Louis D

I like to use cheaper 60 degree wide fields that perform perfectly at f/18 with a Barlow element operating at 3x to keep down weight and bulk.  I can't get my nose between pairs of Delos or Morpheus.  That, and the combined weight of two Delos and binoviewer is just too much for most of my scopes.

If you can replace the 2" focus adapter that comes with the Skywatcher with the ES CC, it shouldn't be an issue.

That's ridiculously bright.  We've got one street light every second street on the main street that our side streets hang off of.  There are no street lights on the side streets.

11 hours ago, Trevor PC said:

what are angled eyepieces?

45 degree bins:

90 degree bins:

8 hours ago, Capt Slog said:

I was told by my optician that the problems occur when it detaches incorrectly.  Mine has totally detached now, which is normal for my age.  There was a  problem a few years ago when it was still attached at one point, which was causing a strange effect of a tiny 'area of confusion' in my vision.  Once it let go completely, that went away.

I've never seen or had any flashes at any time, and as i described above, this wasn't what i would call a flash in my eye.  It was so tiny that I could easily have missed it and although I can't tell you why I'm sure, I AM sure it was something coming through the optics of the scope.

No problem.  I just wanted to make sure you weren't overlooking a possible medical condition.  What I see looks like a lightning bolt inside my eye.  My optometrist said it's how the eye expresses pain since there are no pain sensors in there.

On 24/06/2022 at 04:37, Capt Slog said:

What I saw looked like a camera flash when viewed from miles away, that sort of duration and brightness

A field flash could have come from a passing airplane just outside the field of view if there was a significant amount of haze in the air.  I've seen a similar effect, and it can be startling.  I'll then look up from the eyepiece and confirm a plane just went close by my object of study.

9 hours ago, Steve Ward said:

The vitreous humour is the fluid that fills the eye , it cannot become detatched ... 

Believe that if you want, but you might go blind someday as a result.  I've had it happen, and it's scary to think of the possible consequences.

For the rest of us believers, read up on this:

Vitreous Detachment

If flashing continues, you've got a detached vitreous humor; and you should have it checked by an eye doctor.

4 hours ago, great_bear said:

Usually the eyepiece is fine until you look through it

2 hours ago, Don Pensack said:

Glasses help keep the eyepieces from fogging

I always wear eyeglasses at the eyepiece due to strong astigmatism.  That may be why I've never had fogging issues with any eyepiece even in winter; although Texas winters are normally pretty mild.

2 hours ago, Don Pensack said:

You learn to adapt to conditions, like breathing out of the corner of your mouth away from the eyepiece rather than with your nose, when looking through the eyepiece.

I have a big enough schnoz that it seems to act like a directed exhaust vent in that moist air being breathed out is directed well away from the eyepiece at right angles.  I could see where wearing a balaclava or other face covering would be completely detrimental to preventing fogging.  Even my eyeglasses fog when wearing them in winter up north (not in Texas 🤣).

2 hours ago, Ricochet said:

believe it is radiative cooling of the eyepiece outer skin. Because the delites are all metal there is a conductive path from the glass all the way to the exterior of the eyepiece. In effect the eyepiece becomes a heat sink for the eye lens. With the XWs the rubber/plastic covering breaks that conductive path. The rubber still radiates to space but does not absorb that lost heat from the interior of the eyepiece. Similarly, SLVs and Starguiders don't suffer despite being significantly smaller but the larger 21E does.

I think you might be on to something there.  My Dob has a cardboard Sonotube instead of a metal one, so that may contribute to it never dewing as well.

4 minutes ago, great_bear said:

Where are they the same price as Delites?

Here in the US, both are $269 apiece before taxes.

2 hours ago, Ricochet said:

I suspect this is because your air is a lot drier than mine. During the last few weeks of summer my Delites have been fine but at all other times they have issues. Comparing the time you can have an eyepiece in the focuser it's minutes for the delites vs hours for the XWs. All I can do is report back what I have found using the eyepieces that I own. You cannot claim that I don't see this difference. 

Was this with the XW eye cup all the way down or extended somewhat upward?  I could totally see the XW's eye cup protecting the eye lens better when extended upward.  However, all the way down, I can't imagine how it would help prevent dewing.  Perhaps the sheer thermal mass of the XW relative to the lighter DeLite could explain the discrepancy?

I'm in a near swamp-like environment here in Texas with dewpoints in the mid to upper 70s F during the summer, and I've never had dewing issues with any eyepiece.  Maybe if I observed in the early morning when everything dews up I might.  Perhaps the UK runs closer to 100% humidity all night long?

Maybe you could look into a harmonic drive mount?  That way, you'd save yourself the effort of carrying around and installing counterweights.  The mounts themselves are fairly lightweight while still having a relatively high load capacity.

If it wasn't near optics, I'd recommend CRC 5-56 penetrating oil to loosen those corroded threads.  I've used it successfully to loosen fully rusted bolts inside my gas grill after soaking for a day.

My 10mm Delos bought in the first year of availability is very good.  Even in my f/6 Dob without a CC, it appears perfect.  I swapped the CC in and out several times and could not see a difference even at the very edge on bright stars.

I find my 9mm Morpheus is just about as good.  Maybe it has a tiny bit of edge astigmatism, but I can't confirm it consistently.  Otherwise, it complements the 10mm Delos very well.

32 minutes ago, great_bear said:

Hmmm… Could I be thinking of the Pentax XW that I used to have?

The 14mm and 20mm versions have some FC, along with the 40mm.

