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My Quark Imaging Workflow


Ewan

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I got asked by a member on another forum what my workflow was when doing Solar imaging using the Daystar Quark Chromosphere so thought I would do a new topic for anyone else interested.
I am explaining my process but yours may work as well, it also seems a little simplistic but it's for the benefit of others that have not done as much imaging or use alternative software, sorry for that.

Getting Ready :-

Clean my 2" 0.5 FR, DMK ccd sensor window & 2" UV/IR filter, screw it all together & get it on the Quark so no more dust gets to it, important for me.
Plug the Quark in & leave while setting up, make sure (for me) tuner is on 1 turn CCW.

After pointing the scope North'ish I go through the hand controller inputs like you have to, make sure everything is correct & no align points.
Just pointing out that you don't need to be super accurate with Solar imaging with your mount, make sure it's on Solar Tracking though.

Once Quark is on, IC Capture is running & I have an image, do a rough focus, fairly bright.
While watching the ICCapture image window on the laptop I slew the solar limb to the left side of the image box, about 5mm from going 'out of the box', now I slew up/down to make sure ccd is aligned, if the disc slews at a slight angle, loosen & rotate the Quark imaging train in the scope & re test the slew, if it goes up & down & retains the same gap up/down the left hand side I am good to go.

If not re adjust until it is, very important for mosaic's.

Once that is set up I then check the disc or browse SolarHam online to see what's available on the disc.
I do try & do the mosaic run first but more on that later.

I centre a sunspot in my capture fov, zoom to 200%, drop Gamma to 15, Exposure to 217 (or other) & adjust the Gain up, what you want is the chromosphere detail very dark but no flare area's too bright, this makes the image extremely contrasty & excellent for getting good focus.

Now adjust focus in/out, I stop on the out then go back in slowly already noting previously by feel where the 'good' focus was approximately, once there I lock the focus on the scope tube BUT only gently.
Un Zoom the image to 100%, re set Gain to it's lowest if you don't need it.
Now I don't use the histogram anymore as I now know how my Quark likes to operate & behaves but you should use it to be honest.

Acquiring the images :-

Select your desired frame rate, my max is 60fps, make sure data capture is UNCOMPRESSED, Y800 is mine.
Select your Exposure setting & Gamma just so you have nearly filled your histogram indicator view but not quite, now rack it back a little, 90-95% is good.

Re centre target & capture 1000 - 2000 frames, once saved go to your next target & repeat.
Once you have completed your captures make sure to take a FLAT frame video, DO NOT adjust any Exposure, Gamma or Gain settings.

Flat frame capture :-

Just slew to the solar centre, try to find a pretty blank evenly lit area, de focus the scope & capture 200 - 300 frames, that's all you need, once done goto your capture folder, make a new folder & select all of that sessions data & drag / drop into the new folder.

This avoids any confusion later especially with the flat frame involved.

Now may I suggest you do try some really low Gamma shots as well, go for Gamma of 35 - 40 & an Exposure setting that shows a capture image which has a lot of contrast, then do the above steps again.
I have yet to achieve the same results through post processing with a high Gamma & a low Gamma, low just seems to give more detail I find but your mileage may vary.

Stacking :-

I will assume you use AS!2 to stack your images as it is really the best there is that I have found so far.
Open AS!2, open your FLAT frame capture first, Click Image Calibration & select Create Master Frame, select the same folder where this flat capture was from & give it a name....Flat is good  wink.gif

Once done Open your first solar capture from the same folder, once loaded make sure your settings are as follows.

SURFACE is selected
Improved Tracking is ticked
Improved Tracking ON
Noise Robust on 3 (2 is also good just have a fiddle)
Frame Percentage To Stack = 10%
HQ Refine is ticked

Then select Analyse, once done set your AP Size to 20, Min Bright 0 then click Place AP Grid then Stack.

Post Processing :-

I use IMPPG to do almost all the processing apart from some tweaks in PS, it's an excellent sharpening tool & I recommend you search & download it.

It takes a while to find the correct settings that you are happy with but feel free to try these settings :-

Lucy Richardson Deconvolution Sigma 0.9868
Iterations 300
Prevent Ringing Unticked

Unsharp Masking
Sigma 26.5757
Amount 2.2760

You will know what they mean when you see the program running but have a play with all the adjustments, watch out for clipping the image though using the Tone Curve.

Once you have an image you are happy with save it out for further processing in PS (or not).

Photoshop :-

In PS I first re size the image to 96 in the Resolution box, Width 800 (these are good for me, yours may differ)
I then use a mix of Unsharp Mask, Focus Magic & the High Pass filter on the image, going easy though as after all the detail wants to appear to be soft in texture not all 'pointy', you know what I mean hopefully.

You can also invert the image (also available in IMPPG), colour & add text then save it out.
When saving the image out don't make it too big, if you post a huge image it will only accentuate the bad points not the good.

A few notes :-

If doing mosaic's when looking for a good Exposure / Gamma setting make sure you set this up on the CENTRE of the solar disc, if not what you may find is the captures look fine on screen at the top, bottom & limbs but as you near the middle the image will just overexpose & be way too bright then you start all over again.

If you have a small hard drive or not a lot of room use Compressed format, I did when I first started & they looked fine, no one even questioned the quality  wink.gif (use uncompressed if possible though)

Use 1 or 2 AP Points in AS!2 for prominences or you may find your stacked image looks more Tetris than Solar  cheesy.gif

Grab a lot of captures & use different Exposures & Gamma, you don't want to set up all that hard earned gear, shoot 5 captures go indoors & find they are all bad  sad.gif, fill that drive up & you are almost guaranteed a good final image & you have more chance of imaging with good seeing.

