What would you do if you had to give up all but five of your eyepieces?

[Don Pensack]

17 hours ago, Spile said:

Does that mean I need to buy three more eyepieces?

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.

[Spile]

6 hours ago, Don Pensack said:

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.

Well two eyepieces (a zoom and a low power wide angle) plus a Barlow is enough for me. If I was feeling flush and the weather was more cooperative then I might get something around 28 to 30mm but I am perfectly happy otherwise.

[bomberbaz]

27 minutes ago, Spile said:

Well two eyepieces (a zoom and a low power wide angle) plus a Barlow is enough for me. If I was feeling flush and the weather was more cooperative then I might get something around 28 to 30mm but I am perfectly happy otherwise.

A very lot to be said for this approach. Although if you are a diffuse nebula man (as I am), I do feel a good quality, fixed length EP that gives you the magic 5mm exit pupil that also offers up circa 1 degree FOV or more is a must have.

[IB20]

• 17.5mm Morpheus 
• 10mm XW
• 5mm XW
• 4mm TOE
• 2.5mm TOE 

 

[Guest]

I would keep my Long Perng 14 and 20mm, keep my 24 and 31mm ES, add either the 5 or 9mm 100 degree.  With a 2 inch barlow i would be good to go.  Everything else could go.  

[ED Splitter]

In a 100ED F9 refractor

XW5

T6N9mm*

13ethos

19mm pan

27mm pan
 

* just edged out my UO12mm ortho

 

[The60mmKid]

A pair of 24mm Panoptics

A pair of 13mm Naglers

A 3-6mm Nagler Zoom

Just to do things differently. It's all for fun anyways.

[The60mmKid]

Actually, I'm thinking about replacing everything with 20mm, 13mm, 7mm, 5mm, 3.5mm XWAs. Do I get a prize if I actually give up all but five of my eyepieces?

Edited August 1, 2023 by The60mmKid

[JAC51]

Currently my choice would be

48mm Brandon

17.5mm Morpheus 

9mm Morpheus 

8mm Brandon

6.5mm Morpheus 

Though I also have a total of 5 Barlows to use with them.

 

[Piero]

- N22T4

- docter

- APM XWA 9, 7, 4.77mm

I assume the paracorr2 does not count as an eyepiece, despite the fact that Barlows are not allowed here.

[JeremyS]

58 minutes ago, Piero said:

I assume the paracorr2 does not count as an eyepiece, despite the fact that Barlows are not allowed here.

We won’t mention it if you don’t, Piero 😊

[John]

2 hours ago, Piero said:

- N22T4

- docter

- APM XWA 9, 7, 4.77mm

I assume the paracorr2 does not count as an eyepiece, despite the fact that Barlows are not allowed here.

Out of interest, if you had to dispense with paracorr, how would that affect your choices ?

[IB20]

On 30/07/2023 at 22:17, IB20 said:

• 17.5mm Morpheus 
• 10mm XW
• 5mm XW
• 4mm TOE
• 2.5mm TOE 

 

Now if they were for Ha viewing I’d have to keep the:

• 20mm TV Plössl
• 12.5mm Celestron Ultima
• 11mm TV Plössl
• 10mm XW
• 6mm Vixen LV

and I’d hide the Tak TOEs. 

 

[Piero]

5 hours ago, John said:

Out of interest, if you had to dispense with paracorr, how would that affect your choices ?

That's a good question.

It took me a bit to answer the OP's question, because the whole selection of 5 eyepieces somehow depends on the telescope.

The eyepiece set I mentioned cannot be used with my TV60, so that telescope would go.

As you noticed, the paracorr2 has an impact too. I'm not sure whether I would use an f4 dobson with a set of <= 50 deg AFOV eyepieces because a coma corrector is not available. Therefore that fast telescope would go too.

The two remaining telescopes I have are a 12" f6 dob and the 4" tak f7.4. With these telescopes I very much like the minimal set: 30mm APM UFF, Docter, Zeiss Zoom 25.1-6.7mm and Baader VIP Barlow. The OP said barlows are not allowed though (ouch)! Mm.. I could go for the 30mm APM UFF and the 4 short focal lengths of Pentax XW. However, the limit of 5 eyepieces does not play well as a medium power is left out.. therefore, between the two telescopes the refractor would go. With only the dobson left, I could just use the 30mm APM UFF, docter, Zeiss zoom and skip the Barlow.

A completely different approach could be to use 24 Pan, 13-7-5-3.5mm Nagler T6 and keep all telescopes apart from the f4 one or accept views "full of comets". Planetary observing would be a bit sacrificed with this set though..