I would also keep an eye out for used Pentax XLs.  I have the 5.2mm XL and have never felt a need to change to a 5mm XW.

I like my 10mm Delos a smidge more than my 7mm XW and 9mm Morpheus for star tightness and contrast across the field, but not by a wide margin at all.  I have yet to try the DeLites, but they are reputed to be at least as good as the Delos, so I don't think you could wrong buying them.  You'll be giving up a bit of field over the XWs, but that's about all.

8 hours ago, great_bear said:

Apologies - I must be getting it confused with something else I had in that focal length that was like the starfield was wrapped on a tennis ball. 

It could very well be the eyepiece appeared to make the star field appear wrapped on a tennis ball and yet have no field curvature.  Stars appearing to be wrapped on a ball is a form of distortion.  The field appears curved onto a ball, but that does not mean it has a curved field.  Curved field means that the field of focus is not flat center to edge.  Stars focused in the center get progressively blurrier toward the edge, regardless of whether they appear wrapped on a ball or not.

Did stars stay nice and sharp center to edge as they traversed the apparent ball shape?  If so, it had a flat field, not a curved field, with distortion.

20 hours ago, Neil H said:

Yeah I looked at them, the same as the Orion , so do Orion make them for Stella lyra or stella make them for Orion , still feel WO are better starter kit as they have a good 20mm eyepieces the eyepieces alone are £74 each 

https://www.amazon.co.uk/Orion-Premium-Linear-BinoViewer-Telescopes/dp/B07CG8GBL8/ref=sr_1_4?crid=W5BGFPP8U25X&keywords=binoviewer&qid=1655669120&sprefix=Binov%2Caps%2C476&sr=8-4

20 hours ago, Stu said:

I’m sure it’s neither. Orion and StellaLyra are brand names, and they will source them from a Chinese factory but I’m not sure who that factory is owned by. Sure someone will know.

They're made by Long Perng (Taiwan company, perhaps with mainland suppliers).

Be glad it didn't shear off completely in the threaded hole.  That is what happened to me with one of the two thumbscrews in my GSO CC.  Apparently, they use pot metal instead of tool or stanless steel for their screws.  I swapped out the remaining good screw for a cap head screw made from tool steel.  I have yet to extricate the stuck bit of screw from the other hole.  I recommend swapping out all GSO supplied thumb screws immediately upon purchase for high quality tool or stainless steel cap head screws.

1 hour ago, Steve Ward said:

I'm going to get a holder for mine to use it  as an aiming device when I start to try and get some decent images of the ISS .

Did a quick test the other week to see if it would work to try and keep the station on-chip whilst manually moving the 'scope about with all clutches released , much easier than trying to aim through a finderscope and get your head round up/down/left/right with different tubes.

Just remember to turn it off during image capture, or you'll just get a green fuzzy blob from the laser scatter at high magnification.  It makes aligning them with the eyepiece super simple, though.

On 12/06/2022 at 13:47, Marian M said:

Plenty of trips to car and back but I think  it worth the effort 😀

Is the image in a C8 so "soft" vs a refractor?

A C8 does show softer stars than an 8" Newtonian with coma corrector with its much smaller secondary obstruction in my experience.  It's one of the reasons I went with an 8" Dob over an 8" SCT.  I have never looked through an 8" refractor to make that comparison.  In general, smaller APO refractors show even tighter stars than low obstruction Newtonians in my experience.  However, you've traded light gathering and compactness for this.

Jeff Davis County, Texas, which includes both the McDonald Observatory and the Prude Ranch (home of the annual Texas Star Party), Fort Davis, and the Davis Mountains has very strict lighting regulations to preserve the night skies there.  Streetlights are flat, deep red paddles that I've never seen elsewhere.  Homeowners, businesses and ranchers all work together to keep the skies pristine out there.  At night, it's eerie in downtown Fort Davis because business signs are dim and many stores have blackout shades to prevent light from escaping their interiors.

5 hours ago, F15Rules said:

It's a long story, but essentially the chinese manufacturer who made the Axioms for Celestron decided to sell their own range of optically identical eyepieces, branded Explore Scientific, effectively undercutting the Celestron version.

Celestron then switched to another chinese manufacturer, who made them a very similar looking design cosmetically to the Axiom LX range, but a different design optically, generally thought to be inferior to the original Axiom LXs.

Louis D will I'm sure be along with a more detailed explanation 😊.

HTH,

Dave

Yes, that's basically correct.  Here's my post on the subject from 2016:

No one on SGL knows for certain who makes the Luminos eyepieces.

They're an older line from 10 to 15 years ago.  They're optically the same as the Omegon Redline SW, Astro Tech AF70, Olivon 70°, SkyWatcher SWA 70°, and several other brandings.  The 22mm is excellent, the 17mm is pretty decent, the 13mm has loads of edge chromatic aberration and EOFB, and I have no personal experience with the shorter focal lengths.  The 32mm is reportedly an Erfle or Konig, and as such, nothing special correction-wise.  They have plenty of eye relief for eyeglass wearers once you screw off the rigid eye cup.  With its 43mm thread up top, you can fit it with a Baader Morpheus eye cup if you like.

As I said above, you'd probably like the 40mm Pentax XW at 24.7 oz. (700g).

Has anyone done a comparo between the 40mm Pentax XW and the 42mm Vixen LVW since both are relative lightweights at this focal length?

I only clean the eye lens when it is apparent that shifting a star or planet around the FOV shows some areas are distorted due to smudges/gunk, or I accidentally put a fingerprint on it.