Which Eyepiece To Buy?

[Raya K]

I've always wanted to buy an eyepiece with an extra-large FOV in the 25-35mm range, but there seem to be too many options to choose from. Anyway these are, so far, the ones I have been considering . Are 40mm's with a 1.25 barrel worth it? ANY SUGGESTIONS WELCOME!

1. Meade Series 4000 26mm Super Plossl Eyepiece (1.25")

2. Celestron Omni 32mm Eyepiece (1.25")

3. Celestron X-Cel LX 2.3mm Eyepiece (1.25")

4. Meade Series 4000 26mm Super Plossl Eyepiece (1.25")

[Raya K]

P.S. Also what Barlow would do well with these eyepieces?

[John]

Hi and welcome to the forum !

40mm in the 1.25" barrel will not show any wider field than a 32mm in the same size so I don't feel they are worth having. Of the ones above the 32mm Omni will show the most sky / widest view. I don't know how the 2.3mm X-cell got in there as it's going to have a tiny field of view as it will produce magnfication that is so high that most scopes can't use it.

An alternative to the above would be a 24mm eyepiece with a 68 degree apparent field of view. That would show as much sky as a 32mm but the field will seem wider and the additional magnfication will darken the background sky a little which is useful when looking for faint objects.

If would be useful to know what scope you intend to use the eyepiece in because some will work better with certain scopes than others.

It's not generally a good idea to use a barlow lens with longer focal length eyepieces because the side effects a barlow has (eg: longer eye relief) can make the eyepiece more awkward to use.

[Raya K]

 Not X-cel 2.3 eyepiece sorry. An X-cel 25mm eyepiece.

[Dom1961]

It may be my Un educated idea, but I thought all plossls had 50°?

[Raya K]

Thanks John

[Pig]

You do realise the 3rd eyepiece listed is a 2.3mm high power eyepiece ? The 25mm of this range will suit you more and would be my choice.

A 40mm 1.25 does not give any FOV advantage over a 32mm. However, the lower magnification 40mm delivers may be useful for some applications.

[Raya K]

No. But most people consider 50 as a good amount in general, if that helps.

[John]

It may be my Un educated idea, but I thought all plossls had 50°?

If longer than 32mm they get less than 50 degrees becuase the field stop (the hole that creates the edge of the field) can't be made larger than the 1.25" barrel size. This applies to any eyepiece design, not just plossls.

Some really cheap plossls have less than 50 degrees. 50 / 52 is normal, with the exceptions covered above.

Personally I find the 43 degree field of the 40mm plossls like looking down a tube. The 50 / 52 degrees of the 32mm's don't seem like this, to me anyway.

[Raya K]

I've always wanted to buy an eyepiece with an extra-large FOV in the 25-35mm range, but there seem to be too many options to choose from. Anyway these are, so far, the ones I have been considering . Are 40mm's with a 1.25 barrel worth it? ANY SUGGESTIONS WELCOME!

1. Meade Series 4000 26mm Super Plossl Eyepiece (1.25")

2. Celestron Omni 32mm Eyepiece (1.25")

3. Celestron X-Cel LX 2.3mm Eyepiece (1.25")

4. Meade Series 4000 26mm Super Plossl Eyepiece (1.25")

*Change #4 to a 32mm, my bad*

[John]

The Meade and Celestron 32mm plossls will show essentially exactly the same view.

As I said earlier, knowing the intended scope would help

[alro]

Hello

i have meade 4000 plossl set. I prefer my 26mm over 32mm. In my opinion my 26mm is more comfortable, i dont seem to get on to well with 32mm

Al

[ronin]

One aspect of a plossl is the eye relief varies with the focal length, generally people say 2/3 or 70% of the focal length.

So a 32mm plossl will have about 20mm of eye relief and some find this too much, you end up having to hold your eye/head at a postion sort of in space and not in contact with the eyepiece.

I would opt for the X-Cel, the 25mm will have the same field as the plossls (to within a small percentage), they get good reports, although a couple of recent ones seem to imply they can get dust in them somehow.

I do not know the Omni's - I see it is a plossl, always thought they were more then that.

The Meade plossl will be a GSO item with Meade on the housing, they have been for some time, GSO make good plossl's however.

If you have a fast scope, like f/5, then a plossl may be a problem, they generally start to be at their limit on f/5 scopes, again the X-Cel are reported as OK at f/5.

An option to the X-Cels are the Astro-Tech Paradigms (Astronomics, Agenaastro sell them as Dual ED eyepieces).

If you intend planetary viewing then the X-Cels have a better selection at the short end, 5mm, 7mm, 9mm, 12mm.

[kurtz9]

None of those strike me as having an especially "extra-large FOV"... as I understand it your max field stop in a 1.25" EP will be about 27mm... so I'm with John, I'd suggest a 68 degree AFOV EP in 24mm... Max possible FOV with a bit better magnification too...The Televue Panoptic 24mm is considered the gold standard here but TV pricing is kind of insane... The Explore Scientific one in 1.25 at that AFOV and FL is on sale right now for $134.99 in the US...not sure what it goes for in Canada....and it's 95% of the TV for less than half the price.... and noticeably better than any of the EPs on your list.

Regarding the barlow thing- my understand is if you get a telecentric focal extender (like the ones offered by at least Televue, Seibert, and Explore Scientific) then eye relief remains exactly the same as the original EP... they cost a bit more though.... the ES 1.25" 2x one is $74.99 US on the same sale at the moment.