First Light: Solar Imaging with Quantum Filter

[cshahar]

Hi Everyone:

This was my first outing doing solar imaging. The results surprised me given that seeing was slightly below average and the fact that I was doing it from a jittery balcony. The equipment: Quantum PE .4 angstrom filter, Explore Scientific 4” refractor, 4X Powermate, DMK41 imager (which I plan to use as a starter imager). If there are any improvements you can suggest I would love to hear about it!

I found my experience in image manipulation to be quite helpful when processing these images. There is a fine line between realism and over-sharpening. I tried to find a balance here. I would appreciate any comments on that as well.

I am still working on a few issues, namely getting better polar alignment during the day and finding a way to cut the daytime glare on my laptop.

I want to thank Mike Garbett for his very helpful guidance. It is great to benefit from an experienced imager's suggestions. Also, this forum's posts have been an inspiration!

-Charles

[xtreemchaos]

great image Charles, nice detail, you have done well, keep up the good work.  charl.

[michael.h.f.wilkinson]

Very nice first shot. Excellent detail

[Ewan]

Hi Everyone:

This was my first outing doing solar imaging. The results surprised me given that seeing was slightly below average and the fact that I was doing it from a jittery balcony. The equipment: Quantum PE .4 angstrom filter, Explore Scientific 4” refractor, 4X Powermate, DMK41 imager (which I plan to use as a starter imager). If there are any improvements you can suggest I would love to hear about it!

I found my experience in image manipulation to be quite helpful when processing these images. There is a fine line between realism and over-sharpening. I tried to find a balance here. I would appreciate any comments on that as well.

I am still working on a few issues, namely getting better polar alignment during the day and finding a way to cut the daytime glare on my laptop.

I want to thank Mike Garbett for his very helpful guidance. It is great to benefit from an experienced imager's suggestions. Also, this forum's posts have been an inspiration!

-Charles

Hi Charles,

Your PA will be fine if your doing solar work, in fact a bit of drift actually helps, drift combined with flats will do wonders with your images, PA really isn't needed.

With my setup I just lift the AZ outside, aim it roughly North (I am so used to where it should point it's easy now) & just set the handset up, make sure tracking is on Solar & off you go.

Flats should also help with the uneven illumination in the above image, it's good practice to take a flat file first before imaging anything.

Decide on your target then adjust exposure / gamma to suit, then slew to the middle of the sun, defocus & take a video of about 250 frames or (as some do) the same length as the intended capture, I have no trouble with 250 frames though, once taken off you go & grab your captures.

If you change exp or gamma then re do the flat file, or in fact shooting ROI (Region Of Interest) captures will also need a new flat file.

Bright prominence captures won't need a flat.

Hope some of that helps & good luck, enjoy the sun enjoy the imaging.

[cshahar]

Thanks Ewan for the comments and suggestions. Just wondering why it is that a bit of drift is helpful? Does it not introduce motion blur and constricts the total area the stacker can use? Yes, I forgot to put the drive on solar tracking. That is a good point. I need to find out more about flats. I am not quite clear on how they accomplish what you said. Thanks again!

-Charles

[Ewan]

Thanks Ewan for the comments and suggestions. Just wondering why it is that a bit of drift is helpful? Does it not introduce motion blur and constricts the total area the stacker can use? Yes, I forgot to put the drive on solar tracking. That is a good point. I need to find out more about flats. I am not quite clear on how they accomplish what you said. Thanks again!

-Charles

Hi Charles,

Say for arguments sake you image an area for say 30 seconds, have a little bit of muck or dust blocking some detail, when you stack 10% of the frames you will not have very good detail in that area, drift kind of even's things out.

First thing I do when once setup is check the laptop view for dust then try to find the culprit & clean it off with a fine brush, ie the sensor, UV filter or Focal reducer, since using a 2" FR I hardly see any dust now anyway which is very good for me.

De focussed flats will give you a flat file that is applied to each capture you put through AS!2 or other program, this will apply the same illumination if you will to each stacked image so all your frames are pretty good.

Not so important for single frames (but I would do them) but very for mosaic's.

Get in the habit of taking flat files as soon as you can then avoid disappointment.

The top right of your image has a lot more contrast then the lower left, it looks like your were aiming at an active region but even so a flat file would have improved the image no end.

[cshahar]

Okay, I understand how drift can help deal with dust. I guess if the exposure time is quite fast motion blur will not be a factor. I tried cleaning the sensor with a brush as there was a lot of dust initially. But it only helped a little. I think I need an air blower as well. Sorry, I don't quite understand how the flat field is incorporated into the stacking program (I use Autostakker!2). Please clarify. Thanks!

[cshahar]

Sorry, I did get information from Mike Garbett on how to incorporate flats into the stacking software so that question is not relevant.

[sooot]

very nice first light, look forward to seeing more

[laudropb]

Nice image for your first go and some very interesting discussion.

[Pete Presland]

A good start to your solar imaging.