Solar imaging help!

[StuTodd]

I have use of a Lunt solar scope and use mono CCD cameras (Atik 314, 414 and DMK21). I'd love to get to somewhere near Arthur and others here and would like a link to a tutorial etc if possible?

My latest offering attached..a single image with wavelets done in Registax 6 and curves done in gimp.

I tried stacking 50 or so .fit files in Registax for good S/N but it came out blurred due to the avo seeing etc I guess.

Any help much appreciated!

Stu

[tempestwizz (Brian)]

others are way more expert than I, but usually I shoot an .avi file of about 30 seconds or so. Then optimise and stack with Autostakert2 to a .tif file then registax process the single .tif, or the whole process in Registax.
if you search for Autostakert or Registax you will find help files not too far away.
Cheers Brian

[StuTodd]

Thanks Brian.

I have used a Philips 900 webcam in the past (and still do for planetary stuff) and that records in .avi.

With a dedicated mono CCD like the 3/414, they take stills. Unless that's where I'm going wrong....I had good focus (visually) and good ADU counts at .008 second in Artemis.

I took about 55 stills and went through half of them but it was like looking at a .avi of course (but VERY slowly). Stacking of 30 produced a blurred image so I just used the registax best one and processed in gimp.

I have to say, I'm not a fan of the "inverted" solar disc process as it looks too contrived.

Stu

[tempestwizz (Brian)]

Because the sun is so bright the exposure times can be short. If you take a single short shot, it can be OK, but you are at the mercy of whatever distortion the atmospheric perturbations do to your shot at that instant. That is why you use multiple images to hopefully average out these distortions.
Yes, you can take 50 or so individual shots and combine them, but this is cumbersome and less effective when you compare it to taking video where you get 2000 to 3000 frames to combine.
People generally seek a sensor that can take the fastest frame rate because there are brief times occasionally where there are no perturbations in the atmosphere, and the high frame rate increases you chances of catching one of these moments.
The stacking software is suppose to sort through and identify the highest quality frames and use them first in the combining process. Distorted frames are discarded. Overall, the process works well. I think Autostakert also offers good tutorials on capture and processing of your .avi files.
Hope this helps. Brian

[Arthur Coombs (Arthur)]

Hello Stu,
I am imaging with a Coronado 60-mm DS instrument and project the image into an ImagingSource camera with a 640X480 px chip, using an Hyperion 17-mm eyepiece plus spacer rings. One can, alternatively use a Barlow lens to achieve higher magnification.
Avi's of 400 frames have been my recent choice, of which I would stack 30% in Autostakkert. You can also download 1000 or 2000 images as others have suggested. Depends on storage space etc.
The resulting image is then opened up in Registax and the wavelets adjusted. I try to do minimal work here and save the adjustment numbers to apply to further images taken during the same session.
When exposing, use of the histogram is advised for surface images so that close to the 256 levels are utilized.(2^8 byte) I try to keep the gain of my camera at about 750 with an appropriate shutter speed (often 1/145s in my case)when looking at the histogram.
One cannot use the histogram when exposing prominence images. 1/45s with the gain adjusted so the prominence has no solid white features has worked well for me.
Images are transferred into Photoshop; surface copied and pasted on to the prominence. Using "difference" and the move tool, adjust until aligned. Back to normal mode where I apply a black mask to the top surface image and then bring the underlying surface through the prominence image. Crop, Merge down ,save and action/colour/save for final images.
I trust that this may help you
Kind Regards
Arthur

[StuTodd]

Fantastic Arthur, many thanks.
I'd not thought of eyepiece projection into the DMK, I will have a go when the cloud rolls away.
I also like AutoStakkert, saving the results from that and then doing wavelets in registax.

I guess it is all a matter of practise, thanks again Arthur.

Stu