Low power EP selection @ F10

[rawhead]

Hi Folks,

I'm looking for a half decent low powered wide angle EP for an F10 scope (1.25'')

From what I understand F10 is quite forgiving. Therefore megabucks will not be required (IE: TV 24mm Panoptic)

I'm considering a 24mm Hyperion (68 degree) for £92

or a Meade 5000 series 24mm SWA (also 68 degree) for £129

Any comments / further suggestions?

Cheers

[Matthew.Blake]

I'd go for a Skywatcher 38mm Panaview (£85) or the 40mm Aero (£137). I have the 30mm Aero for my F/5 newt and love it.

[John]

I'd go for a Skywatcher 38mm Panaview (£85) or the 40mm Aero (£137). I have the 30mm Aero for my F/5 newt and love it.

I think those are both 2" format.

I've been testing a bunch of Baader Hyperions recently, including the 24mm, and I was generally pretty pleased with them at F/6.5 so they would be great at F/10.

I used to have a Japanese Widescan III eyepiece which was a 1.25" 20mm but offered a massive 84 degree FoV - it worked great at F/10 They don't make them any more but they do come up used occasionally.

It's not a wide field as such but the Tele Vue 32mm plossl would be within you budget and is a very nice eyepiece.

[Matthew.Blake]

I think those are both 2" format.

I've been testing a bunch of Baader Hyperions recently, including the 24mm, and I was generally pretty pleased with them at F/6.5 so they would be great at F/10.

I used to have a Japanese Widescan III eyepiece which was a 1.25" 20mm but offered a massive 84 degree FoV - it worked great at F/10 They don't make them any more but they do come up used occasionally.

It's not a wide field as such but the Tele Vue 32mm plossl would be within you budget and is a very nice eyepiece.

Ah yes, didn't spot the 1.25" criterion! I'd think about saving up for a focusser that can take 2" eyepieces as well then as with an F/10 scope I'd be looking at around 40mm for a proper low power eyepiece. What is the focal length of the scope?

Given the 1.25" requirement I'd go with your original suggestions. The TV plossl is nice but the others would show you just as much due to their greater AFOV.

[part timer]

Ah yes, didn't spot the 1.25" criterion! I'd think about saving up for a focusser that can take 2" eyepieces as well then as with an F/10 scope I'd be looking at around 40mm for a proper low power eyepiece. What is the focal length of the scope?

Given the 1.25" requirement I'd go with your original suggestions. The TV plossl is nice but the others would show you just as much due to their greater AFOV.

The tal is not upgradeable with a 2".

However 1.25" is all you really need any way! There are binoculars for low power!!

I'd either get a TV 32mm as above or go with the hyperion. I'd be tempted to just save up for a 24mm panoptic though. The pan is not going to make an enormous difference at long f ratios but if you get something shorter later you will be future proofed and it will be better in any scope, if only a little bit!

I used some very cheap 80 degree eyepieces in my Tal 2 at f8 and they were great.

[rawhead]

Thanks for the info

We now have:

1. 24mm Hyperion (£60 2nd hand)

2. TV 32mm (£60 2nd Hand) Will there be a noticeable improvement over my top cheepee Meade 4000 32mm???

Save the cash, 24mm Panoptic (not going to happen )

I'd certainly try a 20mm Widescan III if one became available...

Cheers

[part timer]

TBH the difference wil be small. BUT I could always see there was a difference even at f13.sumat in my old Mak.

If your meade is an old one (clearly stamped as made in japan) then the above is not true as the old meade 4000's were different eyepieces.

It may be worthwhile contrasing your TV10.5 and Tal 10mm. If you think the difference is worth it then maybee it will be for the 32'S.

After wasing lots of money I now prefer smaller field quality eyepieces to larger field el cheapo'S. Others have different prferences so you'll have to judge that for yourself!