Maybe grab your mosaic first, this way if the clouds do turn up afterwards you still have a whole disc to choose some single images from & not just a couple of single shots.

Play safe, use your filters wisely & never ever look through a telescope at the sun without the proper precautions.

I appreciate it is a long explanation but beginner's could do with a detailed account of how you can go about grabbing some solar captures as well as seasoned imagers.

I hope this helps some of you but don't forget this is how it works for me & not everyone's set up is the same.
Have fun, stay safe.

Ewan

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Mercy ........ that's some workflow  :smiley: and here I was thinking of tinkering into solar imaging...... maybe in a little while

My workflow:-

  • Turn on Quark
  • Move setup outside
  • Put on my peaked balaclava
  • Sit on chair
  • Observe the sun
  • Post my findings on SGL

:grin:  I take my peaked hat off to you for your commitment and unselfishness for sharing the images  :grin:

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Good write up Ewan, I'm sure this will aid many a first time imager.

I suspect most of the imagers on here will have a similar process for setup, capture and then processing but with tweaks here and there.

For me there is usually at least one change of wavelength so have to remove camera / filter and reallign the camera, refocus etc. And if I decide to go the whole-hog (Ha and either WL or Ca-K) then I have to switch from PST to Evostar or vice-versa.

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Very nice write up. It is striking to see your much larger sigma in unsharp masking, combined with a lower strength, compared to what I use. Might play around with my settings again

That believe it or not Michael is a preset I have saved & I just apply it to most of my images, more often than not I can use it in batch processing as well, no good on proms though as you probably would have guessed & the Tone Curve also has it's own setting that goes with this but sometimes needs a small tweak.

Don't know how I managed without IMPPG before, it's just so fast & all the settings you need are right there on screen, it's great.

Let me know how you get one, I will be interested.

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Don't know how I managed without IMPPG before, it's just so fast & all the settings you need are right there on screen, it's great.

Ditto, use it for all my Ca-K and H alpha sharpening now. The batch processing mode is really convenient, that and the equivalent process in AS!2 and I can be doing something "useful" in the eyes of other members of the household :rolleyes:

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That believe it or not Michael is a preset I have saved & I just apply it to most of my images, more often than not I can use it in batch processing as well, no good on proms though as you probably would have guessed & the Tone Curve also has it's own setting that goes with this but sometimes needs a small tweak.

Don't know how I managed without IMPPG before, it's just so fast & all the settings you need are right there on screen, it's great.

Let me know how you get one, I will be interested.

I also save presets. I will tweak some recent data with other settings and see how they work

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Mercy ........ that's some workflow  :smiley: and here I was thinking of tinkering into solar imaging...... maybe in a little while

My workflow:-

  • Turn on Quark
  • Move setup outside
  • Put on my peaked balaclava
  • Sit on chair
  • Observe the sun
  • Post my findings on SGL

:grin:  I take my peaked hat off to you for your commitment and unselfishness for sharing the images  :grin:

This is why Stu sticks a phone to the eyepiece :grin:

I can't get anywhere with phone shots

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Nice write up Ewan. A couple of things to add.

Firecapture is well worth a look, I prefer it to IC.

In AS!2, once you have created the flat and then opened your first AVI you have to apply the flat. It will then be automatically applied for all subsequent AVIs.

Quite a few other differences but as you say, they are setup and processing preferences.

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This is why Stu sticks a phone to the eyepiece :grin:

I can't get anywhere with phone shots

Lol :grin:  :grin:  :grin:

Nice write up Ewan. A couple of things to add.

Firecapture is well worth a look, I prefer it to IC.

In AS!2, once you have created the flat and then opened your first AVI you have to apply the flat. It will then be automatically applied for all subsequent AVIs.

Quite a few other differences but as you say, they are setup and processing preferences.

Not sure I can edit it now Freddie but it gives people a basic knowledge I guess.

The other thing is remember to change the flat file loaded into AS!2 for different Exposure & Gamma changes in your captures, also REMOVE the loaded flat if stacking PROMINENCES as they ruin the image.

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I have posted a comparison of different unsharp masking settings yesterday evening here:

http://stargazerslounge.com/topic/251143-experiments-with-unsharp-masking-on-data-from-the-22nd/

For my optics at least, the smaller sigma seems to win

I would imagine the objective size will play a significant role in this, even I am looking forward to running my 152mm captures through it using my own preset, when my gear does turn up that is :grin:

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I would imagine the objective size will play a significant role in this, even I am looking forward to running my 152mm captures through it using my own preset, when my gear does turn up that is :grin:

I think the filter has more of an impact than the aperture, as long as you are working at the same focal ratio. Seeing disk size has an impact too, of course. The Solar Spectrum filter seems to have a high finesse, which probably means the mid spatial frequencies in the image are well represented (the image shows loads more contrast than the LS35 or SM-60), so sharpening with high sigma is not needed as much. Sharpening the finer detail is more beneficial

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Mercy ........ that's some workflow  :smiley: and here I was thinking of tinkering into solar imaging...... maybe in a little while

My workflow:-

  • Turn on Quark
  • Move setup outside
  • Put on my peaked balaclava
  • Sit on chair
  • Observe the sun
  • Post my findings on SGL

:grin:  I take my peaked hat off to you for your commitment and unselfishness for sharing the images  :grin:

Shaun I should say that it's very possible to process solar images quickly!

I think Ant knocks his out in a few mins each.

So which cam you getting? :evil::grin:

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