Stargazing How Can You Improve Your Amateur Solar Imaging Techniques?

[davenn]

The Sun today 22 Sept 2017

Some of the bushfire smoke has dissipated tho the sky is still a little murky ... no clouds just not a clear blue ... today's temp heading for mid 30's C

AR 2680 has gone from the lower left limb and AR2681 ( upper right) is making it's way well onto the solar face

Dave

 

[davenn]

after several days of crappy skies ... bushfire smoke as well as cloud. The sky was clear enough today for a quick sun image

AR 2681 has moved further onto the disk and new AR2682 has come around the east limb
The new AR2682 is the returning AR2673cheers
Dave

 

[davenn]

got another image in the afternoon a little better specially after some processing
The seeing was quite poor as can be seen by the non-sharp (ripply) edge of the sun

Dave

 

[Andy Resnick]

got another image in the afternoon a little better specially after some processing
The seeing was quite poor as can be seen by the non-sharp (ripply) edge of the sun

I tried some solar imaging this weekend, using a few 'random' color filters (in addition to an ND3 = 0.1% transmission):

1) BG3 glass (https://www.pgo-online.com/intl/curves/optical_glassfilters/BG3_BG4.html)
2) RG645 glass (https://www.newport.com/p/FSQ-RG645)
3) a 436/10 bandpass filter (band pass is 436 +/- 5 nm)
4) some UV bandpass filters: a 380/40 and 365/20

I realize the bandpass range of these filters far exceeds 'typical' solar filters, but this is what I have. I couldn't tell at the time, but none of the images came out very well- the exposure guide was apparently totally useless and all 3 images were overexposed in their particular channel (R,G, or B). The UV filters didn't work out at all, I guess the Bayer filter and whatever else is put on the sensor cuts off below 400nm or so. That said, it felt like 90°C at the time (it was 'only' 90°F) and I wanted to get out of the direct sun ASAP.

There was spectral bleed-through: for example, the RG645 image has blue and green components that are properly exposed.

One potentially interesting 'feature' is that the sunspot contrast was highly variable- there appeared to be no sunspot when using the 436/10 filter. I'll probably try filters 1-3 again, if for no other reason than to generate separate RGB images.

 

[Andy Resnick]

Better images today- here's an image taken with the BG3 filter:

equipment details: the lens is a 400/2.8 with a 2x teleconverter. I replaced the 'standard' UV blocking filter with a reflective ND4 (20-stop) filter and added secondary color filters as needed; the BG3 and RG645 color filters got stacked behind the ND4, while the smaller bandpass filters I use for fluorescence microscopy got taped to the front of the 2x tele.

Focusing and exposing was a little tricky: tough to use 'live view' because the display brightness can't compete with ambient lighting. The in-camera meter would typically be around EV -3 or more (possibly EV -7), but then the appropriate color channel would not be saturated. Gain was set to "low 1.0' (approximately ISO 50, IIRC), the lens stopped down to f/4 (f/8 w/ tele) to reduce flare, and shutter speed was about 1/200s.

Minimal post-processing: I manually set the off-RGB channels to zero, and set 'gamma' equal to 1.3 or so to improve the tonal range. Images cropped and downsized about 50% or so. The jpg artifacts appeared during downsizing and again after uploading to photobucket- the full-sized images don't look as 'blocky'.

Here's the RG645 image:

and the narrowband (I mis-stated the spec: 465/10nm filter.

Unfortunately, no real differences between the images...

 

[davenn]

awesome
thanks for posting

Unfortunately, no real differences between the images...

I beg to differ, the red RG645 allows much easier determination of details
the spots blend into the blue one a lot more

keep 'em coming :)Dave

 

[davenn]

the Sun Today 26/09/2017

The quality of seeing is still pretty poor the limb of the sun full of ripples

3 spot groups are visible ... from left to right ... AR2681; 2682; 2683

cheers
Dave

 

[Stavros Kiri]

See why this is useful? I just saw the new group from real photos (even in the first image in #35 above).
Also, AR2682 (old 2673) seems pretty quiet now! ...

