Suggestions for high power eyepiece without costing a fortune.

[Andylast]

Looking for an eyepiece about 5mm focal length for planets and the moon. On the SCTs I have, it will provide the highest mag you would want to use. Don't want to spend several hundred ££ on one, looking for a diamond (one that turns up occasionally that is great performance for a sensible price). Have heard both good things and meh responses to the Long Perng LER eyepieces at that focal length. They are branded by several companies including FLO. 

Anyone have some good experiences with 5mm (ish) that are less than £150?

Thanks

Andy

[John]

Do you wear glasses when observing Andy ?

And what SCT's do you have ?

 

Edited August 3, 2023 by John

[Andylast]

20 minutes ago, John said:

Do you wear glasses when observing Andy ?

And what SCT's do you have ?

 

No glasses. 6" and 11" SCTs.

[Naughty Neal]

Ernests report on the xcel - lx 5mm isn't too bad but only 58 degrees or so.

Michael aka Mr Spock rates the OVL nirvana's but no 5mm there is a 4mm but maybe too powerful.

 

Both about the £85 - £95 mark.

[Mr Spock]

There's a 5mm Vixen SLV. https://www.firstlightoptics.com/vixen-eyepieces/vixen-slv-eyepieces.html

Incredibly sharp eyepieces, like orthoscopics but with long eye relief. Over the years I've had the 12mm, 10mm, 9mm, 6mm, 5mm, 4mm and 2.5mm. They are all equally good. The first three I used with a C9.25 and sold them when I sold it. The 6mm and 5mm were in between others I have (7mm and 4mm Nirvanas) and so weren't required and the 4mm and 2.5mm were replaced with TOEs.

[dweller25]

+1 for the 5mm Vixen SLV, although that will give you x300 and x560 in your SCT’s at native focal lengths - not many nights in the UK have seeing to support that ☹️

I prefer around x190 for Jupiter and Saturn and x240 for Mars.

Edited August 4, 2023 by dweller25

[John]

I really like the Vixen SLV's as well 🙂

Personally I might be tempted to get the 6mm for the 6 inch SCT which will give a useful 250x and the  9mm or 10mm for the 11 inch sct which gives 311x or 280x.

While "maxing out" possible magnification is fun sometimes, a wee bit lower than that is usually much more useful under typical UK observing conditions. I can't see the 466x that the 6mm would give in the 11 inch being used to often to be honest with you.

 

[Mr Spock]

When I had a C9.25 the planetary eyepiece I used the most was 10mm for x235. I find in an SCT the best image quality comes at x1 per mm of aperture; I found the 12mm useful on Jupiter. I would occasionally use an 8mm for x294 on the moon, and a 6mm x392 for doubles.

[Andylast]

1 hour ago, John said:

I really like the Vixen SLV's as well 🙂

Personally I might be tempted to get the 6mm for the 6 inch SCT which will give a useful 250x and the  9mm or 10mm for the 11 inch sct which gives 311x or 280x.

While "maxing out" possible magnification is fun sometimes, a wee bit lower than that is usually much more useful under typical UK observing conditions. I can't see the 466x that the 6mm would give in the 11 inch being used to often to be honest with you.

 

Trouble is I already have a 7mm Pentax. Getting a 6mm would be an unnecessary extravagance. With long focal length telescopes the gap between 7mm and 5mm would be noticeable.  The other option is a quality 2x Barlow with the ability to remove the lens group to attach directly to an eyepiece to give 1.4X or 1.5x. That gives me a range of powers with the eyepieces I already have.

[dweller25]

“The other option is a quality 2x Barlow with the ability to remove the lens group to attach directly to an eyepiece to give 1.4X or 1.5x. That gives me a range of powers with the eyepieces I already have”

Yes, that that could be a better solution as long as your existing eyepieces have enough internal clearance to screw in the barlow lens group.

Edited August 4, 2023 by dweller25

[Naughty Neal]

Going back to the X-Cel lx, earnest mentions that the aperature is 4.5mm rather then 5mm and the same lens as the Meade version.

[vlaiv]

ES 62 degrees 5.5mm

[John]

6 hours ago, Andylast said:

Trouble is I already have a 7mm Pentax. Getting a 6mm would be an unnecessary extravagance. With long focal length telescopes the gap between 7mm and 5mm would be noticeable.  The other option is a quality 2x Barlow with the ability to remove the lens group to attach directly to an eyepiece to give 1.4X or 1.5x. That gives me a range of powers with the eyepieces I already have.

Below 8mm I do have 1mm increment steps and even go down to .5mm steps below 4mm. My scopes are shorter focal length than yours. Having more magnification steps for higher powers is very useful I find - you can find the "sweet spot" that suits the conditions and target with more precision. I guess it can seem extravagant though 🤔

[Paz]

I agree with the SLV being a good choice but that will be a tough ask of the 11" sct.

