Louis D

2 hours ago, 25585 said:

That is some seriously old school eyepiece construction technique.  Exposed retaining ring with spanner wrench notches?  It's probably why they covered it with that rather extensive rubber eye cup.

6 hours ago, 25585 said:

Going by CN; Orion Ultrascopic, Antares Super Plossl, Parks Gold & Baader Eudiascopic all have the same optics 35mm for the pseudo-Masuyama. Celestron should be the easiest to acquire due to brand, in theory. 

Here's a link to Don Pensack's excellent post on the subject from 2013.

15 minutes ago, DRT said:

I have had to let all of my TV eyepieces go

Some my reactions to your news:    

51 minutes ago, carastro said:

What about the 130P on one of those pronto mounts?  They look pretty easy to use, much better than a cheap EQ mount.  It's like having a standing height dob. (ish). 

Carole 

 

The problem comes in with that particular design that you can't leave the altitude clutch loose or the scope will tip backward above a certain altitude.  You have to keep it pretty tight which causes pretty jerky motions when not using the slow motion controls.  The AZ-5 (and AZ-4 before it) mount eliminates most of this issue by keeping the altitude pivot point passing through the telescope's center of gravity, rather than well below it as with the AZ-Pronto mount.  I say mostly eliminates because as the telescope tips backward with a tall, heavy eyepiece like a 17mm ES-92 in the focuser, the horizonal center of gravity shifts farther and farther away from the OTA's center of gravity causing the telescope to again tip backward above a certain altitude.  To counteract this, you need to have an equal weight protruding outward from the bottom of the OTA an equal distance away from the CG toward the objective.

15 hours ago, 25585 said:

Good idea for foam. I expect camping mats are similar.

And those interlocking mats clerks stand on.

Hmmm, I've never tried photography with my 72ED.  I'll have to give it a go sometime to see if I can reach infinity focus without a diagonal or extension tube installed.  You'll definitely want a field flattener.  It has so much field curvature, I rigged up a TSFLAT2 on the front of my 2" diagonal to flatten the visual field.  Without it, it reminds me of using a fast Newt without a coma corrector.

16 hours ago, R26 oldtimer said:

The bgo's have arrived, so has an ES 24/68. All of these plus finder, eaa cams, adapters, camera, 2" diagonal, filters and cables where in desperate need of a new case, so here it is...

Did you layer things on top of each other?  How are you going to get to various bits and pieces that aren't in the top layer in the dark while observing?

Are the axes clutched on that AZ Pronto mount in some manner such that you don't have to turn the slow motion controls to move the scope from one target to another in the sky?

Before buying my first telescope 20 years ago, I asked for buying advice from the astro community.  I was steered toward a very nice Dob that I use to this day.  I had originally been interested in a Meade DS-10 on a pier mounted GEM from Walmart.  It would have been horrible trying to deal with it's myriad issues.  The fact that that particular telescope and mount have practically zero resale value 20 years later because no one would buy it except as parts speaks volumes.

4 minutes ago, britto765 said:

Would the Celestron PS1000 Newtonian Reflector be any good? 

That's a Jones-Bird design which is notoriously difficult to collimate and doesn't yield all that great of images even when properly collimated.  The design uses a fast spherical mirror of 500mm focal length at a low focal ratio (remember, fast scope, losts of issues with a spherical mirror).  It then places a "corrector" below the eyepiece holder to double the focal length to 1000mm.  The corrector doesn't do a whole lot to fix the spherical mirror issues, though, so the images aren't all that great.

I'd also be wary of any telescope including a 3.6mm eyepiece.  It will be all but unusable in this scope because it will yield too high of a power for that scope.

2 hours ago, britto765 said:

Thanks for the advice all, was looking at getting the skywatcher explorer 130 eq2 telescope if that's any good?

That is a pretty snazzy box it comes in.

Since it doesn't say it comes with a parabolic mirror, I'm going to assume it has a spherical mirror which won't produce as sharp of images as a parabolic mirror like the one in the Heritage 130p or the Skyliner 150p.  Ironically, the latter is slower than the Skywatcher Explorer 130, and yet has a parabolic mirror.  Longer focal ratios (longer, skinnier tubes) can often times get away with using a spherical mirror because the difference in figure between it and a parabolic mirror is so miniscule.

Another issue with low end EQ mounts is that they oscillate horribly in wind, or if you touch the tube to focus or point it at another object in the sky.  Dobs are rock solid under these conditions by comparison.

Well, how about the highly recommended Skywatcher Heritage-130p Flextube for £137?  That would leave you with enough left over to buy a nice BST StarGuider 60º 8mm ED eyepiece (£49) for a nice higher power eyepiece that would be much better than the included 10mm eyepiece.

The clear glass filter is only need to reach infinity focus with regular camera lenses due to glass path distance issues.  If this is to be a dedicated astrophotography camera, that isn't an issue because telescopes, unlike camera lenses, can be focused past infinity to compensate for the missing glass filter's focus requirements.

One thing to consider about the Vixen SLV is that the eyeguard does not retract to be flush with the top of the eyepiece.  This costs the user 3mm to 4mm of usable eye relief.