 

[davenn]

the sun today 28 Sept 2017

The quality of seeing is still pretty poor only a couple of glimpses of the sun today during a break in the clouds
The same 3 spot groups are still visible ... from left to right ... AR2681; 2682; 2683

Dave

 

[Stavros Kiri]

2683 has grown significantly (by 110). We can clearly see it in the picture (+cf. previous one). Sizes right now: 2681: 80, 2682: 180, 2683: 270.
[Dave's last photo (today) is clear enough to make out the relative sizes.]

 

[davenn]

the sun today 29 Sept 2017

The quality of seeing today is the best for around a week with a nice sharp limb
The same 3 spot groups are still visible ... from left to right ... AR2681; 2682; 2683

AR2682 ( the middle group) is sporting a few small spots around the main spot

cheers
Dave

 

[davenn]

The sun today 01 Oct 2017

The quality of seeing today is reasonable
The same 3 spot groups are still visible ... from left to right ... AR2681; 2682; 2683
AR2681 is approaching the western limb and will be gone in a couple of days
AR2683 has 2 distinct cores

full disc

close-up of the active regions

cheers
Dave

 

[davenn]

After a number of days of either total cloud if a thinner high cloud, I finally managed to image the sun yesterday

The Sun 05 Oct 2017

cheers
Dave

 

[sophiecentaur]

I have some excess spectral filters lying around

Send them over here if you can't use 'em.
I have only managed pictures through the Baader safety filter, so far and I am horrified at the cost of anything else. It seems that you need an etalon to get those lovely impressive shots that we see on line. What is your experience of solar photography and how many £££ is needed to get a picture really worth looking at?
The attached is good as a 'record' but not much atmosphere about it!

 

[NFuller]

how many £££ is needed to get a picture really worth looking at

Depends what your definition of "a picture worth looking at" is. If you want one of those images showing powerful solar flares and detailed granulation on the surface, then I would ballpark the cost at £1500. This includes proper filters, a telescope which accepts those filters, and a monochrome camera with very small pixels.

 

[sophiecentaur]

Depends what your definition of "a picture worth looking at" is.

As a subject for a photo, the full Sun is pretty short on atmosphere and variation. Over the last couple of years I have seen sunspots and managed to enhance them sometimes with one of my Sharp's toffee paper filters. Seeing and photographing straightforward sunspots is more like train spotting; you see on the website that there's something going on and you see it between the passing clouds and that's it.
I have had some memorable views and a few fair pictures of the Moon, planets and other bits and bobs which are actually atmospheric and I know there's so much more drama going on in the Sun - I just cannot see it at all. £1500 is quite a jump from a Baader filter at £30ish. Is there a happy medium? You can't rely on what manufacturers advertise.

 

[Andy Resnick]

Send them over here if you can't use 'em.
I have only managed pictures through the Baader safety filter, so far and I am horrified at the cost of anything else. It seems that you need an etalon to get those lovely impressive shots that we see on line. What is your experience of solar photography and how many £££ is needed to get a picture really worth looking at?
The attached is good as a 'record' but not much atmosphere about it!

PM me.

Yes, in order to get those sexy solar images, a proper etalon is needed- sub-Angstom linewidths, temperature controlled, etc. big bucks, and I can't justify getting one.

As for "how many £££ is needed to get a picture really worth looking at?", that's a subjective question. I've managed to scavenge spare ND and color filters, so my £££= 0, but are my pictures worth looking at? Some (most) would say 'no'.

One note- I'm pretty sure your posted image (which I find worth looking at!) shows blooming/overexposure. I believe I've mentioned how the auto-exposure and auto-meteriing fails when imaging with narrowband color filters, but I guess it's worth pointing out again.

 

[NFuller]

As a subject for a photo, the full Sun is pretty short on atmosphere and variation. Over the last couple of years I have seen sunspots and managed to enhance them sometimes with one of my Sharp's toffee paper filters. Seeing and photographing straightforward sunspots is more like train spotting; you see on the website that there's something going on and you see it between the passing clouds and that's it.
I have had some memorable views and a few fair pictures of the Moon, planets and other bits and bobs which are actually atmospheric and I know there's so much more drama going on in the Sun - I just cannot see it at all. £1500 is quite a jump from a Baader filter at £30ish. Is there a happy medium? You can't rely on what manufacturers advertise.

