Second Time Around

Brilliant news!

I've got to wait for Android though.

Sounds like me, so you're not alone.

I had to take Handicraft for one year at school.  At the end of the year we had an exam.  The first 50% of the marks were designing something and then doing a technical drawing of it.  The second 50% were for making the object.

If I tell you that I came top after the design and technical drawing, but still came bottom overall, you'll see just how bad I am at anything practical!

It's even worse now as an heritary condition means my hands no longer work properly at all.

My wife won't let me use any tools around the house.  On the other hand I loved designing our extensions and kitchen.

So when it's come down to anything with scopes I too have had to ask for help, so don't feel bad about it.

For further data points, Bill found 20% with a Televue Barlow and an APM 2.7x, 40% with a Klee 2.8x Shorty.

I have the 2.7x APM and several other Barlows:

1.3x/1.6x Omegon GPC

1.5/2x shorty

2.25x Baader Hyperion

I can see some experiments in my future........

28 minutes ago, bosun21 said:

I no longer use a barlow as all my eyepieces have a very good eye relief and I don’t like the fact that a 2x barlow doubles this. 

Author Bill Paolini's tests found that the increase is typically only 20-40%, depending on the focal length of the Barlow, with "shorty" Barlows having a greater increase.

19 minutes ago, SwiMatt said:

Oh and in addition, for those who prefer reading to YT videos, here's a good and convincing rebuttal, which demolishes the assumptions behind the paper.

https://bigthink.com/starts-with-a-bang/universe-13-8-or-26-7-billion-years/

Pretty damning!

I note that the only eyepiece supplied with the 12 inch f/5 is a 32mm Plossl.  This gives an exit pupil of 5.3mm, that for those in light polluted skies or those older observers whose own pupil size is less than this, won't be able to make full use of all of the 12 inch aperture.

Presumably this was chosen to give a wider field of view (1.05 degrees) so that objects that Starsense Explorer found were always visible in the eyepiece.  My own experience suggests that this is conservative as this is easily so even for the 0.83 degree field of view I use for a finder eyepiece.

Yes, Starsense Explorer is that accurate!

Welcome additions. As I've often said I reckon Starsense Explorer is a game changer.

However, the 6 inch doesn't seem to be good value for money at the moment given that the 8 inch with a full size mount costs just £50 more.  At just £549 that's a great price compared with the 6 inch.

I'm pleased to see that the mirrors are all parabolic, and the focuser is a rack and pinion rather than a sloppy helical one.

By the way there seems to be a discrepancy in the copy of the 130mm.  The In the Box section says that the eyepiece focal lengths are 17mm and 10mm.  On the other hand in the specifications section it says 25mm and 10mm. 

@FLOan you please advise?

There are pros and cons between the ES and Stella Lyra.  If you wear glasses at the scope the ES may not have enough eye relief to see the full field of view.

Agreed.  Which is precisely why I changed the title of the article and put in the word suggests!

https://phys.org/news/2023-07-age-universe-billion-years-previously.html?utm_source=nwletter&utm_medium=email&utm_campaign=weekly-nwletter

One other reason why your scope may not be performing properly is that you're looking at objects that aren't far above rooftops.  The heat rising from houses can really wreck images.

Sorry, it's sold now.

Whoops, the advert is wrong.  It is indeed a 2 inch.  Ad now corrected.

Many thanks indeed!

If anyone 's interested I recently put a 2 inch L-enhance up on the For Sale forum. I don't take photos so it's surplus to requirements.

Here's a link to what you need to 3D print an adapter to fit on to  a standard Synta finder shoe:  https://www.thingiverse.com/thing:4868065

Like Dave I upgraded the scope I gave to my grandkids. 

I added a Celestron star diagonal, a 32mm Plossl, a 9-27mm zoom eyepiece and a decent 1.5/2x Barlow.

I also bought a secondhand AZ Pronto mount and tripod with slow motions and added tube rings.  This makes a lot of difference, and it's a nice little package now!

Excellent and comprehensive write up!

