Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Frankenscope? Let's see it!***be advised that NOTHING in this forum has been safety tested and you are reading and using these posts at your own peril. blah, blah, blah... dont mess around with your eyesight when it comes to solar astronomy. Use appropriate filtration at all times...
Post Reply
sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by sywong2000 »

Hi everyone,

Need some advices on my first attempt on solar imaging by doublestacking Daystar Quark Chromopsphere and PST Etalon. I attempted to take a series of SER at AR 2794 & 2795 but I've found the resulting image intensity is quite "flat" after flat correction - I believed there should be some brighter regions just outside the sunspot of 2795 but I didn't see them after flat correction.

Here're a single frames before/after flat correction and my imaging setup.
I rotated the camera 180 up side down, so AR2795 is on the upper right corner.
Setup: Baader ERF -> Tak 76ds -> tube extension -> Televue 4x -> Daystar Quark -> PST Etalon -> ASI 174mm

Was it the Daystar dial settings and the PST Etalon space tuning combination? I only have time to play around tuning the PST and seemed I got the most contrasty image when it's somewhere at 60 degree to the most clockwise position. I keep the Daystar dial at 4-o'clock all the time.

Any ideas?
solar_setup_20201227.jpg
solar_setup_20201227.jpg (257.2 KiB) Viewed 4994 times
054014_20201227_Sun_L_single_frame_before_flat.jpg
054014_20201227_Sun_L_single_frame_before_flat.jpg (121.14 KiB) Viewed 4994 times
054014_20201227_single_frame_after_flat.jpg
054014_20201227_single_frame_after_flat.jpg (126.19 KiB) Viewed 4994 times


User avatar
marktownley
Librarian
Librarian
Posts: 42272
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20435 times
Been thanked: 10243 times
Contact:

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by marktownley »

Hi there and welcome to the forum.

First of all your image is way off band - I would get the tuning sorted with just the Quark first. Secondly, is the PST etalon 'naked'? That is the front collimating and rear refocusing lens have been removed from the assembly?

Mark


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by sywong2000 »

Hi Mark,

Thank you. Let me play around the Quark tuning. I was able to locate some earlier images I've taken (in a C8 off-axis setup, 3 years ago). See attached. That one looks much closer to on-band right? I can see the bright regions shows up... yet I'm not sure if the sunspot is also brighter than it should be.. anways I forgot the dial settings at the time... It was my early started using the Quark and I didn't really study too much the dial settings (well I know I have to). Let me try to test it through from -5 to +5 again to locate which dial setting is on band.

And yes the PST Etalon is naked - I removed the front & rear lens from the assembly.

Additional question: I'm in Hong Kong and the temperature here goes from like 12C to 37C. Would the ambient temperature affect the optimal dial settings under different temperature? I see someone talks about even cooling the Quark?

Stephen

Sun_140754_L_20170402.jpg
Sun_140754_L_20170402.jpg (101.8 KiB) Viewed 4972 times


User avatar
Merlin66
Librarian
Librarian
Posts: 3970
Joined: Tue Dec 13, 2011 1:23 pm
Location: Junortoun, Australia
Has thanked: 173 times
Been thanked: 615 times
Contact:

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by Merlin66 »

The Quark is tuned by heating only, there’s no cooling option.
I can’t remember the on band temperature (30 deg C?) but if the ambient temperature is higher there well may be a problem.
When I looked at getting a Quark for use here in Australia, the temperatures can easily get to 45 deg plus, Daystar said they could supply me one with a much higher on band temperature.
In the end I declined the offer.
Have you considered mounting the PST etalon with lens before the Quark?


"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
User avatar
DeepSolar64
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 18823
Joined: Thu Sep 05, 2019 12:19 am
Location: Lowndesville S.C.
Has thanked: 17572 times
Been thanked: 16693 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by DeepSolar64 »

Nice Tak!!


Lunt 8x32 SUNoculars
Orion 70mm Solar Telescope
Celestron AstroMaster Alt/Az Mount
Meade Coronado SolarMax II 60 DS
Meade Coronado SolarMax II 90 DS
Meade Coronado AZS Alt/Az Mount
Astro-Tech AT72EDII with Altair solar wedge
Celestron NexStar 102GT with Altair solar wedge
Losmandy AZ8 Alt/Az Mount
Sky-Watcher AZGTI Alt-Az GoTo mount
Cameras: ZWO ASI178MM, PGR Grasshopper, PGR Flea
Lunt, Coronado, TeleVue, Orion and Meade eyepieces

Image Visual Observer
" Way more fun to see it! "
sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by sywong2000 »

What I was mentioning is to cool by some external source (ice pack may be? :? ) . I'm not sure if that's even possible but it seemed somebody mentioned about it.
If it's 30 deg C it would be also a problem for me in summer - sometimes here we have like 36 deg C.