If you are trying to get some more detail around sunspots, then you need a low aberration energy rejection filter. The cheap film filters will blur out the details. I think the cheapest I can find is this
http://thousandoaksoptical.com/shop/solar-filters/full-aperture-solarlite/
They claim this filter to have similar characteristics to a glass filter, but as you said, you can't always trust the manufacturer. For an actual glass ERF you are going to pay more. If your looking to see ultra-detailed structure on the Sun, you will need a Ha filter setup. This is where things start getting expensive.
http://thousandoaksoptical.com/shop/h-alpha/h-alpha-9-angstrom-complete-system/

I would take a look at the ERF listed above since its not too expensive. It may give you what you're looking for. Unfortunately, almost everything in amateur astronomy can rapidly become expensive.

 

[sophiecentaur]

If you are trying to get some more detail around sunspots, then you need a low aberration energy rejection filter. The cheap film filters will blur out the details. I think the cheapest I can find is this
http://thousandoaksoptical.com/shop/solar-filters/full-aperture-solarlite/
They claim this filter to have similar characteristics to a glass filter, but as you said, you can't always trust the manufacturer. For an actual glass ERF you are going to pay more. If your looking to see ultra-detailed structure on the Sun, you will need a Ha filter setup. This is where things start getting expensive.
http://thousandoaksoptical.com/shop/h-alpha/h-alpha-9-angstrom-complete-system/

I would take a look at the ERF listed above since its not too expensive. It may give you what you're looking for. Unfortunately, almost everything in amateur astronomy can rapidly become expensive.

The cheaper one looks not too expensive. The other one seems to produce more convincing results but would they convince my wallet?
I guess I will have to scour the secondhand market. I am prepared to wait - which is what all amateur astronomers learn to do.

I believe I've mentioned how the auto-exposure and auto-meteriing fails when imaging with narrowband color filters, but I guess it's worth pointing out again.

I never use auto exposure through the scope. I use wide bracketing and that image was about the best of the bunch. I'm not sure what you are seeing on the picture but I used Unsharp Mask and that may be what you are seeing round the edge(?).
Glad you found it worth looking at, the spots seem pretty well defined. I was struggling with my Live View for fine focussing until I realized about the LCD brightness control. Since that I have seen no sun spots as the Sun has been hiding behind wispy clouds. That's what we find, isn't it? I will PM you now.

 

[davenn]

The attached is good as a 'record' but not much atmosphere about it!

still a great sunspot photo nice job

What is your experience of solar photography and how many £££ is needed to get a picture really worth looking at?

As for "how many £££ is needed to get a picture really worth looking at?", that's a subjective question. I've managed to scavenge spare ND and color filters, so my £££= 0, but are my pictures worth looking at? Some (most) would say 'no'.

yup

Yes, in order to get those sexy solar images, a proper etalon is needed- sub-Angstom linewidths, temperature controlled, etc. big bucks, and I can't justify getting one.

indeed

I just spend AU$2950 on a sub-angstrom Ha solar telescope today !
The main scope and filter unit was AU$2599 and another AU$349 for a zoomable
eyepiece ( the one you can see in the photo)

when I was at the shop, there were a couple of breaks in the clouds. Altho there are no spots on the sun at the moment,
we did see a nice prominence on the limbDave

 

[davenn]

I will get a better photo of it on a tripod soon rather than that small one off the sales www site

This Ha filter is called a Prominence Filter and as the name suggests, shows prominences well, sunspots and
other features. At some stage I will also get a Chromosphere Filter as they show very different information

Typical Prominence Filter images ...

random google image

compare this to a chromospheric filter image ...

from ... https://stargazerslounge.com/topic/246571-17-06-2015-quark-chromosphere/Dave

 

[NFuller]

I just spend AU$2950 on a sub-angstrom Ha solar telescope today !

Can't wait to see your images using this!

