Exploring the Sun: Amateur Solar Imaging Techniques

[davenn]

Solar activity -- 20 Nov. 2017

a quick shot of the prominence and long winding filament on today's sun
gear - Lunt LS60THa solar telescope, ZWO178MC camera and SharpCap software

this is just a single frame

Dave

 

[sophiecentaur]

Smashing picture Dave.
Your cost per recorded pixel is dropping fast!

 

[davenn]

Smashing picture Dave.
Your cost per recorded pixel is dropping fast!

thanks buddy ahhh yes it is

one of the next steps is to figure out using the software to load in a short .avi video file
and it extracts the individual frames and stacks them. When I get to do this, we should see a big
improvement in image quality

At this time just getting used to using the scope, astro camera and software to capture single images

today's image isn't as sharp as the last one, by the time I got home from work today ~ 5pm, the sun
was getting low in the west and the light coming through much more atmosphere causing the usual instabilityDave

 

[sophiecentaur]

load in a short .avi video file
and it extracts the individual frames and stacks them.

I have read that good stacking software will select the best and reject the worst in a video sequence. That IS clever!

 

[davenn]

The Sun, 22/11/2017, about the best image so far

Reasonably good seeing conditions today

quite pleased with the result

Dave

 

[Stavros Kiri]

today's image isn't as sharp as the last one, by the time I got home from work today ~ 5pm, the sun
was getting low in the west and the light coming through much more atmosphere causing the usual instability

Still pretty good and interesting. The previous one was kind of too bright I think. Is that the normal?

 

[davenn]

Still pretty good and interesting. The previous one was kind of too bright I think. Is that the normal?

the centre is always going to be brighter than around the limb.
it's tricky ... bringing up the brightness so the prominences can be seen well and the face is way too bright
lower the brightness so the face is well exposed and the limb prominences fade away
this image is a trade off between the 2 extremes

 

[Stavros Kiri]

image is a trade off between the 2 extremes

What's the best time of the day (regular normal day/conditions) to naturally fall in between, if possible?

 

[davenn]

What's the best time of the day (regular normal day/conditions) to naturally fall in between, if possible?

when the object of interest is high in the sky ... sun moon, planets, deep space object

that is when you are viewing/imaging through the least amount of atmosphere, the lower you go towards the horizon, the thicker the layer of
atmosphere you are viewing through and hence more instability

the image in post #71 was late in afternoon, around 5:30 - 6pm and the sun was getting pretty low
hence the quality was not good.
Today's image was at 430pm still getting a bit low but not as bad, so the stability was much betterDave

 

[Stavros Kiri]

Thanks Dave. What you say makes sense.

 

[davenn]

@Stavros Kiri

The next things that is done, and it's next on my list for experiments is... doing small video clips, 500 frames or so
then these are stacked in programs like Autostakkert! 2 or Registax, it picks out the best 10 - 20% of the frames and stacks themDave

 

[Stavros Kiri]

@Stavros Kiri

The next things that is done, and it's next on my list for experiments is... doing small video clips, 500 frames or so
then these are stacked in programs like Autostakkert! 2 or Registax, it picks out the best 10 - 20% of the frames and stacks themDave

That would be neat! I'm looking forward to it.

 

[davenn]

The Sun 24 Nov 2017

trying a B&W version instead of colour ... sort of have the feeling it gives better contrast of the visible structure ?

A reasonable prominence upper left, a sprinkling of smaller ones elsewhere

some small filaments here and there but the major feature is the long lasting filamentDave

PS ... Just to clarify ... I didn't image this in B&W ( greyscale) It was imaged in colour and then fully desaturated in Lightroom whilst doing the other processing edits

 

[davenn]

The Sun 10 Dec 2017, 05:10 UT

Several really nice prominences on the sun today ... was first chance to do imaging in over 2 weeks ...
Has been a mix of nothing much to image and when there was, it was cloudy for me
But finally a clear sky and good prom's

During the 30 mins I was observing/imaging, that smaller upper right one disappeared
and the lower left one, I could see changes as material was falling back towards the sun's limb

Dave

 

[davenn]

full disk image from the 10 Dec

 

[NFuller]

Are these stacked or just single images?

