22nd August Quark

[keramos]

Folks,

Managed to take some captures using the Quark, I haven't used any Flats, wasn't able to use the tilt adapter (to help remove NRs) however did manage to use the 0.5x focal reducer.

Need some advice and have a few questions:

1) Is there a guide/tutorial for taking flats? Does the process differ between solar and any other type of astro imaging?

2) I couldn't seem to get focus therefore thought i'd try using the 0.5x reducer, I did not get any Newton rings usinf 0.5x reducer but there was a shadow on the image, see example below. In trying to figure out why there image was the way it was, I completely forgot to use the tilt adapter to see if it would eleminate the odd effect.

3) Does 0.5x reducer go on the camera or the Quark, I put it on the camera.

This was ROI on the AR, not the best....

Thanks in advance,

[Davey-T]

Good start.

There's a vid on YT on using flats in AS2, you can take "bag flats" using one of those thin veg bags from the supermarket over the end of the scope also cling film and defocused, tried them all at one time or another, sometimes they don't work for no discernable reason.

Focal reducer in camera.

Don't know about the shadow, never seen that.

Dave

[xtreemchaos]

cool solar images,nice detail.thanks for posting.charl.

[Luke]

Good start!

re: the shadow, it is vignetting, basically the combo of your large camera chip and using a 0.5x reducer is trying to show more of the solar disc than the Quark allows for in your scope. If you were to use an eyepiece you would not be able to see the whole of the solar disc, this is the same thing but with your camera.

So you need a little less reduction. I had the exact same issue witih my Quark, ASI174 and 0.5x reducer.

The closer the reducer is to your camera chip (i.e. the shorter the nosepiece) the less reduction there will be. I think you will need about 15mm nosepiece to get to 0.7x reduction.

What I did was to use an old nosepiece I found that had a continuous filter thread and I cut it down using a hacksaw. It cut it down to about 18mm long and reduction was still a little too much, but I found that by using a Baader Glass Path Corrector as well I could get to about 0.72x reduction. The light bit of vignetting I still get is easily removed with a flat, there is no loss of detail, it's just a bit darker and the flat corrects it.

There is no need to use a glass path corrector, I just didn't cut my nosepiece down short enough (I should have cut to 15mm) so I have fudged my way to about 0.7x.

Hope that helps. It's a very nice camera!

[dazzaa1966]

Well said Luke. You took the words right out of mouth.

[Ewan]

Yep a good start to long solar hobby, just posted my complete workflow here http://stargazerslounge.com/topic/251035-my-quark-imaging-workflow/  you may find it helps, covers most things.

[Pete Presland]

Very nice start.

[laudropb]

Very nice start. Thanks for posting.

[michael.h.f.wilkinson]

Very nice start indeed

[Montana]

Some great images there :)

Alexandra

[David Smith]

Good shot. Have a look at Michael's guide http://stargazerslounge.com/topic/242304-a-short-guide-to-my-solar-image-processing-from-raw-data-to-single-pane/

[dazzaa1966]

Have a look at Houston Haynes tutorials on you tube.

He helped me lots when I first started imaging the sun.

[keramos]

Thank You all for the kind comments, it is really difficult to develop skills when weather is not playing ball....

Luke, thank you as always for detailed responses...

Ewan, I was reading you post on work flow last night...it definately helps beginners like myself.

[1parsec]

Great start there.

For flats, I move to a relatively bland area of the Suns disc as near to the centre of the disc as possible, defocus until all detail is wiped out and record about a 300 frame video

I open that video in AutoStakkert and the select-  Image Calibration > Create master frame. The saved file can then be use with a normal recording by selecting -  Image Calibration > Load master flat.

That flat will be applied to the currently loaded video(s)

The shadow as already said, is vignetting caused by too much reduction by the focal reducer. I'm not sure why the shadow is offset , maybe there is a small misalignment / droop in the image train which often happens with long and heavy H.alpha equipment -