07:29 PM.

[jimeh]

Ok this might seem like heresy, but the Meade 18UHD is on closeout sale for something like $80. It isn’t as good at the edge as the Delite... And you probably wouldn’t be able to tell much difference in the view compared to Delites in your slow scope.

The difference is in the AR coatings, baffling, and polish of the elements.

 

I haven't used a Meade 18UHD, but in my quest for planetary detail and "better than ortho" eye relief, I compared Naglers, ES 82s, Morpheus, Delites, and some other high quality EPs and found that the Delites were sharper on axis and had noticeably better contrast than all the others. I didn't care about FOV, corrected edges, weight, any other factors other than contrast and on axis performance.

 

Saying the OP wouldn't notice the difference assumes his eyepiece priorities align with yours.

 

My recommendation is a 24mm 68* eyepiece that will show the same field as the 32mm plossl, but at higher magnification and with a darker background, but with a smaller exit pupil

[CrazyPanda]

The only thing you may want to consider is a lower power eyepiece to get a bigger exit pupil for use with nebula filters.

 

A 50 Masuyama MOP or 55mm TV Plossl would get you a brighter exit pupil.

[SeattleScott]

The difference is in the AR coatings, baffling, and polish of the elements.

I haven't used a Meade 18UHD, but in my quest for planetary detail and "better than ortho" eye relief, I compared Naglers, ES 82s, Morpheus, Delites, and some other high quality EPs and found that the Delites were sharper on axis and had noticeably better contrast than all the others. I didn't care about FOV, corrected edges, weight, any other factors other than contrast and on axis performance.

Saying the OP wouldn't notice the difference assumes his eyepiece priorities align with yours.

My recommendation is a 24mm 68* eyepiece that will show the same field as the 32mm plossl, but at higher magnification and with a darker background, but with a smaller exit pupil

I didn’t say they wouldn’t notice a difference. I said there wouldn’t be much of a difference. They seemed hesitant about getting an 18mm at the time. I didn’t know if cost was a concern, as in paying a lot for a rarely used eyepiece (for that particular scope). And Cheshire hadn’t said TV only at the time. At this point it seems cost isn’t an issue, and nothing that isn’t Televue will be considered, so yeah 18.2 Delite instead of 18UFF.

I like your idea of a 24 SWA, but I don’t think Chester does, because TV doesn’t make one with long ER, and long ER seems to be taking priority over wider AFOV like a 24 Panoptic.

[SeattleScott]

The only thing you may want to consider is a lower power eyepiece to get a bigger exit pupil for use with nebula filters.

A 50 Masuyama MOP or 55mm TV Plossl would get you a brighter exit pupil.

He is 1.25” only. 2” eyepieces are just a bunch of faff. Or something like that.

[T1R2]

The only thing you may want to consider is a lower power eyepiece to get a bigger exit pupil for use with nebula filters.

 

A 50 Masuyama MOP or 55mm TV Plossl would get you a brighter exit pupil.

Yes, that's mostly true, but with large-ish aperture this isn't as much as a problem as it is with smaller optics. 

[Cheshire Cat]

He is 1.25” only. 2” eyepieces are just a bunch of faff. Or something like that.

Faff [Hassle, messing about (too much), bothersome]

Next week I will explain the laws of Cricket

[Cheshire Cat]

A 32mm plossl used with an eye guard extender is parafocal and is a very similar weight to a Delite and in practice feels like a 32mm Delite

[Cheshire Cat]

Incidentally, what would you suggest as a 2 inch to replace the 32mm plossl? I am fairly wedded to Tele Vue at this point since my scope and mount, and all my other eyepieces are TV.

[SeattleScott]

Incidentally, what would you suggest as a 2 inch to replace the 32mm plossl? I am fairly wedded to Tele Vue at this point since my scope and mount, and all my other eyepieces are TV.

Televue only? At F9?

It would be nice to get closer to 13mm to close that gap. Perhaps a 22T4?

Or go for closer to max FOV with a 35 Panoptic? Makes a big gap between 13 and 35. I could see a 17-18mm and then the 35 Panoptic. Delos or Delite, probably Delite given the rest of the lineup.

A 41 Panoptic goes wider, but it’s a beast of an eyepiece. Likewise, a 21 Ethos would tighten the gap with the 13, but again a massive, heavy eyepiece. And very different experience than Delite. 31 Nagler is a classic, but again, massive and heavy. So personally I would be more inclined to go 35 Panoptic for a TV only 2” eyepiece, as I don’t care for truly massive eyepieces. And that would make an 18.2 Delite feel more important.

[Otto Piechowski]

I forget who I heard or read first said it, it might’ve been the reverend Web back in the 1800s, but the suggestion was made that one needs only three pieces one for wide field view one for intermediate magnification, and one for high magnification. I’ve pretty much stuck with that my whole life with the many dozens of different types of telescopes I’ve had.

[BrushPilot]

Faff [Hassle, messing about (too much), bothersome]

Next week I will explain the laws of Cricket

Cricket has laws? Why ruin it with those?