# FeaturedStargazing Solar imaging and techniques

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1. Mar 6, 2018

### Stavros Kiri

Some day I hope (for me) ... . Sounds like great tool!
Ah, a bit less than twice the perimeter of the earth! ... Ok, No big deal! ...

2. Mar 6, 2018

### davenn

perimeter isn't the important measurement, it is almost 5x the diameter .... that's the important value

remember we are looking at length of prominence say 60,000km round figures
diameter of the Earth 12,700 km round figures. The Earth fits INTO that prominence 4.7x ( 5x if you go out to the 65,000km measurement)

Three Earths side by side will fit through that dark centre part of the loop....

now that is significant

Dave

3. Mar 6, 2018

### Stavros Kiri

I think it's significant anyway! Also it's ~ 1/6 of the distance Earth-Moon ! ...
[The "no big deal" was a joke ...]

(+ light takes about 1/5sec to travel it! ... That means relatively HUGE distance! ...)

4. Apr 10, 2018

### davenn

Haven't been able to do any solar imaging for a bit over a month, mainly due to cloudy skies and or lack of activity on the sun
I could have imaged last Saturday 7th April very clear sky and some good prominences.
Only problem was that it was 35C outside and the heat was unbearable to be in for more than a few minutes,
let alone the amount of time to set up the scope and computer and do imaging. That would have taken at least 30mins,
28 - 29 mins more than I was prepared to endure

How does an astronomer overcome bad condition "blues" ...... buy some more gear

So here is my new scope .... A Skywatcher EVOSTAR120 Black Diamond refractor
120mm objective lens and a 1000mm focal length giving a f-stop of 8.3
f-stop (ratio) = FL / aperture = 1000 / 120 = 8.33333....

It's been around 45 years since I last owned a refractor scope (discounting finder scopes)
This scope will get used for visual observing and imaging of solar, planetary, lunar and deep space
The camera in the photos below is the ZWO ASI 1600MM

Visual observing setup ... eyepiece and diagonal....

visible light imaging.....

Solar Ha imaging through a Daystar Chromospheric filter.....

close-up of the filter and imaging setup......

cheers
Dave

Last edited: Apr 14, 2018
5. Apr 10, 2018

### sophiecentaur

Hi @davenn Nice stuff. Sorry to hear about the weather. It would be nice to have a bit of Sun 'up here' too.
How easy is it to shift that 120mm refractor about? I have a lumpy 8" Newtonian and it's a pain to get it up and onto the mount. No wonder I tend to use my 80mm Equinox nearly all the time. I look around me and 'everyone' seems to be buying or making garden observatories which solve the lifting problem. But the only suitable site for one in my garden is too much in the faces of people using the garden for non astronomical purposes.

6. Apr 10, 2018

### davenn

cheers

lots of sun, but it's been mainly during the week days when I am at work and now that we are getting well into autumn, the days are getting shorter and daylight saving ended easter weekend so the sun is too low in the west for me to observe by the time I get home from work.
Weekends are my only chances for solar observing now.

quite light the tube, mounting rings and that green mounting bar total around 5.5kg

yeah, I know that feeling with my Celestron 9.25" Schmitt-cass .... It's quite heavy

a home observatory is out of the question for me
1... primary reason ... I'm renting the property
2... I'm deep in the red zone of light pollution for doing nite time astronomy

Back in NZ, I had a 2.5 x 2.5m garden shed obs. that I made the roof roll off

just googled it, nice looking scope does your one have the 10:1 Crayford fine focuser ?
http://www.skyatnightmagazine.com/review/telescopes/sky-watcher-equinox-80-ed-apo

cheers
Dave

7. Apr 10, 2018

### sophiecentaur

Can't win 'em all. It's not too bad here as there are no street lamps and the only pollution is from some garden lighting next door (she is security mad). My astrophotography efforts are put to shame by some club members who live close into London. The worse the conditions, the more nerdy you have to be. My problem is I have problems with the cold and laziness, limited budget and some other spending priorities. Some of your solar pictures are good justification for your spending, though.
BTW, what sort of solar energy rejection filter can you use with your 120mm? I thought there were limits to objective sizes for 'rear end' filtering. I have a shiny Baader filter for my 80mm objective but that is a poor man's solution to solar, I think.

8. Apr 10, 2018

### Stavros Kiri

Lol ... That always works, doesn't it?

9. Apr 10, 2018

### NFuller

Nice choice, Skywatcher has been known to put out some good equipment for a reasonable price. I actually just purchased my first refractor a few weeks ago: a Skywatcher esprit 80mm. But of course, I haven't had a clear night since I bought it!

10. Apr 11, 2018

### davenn

11. Apr 11, 2018

### davenn

grrrr .... been there too in days gone by

yup, that's where you can use some of narrow band filters .... they give weird colours but still give awesome results in heavily light polluted areas
I haven't gone that path as yet. I just travel around an hour out of the city area to get to darker areas.

cheers

For the Daystar Quark as shown in my photo above, it can handle up to 150mm objective before a ERF is needed
I bought the 120mm scope rather than the 102mm with the thought that I can always stop it down to ~ 100mm. This would still give a 40mm improvement over the Lunt 60mm scope and it would also kick the f-ratio up a bit to improve image sharpness over it's f8.3 @ 120mm

The Baader filters are good white light filters and I will still use my one for sunspot imaging ( not that there are many of them lately .... solar minimum)

Dave

12. Apr 12, 2018

### NFuller

Yep, that's it.
Yes. I don't know much about those scopes, but I'm sure they are of good quality. I believe it is a FPL53 doublet...

13. Apr 13, 2018

### davenn

14. Apr 13, 2018

### davenn

The Sun in Ha 13 Apr 2018

Been off work all week with a not nice case of bronchitis, am feeling very unwell
but did decide to haul the gear out today and do some solar imaging
Reasonably quiet, 4 or 5 small filaments across lower part of disk, 2 groups of prominences on opposite limbs.
The new active region has moved further onto the disk and is showing an associated filament ...
The seeing conditions were better than yesterday
Lunt LS60THa, ZWO ASI1600MM and SharpCap capture software

Cheers
Dave

15. Apr 13, 2018

### sophiecentaur

Yes. That one looks like mine. It'svery nice. A great (some might say too blingy) finish and focuses well. The rotatable focuser could be better, though. A lot of manual filter changing and suchlike could perhaps make it come loose.

16. Apr 13, 2018

### NFuller

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

17. Apr 13, 2018

### davenn

nice mount

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

18. 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.

19. 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
20. Apr 14, 2018

### NFuller

21. 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
22. 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 23. 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

24. 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

25. Jun 10, 2018

### Zeke_D

Thermal flows imaged with Baader Astrosolar 5.0