Photographing the sun in detail?

[sologuitarist61]

Lovely shots, especially the WL, I don't seem to be getting the surface detail that you have.

[Steve Ward]

Have you tried taking multiple exposures and stacking ?

I'm still experimenting but find that stacking around 50 RAW frames in Reg5 gives up some nice results.

[sologuitarist61]

No I haven't tried that - I can understand why you would do that with dark astro subjects to collect more photons etc, but aren't images of the sun bright enough, or am I not thinking in the correct way? Although having said that I did get some other detail in the shots I took, but assumed they were 'grain effects', perhaps they were indeed surface detail, see below.

[Steve Ward]

Not really sure how it works but it does.....

Single frame.

Result after stacking 50, tweaking wavelets and minor adj in WindowsPhotoGallery.

Have avoided PS , bit complicated but will persevere with it.

[iwatkins]

Ian, those are some monumentally good shots. Super impressive! How did you take that sunspot close up? The seeing would need to be superb to get that, surely?

Thank you

The close up is simple really. If I take say a thousand frames, put them into AutoStakkert, there is an option to x1.5 or x3.0 drizzle. When it than goes and stacks it also blows the image up. File comes out much bigger, crop the bit you want, then there you go. Even so, this was with a DMK camera so that tends to "zoom" the image anyway just as a webcam does compared to a DSLR.

Cheers

Ian

[iwatkins]

No I haven't tried that - I can understand why you would do that with dark astro subjects to collect more photons etc, but aren't images of the sun bright enough, or am I not thinking in the correct way?

Kind of.

For DSOs you stack multiple images to raise the signal to noise and hence to increase the level of detail.

But for planetary work (including the sun), signal levels are usually ok but the seeing conditions are the next problem.

If you look at Saturn for example. In two minutes of constant visual, there will be periods of mushy image and a few periods where the seeing clears and everything becomes clear and sharp.

Put a camera in the scope and take a single image, the chances are that you'll capture during a moment of poor seeing.

But if you shoot multiple images, say 1000 (as stills or part of a video), there is a much better chance you'll record a period of good seeing. It's called "lucky seeing".

Registax, AutoStakkert etc. will take your 1000 images and process them to get the best frames out. You may choose to stack the best, say, 20% of the images. Post alignment and stacking you'll get a much better image.

For solar WL you do the same as for planets but you are fighting generally poorer seeing conditions due to the suns heat causing convection and turbulence in the lower atmosphere. So imaging usually gives better conditions not long after sunrise or a few hours before sunset. You can of course image at midday but just bear in mind that you'll usually have fewer good frames.

Hope that all makes sense.

Cheers

Ian

[iwatkins]

Ian that last shot is a peach If you can get that with a PST and a DMK41, you have probably just saved me a grand

Hey, thanks Rik.

Yep, a DMK41 in the top of a standard PST, on a mount. Grabbed 1000 frames on band exposing for the surface (@15fps this takes just over a minute). Then slow the exposure time right down to bring out the prom details then shoot another 1000 frames. Total time to take the imaging, just over a couple of minutes.

Stack both videos individually in AutoStakkert. Think I took the best 10% of frames for both. Get the two resultant TIFFs and layered the disk image over the proms image. Little bit of sharpening and colouring and job done.

Are you thinking of going for a Lunt Rik? I'm the same but as I'm getting results I'm happy with with the PST I'm not rushing now. If I do go for one, it'll be an imaging version with the larger blocking filter, pressure tuned etc. But it soon adds up then I think but will I be happy at 60mm, what about 80mm? Next thing I know I'll have to sell the car and my first born :).

Cheers

Ian

[sologuitarist61]

Not really sure how it works but it does.....

Single frame.

Result after stacking 50, tweaking wavelets and minor adj in WindowsPhotoGallery.

Have avoided PS , bit complicated but will persevere with it.

Impressive, will have to try that

[RikM]

Are you thinking of going for a Lunt Rik? I'm the same but as I'm getting results I'm happy with with the PST I'm not rushing now. If I do go for one, it'll be an imaging version with the larger blocking filter, pressure tuned etc. But it soon adds up then I think but will I be happy at 60mm, what about 80mm? Next thing I know I'll have to sell the car and my first born .

Cheers

Ian

I was thinking of a Lunt LS60T-B1200 but it's quite a chunk of change and we are supposed to be saving for deposit on a house. I love PST's to look through and it was only that most people generally say that imaging is poor through one. Your images put that myth to bed nicely I have never been afraid of a bit of effort to get results and a PST and DMK41 together is about half the price of the Lunt (with the nice focuser) so it makes the decision easier

[Black Knight]

Would a DMK41 be better with a PST than a DMK21?

Sent from my mobile using Tapatalk, so please excuse the speeling and granma!

[iwatkins]

Would a DMK41 be better with a PST than a DMK21?