I thought mounting the Etalon behind the Quark would be safer as the blocking filter blocks most of the light. To mount it before the Quark in the optic train - I'm not sure if I can do it without damaging the PST etalon? I do have a baader ERF at the front, would that be safe to do so?

And what would be the different putting the PST etalon before the Quark?


User avatar
Merlin66
Librarian
Librarian
Posts: 3970
Joined: Tue Dec 13, 2011 1:23 pm
Location: Junortoun, Australia
Has thanked: 173 times
Been thanked: 615 times
Contact:

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by Merlin66 »

The PST etalon will be OK behind the ERF.
It may be better getting both etalons on a NR if the PST was up front....don’t know but well worth trying.


"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
User avatar
marktownley
Librarian
Librarian
Posts: 42272
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20435 times
Been thanked: 10243 times
Contact:

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by marktownley »

sywong2000 wrote: Wed Dec 30, 2020 10:28 am What I was mentioning is to cool by some external source (ice pack may be? :? ) . I'm not sure if that's even possible but it seemed somebody mentioned about it.
It's how much control over the cooling; you may be able to cool it but you will need it to be a specific temperature for it to be on band.


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by sywong2000 »

Guys,

I've done the tuning and I've found I did messed up the Quark dial settings. I was in +4 CW for the earlier shots. And after capturing sets of images at different dial settings, seemed the best for my Quark is -3 CCW (or may be -2, the image after upload is smaller but i think still able to tell). So I set the dial way off earlier...

Next would be tunning the PST Etalon.... and then put them together....

Thanks
ar_comparison.png
ar_comparison.png (16.92 MiB) Viewed 4874 times


User avatar
marktownley
Librarian
Librarian
Posts: 42272
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20435 times
Been thanked: 10243 times
Contact:

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by marktownley »

I found tuning the PST etalon on the tuned quark worked best for me, you're looking for an evenly illuminated field.


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by sywong2000 »

Today I try out a little bit on doublestacking again.... looks like the result is much better...

Mark, thanks for the tip for the even illuminated field... I can go quickly to the best setting at the PST Etalon... I made three markings at the PST etalon ring to tell where the ring turns, and the best setting is somewhere near the middle of the full turning range...

However the sunspot didn't shows up on AR 2797... not sure why

and although i've taken the flat, it somehow 'recreated' the newton ring (I used the thin platic bag approach). the flat cancels orginal newton bands but somehow create another ring pattern... I may have to use a tilt adapter next time

051737_20210123_Sun_L_pipp_lapl6_ap135_processed_mono.png
051737_20210123_Sun_L_pipp_lapl6_ap135_processed_mono.png (3.53 MiB) Viewed 4773 times
052813_20210123_Sun_L_pipp_lapl6_ap72.png
052813_20210123_Sun_L_pipp_lapl6_ap72.png (4.2 MiB) Viewed 4773 times


User avatar
marktownley
Librarian
Librarian
Posts: 42272
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20435 times
Been thanked: 10243 times
Contact:

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by marktownley »

Very much improved! You've got that sorted.


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
SimonM
Ohhhhhh My!
Ohhhhhh My!
Posts: 108
Joined: Mon Dec 28, 2020 1:01 am
Has thanked: 42 times
Been thanked: 49 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by SimonM »

It may be obvious to others, but not to me!

In the images above e.g. ar_comparison.png for Quark -5 to 0 to +3

What is the cause of the vertical bands when the Quark is off-tune?

In the image using the flat e.g. 052813_20210123_Sun_L_pipp_lapl6_ap72.png

What is the reason for the circular patterns that disappear over the sun's horizon?

Simon


sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by sywong2000 »

Hi Simon,

I think the bands in ar_comparison.png may be the newton rings? Today I was able to take some images again and found the bands can be "minimized" by a tilt adapter, yet cannot be completely eliminated. See attached vertical_bands.jpg. However not sure why it appears more "constrasty" when the quark combo is off-band...

