Louis D

21 minutes ago, KP82 said:

A 9mm Morpheus would make more sense. An 1.4x-ish difference in focal length is often used when choosing eyepieces.

I have the 14mm and 9mm Morpheus.  The 9mm is world class sharp.  It's very close to my 10mm Delos.

The 14mm is very nice in the central 85%.  The outer 15% tends to fall off in sharpness slightly due to astigmatism and field curvature.

50 minutes ago, StuartT said:

I doubt there would be a lot of point in having a 12.4 and a 14 surely? Hardly any diff in power

I wouldn't get a 12.5mm Morpheus if I already had a 14mm Morpheus.  My 12mm ES-92 views entirely differently and is 2-inch only.

If that new APM wonder-zoom pans out, I may get it next.  It would cover my most used focal lengths.

35 minutes ago, StuartT said:

my new 12.5mm Morpheus has just arrived. It's HUGE! Never seen an eyepiece that big before!

If you think the 12.5mm Morpheus is big, you'd better stay well away from the 12mm ES-92 shown below on the far left.  Your Morpheus is similar in size to the 12mm Nagler T4 or 13mm AstroTech AF70 below:

Probably a 1/4-20 nut/bolt which is the same as camera tripod threads.  It's an incredibly common size over here.

On 07/03/2021 at 05:31, StuartT said:

2. they should be the metallized kind (like Baader planetarium film). For example this

Thousand Oaks makes a polymer based solar filter which is also perfectly safe to use as well.

5 hours ago, Deeko said:

I wonder if I can remove that and just rotate the whole focuser for framing instead

I don't do imaging, but rotating the focuser on my fracs on my alt-az mounts can lead to the focuser knobs being in really awkward positions.  I do have a built-in camera rotator on my 90mm Sharpstar made TS-Optics APO focuser that is handier to use than loosening the diagonal screws or rotating the focuser to bring the eyepiece to the side.

I suppose if you have a motorized focuser on your frac, then the orientation of the focuser is irrelevant as long as the motor clears the mount.

Perhaps if you manually focus once and then take hours of data, then focuser awkwardness could be lived with.

32 minutes ago, vlaiv said:

Heat capacity of glass is higher than most metals and comparable to aluminum and magnesium and glass elements in eyepiece are often heavier than barrel - it's unlikely that metal will pose more problems than glass.

I was thinking in terms of a 4mm orthoscopic eyepiece that the quoted post might have been referring to.  In that case, the metal barrel thermal mass far outweighs the thermal mass of the tiny amount of glass.  Perhaps that poster has large transference of heat from the metal barrel into the glass leading to the image boiling they saw.

I was just theorizing to try to explain what they are seeing.  I don't use tiny, high power eyepieces due to their limited eye relief; so I have no direct experience to draw upon with regards to that person's experience.  My high power Pentax XL and XW eyepieces sit outside with the scope cooling in their case, so there's no equilibrium issue with them.  I could try leaving the 3.5mm XW inside sometime on a cold night to see if there is any effect on the image.  However, we're rapidly moving toward spring here, so the nights will be warming up dramatically over the next month, limiting any time to try such experiments this season.

22 hours ago, StuartT said:

I think I may be missing something here... are televue eyepieces very fancy then? Is that why @faulksy was warning against them?

Tele Vue designs their eyepiece in-house in the USA which leads to increased R&D costs to recapture.  They also manufacture them in dedicated factories in Japan and Taiwan to avoid design copying by Chinese firms.  TV designs their eyepieces to work well down to at least f/4.  They also tend to have higher levels of polish and better stray light control internal to the eyepiece, leading to less ghosting and light flooding with bright objects.  I believe they also test every eyepiece in-house before shipping them to retailers as a quality control check.  All of this attention to detail increases the cost of their eyepieces relative to Chinese made eyepieces.

Nikon, Pentax, and the late Docter/Noblex also had similar design, manufacturing, and marketing methodologies with prices to match.

13 minutes ago, mikeDnight said:

It doesn't have to be a complex multi element affair, even a simple Mono or orthoscopic will do. The view will boil and agitate until the eyepiece reaches thermal equilibrium.

Reaching thermal equilibrium should take just a few minutes given the small element sizes.  The metal barrel may pose more of a cool down issue.  Perhaps at high power this boiling might be briefly observed.

At low powers, I've never noticed any boiling effect when doing this with large eyepieces I grab from cases left in the house for later comparison.  For instance, I was swapping my 40mm Meade 5000 SWA with my 40mm Pentax XW-R, and could see no initial boiling effects this winter despite grabbing the Pentax from off the dinette table by the back door since it doesn't have a permanent eyepiece case home yet.  The temperature drop was about 30 degrees F.  After 45 minutes of swapping on different targets, the difference in views between the two eyepiece remained unchanged despite both reaching thermal equilibrium by then.

