Plossls or expanse: Which one is better?

[John24]

In terms of optical quality and correction.

[ollypenrice]

Expanse? Can you...ah...expand???

Olly

[stev74]

Expanse.....do you mean eyepiece's with a wider field of view than a standard plossl?

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[Tribal-Wolf]

I assume you mean these - Expanse

From what I know they are the same as Skywatcher Ultrawide EPS made by the same people I think just a different badge.

[John24]

Tribal wolf is right about expanse. And Super plossl of orion. I know expanse has better Eyerelief and wide FOV which is useful for me as I have spectacles. I dont have any idea about the plossls. Both cost around the same price. So thought about asking on SGL.

[Moonshane]

for me it depends on what you want to spend. if money is no object you can have an excellent view across a wide field. if not then you would be better for me to buy a narrower field eyepiece. I have Baader Genuine Orthos (40 degree field) and an Ethos (100 degree field) and optically the BGO is in my opinion as good as the Ethos. It costs about 6x less than the Ethos though. If observing planets and moon I'd choose the BGO. If observing open star clusters I'd choose the Ethos.

Personally I would sooner have a narrower all sharp field than a wider not sharp field.

[John24]

Well I would sacrifice wide field for sharper objects. But if expanse and plossls have the same optical quality then.... I dont have any idea though perhaps you all can help me. I am a total noob right now with some idea how telescopes work and I own one.

[acey]

I agree it all depends on what you want to look at. Wide field is irrelevant for me, except at very high power where it helps dob tracking. If you want wide field then get your wallet out, otherwise save your money and get a high-quality plossl or ortho: the view in the centre of field is the same.

[John24]

How are orion super plossls?

[acey]

Don't know but here's a review of Expanse

Head to Head: Orion Expanse vs. Siebert Optical Standards - Shootout

If I were going to buy Plossls to replace whatever came with my scope, I'd get Televue. I had an Orion 8" dob that came with Orion Sirius Plossls (25mm and 10mm) and my first upgrade was to replace the 10mm with a TV which was way better.

[John24]

Well that is quite shocking I d better off with the EPs that came with the scope

[John24]

How do I calculate the eye relief?

[John24]

Thanks acey for the link. And televues are wayyyy toooo costly. Plossls are fine but nagler just cost more than the scope itself

[John]

I've used some of the Expanses and the Skywatcher Ultrawides (same eyepiece more or less). In slow scopes (eg: F/8 or slower) they work quite well and seemed about as sharp as a decent plossl but with the wider field of view and the more comfortable eye relief. If your scope is faster than that a good plossl would be a better bet. Of the Expanses, the 9mm is the best followed by the 6mm. The 15mm and 20mm are not bad but only in slow scopes. The 9mm in this design (ie: the Skywatcher UWA's as well) is regarded by some to be somewhat of an "unsung hero". Don't pay too much for these though - I got a set of the Skywatcher UWA's for around £50 and sold them for the same.

[Tribal-Wolf]

If the orion super plossl is the Sirius range then I found the 10mm to be worse than the skywatcher 10mm that came with my scope so I sold it, it wasn't as sharp for me. I am gonna stick with BSTs I think.

[John24]

Thank you friends for all your help

[tjayh913]

I had chosen to buy a 9mm Expanse (from Orion) over a similar length Plossl when I bought my telescope mostly for its increased eye relief, and I have been happy with it since. (Of course I don't really have much of a standard of comparison).

[Moonshane]

I had chosen to buy a 9mm Expanse (from Orion) over a similar length Plossl when I bought my telescope mostly for its increased eye relief, and I have been happy with it since. (Of course I don't really have much of a standard of comparison).

this is an excellent point. I am lucky etc and have premium eyepieces but many people observe their whole life, perfectly happy with much cheaper (but still very good) options and if they work for you and they are showing you great things in the sky then that's what it's all about.

many people worry when told that this eyepiece is the best and theirs is not as good but the fact is they all work, and provide a better view than you would get without them (even the really shoddy cheap ones). I have never looked through an eyepiece that showed me nothing!

I use Televue eyepieces and they are clearly better than the 10mm that comes with scopes generaly in the package but I have used that 10mm eyepiece on my school telescope and unbarlowed it provided perfectly satisfactory views of the moon and the main cloud bands on Jupiter.