For the ring that disappear over the sun's horizon.... I am just guessing the pattern is in fact there, just not noticeable. Both light frames and flat frames show similar pattern. I attached the flat (flat.jpg). When I apply the flat, not sure how, some of the video series can eliminate such rings better, but some others video results in a different ring patterns. Probably some of the components in the optical train were moved a little bit and causing a little shift in the intensity or may be the position of the flat pattern...

Today I've found more artifacts double-stacking together with the Quark and PST Etalon. See disc_Ring_artifact.jpg.

There's a ring/disk pattern when I pump up the gain. My guess is that this may be internal reflections. Although it may be caused by optical train alignment, however unlikely as the pattern stays in the middle and pretty circular. I also T-threaded everything. May be I try to swap the position of the PST and Quark Combo and experiment a little bit more...

I've also find it's kind of difficult to get a real evenly illuminated image across the frame during tuning of PST Etalon. I can get an imagine that the middle part is evenly illuminated but the corners are vignetting... or I can get an image with a circular evenly illuminated, but the middle is dimmer in a spherical shape. (I try my best to describe.. hope you understand) So i just try to balance it...

Not sure if it's due to the focusing distance...


Stephen
vertical_bands.jpg
vertical_bands.jpg (144.66 KiB) Viewed 4672 times
disc_Ring_artifact.jpg
disc_Ring_artifact.jpg (188.22 KiB) Viewed 4672 times
flat.jpg
flat.jpg (92.15 KiB) Viewed 4672 times
Last edited by sywong2000 on Sat Jan 30, 2021 12:20 pm, edited 2 times in total.


User avatar
marktownley
Librarian
Librarian
Posts: 42272
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20435 times
Been thanked: 10243 times
Contact:

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by marktownley »

It does take a bit of tweaking to get systems like this up and running effectively. Looks like there are some newtons rings there which should be easy to get rid of by tilting the camera. Any other artifacts should go with a flat.


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by sywong2000 »

Finally decided to tidy up the artifacts using gaussian blur, and as the bands are minimal, just using brush to lighten up a little bit at the dark bands and make the intensity more even.....

Anyways I think it's getting much better...
061554_20210130_Sun_L_lapl6_ap354_processed.png
061554_20210130_Sun_L_lapl6_ap354_processed.png (5.19 MiB) Viewed 4663 times


User avatar
marktownley
Librarian
Librarian
Posts: 42272
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20435 times
Been thanked: 10243 times
Contact:

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by marktownley »

Great results!


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
RodAstro
Im an EXPERT!
Im an EXPERT!
Posts: 385
Joined: Sun Oct 29, 2017 9:51 pm
Has thanked: 286 times
Been thanked: 399 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by RodAstro »

Hi

Vertical lines are your camera, if you look at every image you have taken during testing the lines are always the same, I assume you have taken things apart throughout testing.
If you have it is very unlikely you have put it all back together exactly the same and also unlikely anything else would be exactly in line with the vertical axis of the chip.
My guess, it is the chip itself, or the way the chip is read but most likely the chip.
It could be the front dust cover window of the camera causing an artefact I have had this on QHY cameras and normally remove the window by just unscrewing it, worth a try, if that doesn't work try a different camera.
Another thing to try is to take several flats but rotate just the camera between each set of exposures, if the vertical lines stay the same on the final flat images then that will narrow it down to the camera. Notice the newton rings are oval on your flat, probably due to the tilter, these should rotate on the flat images as you rotate the camera.

Cheers Rod


User avatar
marktownley
Librarian
Librarian
Posts: 42272
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20435 times
Been thanked: 10243 times
Contact:

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by marktownley »

RodAstro wrote: Sat Jan 30, 2021 2:49 pm Hi

Vertical lines are your camera, if you look at every image you have taken during testing the lines are always the same, I assume you have taken things apart throughout testing.
If you have it is very unlikely you have put it all back together exactly the same and also unlikely anything else would be exactly in line with the vertical axis of the chip.
My guess, it is the chip itself, or the way the chip is read but most likely the chip.
It could be the front dust cover window of the camera causing an artefact I have had this on QHY cameras and normally remove the window by just unscrewing it, worth a try, if that doesn't work try a different camera.
Another thing to try is to take several flats but rotate just the camera between each set of exposures, if the vertical lines stay the same on the final flat images then that will narrow it down to the camera. Notice the newton rings are oval on your flat, probably due to the tilter, these should rotate on the flat images as you rotate the camera.

Cheers Rod
I get them with my IMX174 chip too - tilting removes it.


