Louis D

I've used plenty of eyepieces that are fuzzy due to astigmatism or chromatism from 50% or 70% out to the edge in slower (sub-f/6) scopes.  While they all somewhat sharpen up in slower f/10 to f/12 scopes like SCTs and Synta Maks, the better eyepieces which are nearly sharp to the edge in faster scopes completely sharpen up to the edge in slower scopes appearing like an ultra-premium eyepiece in a slower scope.  If you go to f/18 or f/24 with Barlows, GPCs, OCSs, etc., then the gap narrows considerably as with my Svbony 20mm 68 degree UWAs that I use in my BV.

I would go for the 24mm UFF over the 24mm Hyperion any day for about the same money.  I have the original APM version, and while not perfect at f/6. it is still quite good center to edge.  These images were taken through an f/6 72ED refractor:

At f/12 in a 127mm Synta Mak, it's very good:

As you can see, though, going with a 2-inch visual back and diagonal really opens up the true field of view (TFOV) with some vignetting toward the edge.

Just remember, if you store your eyepieces in a waist pouch for easy access while observing, it's called a bum bag on here.  Don't even think about calling it a fa**y pack on here.  It's a really weird UK-US English difference that I just don't get. 

I think I looked through an Ha scope once at an outreach event, but I found the deep, dark red color too difficult to make out any details.  Is that what Ha scopes view like?  For me, I'd probably only use one for imaging rather than visual.

With my 1.25" Hercules Herschel wedge, I generally put a Meade UV/IR filter on the front of the wedge.  Being an interference type filter that reflects rather than absorbs rejected energy, it doesn't heat up that I've ever noticed.

The Hercules comes with an integrated ND3 filter below the eyepiece holder.  I don't even know if it can be removed.  After all, why would I want to remove it?

I generally set the variable polarizer it came with to about an ND1 to ND2 level, and attach it to the bottom of the eyepiece.  I can then rotate the eyepiece to darken the image more because the wedge itself partially polarizes the sun's light.

If I use another filter, I stack it ahead of the polarizer so I can swap it more easily to try other filters.

The Hercules even comes with an integrated variable iris, but all it does is decrease the effective aperture, which might be useful for an achromat, but not for an APO.

If edge correction isn't all that important to you, then the Pentax XW-R 30mm is fine.  I have the 40mm version, and it's pretty decent, but not perfect.

The various 30mm UFFs are basically flawless to the edge.

Here's a post with an image from another forum showing the difference in edge correction:

Welcome from a fellow Texan!  You'll enjoy SGL.

Since my 127 Mak's focuser shaft's rubber grip split and wouldn't stay on anymore, I wrapped racquet grip tape around the bare shaft.  I then slipped a shortened handlebar foam grip over the grip tape.  All of that foam and foam tape really help to limit the transmission of vibrations when focusing.  I still put Sorbothane pads under each tripod leg to dampen residual vibrations in about a half second.  If I touch the foam lightly enough, I can fine-tune focus without transferring vibrations.

3 hours ago, Don Pensack said:

The 22mm is excellent, but the 13 is a dog--the worst EOFB of any eyepiece I've ever seen..  Go figure.

I still keep meaning to look for EOFB in the 13mm AF70.  Right now, we're in our rainiest season, so we haven't had clear skies in weeks.  Not complaining too much, though, because we need the rain to break a multi-year drought.

@Naughty NealWhat do you think of the 22mm Angleyes 70 degree eyepiece?  Someone on CN reported it as having chromatic aberrations (turning stars into rainbows).  That's what my 13mm Astro-Tech AF70 (Redline) has in spades.  It's really annoying to the point of making it unusable.

1 hour ago, Buqibu said:

I suppose I'd get it out of the box before taking it with me. Will that negate import fees?

It's going to depend on the country.  Many require a list of equipment that is verified as pre-owned when exiting/entering the country, so it doesn't get hit with import tariffs.  This is especially important for photographers and videographers who may have tens of thousands of dollars of equipment with them as they travel on assignments.

Watch out for import duties if you bring it back with you.  I have no idea what your De Minimis Value is for your home country (it's $800/day in the US), but you could end up paying quite a bit upon return.

That seems really weird to encourage someone to travel to a town or city to stargaze instead of getting out to the countryside.  It seems like they should have listed the best publicly accessible parks, beaches, trail heads, rural B&Bs, etc. from which to observe.  If you're going to travel, you might as well go to the best places to observe in absolute terms rather than limiting it to towns and cities.

No one travels to the Texas Star Party at Prude Ranch and then decides to observe from Fort Davis nearby instead.  However, this would be my vote for best town in the US to do this from.  I've stayed there at night, and they take dark skies seriously with the McDonald Observatory nearby.  All street lights are full cutoff designs with deep red filters over them.  There is no exterior illumination of anything at night.  Store windows have blackout curtains over the windows.  It's actually kind of eerie how seriously they take dark skies.