I have a C8 and I think 8mm is as far as I normally go with that scope.

Having said that, when noone was looking I have in the past secretly tried a 2.5mm SLV in a 14" reflector, that was fun!

[IB20]

10mm BCO with a 2 x barlow works very nicely.

[stormioV]

On my SCT I  use BST Starguiders , ES & Meade Plossls.  If you don't need a wider fov Starguiders are great at about £50 and there is a 5mm. There may well be better choices, but they will most likely be at least x2 cost. As i am sure you are aware SCTs are kind on eyepieces. Svbony zoom 8-3mm could be a good choice? I haven't used this but there are a lot of positive comments about this zoom.

Edited August 5, 2023 by stormioV

[Cosmic Geoff]

SCTs with their typical f10 focal ratio, are not demanding of eyepieces, so no desperate need to buy exotic eyepieces. I use Plossls for the lower powers.

An 8mm eyepiece is the highest power you are likely to need.  I have a 5mm Celestron X-cel LX I acquired as part of a bundle, but have only used it once or twice in my SCT. 

[Stu]

23 hours ago, Andylast said:

Trouble is I already have a 7mm Pentax. Getting a 6mm would be an unnecessary extravagance. With long focal length telescopes the gap between 7mm and 5mm would be noticeable.  The other option is a quality 2x Barlow with the ability to remove the lens group to attach directly to an eyepiece to give 1.4X or 1.5x. That gives me a range of powers with the eyepieces I already have.

I don’t agree, 7mm to 6mm in a 2350mm focal length scope is a jump from x335 to x391, quite a lot. As John says, small increments at higher powers are useful, especially in a long focal length scope as the mag jumps get bigger.

[Don Pensack]

4 hours ago, Stu said:

I don’t agree, 7mm to 6mm in a 2350mm focal length scope is a jump from x335 to x391, quite a lot. As John says, small increments at higher powers are useful, especially in a long focal length scope as the mag jumps get bigger.

In a 9.25" scope, a jump of 56x is not a large jump unless the seeing supports 335x and not 391x.

Over the years I've done this, I don't really find seeing supports 335x and not 391x, though.

On the nights where 335x is clean, clear, and sharp, so will 391x be.

 

In my 12.5", if seeing supports >300x, it usually supports 500x.  If it doesn't support 300x, 200x might be the maximum sharp magnification, not 260x.

So I would argue that a 56x increase at that power is probably fine, maybe a bit small, actually. 

 

That being said, there is a rational reason to make the % jumps at high powers be smaller than at lower powers.

One way to do that is to choose eyepieces that yield an even step in magnification, like 50x.  That will automatically produce smaller % changes at high powers.

Even % changes usually results in low powers too close together and high powers too far apart.

[Stu]

25 minutes ago, Don Pensack said:

So I would argue that a 56x increase at that power is probably fine, maybe a bit small, actually. 

The alternative being dropping from 7mm to 5mm which would be a jump from x335 to x470; to me, and under UK skies the 6mm would be useable a heck of a lot more than the 5mm I would say.

[Mr Spock]

I used a C9.25 for eight years. I can say from experience of SCTs that unlike my current 12" Newt they are sensitive to small changes in magnification. With the 12", if x217 is sharp (7mm), I jump straight to x380 (4mm); and just recently I've started using a 3.3mm TOE for x461. Not so the C9.25 - x235 might be sharp, but x261 mushy. That's why my eyepieces went 12mm, 10mm, 9mm, 8mm, 7mm, 6mm. 

[Louis D]

12 hours ago, stormioV said:

Svbony zoom 8-3mm could be a good choice? I haven't used this but there are a lot of positive comments about this zoom.

If the OP doesn't mind tight eye relief, it is an excellent performer between 5mm and 8mm.  For the money, it would be a good buy to be able to exactly tune the magnification to the seeing conditions.

[moggi1964]

I always enjoyed using my 6mm TMB/Burgess planetary on whatever scope I owned including my 10" SCT as well as my F/6 dob.

Not a particularly expensive eyepiece but 60° FOV if I recall and comfortable to use.

I used some Televue Plossl's some years back, nice glass but I found the FOV to be too narrow on the higher magnifications. 

I did try out some of the Explore Scientific eyepieces when they were about to be released and they seemed decent and good value. I think FLO has them in the UK.

[Mr Spock]

I have a TMB 6mm sitting in a drawer somewhere. I've never sold it as I didn't think it was worth much. Good performer though - that was the 6mm I used in the C9.25.

[John]

The TMB/Burgess 6mm was a very good performer and comfortable to use. Similar to a Tele Vue Radian in many ways. The early ones needed an internal lens retaining ring replacement to remove excessive off axis glare - I seem to recall that Burgess Optical sent these out for owners to make the replacement themselves.