[SiriusB]

A few more for you to look out for while you're combing the 2nd hand ads: University optics 32mm Konig (52afv), Celestron Ultima Japan 30mm (52afv), Parks Gold series 30mm(52afv)- still available new from Lumicon $139, its an Ultima clone. all widely regarded as good LP 1.25" ep's.

I'm not sure from your post whether you were after extra fov, better optics or both?

I doubt you'll better the Meade 32mm's true field of view by much.

The APPROX:icon_scratch: maths goes something like this.

Max linear fov of 1.25" ep is 27-28mm ish due to thickness of barrel walls

1deg true field = fl of telescope/ 57.3

Eg: 2000mm /57.3 =34.9.

So 1deg true field =34.9mm at the focal plane

So max true field is 27/28mm, (say 28mm)/ 34.9=0.8 deg

tfv=afv/mag

Some examples using the 2000mm fl

32mm 50afv gives 62x & 0.8 deg true field of view

24mm 68afv gives 83x & 0.81 tfv

20mm 80afv gives 100x & 0.8 tfv

So i guess that leaves us with the IQ criterion..over to ...anyone?

Hope that helps.

[rawhead]

After wasting lots of money I now prefer smaller field quality eyepieces to larger field el cheapo'S.

Good point well made

Will also do the 10mm comparison...

A few more for you to look out for while you're combing the 2nd hand ads: University optics 32mm Konig (52afv), Celestron Ultima Japan 30mm (52afv), Parks Gold series 30mm(52afv)- still available new from Lumicon $139, its an Ultima clone. all widely regarded as good LP 1.25" ep's.

Thanks for the list. Have already started to Google...

32mm 50afv gives 62x & 0.8 deg true field of view

24mm 68afv gives 83x & 0.81 tfv

20mm 80afv gives 100x & 0.8 tfv

So....

All these examples will give the same view, just a different mag?

Cheers

[old_eyes]

I have a second hand 24mm Hyperion and I like it a lot. I wear glasses and it is dead easy to use. However, I love my SW Aero 40mm even though I have to change the diagonal.

old_eyes

[rawhead]

I think I'll wait for a 2nd hand 24mm Hyperion

My 13mm was superb tonight

Thanks for all the feedback.

Cheers

[michael.h.f.wilkinson]

For a given true field of view, I much prefer to use a higher magnification. This gives you darker backgrounds at for me makes it easier to pick out DSOs. This is why my 26mm Plossl became almost redundant when I got a 14mm Meade Series 5000 UWA. The true FOV was similar (0.65 vs 0.56 deg), but picking up the ring nebula was WAY easier in moderate light pollution with the 14mm. TV Plossls are great by all accounts, but a wider angle quality EP is preferable. Hyperions might not be the absolute top, but they are very good. The difference between a Hyperion 36mm and 40mm TMB Paragon on the 16" F/8 RC telescope we have here is not very big (the main difference I noticed was a slightly higher tendency to "kidney-bean" in the Hyperion). Go for the Hyperion, I would say.

[rawhead]

I’ve now found a brand new Meade 5000 series 24mm SWA for £102 delivered!

Should I still go for the Hyperion at £90 delivered?

Just when I had made my mind up.......

[Matthew.Blake]

I'd go for the Meade. I've never heard anyone prefer the Hyperion but have read quite a few reviews where people preferred the SWA.

[michael.h.f.wilkinson]

The Meade has the higher reputation

[rawhead]

Just bought the Meade

[AndyH]

For some reason I've just found this thread.

Fine choice Jon.

I would also have gone with the higher mag eyepiece too, if I hadn't already got the 32mm U.O. Konig. As previously stated, 0.8 degrees is about the max for the 200K.

I have a cunning plan regarding my 2" 24mm Tal UWA and an old 40mm Takahashi prism diagnal. But even after getting a machined piece, the most I can expect is a tad under a degree, I think.

Let us know what the views are like with the Meade. It's an eyepiece that I had considered for a long time for some of my 1.25" focuser scopes.

Cheers,

Andy.