Search found 507 matches

by thesmiths
Tue Aug 16, 2022 4:36 pm
Forum: Solar Scope Modifications
Topic: Summary of Aluminized Newton Imagery (2022 August)
Replies: 4
Views: 119

Re: Summary of Aluminized Newton Imagery (2022 August)

The results are impressive and speak for themselves. My own modest experience with solar Newtonians is there was more than enough light when the primary was non-aluminized. I even experimented with both the primary and secondary having been stripped, but this did cut down the light too much. I have ...
by thesmiths
Tue Aug 16, 2022 4:02 pm
Forum: This is SolarChat !!
Topic: Hello All
Replies: 14
Views: 138

Re: Hello All

I can't really do night time stuff with all the light pollution here too. I used to think that way too, then I discovered the ProPlanet 642 BP filter . You can get some quite surprisingly good images of galaxies and such even from the worse light polluted locations. See my post from last year: http...
by thesmiths
Mon Aug 15, 2022 8:39 pm
Forum: This is SolarChat !!
Topic: Is imaging the sun still within reach?
Replies: 47
Views: 849

Re: Is imaging the sun still within reach?

It's surprising that the seeing is so good with you just after the sun rises. You are looking through such a thick layer of atmosphere. I generally have to let it rise a bit. Usually between 9am-10:30am I have the best seeing. At the moment, sunrise in London is at 6:30m, but because of trees, the ...
by thesmiths
Mon Aug 15, 2022 3:21 pm
Forum: This is SolarChat !!
Topic: Sun FD in H-Alpha, CaK and Continuum 14th of August 2022
Replies: 7
Views: 108

Re: Sun FD in H-Alpha, CaK and Continuum 14th of August 2022

To relate these nice images to another discussion thread (" Is imaging the sun still within reach? " https://solarchatforum.com/viewtopic.php?t=37525 , I think Arne's almost daily imaging using the same equipment setup, and not even particularly exorbitant apparatus, demonstrates that prac...
by thesmiths
Mon Aug 15, 2022 2:55 pm
Forum: This is SolarChat !!
Topic: Is imaging the sun still within reach?
Replies: 47
Views: 849

Re: Is imaging the sun still within reach?

My simple " secret ingredient " to get the best imaging (at least where I am): wake up at dawn and setup up all equipment to image right as the Sun peaks over the local horizon (trees, mountains, preferably not too many houses). This is consistently the best seeing for me and after 90 minu...
by thesmiths
Sun Aug 14, 2022 6:02 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha SHG images from early morning Aug 11
Replies: 4
Views: 98

Re: H-alpha SHG images from early morning Aug 11

Normally, the spectroheliograph is best for surface structure (filaments in particular), but prominences are also observable. I processed this crop to bring out the prominences in one particular region. I don't think the very narrow bandwidth of the SHG gives any advantages for prominence imaging so...
by thesmiths
Sat Aug 13, 2022 9:56 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha SHG images from early morning Aug 11
Replies: 4
Views: 98

H-alpha SHG images from early morning Aug 11

I woke up early on Thursday morning and took some H-alpha scans before catching a 2pm flight from Heathrow. I processed some of reconstructions on the plane and then managed to find time to do some stacking and Photoshop while on holiday. Doing processing on a laptop is harder than on the big screen...
by thesmiths
Sat Aug 13, 2022 2:22 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha and H-beta full disk SHG images from Aug 7
Replies: 4
Views: 137

Re: H-alpha and H-beta full disk SHG images from Aug 7

To me it seems like the filaments are not as full and some seem transparent or missing features in the beta version. Kind of like we’re only seeing the lower levels? See this conversation: https://solarchatforum.com/viewtopic.php?p=349452#p349452 I really like your limbs. There not the usual jagged...
by thesmiths
Wed Aug 10, 2022 1:58 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Full-disk Solar H-alpha Images From GONG
Replies: 3
Views: 115

Full-disk Solar H-alpha Images From GONG

I was wondering exactly what the GONG images were and I stumbled on this abstract, as well as a presentation on the instrument. It uses a Daystar Quantum PE 0.4 angstrom. They apparently also evaluated Coronado and Solar Spectrum. " Since mid-2010 the Global Oscillation Network Group (GONG) has...
by thesmiths
Tue Aug 09, 2022 8:17 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing
Replies: 8
Views: 187

Re: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

Do you know what height in the chromosphere hydrogen beta is looking at? That's a really interesting question. I had a look around and the best I could find was the following statement regarding H-beta : " the features originate from a height region in the solar atmosphere that spans the photo...
by thesmiths
Tue Aug 09, 2022 7:33 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: Comparing Ca-H and Ca-K SHG images
Replies: 9
Views: 126

Re: Comparing Ca-H and Ca-K SHG images

CaK is a definite winner in the proms I realised that I could make the prominence images nicer looking by turning off the " transversalium correction " in the reconstruction software. This filter compensates for the small dark lines due to things like dust on the slit. The problem is it c...
by thesmiths
Tue Aug 09, 2022 10:32 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: Comparing Ca-H and Ca-K SHG images
Replies: 9
Views: 126

Re: Comparing Ca-H and Ca-K SHG images

For me the CaK has the edge. I tend to agree. I was actually surprised that the difference was fairly noticeable. This was a fairly controlled experiment, the only difference really would be the seeing conditions could have changed. But in fact, I think it was very slightly worse seeing for the CaK...
by thesmiths
Mon Aug 08, 2022 6:23 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: Comparing Ca-H and Ca-K SHG images
Replies: 9
Views: 126