 

[mr1batman]

I took this one about a year ago. Not too much happening here but I think the image came out well.
View attachment 211366

this is fantastic

 

[davenn]

The Sun in Ha -- 11 Dec 2017
There were 5 respectable prominences around the limb today

 

[Andy Resnick]

The Sun in Ha -- 11 Dec 2017
There were 5 respectable prominences around the limb today
]

You're encouraging me to take out a loan for some solar etalons...

 

[davenn]

You're encouraging me to take out a loan for some solar etalons...

that's good to hear
I would welcome more active solar observers I am so wanting to see more people post their solar images in this thread
White light, Ha etc :)

 

[davenn]

Are these stacked or just single images?

Hi ya,
Oops, sorry for the slow response. They are all just single shots

 

[NFuller]

They are all just single shots

Wow, these are very sharp for single exposures! I imagine if you do start stacking these they will come out very well resolved.

 

[davenn]

I imagine if you do start stacking these they will come out very well resolved.

yes, it would very much improve the result
Most of the guys that are into doing that do video clips consisting of around 500 to 1500 frames and then use programs that will take the best ~ 20% of those frames and stack them

 

[davenn]

2017-12-27 The Sun in Ha ...
a couple of nice prominences on the sun today ...

 

[sophiecentaur]

Good image and convincingly sharp!
Not much Sun visible here today.Thick cloud and flurries of rather wet snow, along with rain.
Time to light the log burner, I think.

 

[davenn]

Good image and convincingly sharp!

thanks ... it's still sharper visually than when imaged

Not much Sun visible here today. Thick cloud and flurries of rather wet snow, along with rain.
Time to light the log burner, I think.

been cloudy here for last 4 days. Missed some nice proms 3 days ago
It doesn't snow here at home It does occasionally do so up on the Blue Mountains ~ 8u0km to the west of SydneyDave

 

[sophiecentaur]

thanks ... it's still sharper visually than when imaged

Calls fo Unsharp Mask, perhaps?

 

[davenn]

Calls fo Unsharp Mask, perhaps?

possibly, yes ... I'm aware of the process but haven't played with it yet

 

[davenn]

2018-01-01 The Sun in Ha ...

these next two prominences were large but VERY faint ... really had to wind the exposure time up to see them

Dave

 

[Stavros Kiri]

2018-01-01 The Sun in Ha ...

My first view of the 2018 sun (haven't been out yet) ...

[and the 100th post! Al right! Yeah! ... ]

 

[sophiecentaur]

possibly, yes ... I'm aware of the process but haven't played with it yet

Unsharp mask does the biz for most pictures. It's basically a sharpening process (high pass / boost) with a threshold, below which it doesn't operate. So it enhances transitions but you can hold back for low level patterns / noise. The 'radius' button adjusts the range over which you do the enhancing. You always have to check the whole picture or a sharp edge can have a black / white border.
You really have to try it. It does a lot for craters and highlights in eyes.

 

[davenn]

well, it's been a productive summer holiday in a number of ways.
Got a few things done around the place that had been outstanding for a while. One of them was to finally put my HEQ5 PRO GOTO
telescope mount to use ... it's only taken one and a half years

Below a couple of images of the mount with the Lunt LS60 THA solar scope mounted to it

Dave

 

[davenn]

A couple of images from today 05 Jan 2018

one very large prominence and several smallish filaments

Dave

 

[davenn]

The Sun in Ha for 7 Jan 2018

some nice large prominences and a long filament

Dave

 

[davenn]

The Sun in Ha for 15 Jan 2018
some nice large prominences and a couple of filament near an active region

Dave