Is the ES 24mm 68 deg better than bst 25mm in f5 scope?

[djhartist]

Hi

Just a quick query if anyone has had the chance to compare these two eyepieces?

My BST 25mm tends to lose clarity in about 30-40% off-axis edge of view in my 130p f5 Explorer. On axis it's nice and sharp. This may be coma or field curvature or something, not sure. It's usable but a bit annoying. Collimation using a cheshire seems ok, as i can get good sharp views with 9mm ortho + 2.5 ed barlow, but that's the other end of the spectrum so not so relevant!

My question is, would the ES 24mm 68 deg eyepiece perform better and be sharper across the view, therefore benefiting from a wider fov than a plossl?

( Don't want to upgrade to more expensive eyepiece if there isn't going to be much improvement. Maybe it's just the nature of the mirror, and something to live with without a coma corrector, which i don't want to get at mo. Have been reading about other options such as Vixen LVW, Panoptic etc. Also the Vixen SLV's sound interesting but have less fov again! Looking to get a small collection that work in both f5 and f13 and can be future proof for a larger scope down the line.)

[Paul73]

Yes. Miles better. I had the MV 68° version and now have the ES82° version.

I think that the ES coatings may be better than the MV (subjective view) and the MV beats the BST.

Paul

[Moonshane]

Should be better although I have only used the BST which was pretty good at the price. Make sure that the effect you are seeing is not coma as this won't be correct by an eyepiece (although poorer designs can mask coma with other aberrations in fast scopes e.g. f5). I have used a similar 24mm TV Panoptic which is in my opinion a sublime choice in this format albeit at a higher price - maybe £150 used.

[ronin]

First which ES 24mm 68 degree?

Seems there are 2 of them.

If the Maxvision variety then I would guess little improvement, simply based on the information that:

"Suitable for use with telescope f-ratios f/5 or higher."

See the Tring Astro site: ES-24-68

Tring are not going to say this unless ES have said it.

If the "other" not called Maxvision one:

ES-24-68-2

That may be better performance, well ES say it is good, but doubt they would say otherwise , cost a bit more, but not much.

Unfortunately at the £50-70 mark for a widish eyepiece you cannot have everything and it is usually the sharpness at the edges that cannot be maintained. Throw another £200 into the pot and you will get better. :grin:

It also depends how mad it drives you not to have a fully sharp field in the view.

[djhartist]

Thank you Paul and Moonshane. Confirms some of the conclusions am coming to, and appreciate the quick replies and beneficial feedback.

The 25mm bst is fine in my Mak, and the 12mm bst works great in both scopes, and they are both an improvement on the cheapy plossls i had in terms of quality and comfort. At the mo am wanting to stay within 1.25 format so that i can use in both scopes.

Haven't had chance to compare the quality of the f5 mirror to any others, but i think i should start saving both money and patience.

[Moonshane]

There's always the option of a wanted ad or keeping an eagle eye on astro-buyand sell pending finding your eventual purchase of a really decent quality eyepiece. people often do this as they work up and start to see the imperfections in their kit. in a way it's pointless before you do.

http://umich.edu/~lowbrows/reflections/2007/dscobel.27.htmlis a great link explaining the aberrations you see, and coma is well illustrated.

[djhartist]

Hi ronin

Am considering the Explore Scientific version, as the 24mm Maxvision doesn't seem available now. Am having to bite the bullet and acknowledge that eyepieces cost as much or more than a scope sometimes, but as i'm new to astronomy this year, am gradually learning all about equipment as well as the mystery of the stars! I'll keep an eye out for offers / 2nd hand too. I do appreciate a nice crisp view if possible, seems best to see what one is looking at in detail. Or maybe that's the photographer / visual artist in me being fussy

[djhartist]

Have picked up some nice 2nd hand bits lately, and as you say it's a good way to try out equipment.

Thanks

[YKSE]

When I had SW 130p, I used both 24mm Maxvision 68deg and TS 32mm plossl. The plossl showed some astigmatism in 20-25% from the edge, not distracting to my eye in any way, while the 24mm MV showed less astigmatism, some 10-15%.

[djhartist]

There's always the option of a wanted ad or keeping an eagle eye on astro-buyand sell pending finding your eventual purchase of a really decent quality eyepiece. people often do this as they work up and start to see the imperfections in their kit. in a way it's pointless before you do.

http://umich.edu/~lowbrows/reflections/2007/dscobel.27.htmlis a great link explaining the aberrations you see, and coma is well illustrated.