Personally, I think the 9mm Meade HD-60 is a fine eyepiece.  In direct comparison to my 9mm Vixen LV, the Meade appeared to be better corrected in the center 50 degrees which surprised me quite a bit.  Even at the edge it is nearly free of astigmatism or field curvature.  It's also quite easy to take in the whole view with eyeglasses.  Here's an optical test bench review of it by Ernest in Russia.

2 hours ago, Alan White said:

Wish we had someone in the UK who did similar, as imports from US involve VAT and Import duties so make things more expensive than in the US.

Don't get me started on the non-reciprocity in this UK-US relationship.  There is no sales tax (VAT equivalent) on imports and no import duty on individuals importing less than $800/day/person into the US from anywhere.  I've picked up several bargains from the UK with the favorable USD-GBP exchange rates of late.

I don't know about UK and European suppliers, but there are a copule of American custom wooden eyepiece case manufacturers.  One is Wood Wonders and the other I know of is A Case for Astronomy.

4 minutes ago, happy-kat said:

Except that the cc is optional on the 130p-ds that telescope is designed to reach focus with a dslr

I just wonder why anyone would use a Newtonian for astrophotography without a CC.  Perhaps for planetary imaging dead center?

41 minutes ago, Stub Mandrel said:

The Skywatcher CC seems not to affect focal distance, plus you don't get a Crayford focuser with a 130P.

The Skywatcher CC has a 55mm backfocus requirement while the GSO CC is 70 to 75mm.  This could account for part of it.  The other part is probably that the GSO is a mild barlow at 1.1x while the Skywatcher is a mild focal reducer at 0.9x.  Barlows add to back focus while focal reducers eat up back focus.  Plus, there's the issue that the Skywatcher has what looks to be a nonremovable flange preventing insertion below the level of the focuser to intercept the focal plane earlier.  The GSO CC is smooth, so it can be inserted below the focuser like a barlow to intercept the light cone earlier and project it back farther.

1 hour ago, happy-kat said:

The 130p does not reach focus with a dslr hence the 130p-ds which then for visual you need a 2 inch extension tube before the eyepiece. 

Neither does my Dob without the CC.  I would imagine the 130p would reach focus with a GSO CC.  Who would use the 130p-ds without a coma corrector when taking astrophotos?  Thus my point, if you're using a CC anyway, it allows you to reach focus, so you might as well use the 130p.

11 minutes ago, Dinoco said:

I’ve also wanted to know this  

I couldn't find the specs related to the secondary obstruction by diameter, so who knows what change was made there.  I can reach focus with my limited backfocus Dob using a GSO coma corrector, so I doubt a dedicated, short tube is necessary for photography.

1 hour ago, Dinoco said:

There was this one I was looking at  ( think the same one you’re talking about) https://www.firstlightoptics.com/sky-watcher-az-pronto/sky-watcher-explorer-130ps-az-pronto.html also  I was looking at the 6” dob in this range but the awkwardness and weight of it all slightly put me off.

Dobs are awkward and heavy to move, but tripod mounted tubes are awkward to use compared to Dobs in my experience.  Balancing heavy eyepieces is a pain with alt-az mounted telescopes on a tripod, but not a problem with a Dob with large trunnions.  The former are also more prone to vibrations than the latter.  There's a thread on SGL about someone struggling with eyepiece balancing on an ED80 mounted on a SkyTee 2.  These issues largely go away with a well designed Dob.

31 minutes ago, Saganite said:

 

I'd love a pair of those Mike, trouble is they only appear once in a blue Moon 

Well, we just had one blue Moon last night and the next is March 31st, so you should be in luck. 

23 hours ago, Alan White said:

I am working at balancing my ED80 scope.

No one has asked what sort of mount you're using that is so sensitive to balance, so I will.  What mount are you using that gets thrown out of balance by a few extra ounces in the focuser?  I'm using a DSV-2B alt-az mount, and it takes a 1.5 pound or heavier eyepiece to throw it out of balance.  Anything 1 pound or less (all 1.25" Delos/XW/Morpheus/etc.) don't upset the balance enough to require adjusting the tube in the cradle.  I do need to lock the altitude axis when changing eyepieces, but that's about it.

2 hours ago, Ricochet said:

How about a 25mm Starguider? OK, it's not a TV or Vixen eyepiece but the AFoV will be 10° up on your Plossl and it's in the right weight range (182g according to TS).  Plus at £40 (Skies the Limit sale) I'm guessing you could probably afford to keep the LVW for other scopes rather than selling to finance a Panoptic.

If the 25mm Starguider is as bad at the edges as the 25mm Meade HD-60, there is no way anyone with a 22mm LVW or 24mm Panoptic would be satisfied with its performance.  There's a reason it doesn't cost $200+, and that reason is poor correction across the field.  If it was as good as a Panoptic or LVW, who would buy those expensive eyepieces?

Kidney beaning (SAEP) is pretty much confined to negative/positive designs with poorly matched sections.  The Nagler T1s and Radians both had it.  The 6mm and 9mm Expanse type eyepieces have it, and most of the original Celestron X-Cel eyepieces had it.  A positive-only design can't really produce SAEP.  I'm pretty sure the Revelation to which you refer is positive only and so probably cannot have SAEP.  You're probably just having issues with the long eye relief and large exit pupil as described by others here.  I find sitting and keeping a light touch on the focuser or tube can help steady my alignment with the eyepiece's exit pupil to prevent blackout.