Search found 36 matches

by EdAstle
Thu Aug 24, 2023 8:29 pm
Forum: This is SolarChat !!
Topic: Has anyone here ever looked through a Lunt LS300T? Has any been sold?
Replies: 8
Views: 321

Re: Has anyone here ever looked through a Lunt LS300T? Has any been sold?

See for example Jean-Pierre Brahic scope in France (320 Aries ERF + 350 mm CFF Cassegrain) : https://www.astrobin.com/anvnl8/ Oh wow, it's this guys fantastic image that adorns the front of the Solar Astronomy book! Ok everyone here probably knows that, but I'm still finding things out :) https://c...
by EdAstle
Thu Aug 24, 2023 8:04 pm
Forum: This is SolarChat !!
Topic: August 20 2023, smaller scope Imaging.
Replies: 21
Views: 788

Re: August 20 2023, smaller scope Imaging.

"carpe una sabbatorum"
Google translate is your friend ;)

Carpe Solem!
by EdAstle
Wed Aug 23, 2023 8:44 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Astronomik and quark
Replies: 9
Views: 1169

Re: Astronomik and quark

Hi there - the KGs are heat protection from the longer IR. They are fairly transparent < 400nm. https://www.edmundoptics.co.uk/p/schott-kg3-50mm-sq-2mm-thick-colored-glass-heat-absorbing-shortpass-filter/42570/ Look at the "Technical info" tab: https://productimages.edmundoptics.com/8779.P...
by EdAstle
Mon Aug 21, 2023 11:18 pm
Forum: SPoD Archive
Topic: August 2023 Solarchat meeting archive
Replies: 2
Views: 848

Re: August 2023 Solarchat meeting archive

I hadn't appreciated what goes on behind the scenes here at SC. The level of outreach and the tenaciousness to get that done is truly moving. I know just a few Greek words. One being Philanthropist. Actually it's two words; filo (a friend) Anthropos (of mankind). Nice to see Alexandra unifying the n...
by EdAstle
Mon Aug 21, 2023 9:57 pm
Forum: Solar Reference Library
Topic: Summer solar visual and imaging challenge : "What is the color of sunspots ?"
Replies: 75
Views: 17299

Re: Summer solar visual and imaging challenge : "What is the color of sunspots ?"

That's a result Alexandra! And top tip re levels. That inner glow really adds to already great images. Photographers used to use a 50% grey card to set white balance. Digi cams now look for the "whitest" colours and readjust everything based on that, kinda. You've made a "solar grey&q...
by EdAstle
Sun Aug 20, 2023 11:02 pm
Forum: Solar Reference Library
Topic: Summer solar visual and imaging challenge : "What is the color of sunspots ?"
Replies: 75
Views: 17299

Re: Summer solar visual and imaging challenge : "What is the color of sunspots ?"

There must be a palette of colours inside. A whole bunch of photons of different frequencies. The RGB mix must fluctuate within. Page 104 of the Solar Astronomy book asks "Do sunspots have color"? The answer the book gives, in a nutshell, its "yes". ~3800K is the number given. Bu...
by EdAstle
Thu Aug 17, 2023 9:27 pm
Forum: Solar Scope Modifications
Topic: Baader 2" Cool-Ceramic Safety Herschel types telescope?!
Replies: 5
Views: 1168

Re: Baader 2" Cool-Ceramic Safety Herschel types telescope?!

If you fancy a challenge Oleg, there's always this 8.5" f12 frac: https://www.ebay.co.uk/itm/274133624413 The bench isn't included. https://i.ebayimg.com/images/g/OqIAAOSw1MNd7UG0/s-l1600.jpg The ND filters you'd use would need to be increased proportionally to the extra wattage collected, meth...
by EdAstle
Tue Aug 15, 2023 11:01 pm
Forum: Solar Astronomy Shop and Swap
Topic: Baader - AstroSolar Photo Film OD 3.8
Replies: 9
Views: 1491

Re: Baader - AstroSolar Photo Film OD 3.8

I've registered my email here: https://www.baader-planetarium.com/en/solar/whitelight/astrosolar-photo-film-od-3.8.html "Choose an option...100x50" "Please notify me when this product is back in stock". Perhaps increase the noise in their inbox and they'll get fed up with us and ...
by EdAstle
Tue Aug 15, 2023 12:03 am
Forum: Solar Reference Library
Topic: Summer solar visual and imaging challenge : "What is the color of sunspots ?"
Replies: 75
Views: 17299

Re: Summer solar visual and imaging challenge : "What is the color of sunspots ?"

Visually through my C9.25 (ND5 film), alessbonsai nailed what I saw: https://solarchatforum.com/viewtopic.php?p=397453#p397453 "Straw" penumbra exactly like that. My eye saw nothing but black in the spot. Not surprising considering my pupil was constricted. Intensity is proportional to the...
by EdAstle
Sat Aug 12, 2023 1:51 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: A simple trick for better SHG imaging in Ca-K/H
Replies: 5
Views: 1089

Re: A simple trick for better SHG imaging in Ca-K/H

As I understand it, camera lenses have a best f-stop, which is a compromise between various aberrations (improved by stopping down) and diffraction limits (improved by increasing aperture). Usual this is f/5.6 of f/8, but this probably depends on wavelength. 100% - people pay good (sometimes obscen...
by EdAstle
Fri Aug 11, 2023 12:00 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Hinode Solar guider no longer available?
Replies: 13
Views: 2226

Re: Hinode Solar guider no longer available?

LuSol-Guide doesn't seem to be available anymore It isn't but it's been archived here: https://stargazerslounge.com/topic/271709-solar-guiding-lusol-guide/ Works fine with my ZWO ASI120. It needs "legacy" DirectX Direct Show drivers. eg https://www.zwoastro.com/downloads/others Download t...