That's a useful article moonshane. What i'm seeing appears to be predominantly Field Curvature. So would the ES 68 resolve this better?

[RikM]

I don't know about the 24mm ES 68° but I have the ES 28mm 68° and this has a reasonably flat field in my f/4.7 Dob.

[djhartist]

Lots to think about and consider, thanks for feedback everyone.

[Moonshane]

often the scope is the cheap bit. 

[Moonshane]

I think the 25mm BST in particular is known to suffer from more aberration than the others so yes, I'd expect it to improve with the maxvision. that said, improving on general aberrations can of course reveal coma!

[djhartist]

often the scope is the cheap bit. 

Well, my 130p was, £45 from astroboot!

But it's great, have found and studied lots of galaxies and globulars with it this spring / summer, which is what i wanted, plus it can be carried to sites. Certainly better for dso than my skymax 90... , but i have a real fondness for that too, often surprises me, found the Ring Nebula with the mak for the first time. It's good for white light solar too. But its limits for deeper viewing led me to get the 130p.

Swings and roundabouts with scopes though isn't it. Briefly had an Evostar 90 refractor, and i still remember & miss some of the views from that, especially doubles and star fields. At the time seemed too big, and even though there is a certain charm about rolling around in muddy cold fields when trying to view the zenith ( a great way to connect with nature and the mice, badgers and sheep) i got rid of it and replaced with the mak. So it's either deal with coma, CA or some other thing. Can't wait to get more aperture

[djhartist]

Sorry, think i was rambling and swaying off topic a bit there again. General consensus is that ES / Maxvision 68 would most likely be better across more of the view which is what i was wanting to find out. And a panoptic would be better. But viewing is of course also affected by coma and such like too. Thanks, i'll give it more consideration and also keep an eye on used market too.

[John]

I've read reports that the ES 24mm 68 degree (not the Maxvision) is close or equal to the Tele Vue Panoptic 24mm in performance. The TV 24mm Pan used to be described as one of the best 1.25" eyepieces ever made so the ES must be pretty good.

[kurtz9]

I've read reports that the ES 24mm 68 degree (not the Maxvision) is close or equal to the Tele Vue Panoptic 24mm in performance. The TV 24mm Pan used to be described as one of the best 1.25" eyepieces ever made so the ES must be pretty good.

Having directly compared the ES24-68 and the Panoptics I'd say this:

The ES is at least 95% as good, for 50% the price.

Folks who have compared their even-wider AFOV EPs to the equivalent Televues (Naglers and Ethos) have said the quality difference is even smaller than that  in those lines while still being half the price.

[kurtz9]

(disclaimer- my own testing was on a slow scope, but I've seen plenty of comments from owners of a wide array of scopes saying about the same between ES and TV)

[John]

Having directly compared the ES24-68 and the Panoptics I'd say this:

The ES is at least 95% as good, for 50% the price.

Folks who have compared their even-wider AFOV EPs to the equivalent Televues (Naglers and Ethos) have said the quality difference is even smaller than that  in those lines while still being half the price.

Yes, I've done those comparisons. The competition is pretty close now. When it's as good or better I'll sell my Naglers and Ethos's and save some money

[Moonshane]

Sorry, think i was rambling and swaying off topic a bit there again. General consensus is that ES / Maxvision 68 would most likely be better across more of the view which is what i was wanting to find out. And a panoptic would be better. But viewing is of course also affected by coma and such like too. Thanks, i'll give it more consideration and also keep an eye on used market too.

If you are the op and talking astro it's relevant!

[djhartist]

I've read reports that the ES 24mm 68 degree (not the Maxvision) is close or equal to the Tele Vue Panoptic 24mm in performance. The TV 24mm Pan used to be described as one of the best 1.25" eyepieces ever made so the ES must be pretty good.

Thanks John. Seems like it's ok then

[djhartist]

Having directly compared the ES24-68 and the Panoptics I'd say this:

The ES is at least 95% as good, for 50% the price.

Folks who have compared their even-wider AFOV EPs to the equivalent Televues (Naglers and Ethos) have said the quality difference is even smaller than that  in those lines while still being half the price.

95% as good as sounds acceptable, 50% of the price even better. The wider view eyepieces do sound interesting too, and something that's been teasing and tempting, i should imagine it's like dipping one's face into space...

[djhartist]

If you are the op and talking astro it's relevant!

Thanks, bit like my observing sessions though, occasionally random and off in different directions.

[Moonshane]

Once you realise that as with most things in life you will have to compromise on something even if you have an endless pot of money, there will be much less pain in the decision making process