Somehow all this reasoning shows that if one has more telescopes, more eyepieces are likely needed too.

Edited August 10, 2023 by Piero

[AstroKeith]

On 30/07/2023 at 15:06, Don Pensack said:

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.

Interesting Don,

I used to have many, but about 4 years ago rationalised down to 4 quality EPs and a x2 powermate (which I dont often use). I can honestly say I havent found a need for more and yet I do push visual boundaries a lot.

I recently did quite a lot of research and modelling on human contrast thresholds and found that the optimum magnification wasnt in general well defined, but usually a much broader range than often quoted.

But I do get that many observers find different magnifications and EPs make a difference. I'm now interested in why that is!

[Don Pensack]

15 hours ago, AstroKeith said:

Interesting Don,

I used to have many, but about 4 years ago rationalised down to 4 quality EPs and a x2 powermate (which I dont often use). I can honestly say I havent found a need for more and yet I do push visual boundaries a lot.

I recently did quite a lot of research and modelling on human contrast thresholds and found that the optimum magnification wasnt in general well defined, but usually a much broader range than often quoted.

But I do get that many observers find different magnifications and EPs make a difference. I'm now interested in why that is!

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.

[niallk]

I have 5 EPs for my 15" f4.5 dob: but could live with these three if i had to: 6-10-17 Ethos.

I'd have to keep one 15mm TV plossl for my LS50DS.

That's 4 EPs, and I'd probably have to hold on to my N13T6 ... just because it's simply a remarkable EP for its size and weight, and was my first TV EP, and it blew me away in my 10" f4.7 dob (gone now).

That would mean I'd be giving up: N7T6, 8E, 24Pan, N31T5, TS 7-21 Zoom, and the easiest decision, the 20ES100!

[Franklin]

If only 5 I'd give up all the SLV's, the NPL's, the HR's and all the LVW's except the LVW22mm.

I'd keep the LVW 22, the SSW 10, SSW 7, SSW 5 and SSW 3.5. These are great performing eyepieces and give a perfect selection of magnifications with both my scopes.

But of course I am actually going to keep them all, along with my collection of vintage Vixen eyepieces and the 2" long focal length ones.

[Paz]

I might answer this differently from time to time but most likely I would go with Delos and I would pick the 17.3 8, 6, 4.5, and 3.5, and I would have to agonize about whether to go for the 12 or 10.

It would be a shame to go without 2" eyepieces or binoviewer sets but if it had to be just 5 and if I think about what observing I do most of the time in what scopes, those would probably be it.

[niallk]

1 hour ago, Paz said:

I might answer this differently from time to time but most likely I would go with Delos and I would pick the 17.3 8, 6, 4.5, and 3.5, and I would have to agonize about whether to go for the 12 or 10.

It would be a shame to go without 2" eyepieces or binoviewer sets but if it had to be just 5 and if I think about what observing I do most of the time in what scopes, those would probably be it.

Cheater!! 😁 That's 6 if you keep a 10 or 12 too!!

Yeah I'd be giving up on bv'ing too... my pair of 15mm TV plossls are what I generally use.  Just got a linear bv recently too - looking fwd to seeing what its like in the dob!!  Maybe I'd have to forego my N13T6 for a second 15mm.

[Paz]

19 minutes ago, niallk said:

Cheater!! 😁 That's 6 if you keep a 10 or 12 too!!

Oops, it was worth a try! 🤪

[John]

If zooms are permitted I reckon I could get by with just 3 eyepieces:

- Something nice and wide around 20-25mm

- The APM 15.4mm - 7.7mm zoom

- The SVbony 8mm-3mm zoom

While not perfect the above would cover practically all situations with my scopes and their performance is really pretty good 🙂

 

[Mr Magoo]

30mm UFF

24mm Panoptic

17.5mm Morpheus

13mm Ethos

8mm Ethos

[Littleguy80]

Assuming no zooms, I’d go with my most used eyepieces:

APM HDC 20mm

Docter 12.5mm

Delos 10mm

Pentwx XW 5mm

Vixen HR 3.4mm

These to cover 10” F4.7 Dob and 4” F7.4 refractor. 

[Littleguy80]

Since posting, I keep pondering the loss of my longer focal length eyepieces (APM 30mm UFF/Aero UFF 40mm). I recently had the whole Veil complex in the FOV with the Aero and Tak. Not sure I wanna lose that but then what would I give up?!? I don’t think I’m gonna sleep well tonight now. Just need to keep me reminding itself that it’s not real 😂