I've repeated this observing pattern dozens of times in the past 20+ years when comparing eyepieces against other eyepieces left in the house in auxiliary cases, and I've never seen boiling attributable to low to mid power eyepieces not being thermally acclimated.  I'm incredibly picky about image sharpness, and I just haven't seen this effect.

I was surprised to see spiky stars in my 90mm triplet APO for 30 minutes or more after bringing it out into the cold.  Everyone always talks about how refractors don't require cool down time.  Well, I found out otherwise.

My first astronomy observing book was Binocular Astronomy by Crossen and Tirion, 1st edition.  I still think it's a decent read, and the start charts in the back are excellent.

There's a Kaiser 100mm Push-On Lens Cap at B&H Photo in NYC, so there should be something similar in the UK.

Not really.  The thermal inertial of the glass in eyepieces is very low compared to objective lenses and mirrors.  They are also very small pieces of glass in comparison, so temperature differentials within them even out in very little time.

As others have said, keeping them warm enough to prevent dewing is a good idea.  I wear eyeglasses at the eyepiece, so they act as a moisture barrier between my eye and the eye lens.  As a result, I rarely have dewing issues.

50 minutes ago, StuartT said:

@Louis D would you be able to point me to where these diagrams came from? I need the legends to explain them (e.g. what F e and C mean and how the colours mean). Thanks

To expound upon @vlaiv's response to your question, the exact section of the website is 12. TELESCOPE EYEPIECE.  The diagrams are in sections 12.3 and 12.4.

1 hour ago, StuartT said:

I must admit you've lost me a bit there... 😔

Sorry, but I think @vlaiv covered it pretty well.

18 hours ago, Cyril said:

A government spokesperson said: "The new VAT model ensures goods from EU and non-EU countries are treated in the same way and that UK businesses are not disadvantaged by competition from VAT-free imports.

"The new system also addresses the problem of overseas sellers failing to pay the right amount of VAT on sales of goods already in the UK at the point of sale, raising an anticipated £300m every year.

Campaigner Richard Allen, founder of Retailers Against VAT Abuse Schemes, told the BBC that the massive increase in international online shopping had led to VAT evasion on a huge scale.

"For providing this service, [HMRC] intend to charge a fee to every company in the world in every country in the world which exports to the UK," said Dutch Bike Bits on its website."

After the US Congress passed the Foreign Account Tax Compliance Act (FACTA) in 2010 requiring foreign banks to report any assets held by Americans in them to the US government, most foreign banks simply refused to open accounts for Americans, so they wouldn't have to deal with the expenses and bureaucracy associated with compliance.  This has made it incredibly difficult for Americans to permanently live abroad.  Combine that with tax laws that require US income taxes be paid on all income, foreign and domestic, even if you haven't lived in the US for decades, and Americans abroad have been renouncing their US citizenship in droves.

Likewise, I foresee many, if not most, EU and non-EU retailers simply refusing to do business with the UK to avoid the hassle and expense of collecting VAT for them.  I can't imagine small American retailers wanting to deal with the hassle of VAT.  They already have to deal with 50 different state sales taxes along with myriad different local sales taxes.

On 06/03/2021 at 03:19, jonathan said:

I consider a moon filter (ND) rather essential as even a 1/3 lit moon is too bright for my eyes, even if I keep the main cap on the OTA and only remove the small cap.  Look at the variable / circular polarising ones, they can offer a bit extra compared to a plain one.

Look into getting an entry level binoviewer.  I find it comfortable to view even the full moon in binovision unfiltered.  The discomfort in monovision has something to do with the huge disparity in brightness between the open eye and the closed eye.  It's as if the brain's image processing center just can't cope with it.

The primary is about an f/2 concave, thus the very short tube.  The secondary is about an f/5 convex, thus the magnification to a combined f/10 system focal ratio.  Both mirrors are spherical.

To correct spherical aberration, the corrector plate is aspherical.  The resultant system also has low astigmatism.

An SCT has uncorrected field curvature and coma in its standard commercial form.  That's why there are various correctors for them for photography that are placed near the rear port.

I could see how exposing the objective lenses to direct sunlight could help to keep fungus growth at bay.

19 hours ago, StuartT said:

So are Plössl eyepieces basically entry level, economical eyepieces? A bit like the 'kit lens' on a camera?

Besides MA, there are Ramsden, Huygens, and Kellners which are typically lower than Plossls in the pecking order of eyepieces.  They're the designs typically packaged with "department store" scopes for $20 to $40 for an entire telescope package.  Here's an image showing various simple eyepiece designs and their spot diagrams which show how well they display a star at various points within the field and with different f-ratio scopes.

