# FeaturedStargazing Solar imaging and techniques

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1. Apr 13, 2018

### NFuller

I have a celestron cgx mount I use for this as well as another scope.

2. Apr 13, 2018

### davenn

nice mount

that now begs the question ..... what is the other scope ?

3. Apr 13, 2018

### NFuller

Thanks, I've been happy with it so far.
The other scope is a celestron EdgeHD 800. I use this one for smaller objects like planets and galaxies.

4. Apr 14, 2018

### davenn

the one you see in my posts #102 and #129 is the Skywatcher HEQ5 PRO, also a good solid mount :)

Sweet !!

My main scope is the Celestron CPC925, bought that at the beginning of 2012, it's a fork mount scope on an Al/Az mount

without going back through pages of posts, I cant remember if you have any sort of solar filter

I commented to Sophicentaur a few posts ago that the Baader filters are good white light filters for sunspots, and some other visible light surface features. It can be purchased as a roll or sheet of film
quite cheaply. I bought a roll of it, enough to make several filters for scopes and camera lenses etc.

eg .....
https://www.ozscopes.com.au/accessories/eyepieces/filters?p=3

the first link is the one I got .... will do many filters

dunno where you live, probably some where with sales closer to you

Dave

Last edited: Apr 14, 2018
5. Apr 14, 2018

### NFuller

Currently, I don't, but I have been thinking about getting an Ha setup for my 80mm and a white light filter for the 8" from 1000 oaks optical. I've heard many good things about their products. Here are the links below.

http://thousandoaksoptical.com/shop/solar-filters/full-aperture-solarlite/
http://thousandoaksoptical.com/shop/h-alpha/h-alpha-9-angstrom-complete-system/

6. Apr 14, 2018

### davenn

yup, the 1000 Oaks W/L filters are good, I have 2 of them one for the CPC925 and one for the 100-400mm Canon camera lens

hadn't seen this system before ....
http://thousandoaksoptical.com/shop/h-alpha/h-alpha-9-angstrom-complete-system/

just be aware that at 0.9A you are not likely to see the filaments on the face of the disk ( at minimum only a hint of the very largest ones)
as you can see from their supplied images ... the surface features are very blurred
0.9A is quite a broadband bandwidth. for every 0.1A you drop in bandwidth, the features become sharper and sharper
so dropping from the 0.9A down to the 0.65 - 0.7A of my Lunt system lots more details appear.
Dropping to the 0.45 - 0.5A, of my Daystar Chromospheric filter, is even better for surface/disk face features

I would suggest you do some research on the different filters and spent the most your budget can afford ...
it will possibly save disappointment and having to pend a whole bunch more money later on

when buying expensive gear, I'm a firm believer in the saying "do it once, do it right"

you have spent good money on excellent scopes .... DON'T skimp on a lesser quality a Ha solar filter

hope that all makes sense ?

Dave

Last edited: Apr 16, 2018
7. Apr 16, 2018

Thanks for the advice. I just started looking at Ha solar filters so I haven't really decided what to go with. The daystar filters look very nice, but you definitely pay a premium on them... $10000 for 0.3A 8. Apr 16, 2018 ### davenn Take your time, wouldn't want you to have any regrets it took me 25+ years to finally be able to afford a Ha filter/scope, their prices have dropped considerably ( also their quality has probably improved in that time) It was only last August (2017) that I finally lashed out on the Lunt LS60Tha ... AU$2599.
The Daystar Quark Chromosphere one came a month later at around AU$1600 (~US$1295)

My wish list for another filter, if I could afford it, a Calcium-K filter. It gives a very different view of the disk features

Photo credit: Guilherme Grassmann

he is one of the member s of the
Uk Solar Imaging & Observations. on facebook

a good group to see what people are up to with solar observing

Dave‎

9. Apr 20, 2018

### davenn

The Sun in Ha 21 Apr 2018
Absolutely crap seeing conditions... even the "blue" parts of the sky between the cloud gaps had a high haze.
Nice new active region with spots and a nice prominence showing a large detached section
Lunt LS60THa, ASI 1600MM camera and Sharpcap capture software

Full Disk

AR2706

large detached prominence

Dave

10. Jun 10, 2018

### Zeke_D

Thermal flows imaged with Baader Astrosolar 5.0

11. Jun 10, 2018

### sophiecentaur

Hi and welcome to PF
Can you tell us how that image was obtained? I have a Baader ASTF 80 and I'd like to be able to do more interesting images than I have obtained so far - not much more than the more obvious spots.

12. Jun 10, 2018

### Zeke_D

I am using a Nikon P900 with a Baader 5.0 filter on a regular camera tripod. Usually shoot at maximum optical, 83x, sports mode for a burst of 7 in 1 second. Greater than a minute between shots, it starts to noticeably blur the final image.

I'll post some images to walk through the process.

The spectral response of Baader in the NIR and into the IR appears like an etalon comb response, it is a multilayer metallic sandwich - so maybe. My IR blocking filter extinguishes completely at ~ 750nm, so there are only a few candidates for the NIR terrestrial spectrum making it to my camera.

'Grain extract' subtracts two images and adds 128. Differences between my images are caused by many things, image stabilization being the most consistent for sub-pixel offsets, then there is my inherent alignment error between the stacks.

I have spent a few months comparing the SDO and SOHO images to the Baader/differencing technique - I am posting this because the correlations are significant. The thermal envelopes and shock waves are almost like a ghost of the UV activity seen in SDO.

Working on OpenCV for real time video processing with this technique, will move the design over to an FPGA next month to get the frame rates up.

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13. Jun 10, 2018

### Zeke_D

Sun 6 10 2018 7:51MST
Nikon P900, 83x, Baader 5.0, sports mode burst on standard camera tripod.

Horizontal banding appears to be layers of the atmosphere. Differencing technique works well for imaging objects close to, or crossing the Sun.

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14. Jun 10, 2018

### sophiecentaur

@Zeke_D Thanks for that. So you seem to be basically temporal high pass filtering (plus some DC offset) and that removes most of the energy - explaining the high noise, I guess. I would imagine that processing a long sequence of movie frames could allow you to dredge more patterns up from the noise with long sequences of frames (less than one minute, from your comment about gap between frames.)
It's encouraging to see that worthwhile information can be obtained about the Sun without having to spend vast sums on filters.

15. Jun 11, 2018

### davenn

Hi there Zeke_D

welcome and thanks for posting in the thread. It's good to see something a bit different
Even with your walk-through of your processing, I have to admit, I'm still not totally sure of what I am looking at … detail wise ??
Continue to post and keep up the explanations

regards

Dave

16. Jun 11, 2018

### Stavros Kiri

17. Jun 11, 2018

### davenn

since I don't appear to see any specific detail/feature in the images …. I'm not sure what I am missing

D

18. Jun 11, 2018

### sophiecentaur

Yes. There is just one image where there is a clear area, to the right of the Sun where 'something is going on' but I think we need some help to make more sense of some of the images in post #152.

19. Jun 16, 2018

### davenn

16 June 2018, The Sun in Ha.
Some small prom's and a large but ( for me, ill defined) active region probably mainly due to poor atmospheric conditions
LUNT LS60THa and ASI1600MM

Dave

20. Jun 16, 2018

### sophiecentaur

Nice images as usual, Dave.
The first and third images seem to have areas of light as if it's a slightly polished sphere, illuminated from one side. The spherical appearance is quite noticeable. How's that happening, I wonder? It's almost as if the Dodge Tool had been used.