 

[davenn]

I still have to sort out the imaging, plus the weather over the last week hasn't been playing ball
Got some views on Thursday and could see some prominences on the limb and a dark filament stretching across the face

Today, Saturday, lots of clouds but got some glimpses
This photo below from a mate, Ian Griffin, back in my old home town, Dunedin, New Zealand,
shows almost exactly what I was also seeing today. I just didn't see some of the finer details

note the large prominence loop on the lower left of the limb ( 7 o'clock position)
smaller ones at 8 and 2 o'clock positions
The very long filament right of centre
I could also see that small filament towards the left edge

Prominences and filaments are the same thing. It is just their position that defines their name
Prominence = on limb
Filament = on the diskDave

 

[davenn]

well dang it !

I can't find any software that I can do standard imaging with my auto guider camera.
I was hoping to use it as an imaging camera as well. I spent hours last nite downloading and installing a number (5)
of programs. Two of them were supposed to work with my cam, but unfortunately they won't recognise it.

Ohhh dear, more money to spend haha.

looking at something along the lines of this ...

https://www.bintel.com.au/product/zwo-asi178mc/

needs to be suitable for both planetary/sun as well as deep space objectsDave

 

[Drakkith]

I can't find any software that I can do standard imaging with my auto guider camera.
I was hoping to use it as an imaging camera as well. I spent hours last nite downloading and installing a number (5)
of programs. Two of them were supposed to work with my cam, but unfortunately they won't recognise it.

I had the same problem with one of my auto-guiders. I ended up buying another cheap camera instead.

 

[davenn]

I had the same problem with one of my auto-guiders. I ended up buying another cheap camera instead.

hey mate,

like a lot of interests/hobbies, tis a hole that money continues to get thrown into haha

The cam I currently have is the Orion Starshoot autoguider

https://optcorp.com/products/or-52064-starshoot-autoguider

It works well with the PHD2 autoguiding software, but with nothing else I have so far triedD

 

[Drakkith]

The cam I currently have is the Orion Starshoot autoguider

https://optcorp.com/products/or-52064-starshoot-autoguider

It works well with the PHD2 autoguiding software, but with nothing else I have so far tried

That's the exact auto-guider I was referring to.

 

[davenn]

That's the exact auto-guider I was referring to.

ohhhh WOW "snap" LOL

I never bought it to do imaging with, at that time it was for autoguiding and I got a small 50mm scope to use it with and the HEQ5 PRO GE mount
It's just now a couple of years later and with my solar scope, I was hoping to press it into use for imaging, sadly it seems its not to beD

 

[NFuller]

I can't find any software that I can do standard imaging with my auto guider camera.

Wow, that's disappointing. Orion claims that the star shoot camera can be used for imaging. Are you sure it's not just a bad setting somewhere. I think the star shoot camera is actually a QHY camera. If you set your software to connect to a QHY it might work.

looking at something along the lines of this ...

https://www.bintel.com.au/product/zwo-asi178mc/

I own an ASI120 which I use for both guiding and planetary imaging. I think they are very good cameras for the price, although some software can be a bit finicky with them.

 

[davenn]

Wow, that's disappointing. Orion claims that the star shoot camera can be used for imaging. Are you sure it's not just a bad setting somewhere. I think the star shoot camera is actually a QHY camera. If you set your software to connect to a QHY it might work.

yeah, just a bit sad

the 2 significant programs I tried (out of the five) were Sharpcap and Firecapture
both of them auto detect camera type, they don't give you the option of specifying a specific camera

they both come up with "camera not connected" or words to that effect

I own an ASI120 which I use for both guiding and planetary imaging. I think they are very good cameras for the price, although some software can be a bit finicky with them.

that has been one I have been looking at. There's a number of versions of that model to choose from
ZWO ASI120MC Colour, ZWO ASI120MM Monochrome, and the same 2 again but with USB3.0 capability

I suspect that these are great for planetary/sun but they may not do so well with deep space objects
So I am looking at something that will give me the best of both worlds. On Monday, I will talk to the guys in the shop and get some good advice and then decide which way to go Dave