niallk

Nice one.

I think Jim Al-Khalilli makes great documentaries, and is a really engaging presenter! 👍

I remember being swept up in the first space shuttle landing in 1981 - I was 5.

I also had two kids' space cartoony picture books: one on the viking landers  and one on planets which I'm sure speculated about dinosaurs living on Venus! 😂  This also mentioned Pioneer and Voyager which captured my imagination. 

I did get taken by my Dad to see Halley's comet at Dunsink Observatory in '86... it was an underwhelming experience!  I remember the Giotto mission, and the reports on the Voyagers as each gas giant was encountered. 

Then I fell out of a pub drunk aged 32 and saw an amazing super dark sky in Allihies: wow. I found the 'Pocket Universe' App for my Apple iPod Touch in 2008, and shortly afterwards found Stargazers Lounge... and read about these 'dob' things, and just had to try one - got my first telescope in about 2011!! 😂

My understanding is that RMS is computed from a grid of sampling points across the optic: I can't remember exactly, but I believe in OMI's test setup for example, 300 points or so are recorded, and they tested at 523nm.  That's a good sample size for computing a 1-sigma estimate... the reported RMS number.

However, it doesn't necessarily capture smoothness, due to the finite sampling grid.  As you mention, it's comparing the shape at the sample points versus the theoretical.

I'm not an expert and open to correction, but a test that is 'continuous' can show poor surface ripple eg knife edge, or also integrating scattered light.

For me, it's my 17-10-6 Ethos.

The 10E is my most commonly used EP - just a beaut giving 200x in my 15" with a Paracorr 2 in place.

The 17E is great as a starting point on a target - or for larger targets.  Great for 'standing back' and seeing a glob or DSO in situ in a star field.

The 6E is great for planetary nebs, and planets ~330x.

I've a N31T5 for greater tfov, and an 8E between the 10E and 6E.  It does get use, but it's a luxury tbh.  I've a 2xPM for planetary nebs and nights of exceptional seeing.  Rarely gets used!! 😂

If I had to give them up, I'd drop the 2xPM, then controversially the N31T5 and lastly the 8E.  Subjective based on the targets I tend to chase!

All the EPs I see as lifetime investments.

You could go into business... Maybe FLO would stock them? 😂

Totally agree 👍 

I drive for 10 mins to a spot on the coast where a river meets the sea in a bay sheltered by a peninsula.  There's a marsh, and you get the sounds of the birds throughout the night, as well as the waves lapping on the beach.  Good for the soul 😉

A couple of times I've watched the arrival of dawn - magical to watch the colours spread across the sky, and the birds greeting it in the marsh.

On 25/11/2021 at 13:50, Kon said:

I am looking to purchase a good book for DSOs similar to 'Turn Left at Orion', with charts and sketches. (I have an 8" Dob if that matters). I came across the 'Interstellarum Deep Sky Guide Desk Edition' and I have seen some nice reviews on it (I already have the 'interstellarum Deep Sky Atlas'). I am mostly interested in nebulas but of course other DSOs are of interest. Is that the best book for my needs or do you recommend others (I am very kin on sketches rather than astrophotography images, so I know my expectations)?  Or feedback on the Interstellarum Deep Sky Guide Desk Edition from personal experience?

Kostas

Hi,

I too have the Interstellarum Deep Sky Atlas, and did pick up a copy of the Deep Sky Guide companion.  I do really like the combo, though some sketches are done with greater aperture than what I have (15").

I use the two together, and also Google sketches in a 16" too when planning a session, or reviewing after I've found a new target.  The 2 book combo are great with Google for extra info.

Best regards, 

-Niall

On 07/12/2021 at 13:32, jetstream said:

It took me forever to see the HH initially in my VX10, now its much easier. Transparency is crucial as is fine tuning the exit pupil for use with the Hb, a bit too dark and away it goes.

These days I have two nemesis... the Eridanus Loop and Einsteins Cross, got the lensing galaxy so far after 3 years and still hunting for the "apparitions".

What I'd give to see a gravitationally lensed object!

The skies can be very variable where I am - perhaps moisture content in the atmosphere (?).  When I go to the coast to be as far from light domes as I can get, there has only been 1 night I can remember when the Flame neb was in-your-face very detailed.  A real treat!  I had one outstandingly magnificent night on the Omega neb - wow the detail.  And one really extra special night on the Orion neb where it was even way more detailed than usual  offering a curiously 'scooped out' 3D appearance, and tinges of pink - I always see green. So I think transparency and reflection of light pollution is a big and variable factor for me locally.  Some nights it can be moonless, no jetstream, etc - but still not as rewarding as you'd hope.  I do always strive to allow the mirror cool for a few hrs for DSOs.

That's a very interestingly mounted 18" club scope, John.

In terms of aperture fever, mine was cured when I watched a 20" Obsession Classic being wrestled out of the back of an estate car at a star party.  The ramps slipped and it dropped 2.5 feet or so to a gravel drive 😳  thankfully no damage!  I did get to see M13 through it... up a ladder in the dark 😬

After that I have realised that 15" suits me   Yeah, a lighter mirror box and a thinner mirror made by Zambuto would always be nice 😀 

I'm very curious to look through something like a SW120ED - I've literally never looked through a frac!  (aside from a finder, or a Ha solar).