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
Fabio_Imm
Ohhhhhh My!
Ohhhhhh My!
Posts: 91
Joined: Sun Oct 18, 2020 2:33 pm
Location: Emilia Romagna [Italy]
Has thanked: 214 times
Been thanked: 146 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by Fabio_Imm »

I can confirm,
I get the same artifacts with my Basler acA1920 (IMX 174 sensor): Newton Rings and horizontal striping in my case.
They both disappear with tilting.

Cheers

Fabio


User avatar
MalVeauX
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1858
Joined: Tue May 09, 2017 7:58 pm
Location: Florida
Has thanked: 1171 times
Been thanked: 1360 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by MalVeauX »

Heya,

The sunspot umbra will diminish on a double stack; this is appropriate and normal. You should see less "sunspots" in the chromosphere when you're double stacking and both etalons are tuned together on band, because the sunspot is a feature of the photosphere underneath the chromosphere layer. You will still see a darker area where the spot should be, but it will not a starky dark spot like you would see with a single stack or straight up photosphere filtered view. So if you see the sunspots vanish, this is appropriate, and it means you're on band likely and your double-stack is functioning correctly.

The best configuration is the Quark then the PST etalon, so that the etalon is in a telecentric beam. You seem to already have this sorted out, so from here, it's more about getting the tuning right (which you seem to have gotten quite close a few times now) and then the final thing is processing; you'll need a tilt adapter to address those newtonian rings and potentially flat calibration to get a cleaner image with less artifacts, dust and rings. So that's the next big hurdle.

When tuning, your disc should get darker as the photosphere light is reduced. So when imaging the limb, there shouldn't be a big difference in brightness that forces you to do two exposures. If you're having to do that, then you're not on band completely with both etalons and have that area in the sweet spot of both etalons.

These are Quark + PST etalon (no collimating lenses) double stack on an IMX174 sensor.
QuarkPSTDS_12232018.jpg
QuarkPSTDS_12232018.jpg (54.73 KiB) Viewed 4626 times

Here's the limb and a little prom, when both etalons are on band together and you're in the sweet spot of both etalons; there should be no double limb and the brightness from your disc to the limb and some brighter proms should be much less, so that you can capture in one shot:

Image

Image

Image


And that note on sunspots with a diminished umbra, as you saw, as the single stack allows more photoshpere parasitic continuum to come through so you will see more of the sunspot's features (remember the photosphere is under the chromosphere and much brighter):

Image


Verus, when you double stack, both are on band and have your image in the sweet spot of both, the photosphere should be gone mostly and only the chromosphere showing, so chromosphere features should increase in contrast, the disc should darken, filaments should darken, spots should diminish or disappear all together (small ones; big ones will be obvious still), plages should brighten relative to the disc, as you're isolating the chromosphere network that is laying over the photosphere:

Image


Tuning the Quark + PST is actually really challenging I found. It' so easy to go off-band due to the poor uniformity of both etalons and the PST's very small sweet spot limits your FOV for what's on band and entirely in the sweet spot. It's also dim, usually, so it takes a lot of gain and longer exposure which doesn't help. I've seen great results from a Quark + Quark Combo to double stack, but it too was dim and didn't catch on (no one else seemed to want to recreate it so that says a lot).

Ultimately I'm waiting for the unicorn... the 1A blocking filter to do the double-stack work instead of two etalons. Double stacking with higher resolution systems is really hard unless you have excellent filters and excellent spacing (like Harold's unigraph!). His limbs are unreal!

I gave up on my double stack for high res work. My etalons are just not good enough and my PST etalon, while very good, has too small of a sweet spot for me.

Very best,


sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by sywong2000 »

RodAstro wrote: Sat Jan 30, 2021 2:49 pm Hi

Vertical lines are your camera, if you look at every image you have taken during testing the lines are always the same, I assume you have taken things apart throughout testing.
If you have it is very unlikely you have put it all back together exactly the same and also unlikely anything else would be exactly in line with the vertical axis of the chip.
My guess, it is the chip itself, or the way the chip is read but most likely the chip.
It could be the front dust cover window of the camera causing an artefact I have had this on QHY cameras and normally remove the window by just unscrewing it, worth a try, if that doesn't work try a different camera.
Another thing to try is to take several flats but rotate just the camera between each set of exposures, if the vertical lines stay the same on the final flat images then that will narrow it down to the camera. Notice the newton rings are oval on your flat, probably due to the tilter, these should rotate on the flat images as you rotate the camera.