Re: Comparing Ca-H and Ca-K SHG images

Are you still using an asi183 camera for these results? Yes, I'm exclusively using the ASI 183MM lately. The 178MM is also very good, maybe better in some ways (it doesn't seem to ever drop frames like the 183MM does sometimes). But with the 13.2mm width of the 183MM, I can see the whole length of ...
by thesmiths
Mon Aug 08, 2022 4:40 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: Comparing Ca-H and Ca-K SHG images
Replies: 9
Views: 126

Re: Comparing Ca-H and Ca-K SHG images

I’m guessing you are using a special reconstruction program? Do you use a pre-filter to help show the proms? In this case, there is no pre-filter at all. It's quite difficult to find an appropriate filter for this wavelength. It's easier for H-alpha and H-beta. Those filters can help darken the sky...
by thesmiths
Mon Aug 08, 2022 2:17 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: Comparing Ca-H and Ca-K SHG images
Replies: 9
Views: 126

Comparing Ca-H and Ca-K SHG images

This is a bit of an academic topic, but I've been curious for some time just how different are images from the Ca-H and Ca-K lines . Let's start by looking at the lines themselves. The image below is a photo taken using FireCapture while our spectroheliograph (SHG) was focused on the Sun. Quite a bi...
by thesmiths
Sun Aug 07, 2022 10:03 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing
Replies: 8
Views: 187

Re: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

I’m currently using the Sol’Ex but am limited by the slit to 480 mm focal length for a full disk. I just noticed this nice image by my friend Jean Francois (JFP), who also uses the standard Solex. He made the following nice image using a 102mm focal length telescope, just with 3 passes and then did...
by thesmiths
Sun Aug 07, 2022 7:47 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha and H-beta full disk SHG images from Aug 7
Replies: 4
Views: 137

H-alpha and H-beta full disk SHG images from Aug 7

Here's a mosaic of H-alpha (inverted) on the left and H-beta (non-inverted) on the right. Side-by-side is usually the best way to compare two different wavelengths. For full-disc H-alpha imaging, the spectroheliograph is probably a little better than the other options (although quite a bit more labo...
by thesmiths
Sun Aug 07, 2022 7:09 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing
Replies: 8
Views: 187

Re: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

I’m currently using the Sol’Ex but am limited by the slit to 480 mm focal length for a full disk. Is it possible to get a longer slit or would I need to modify the entire SHG? The Solex design is fairly optimised so that all the lenses, slit, grating work together. You could probably figure out how...
by thesmiths
Sun Aug 07, 2022 3:24 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing
Replies: 8
Views: 187

H-alpha and H-beta SHG full disk images from 7 Aug -- good seeing

The weather remains sunny in London and now it's not so hot. The early morning gave some good seeing conditions. Another 330 GB of disk spaced used up by SHG video files, this time with H-alpha and H-beta (yesterday's H-alpha and Ca-H was about the same about of GBs). Two wavelengths is about what I...
by thesmiths
Sun Aug 07, 2022 11:18 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: Ca II I at 8542.1A
Replies: 5
Views: 103

Re: Ca II I at 8542.1A

You definitely need even a cheaper 150mm Cass as a feeder for Ca-II - I 854nm line. Seeing at 854nm will be remarkably better than at Ca-H and even than at H-a. In my last attempt at this wavelength, my impression was the problem was not only the optics of the telescope but that of the camera lens ...
by thesmiths
Sat Aug 06, 2022 11:42 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha and Ca-H closeup SHG images -- 6 Aug
Replies: 11
Views: 135

H-alpha and Ca-H closeup SHG images -- 6 Aug

We've been working to improve the imaging capabilities of our spectroheliograph. Here are some closeups in H-alpha and Ca-H taken on Aug 6. They are actually crops of full disk images, which can be found here https://solarchatforum.com/viewtopic.php?t=37438 , along with the imaging parameters. Click...
by thesmiths
Sat Aug 06, 2022 10:33 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha and Ca-H full disk images from 6 Aug -- very good resolution
Replies: 3
Views: 120

H-alpha and Ca-H full disk images from 6 Aug -- very good resolution

London has had a streak of nice days of weather so I've taken the opportunity to keep practicing with our updated SHG. Today's seeing was better than yesterday and the SHG images were noticeably sharper. For the Calcium imaging, I chose the Ca-H line (it is a little narrower than Ca-K, which makes i...
by thesmiths
Sat Aug 06, 2022 9:47 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: Ca II I at 8542.1A
Replies: 5
Views: 103

Re: Ca II I at 8542.1A

You are correct. I believe that a reflective telescope like Cass or RC with 125mm aperture and F/8-F10 willl be OK for such an experiment. I tried again today with another telescope, this time a 90mm f11 achromat from SkyWatcher, but the focus again was not good that far into the infrared. It looks...
by thesmiths
Sat Aug 06, 2022 11:13 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: CaII K3 spectroheliogram of today
Replies: 3
Views: 95

Re: CaII K3 spectroheliogram of today

Looks like the lithographed chrome slit is working out very nice! The ones you ordered from Lenox should work out about the same. As I mentioned before, because they are glass and not quartz, you will just have to be careful about thermal shocking them. The typical way to do that is with an ND filt...
by thesmiths
Sat Aug 06, 2022 12:48 am
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: H-alpha and Ca-K SHG images -- Aug 5
Replies: 2
Views: 67

H-alpha and Ca-K SHG images -- Aug 5

I think we finally sorted out all the small optical issues that were keeping us from getting good focus across the whole solar disk. Today had fairly clear weather in London, although not the best seeing. First H-alpha , which typically has the most details. See at full resolution by opening in a ne...