In this next diagram, you can see how as eyepieces get more complex, correction gets better farther and farther off axis.  Your Morpheus falls into the more complex, modern design category similar to Nagler or Speers Waler.  You will need to click on the image to expand it.

13 hours ago, Gavin chapple said:

Thanks for all the help guys I didn't expect to get so many replies. Louis D, the field does face away from the center, towards the coast so maybe it will help a bit. Starwatcher2001, I'm from up north too, whitley Bay near Newcastle 😁

Your situation is similar to mine, except replace my farmland with open seas.  If you look to the east, northeast, and southeast, you'll probably be able to pick out fainter objects thanks to less light pollution in that direction.  Basically, start observing objects as they rise in the east after sunset.  You'll be able to see objects earlier in the season than those like me who have to wait for them to be in my southern skies due to obstructing trees.  At that point, they are less than optimally placed for me light pollution wise.

If the bright local lights to the east around that open field bother you, you can invest  in an observing hood, or simply cover your head with a towel or opaque cloth.

Your southern, southwestern, and western skies are probably completely washed out with severe light pollution as mine are.  Other than solar system objects and the brightest stars and clusters, there won't be a whole lot to observe in those directions.

It looks like you have decently dark skies nearby to the northwest in Northumberland NP and vicinity if you ever decide to observe from a dark sky site.

Simon B on CN received one in 2018 and posted images in this posting.  I'm not sure if there are any actual reports of using it in a scope, though.

Wait for Mars to come back around to opposition in 2 years (December 8th, 2022).  It looked terrific through my 8" Dob with binoviewers last fall.  I could make out lots of light/dark details very much like the below images.  It was amazing, but fleetingly quick.

Most of the previous recent Mars oppositions were ruined by global dust storms on Mars that obscured all details, so hopefully 2022 will be more like 2020's opposition.

4 hours ago, Carl Au said:

 I wonder how much difference using a refractor makes, that and a little longer fl at fl7, to me all the stars look pin point with the 30 ED.  I bought it to use for open clusters and so far have been delighted with it's performance, its really very good for the money. I think you can get one from FLO for 90 quid at the minute, amazing. I think I am right in saying the that both my Starwave 102 ED-R and ED30 eyepiece were made by KUO. I wonder if they were made in the same factory?

I was using an f/6 AT72ED refractor, so no difference there.  I could try my 35mm in my f6.6 APO to see if it makes any difference.

Understand, I'm being hypercritical when I'm looking for edge astigmatism.  I take as bright a star as I can find, focus it in the center, note the sharpness, move it toward the edge, refocusing it for the edge to eliminate field curvature issues as needed, and then note the sharpness in comparison.  I then rack the focus on either side of best focus to look for astigmatism in the form of radial or tangential lines instead of a nice, off center circle.  The 30mm APM UFF passes this test without any issues.

All that matters is that you really like the eyepiece in your scope, and it works extremely well for your needs.  How it performs under test bench conditions is irrelevant.

As for your scope, it does indeed appear to be KUO made.  As far as factories go, there's a good probability they were made in the same town, but possibly in two separate buildings dedicated to different optics.  As companies expand, it's typically easier to build a new building instead of expanding an existing one, so you end up with a collection of buildings on a campus or even spread around town.

I just realized they're based in Kunming (hence their name).  That was the terminus of "The Hump" US air supply route for the Chinese army of Chiang Kai-shek in WWII.  I also used to work for a guy born and raised in Kunming.  Really nice fellow.

I rigged up a mount for my phone on my frac and use SkEye to get me in the ballpark of objects without bright stars nearby.  From there, I can usually find them in the finder scope.

46 minutes ago, osbourne one-nil said:

Oh, I’ll just cancel it if I get any grumpier! Im sure they’d not quibble. I’m just gauging whether I’m being unreasonable or not given the current state of things. 

The retailer may not let you cancel, claiming it has already been shipped and is tied up in customs, continuing the runaround.  That's why I suggested going through your CC company.  Tell their representative what you've told us, and that you'd like to cancel the order if the retailer cannot provide proof of shipment to the CC company.  The retailer should be able to provide the name of their shipping company, tracking number, and the name of their customs broker.

On 04/03/2021 at 11:29, Pixies said:

Yep - looks identical to my OVL Aero ED 30mm.

I see some astigmatism at the outer 20% of the view - in an F6 dob. Now, that could be my eyes, as I suffer a little astigmatism and this EP has a 5mm exit pupil in an F6 scope.

In my OVL Aero ED 35mm, I'd peg it at the outer 25% of the field of view at f/6.  Notice in my above image how fuzzy the marks get about 4.5 inches in from the edge?  That's 4.5/17=26% from edge to center.  I like to tell folks that the central 75% of the field of view is acceptably sharp based on this assessment.