Regulars will know I'm a great fan of Starsense Explorer, especially for beginners.  Indeed, having bought the 70mm for two of my grandkids I promptly bought another for myself.  This was just to get the SSE unit, that I adapted to fit standard Synta finder shoes.  I then donated the scope to a pair of beginners.

From reading Stu's report I suspect that the 70mm might be better as a scope, purely as the lighter weight and shorter tube makes it less wobbly (the mount's the same it seems).  It wouldn't resolve as close doubles of course, but would have a wider field of view - useful for the Pleiades for instance.

Thanks again, Stu. 👍

Ags, I use my Askar 180mm as a 40mm RACI finder.  It works perfectly with the supplied kit and a RACI prism and eyepiece.

The eyepiece I use is a  Svbony 20mm crosshair Erfle. It gives 9x magnification with a FOV of just under 8 degrees.

If you bought the scope online you have the legal right to change your mind within 14 days of delivery under the Consumer Contracts Regulations 2013.  This is regardless of whether the item is faulty or not.

Full details are given at https://www.which.co.uk/consumer-rights/advice/i-want-to-return-something-bought-online-aqsD32m9r5P3

Whoops! Sorry, Don is right of course.  I'll correct my post.

Quite a few  2x Barlows can also be used at 1.5x.

On these dual 1.5x/2x Barlows the black lens cell at the bottom of the Barlow can be unscrewed from the body and then screwed into the filter thread at the bottom of an eyepiece to give approx 1.5x.

US retailer Agenda Astro say in the specification section of each Barlow they offer whether the lens cell can be removed.  Go to https://agenaastro.c...-extenders.htm

FLO do a good own brand such 1.5x/2x Barlow that also has a T" camera fitting at the eyepiece end.  Go to https://www.firstlightoptics.com/barlows/astro-essentials-125-2x-barlow-with-t-thread.html

There's also the Baader 1.3x/2x Barlow Q Barlow, but this can't be used with all eyepieces.  This is because if there's a lens near the bottom of the eyepiece there may not be room for the Barlow cell to be inserted.

Whether or not a Dioptrx will help depends on  the degree of astigmatism you have in your observing eye.  You can find this on your prescription under cylinder, often abbreviated to CYL.  Note that your left eye appears on the right hand side of the prescription and vice versa.  The higher the number, the greater the astigmatism.

It also depends on the exit pupil of the scope with a given eyepiece.  I assume that your Starfield refractor is an f/7, in which case a 5mm eyepiece will give an exit pupil of 5/7, i.e. less than 0.75.

As Don has pointed out, with such a small exit pupil your astigmatism would have to be fairly bad to need correction.  The graph on the link below will quantify this.  From this you'll see that your astigmatism would have to be about 3 dioptres or worse for a Dioptrx to be any use to you with an exit pupil of 0.75.

https://www.televue.com/engine/TV3b_page.asp?id=54&Tab=_Choose

At bigger exit pupils/lower magnifications you may benefit from a Dioptrx even if your astigmatism isn't very bad. Again the above graph will help here.

I'd add that it's not just Televue eyepieces that accept a Dioptrx.  Quite a few others do as well such as the Pentax 70 Deg XW and Baader Morpheus ranges.  However, that really needs a separate topic.

The same applies to whether to observe with glasses or a Dioptrx, for which there are pros and cons.  Don prefers the former while I prefer the latter.  A search (certainly on Cloudy Nights, but possibly here on SGL as well) should show our reasons and that of others.

Cheers.  Will post tomorrow when back home.

10 hours ago, Franklin said:

An active night vision eyepiece, something like a Quark that just plugs into a regular scope but allows you to see in NV.

Many NV devices already do just that!

That's interesting!

Support for the latest 32mm series, that's based on new technology, is being withdrawn in 2026.

Yet all the current versions of the older 36, 42 and 50mm models are still being supported.

I wonder what that tells us? 

I'm certainly glad that for other reasons I decided to go for the 12x36 III rather than one of the 32mm models.