But a run of great weather is the real dream - I read of super seeing conditions in the likes of Florida over on CN 😜

The other dream would be using a scope in the dark outback in Oz on southern sky DSOs... droooooooool 🤣

9 hours ago, John said:

 

 

A great advertisement for dobs 🙃

Hope the lens caps are on... 🔥

Would love a look through it of course 😉

I don't hate Bortle - just frickin 'security' lights 😂

I pushed the boat out to get my Obsession 15" Classic.  It was the scope I lusted over for a long time.

What I really long for now is the chance to regularly use my scope in excellent seeing, with really dark, transparent skies 😃

I'd also love a large aperture double stacked Lunt 😉

9 hours ago, dazzystar said:

Problem is this isn't a small piece of kit and the wife doesn't really want it in the living room!

Corner of the master bedroom?  This is where mine lives 😂

Nice report John!  I haven't observed Uranus this year, but was thrilled to also catch 4 moons before during a run of good seeing and dark transparent nights before (15", ~330x).  Seeing Uranus as sharply defined disk was also fantastic- albeit featureless to my eyes.

Any hint of a lighter polar region??

+2 for the Lacerta upgrade. 

I got this for my 250px, and it was wonderful.

I have a Moonlight on my Lunt and a beautiful Feathertouch on my 15".  While they are both far superior to the stock SW focuser, I have to say that on my 250px, the Lacerta mod made it a pleasure to focus, and together with the stock focuser, was perfectly functional and usable.

I spent the money I saved on other accessories!! 😉

On 11/12/2021 at 09:57, F15Rules said:

- Binoviewing ( on selected targets)

 

+1

I saw the Cassini division for the 1st time in my 10" dob with my Maxbrights and cheap plossls.  Also great on Jupiter, Mars, and the Moon.  I think that apparition coincided with the rings tilting and opening more - could see it mono afterwards too - always easier to see things again after you've seen them once!  But the gain from using two eyes was really noticeable.

They don't reach focus in my 15"... must see if I can try a different GPC.

On 01/12/2021 at 17:33, M40 said:

Hello Jassy and welcome to the site. Can I offer an alternative option, how about buying "stuff" like a book called "Turn left at orion", a planisphere, some warm gloves/hat and get a gift voucher from somewhere like First Light Optics. I am sure he would love to be involved in the decision making. All the best.

Great suggestions - a really important point about your partner appreciating being part of the decision making!

Strongly recommend a dob: 8" or perhaps 10".  Fine instruments which can really open up what's visible. Huge fun and enjoyment to be had learning how to use it and learning how to find stuff- and the sense of achievement seeing a target object for the first time!

While a dob can be very convenient and manageable to lift and quick to set up, it is worth considering personal circumstances, where it would be stored, and the path to where you'd observe - eg are flights of stairs involved.  It is very important that setup is easy!

I'd suggest minimising the amount of electronics involved at this price point.  A dob puts the money in the optics - which makes a lot of sense 😉.

Honestly, I'd not recommend spending £100+ on binoculars and a tripod.  It will not deliver anything like the amazing views a 8"-10" dob can.

However, using a dob involves one important step: learning to collimate.  This involves carefully following instructions with a little patience to align the primary and secondary mirrors.  If you think your partner is not the kind of person to do this and learn the process, then a dob may not suit them!

Smashing report John!

I must look up NGC2419 👍

Edit: very interesting indeed

https://www.universetoday.com/120628/ngc-2419-wayward-globular-or-the-milky-ways-own/amp/

Agreed - its always about following the money.

I heard an interesting one: LEO networks offer lower latency than other global connection options (the RF up/down links + importantly intra satellite laser based optical relay links).

This can be exploited by market traders...

Unfortunately it seems like LEO networks will proliferate as they are a key facet for 6G proposals- BW, latency, coverage

Only spotted this thread now! Saw the original comment in John's thread 😉

For me my 250px was my first scope.  Aside from the act of getting the scope itself, three things stand out for me:

1. Getting a Telrad - instantly helped locating objects. 

2. Getting a N13T6 + a 2.5x PM - wow compared to the crappy cheap plossl set EPs I had.   First look at M42 was strongly green, not grey.  82 deg afov soooo much nicer in a manual dob.  The PM is just sweet.

3. Getting the Lacerta dual speed focuser upgrade for Skywatcher dobs - really made a difference at the EP.  Wonderfully engineered for 70 quid.

If I was to add a 4th it would be my 15" dob - incredible difference at the EP compared to the 250px: not just the aperture but the mechanical movement and balance.

A 5th would be the €20 A4 sheet of Baader solar film!  Maybe this should even be in the top 3: adding the capability to view sunspots in white light is revolutionary.  And I've since gone all in on a double stacked Ha setup!

On 26/11/2021 at 16:33, mikeDnight said:

Here are a few of my own sketches which might inspire you to have a go at sketching. It really isnt as difficult as it might appear. You can sketch with a normal graphite pencil, take an image of the drawing, then convert it into negative on your tablet or computer. ☺

 

M27 Dumbbell nebula

M

 

Man - you've gotta get yourself a dob... 🤣🤣 (couldn't resist!)

Fabulous sketches 👌

If with your fix it doesn't need lubricant, it might be good to go without - just in case any gas emissions could possibly corrode filter coatings (???)  That might be just paranoia though!

👍 Love Frasier Cain's enthusiasm and passion!

Thanks for the list - must check some of them out! 😉