It all depends what you want really. A mono, non IR, DMK21/31/41/51 will all do the same job, obviously just different image size because of the different chip sizes and different range of frame rate.

A DMK21/31 chip size means that the whole disc won't fit in a single shot, but you can do mosaics easy enough. With a DMK41 the whole disc fits with a little room to spare.

If I was buying a camera just for PST usage, the the mono, non IR cut DMK41 would be my recommendation. But if you'll put it to other uses, e.g. Planetary, you might want to compromise.

Cheers

Ian

[Black Knight]

Thanks Ian . It would be mono, yes. I don't have a PST yet, but I'd love to get one. I'd probably want to use the DMK (which i don't have yet either ), for planetary as well, so it's worth me planning for that at the outset.

Sent from my mobile using Tapatalk, so please excuse the speeling and granma!

[iwatkins]

I love PST's to look through and it was only that most people generally say that imaging is poor through one. Your images put that myth to bed nicely I have never been afraid of a bit of effort to get results and a PST and DMK41 together is about half the price of the Lunt (with the nice focuser) so it makes the decision easier

Tough choice Rik. I would say that if you can afford a properly spec'ed Lunt then I would go for it. But if you are not sure a PST + mono DMK41 will keep you going in Ha for visual and imaging for quite a while I think. Yes, it does require some effort, especially capture as focusing is fun, but the results are worth it.

I looked at this way. I was already an enthusiast of WL. I thought I would love a spec'ed up Lunt for Ha. But not sure if I would like it went for the PST for visual on the understanding that if I got into it, I could go for the Lunt at a later date and sell the PST. The fact that you can use a DMK with a short and shoulderless nose piece for imaging has just extended the PSTs stay of execution

On a side note, I must get joined up to the Cotswold AS. That way I can come out on your outreach days

Cheers

Ian

[RikM]

On a side note, I must get joined up to the Cotswold AS. That way I can come out on your outreach days

Cheers

Ian

It would be great to see you there. We are supposed to be doing a solar day at Highnam Court tomorrow but the weather is not looking hopeful

[badgerchap]

Not really sure how it works but it does.....

Have avoided PS , bit complicated but will persevere with it.

Steve, where does the colour come from in this? Is it added by your good self, or is it a direct result of the stacking process?

Also, what sort of filter are you using?

[Steve Ward]

I use Baader film in a readymade AE filter.

I always shoot in RAW and the colour seems to be hidden in there somewhere although not immediately apparent.

I tweak only in WindowsLivePhotoGallery , shoving the saturation up full and playing with temp and tint until I like it.

I have some guidelines saved somewhere about colouring with PS, i'll try and find them.

[sologuitarist61]

Yes I was wondering about the colour as well.

There you go - answered before I asked it

[sanmatt]

ahhhh this is a good read. I have enough RAW solar images form today to be able to stack around 16 or so...I cant get my head around Registax, what is this windowsphotogallery? is it a free one?

eta - downloading it now. How do you stack in it?

[Steve Ward]

Have kinda "lost" those guidelines somewhere in the depths of the chaos a.k.a. my harddrive (must start labelling things)

Was very kindly given the instructions by Bizibilder , I'm sure that if you PM Roger he would help you better than i can.

[Steve Ward]

Have to use Reg5 , 6 doesn't seem to support RAW frames.

In select box tick RAW images as opposed to Video.

Takes a while to load frames compared to AVI's so bear with it.

I align using a sunspot generally but the centre of gravity thing works especially if you've been shooting between clouds and the image has 'wandered' a long way.

It's then much the same as if it was an AVI , limit ,optimize, stack, wavelets etc.

As i said everything takes longer because of file sizes.

WindowsLivePhotoGallery is the basic picture editing s/w that came with my W7 laptop. A lot simpler to negotiate than Photoshop when you don't really know what you're doing like me.

Hope this is of some use , but bear in mind I AIN'T NO EXPERT:icon_salut:

[Steve Ward]

Try these....

[Jon Sales]

To give you some idea Peter Lawrence reviewed the Lunt 6" Achro Solar scope in the current issue of S@N the manufactures did not use a full size Etalon ( special narrow band pass filter ) because of cost, but placed a much smaller h-alpha unit in the light train inside the tube, the cost of this scope, just a whisker under £9000

John.

Think I might buy two of them

[badgerchap]

Have kinda "lost" those guidelines somewhere in the depths of the chaos a.k.a. my harddrive (must start labelling things)

Was very kindly given the instructions by Bizibilder , I'm sure that if you PM Roger he would help you better than i can.

I'll have a fiddle with PS when I get a break in the clouds - I'm fairly used to it from a graphic design POV, sure I can have a tinker I''l let you know how it goes :/

[Woody]

Some great information and fantastic images here, thank you.

Just made a Baader filter for my ED80 and starting to practice for the main event on June 6.

Clear skies

[Fandango]

Terrific photos!