Wide field eyepiece that's suitable for F4.7 newtonian.

[Guest]

Hello.I have a skhywatcher 10 incg pds.This is a focal ratio of f4.7.I am looking for a wide field 24mm ish 1 1/4 inch eyepiece that would perform well in my telescope (f4.7 being quite fast). I understand that some eyepieces may not give good sharp view right to the edge.Can anybody suggest an eyepiece that does perform well that may not break the bank?At the moment I aM USING 20MM WIDE FIELDS WITH DO NOT WORK WELL ACROSS THE FIELD TO THE EDGE.

Thanks,

Martin

[John]

Can you define breaking the bank ?

The challenge is that wide field / fast scope / sharp to the edge of the field don't come at low prices as they are difficult to achieve.

[Guest]

Some televue eyepieces are quite expensive and more than I could afford.£350 to £500.As an example,there is a Skywatcher 26mm Panaview eyepiece being sold.These are around the £90 mark.The selller has described using it on an f6 newtonian and it working fine,but not giving sharp to the field edge views on his faster f4.5 newtonian.I am enjoying using my 10 inch f4.7 newtonian and would like a good sharp to field edge eyepiece.Perhaps a good used would suit.Around £150 ish.Thanks for your post John,

Martin.

[Naemeth]

Some televue eyepieces are quite expensive and more than I could afford.£350 to £500.As an example,there is a Skywatcher 26mm Panaview eyepiece being sold.These are around the £90 mark.The selller has described using it on an f6 newtonian and it working fine,but not giving sharp to the field edge views on his faster f4.5 newtonian.I am enjoying using my 10 inch f4.7 newtonian and would like a good sharp to field edge eyepiece.Perhaps a good used would suit.Around £150 ish.Thanks for your post John,

Martin.

The Panaview is far better suited for F/6 and slower.

At that budget, you are looking at ExSc / Maxvisions, either 68 or 82 degrees. Personally though, I'd stretch to getting a 24mm Panoptic (£265 new). If you can get it 2nd hand, you may be able to get it for around £170.

[Guest]

I have actually put a wanted notice for this type of eyepiece.

Thanks for the advice,

Martin.

[JamesF]

At that budget, you are looking at ExSc / Maxvisions, either 68 or 82 degrees. Personally though, I'd stretch to getting a 24mm Panoptic (£265 new). If you can get it 2nd hand, you may be able to get it for around £170.

I love my 27mm Panoptic that I bought second hand for less than that IIRC. It's a 2" ep though. I've not tried the 24mm version, but if one came up second hand at the right price I'd probably buy it on the strength of the 27mm.

James

[John]

The two that you are looking for in your "wanted" ads would be my top suggestions Martin. You should certainly get the Vixen LVW 22mm for around £100-£120 and it's an excellent eyepiece. It's as sharp as the Panoptic 24mm but does not have quite as wide a field of view (65 degrees vs 68 degrees).

As well as being less than sharp to the edge below F/6, the Panaview 26mm is a 2" format eyepiece.

An alternative approach in the 1.25" format would be to look at a Tele Vue 32mm Plossl. While not a wide field it does show as much sky as a 24mm wide field does, albeit at lower magnification. They are designed to work well down to F/4 so should be sharp in your scope.

[Tinker1947]

This one of those things (EP's) you get what you pay for (most of the time) my 31 mm Baader does get a thin white line round the edge when there are stars on the edge of the FOV, my Pentax 30mm doesn't but cost 4 times a s much, the 24mm Baader i have never noticed there are and defects arounf the edge of the FOV....as for the view its good in all of them, but my eyes are 66 years old so a younger person would be a better judge...

[Naemeth]

The two that you are looking for in your "wanted" ads would be my top suggestions Martin. You should certainly get the Vixen LVW 22mm for around £100-£120 and it's an excellent eyepiece. It's as sharp as the Panoptic 24mm but does not have quite as wide a field of view (65 degrees vs 68 degrees).

As well as being less than sharp to the edge below F/6, the Panaview 26mm is a 2" format eyepiece.

An alternative approach in the 1.25" format would be to look at a Tele Vue 32mm Plossl. While not a wide field it does show as much sky as a 24mm wide field does, albeit at lower magnification. They are designed to work well down to F/4 so should be sharp in your scope.

I'm not so sure a 32mm plossl would be a good widefield eyepiece for the OP's scope, John - it gives a 6.8mm exit pupil which is really only usable in darker skies.

[John]

I'm not so sure a 32mm plossl would be a good widefield eyepiece for the OP's scope, John - it gives a 6.8mm exit pupil which is really only usable in darker skies.

Ah, yes - I'm not thinking straight there tonight !

Best stick to the 22mm - 26mm focal length range.

[michael.h.f.wilkinson]

Ah, yes - I'm not thinking straight there tonight !

Best stick to the 22mm - 26mm focal length range.

A bit wicked, bracketing the focal lengths with two of the greatest Nagler designs I have looked through: the 22T4 and 26T5. I own one and have looked through the other at Olly Penrice's place. Having said that, the MaxVision 24mm 68 deg is no slouch, and certainly works well at F/6, although it might do a worse job at F/4.7. The 24mm 82 deg is rated as working well at F/4, and I have used the (same design) 14mm Meade Series 5000 UWA at F/4.1 and noted no real problems. The performance was very close to that of the Nagler 17T4.

BTW, at these ultra wide angles, coma might affect the stars at the edge as much as faults in the EP.

[Stargazer_00]

Can I bring back to a point in the OP?

Which 20mm Wide Angle eyepiece are you using right now? It's just a question of perception for me. If this is say a 20mm WO SWAN then the edge performance wont be good at F4.7 but a 24mm Maxvision or an ES68 or ES82 even would be good by comparison. not TV quality, sure, but good compared to a SWAN.