20 minutes ago, John said:

Over here in the rural areas of my part of the UK there are plenty of small lanes where the hedges will almost be touching the wing mirrors on both sides of my small hatchback 😬

That's my point.  You simply can't take a big vehicle out to the British countryside to haul a big telescope even if you had one and could afford the gas (petrol) for it.  I suppose you could try to go with a long and slim trailer to haul a large telescope, though.

6 hours ago, JOC said:

I have travelled with my baby Vixen, it and it's 'folding all inside itself mini tripod' all fit into a tiny plastic tool box I bought for it.  Here it is in action when I took it to Scotland

 

I notice a lot of really small cars in the parking lot.  I'm not sure our full sized SUVs could even fit down most country roads in Britain.  A Chevy Suburban is 81" wide while compact hatchbacks are more like 66" to 70" wide, which is an entire foot narrower.

Add to that, a lot of Americans like to bring their RV to remote campsites.  A fifth-wheel trailer is around 100" wide while the dually pickup truck hauling it is 96" wide.  I'll bet it would get interesting passing two of those on those narrow country roads in Britain.

1 hour ago, LondonNeil said:

I was about to say a sct or mak gives a very compact form for FL, but that Dall example is incredible!

I put together a 127 Mak on a DSV-1 mount and Manfrotto 3036 tripod for my grown daughter's family's camping trips.  It fits nicely in the back of their Chevy Equinox along with their camping gear.  5 years ago, I put the entire kit together for under $400 buying used.  It would be more like $600+ now.

I only travel with my 25 year old ST80 in case the car gets broken into.  It hasn't happened yet, but if it did, I'm not out a very expensive scope.

The Heritage 130 might be an option if you can come to grips with its focuser and other foibles.

Or, build your own suitcase Dob:

Download planetarium software and learn how to use to it to know what is up at night, when, and its position in the sky.  I use Stellarium on my desktop (I know, I'm old school to still have a desktop).

2 hours ago, radiofm74 said:

As my "astro-month" IS July

I've gotten the impression on here that it never really gets dark in Europe during the depths of summer.  Are you far enough south that this doesn't apply?

2 hours ago, Paz said:

I would use an 8mm pair with either a 2.6x gpc with refractors or a 1.7x gpc with the VX14. It would only be used where I'm using my 10mm SLVs and feel the conditions would allow more, which isn't often but it can happen, particularly with the VX14. With that scope 8mm eyepieces would get me to 340x but still giving a 1mm exit pupil!

Are you sure about that exit pupil size?  I looked up the VX14, and it is claimed to be an f/4.6, making your exit pupil 8/2.6/4.6 = 0.67mm.  That is doable for me with BVs, but not in monovision due to my prodigious floaters.  1mm is doable for me in monovision.  It's sort of like a cliff-edge just beyond 1mm with my floaters.

Do you already have a Barlow element somewhere in the optical train with your BV?  I find the SVBONY 68° Ultra Wide Angle to be very comfortable with eyeglasses.  With the optical element of the Meade 140 2x Barlow screwed into the nosepiece of my Arcturus BV, I get a 3x result.  Thus, the eyepieces operate at 20/3 = 6.7mm.

My understanding of the TV Plossl design is that Al Nagler made the two outer elements slightly concave to improve edge sharpness.  The success of his Plossl design's sales gave him the financial wherewithal to bring the 13mm Nagler Type 1 to market.

For me, I'd like to know how they compare to the vintage Vixen LV line since they usually come up for sale in the classifieds for around $70 each.  My 9mm LV views a bit dark, but is otherwise very similar to the Pentax XL and XW lines, just narrower.

Ecuador used to be a favorite of American ex-pats thanks to its almost perfect weather year-round in the capital Quito at 9350 feet elevation and in Cuenca at 8500 feet.  However, the cartels have recently started a turf war over control of Ecuador, so the homicide rate has shot through the roof. 

Nice report.

While the upper, positive, image forming part of the eyepiece may be quite similar to the Panoptic design, the fact that it has a negative, Smyth lens section down in the insertion barrel makes this a negative/positive design more along the lines of the 6mm and 9mm Redlines, just with much better SAEP control.

Based on your image of the bottom of the eyepiece, I'm pretty sure it has 7 or 8 elements just like the others in the line.  The 6 elements claim is probably just a typo.

Generally, eyepiece lines like the Radian, Delos, Delite, Pentax XW, Pentax XL, Baader Hyperion, Baader Morpheus, and many others with constant eye relief and field of view across focal lengths generally have similar, if not identical, upper image forming sections.  Only the lower and intermediate lens sections vary from focal length to focal length.  This rule of thumb tends to break down at 17mm and above in many eyepiece lines.  Even the upper section gets some redesign work done on it to get to lower powers.

Study these Pentax XL and XW lens diagrams to see what I mean:

On 30/04/2024 at 06:54, LukeTheNuke said:

Thanks, Louis. I'd consider a move to your side of the pond, but I'm pretty sure you wouldn't have me!

Nah, come on over.  We've been rolling out the welcome mat lately to anyone and everyone it seems. 😏