Cheers Rod
Hi Rod,

Thank you. That's QHY 174 I'm using. It looks like to me the vertical bands were the same regardless of the rotation of the camera. I'll try to unscrew the front window and see if it gets better. Thank you!

Stephen


sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by sywong2000 »

MalVeauX wrote: Sat Jan 30, 2021 11:09 pm
The best configuration is the Quark then the PST etalon, so that the etalon is in a telecentric beam. You seem to already have this sorted out, so from here, it's more about getting the tuning right (which you seem to have gotten quite close a few times now) and then the final thing is processing; you'll need a tilt adapter to address those newtonian rings and potentially flat calibration to get a cleaner image with less artifacts, dust and rings. So that's the next big hurdle.

When tuning, your disc should get darker as the photosphere light is reduced. So when imaging the limb, there shouldn't be a big difference in brightness that forces you to do two exposures. If you're having to do that, then you're not on band completely with both etalons and have that area in the sweet spot of both etalons.
My Quark was the combo one (no 4x lens). What I've got is a televue 4x which generates (close-to) telecentric right after the focuser and the camera rotator so allowing me to switch the position. However it looks like it's true that the sweet spot of the PST Etalon is small and placing in the front may not help. I'll have to experiment that and see...


sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by sywong2000 »

I just went for an imaging session. This time I swapped the positions of the PST and the Quark combo (i.e. from the objective, PST Etalon before the Quark combo) and surprisingly the result improves quite a lot!! I do not see any ring artifacts anymore in high gain. The sweet spot still small but a little bit more easier to get an evenly illuminated area. So putting the PST Elaton before the Daystar Quark is definitely worth a try. Yet need to have a telecentric beam before that.

I also did take away the front window from my QHY 174. However that doesn't help on the vertical bands. I observed again the bands are in the same direction no matter what is the rotation - so it's on the imaging chip. However by tilting (much more) and the bands are no longer visible.

Here's the result - did ImPPG processing, dust spot removal, crop and a little output level adjustment...
053837_20210131_Sun_L_lapl6_ap4221_processed.png
053837_20210131_Sun_L_lapl6_ap4221_processed.png (2.32 MiB) Viewed 4608 times
Last edited by sywong2000 on Sun Jan 31, 2021 12:36 pm, edited 1 time in total.


User avatar
marktownley
Librarian
Librarian
Posts: 42272
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20435 times
Been thanked: 10243 times
Contact:

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by marktownley »

That's great news and very interesting to know about the improvements with the change in placement of the PST etalon. Something I will have to try myself later in the year.

It's frustrating about the vertical banding, I got it with my IMX249 chipped camera (slower version of the IMX174) too - again, with both cameras easily removed by tilting. Don't get it with CaK, so not sure how it comes about...


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by sywong2000 »

Hi Mark,

Did you try FireCapture? There's a "in-place" flat function that I've found it's quite handy to use for removing any bands and artifacts like dust buddies.

I tilt the camera until the rings are not noticeable, focus the telescope, and then put the thin plastic bag on the objective and use the flats function in FireCapture, pointing the telescope to the middle of the sun (so the imaging field is fully illuminated). It will take a set of flats and applies to the preview and the subsequence video in real-time. When I see the result is good then I start the imaging session. This only takes me another 3-4 minutes to do so. There're few advantages: this saves me a lot of post-processing time and I don't have to be dead-on at the tilt. I just tilt until I do not (or barely) notice the rings and the flats will take care of the rests. The results are shown on screen which I can see if it's good in realtime.

Also coming back and share some of the results I achieve with the same setup a week ago. These were taken on 15-May-2021 GMT 8:00
Attachments
2021-05-15-0759_5-U-L-Sun_Halpha_lapl4_ap188_processed.png
2021-05-15-0759_5-U-L-Sun_Halpha_lapl4_ap188_processed.png (2.86 MiB) Viewed 1352 times
2021-05-15-0802_6-U-L-Sun_Halpha_lapl4_ap119_processed.png
2021-05-15-0802_6-U-L-Sun_Halpha_lapl4_ap119_processed.png (2.47 MiB) Viewed 1352 times


User avatar
marktownley
Librarian
Librarian
Posts: 42272
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20435 times
Been thanked: 10243 times
Contact:

Re: Advices needed on doublestacking Daystar Quark Chrom and PST Etalon

Post by marktownley »

Nice results! I have used the flat feature on firecapture, but tbh, rather just clean off dust bunnies and / or tilt the camera if have issues.


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
Post Reply