DaveS

How about an R2D2 dome?

CCD cameras started as NASA tech.

Is Astrograph still selling NV? The last time I saw prices I thought "I could put together a quite nice little imaging set up for that money".

TBH I would much rather go deep with imaging or use direct eyeball than any form of NV.

Yep, a cracking episode, and good to see the Baker Street Irregulars get a mention, with our own @GavStar.

Depressing about the light pollution though.

In any case it's a moot point since Stargazine flatlined some months ago.

Does anyone still use setting circles?

Silly to make any astro plans when this is the view from my conservatory.

Well, it's not actually raining at the moment but it is foggy. Everything is drenched.

The inner solar system is not a good place for big telescopes due to the light pollution from the Zodiacal Light, yep even HST suffers from LP. Plus, of course, the attendant micro-meteorites.

Once we get spacecraft and engines that are better than our current stone-age dugout canoes then the place to put a big (100m+) telescope is out in the Kuiper belt.

Thanks. Will have to use my "smart" BD player as my "smart" TV doesn't have Amazon Prime on it's list.

Edit:

Can also recommend Sabine Hossenfelder's YT channel, where she has a multi-part series on Quantum Mechanics. Pretty serious stuff.

https://www.youtube.com/c/SabineHossenfelder

Wow! looks like it's "boiling"

The bottom one looks pretty good for a DSLR Rosette, but the RASA version knocks it not just for six, but over the pavilion and out of the ground.

Some lovely colour and detail in there.

I have a few targets, but I'm asking myself if there will be another clear night. Ever

Time was when winter was prime stargazing time, with those long crisp, clear nights. Now it's just endless cloud and murk. On the odd nights when the clouds forget to turn up the moon does, just to spoil the party.

Well, this is my prospect for the week

A full house

UPS? In that case they'll just leave a card saying nobody was in when they tried to deliver.

No plans at all for astronomy in 2022, think it's become a waste of time.

Can barely believe that we've finally launched the wretched thing after so many delays. Now for the 30 days of terror while it deploys.

Your best bet would be a S/H ASA DDM 85. Although I don't run 20 min exposurs, I do run 17 1/2 min at 2040 mm. 20kg is a bit near the limit for a DDM 60, which is 25kg.

But short of prising it from someone's cold dead hands, your only hope is for someone upgrading to a DDM100.

Other than that look at Planewave, but the cheapest is still more than £13k

Yes, I know. He said it was rather rough (More so than he intended), my beef was with his methods, just grabbing the lens and running emery cloth over it, then buffing on a wheel. Not gonna have 1/20th wave and 099 strehl!

2 minutes ago, vlaiv said:

Why? I really like the idea - 100% 3d printed telescope - even lens.

It won't be very useful telescope, but I find it interesting project.

Sanding it? If he's modeling it from am existing lens, then molding a pitch lap would be best.

15 hours ago, johninderby said:

One of the big potential problems with plastic or polymer lenses is that as they age they tend to yellow and darken. 

BTW plastic is a specific type of polymer made up of long chain polymers  whereas polymer is made up of smaller more uniform molecules. All plastics are polymers bit not not all polymers are plastic.

"Plastic" refers to the type of deformation it can undergo. Plastic deformation is where the material stays in the same shape after being deformed (eg when putting marzipan over a cake, something I've just done) as distinct from Elastic deformation where the material springs back into shape after being deformed.

There are thermoplastics (Mst of the common types used in packaging or in FDM printing) and thermosetting, where the material cannot be melted again without decomposition, eg epoxy resins. There are also photopolymers, eg in SLA printing.

15 hours ago, vlaiv said:

Apparently - one can 3d print lens both with SLA and with FDM clear filament.

Sanding and polishing is still needed.

 

Gawd, how NOT to make a lens.

The kit I have in my obsy cost roughly as much as my car (Which wasn't cheap). Whether it's *worth* as much as my car depends on your definition of "worth".

Looking at my folders on the NAS, my last session was on the 1st of this month when I captured 4 hours [OIII] on M1 to go with the 6 hours H-alpha I got back in Jan / Feb. Yep, that's what I have to think about now, building a deep image is something for a multi-year project.