HELP QUARK

[rsfoto]

Hi,

As a few know I have a QUARK and looks like I will have some Sun today and I would like to know if I focus with an eyepiece, will the focus for a camera be the same or at least near ?

Thanks

[MalVeauX]

It will be close in my experience, but not exact. I've had variation of up to about 1cm either way with different positions of my sensor for focus, relative to an eyepiece. Depends on how deep the nose goes, etc.

Very best,

[PDB]

Rainer,

it is not varying that much. Think I have some difference of 5 mm more out-focus on the 80mm f/6. (did not measure on the 120, but the difference is also small)

Rgrds,

Paul

[MalVeauX]

The fuzz are spicules if I recall

Some examples:





I focus on a surface feature with the camera at a high (near clipping off the right of the histogram) exposure value. I let the seeing show me what it's doing for a few seconds. If I see a sharp pencil drawing look, then I'm focused enough and I don't further change it for the time being, otherwise you can chase the seeing with focus all day. Then I change my exposure values for the limb/prominences (totally clipping the surface) to capture the spicules & proms as a separate exposure from the surface. I capture 300 frames of the proms/limb at one exposure value (usually 10ms, 99 gamma, and whatever gain it takes to see the proms, usually 150~180 at F35), then quickly change exposure to 10ms, 0 gamma, and reduced gain for the surface in the same position (often 50~80 gain at F35). I make a composite of the two later in post.

Very best,

[rsfoto]

Hi Marty and Paul,

Thanks. I found focus yesterday by first using an eye piece and then sticking in the quark with an eye piece and then I exchanged the eye piece with the camera. Unfortunately the Sky conditions did not allow to get into perfect focus.

I was able to see the fur on the limb. What is it called correctly ?

The video I made did not come out as I had some wrong settings. That happens when one does not use it for a long time and one forgets how to set the software

Look at the image of the sky conditions Perhaps today it is better so I can keep testing it.

IMG_3630_C1.jpg (93.61 KiB) Viewed 1996 times

[rsfoto]

The fuzz are spicules if I recall

Some examples:





I focus on a surface feature with the camera at a high (near clipping off the right of the histogram) exposure value. I let the seeing show me what it's doing for a few seconds. If I see a sharp pencil drawing look, then I'm focused enough and I don't further change it for the time being, otherwise you can chase the seeing with focus all day. Then I change my exposure values for the limb/prominences (totally clipping the surface) to capture the spicules & proms as a separate exposure from the surface. I capture 300 frames of the proms/limb at one exposure value (usually 10ms, 99 gamma, and whatever gain it takes to see the proms, usually 150~180 at F35), then quickly change exposure to 10ms, 0 gamma, and reduced gain for the surface in the same position (often 50~80 gain at F35). I make a composite of the two later in post.

Very best,

Hi Marty,

Thanks for the info how you do it

Rainer

[rsfoto]

HI,

Well I found out how to focus my QUARK but the Sky thinks my QUARK is obsolete

IMG_3645_C1.jpg (75.13 KiB) Viewed 1966 times

[Merlin66]

The furry edge is the spiculation layer.

[rsfoto]

The furry edge is the spiculation layer.

Thank you

[rsfoto]

Hi,

Continuing with this story well yesterday I manged to find th approx focus point but of course the details on the Sun where impossible so I just made a short test image. Looks like today I have a bit more of Sun.

But what I do not like are those very fine newton rings. I am using the Quark on a FS 78 with a Lumenera Infinity 2-1RM

Here is the very first Light image of the QUARK and the following days I need Sun and patience. It is a PITA not having an electric focuser on this sort of focal length 630 x 4.3 = 2700 mm

2018-05-13_18-54-55-1f_500.jpg (599.54 KiB) Viewed 1847 times

[Merlin66]

Rainer,
I’ve fitted the simple SW electronic focus motor to all myscopes -works very well for me.

[PDB]

Hello Rainer,

electric focusers are not that difficult to build, and there are plenty of good designs to make a controller (inlcuded ascom) using arduinos with motorshields or steppermotor driver. The most difficult thing for me was making an attachment to the focuser. (I am a software man, not very handy in building stuff, maybe I need a 3D printer). I have used https://sourceforge.net/projects/arduin ... erpro2diy/ There is now also a version if you prefer DC motors https://sourceforge.net/projects/mydcfo ... dcfocuser/ (these work better than some crap I bought to automate my C8 with Crayford focuser)

The newton rings are easy to deal with. What I found is the higher the f/num the more chance of Newton rings. So a reducer after the Quark sometimes helps. Or just a little tilt. And there is also a software solution using Fast Fourier Transforms in Photoshop, Gimp or AstroImageJ.

To focus in difficult conditions I use the histogram. Aim at the solar limb, and you see a dip in the histogram. Then change focus and the dip will go up/down. When it is at its lowest point, you should be in focus.

But: was your Quark heated? Even wih bad atmosphere, there should be some detail visible. The image looks very pale.

Regards,

Paul

[Montana]

Yes I would be more concerned with the lack of surface detail than the NR at this moment!

Alexandra

[rsfoto]

Rainer,
I’ve fitted the simple SW electronic focus motor to all myscopes -works very well for me.

Hi Ken,

I expressed myself unfortunately. What I wanted to say is that I still would ahve to put one of my focusers on the scope. I have all my scopes with own made focusers just the 2 telescopes I have at home are still not fitted with them

Look here how my focusers look like. I also have a motorized rotator on each telescope in the Observatory.

RS-Focus-BabyQ-00.jpg (617.61 KiB) Viewed 1783 times

[rsfoto]

Yes I would be more concerned with the lack of surface detail than the NR at this moment!

Alexandra

Hi Alexandra,

Same here I did not put enough Information. With that sort of Sky conditions I had I was happy to see the limb on the Sun and make Focus tests So taking in consideration the Sky conditions there is not yet a reason to worry about it.

Yesterday it was better but still very high thin clouds which kill all sort of Details.

As I said I need a really clear sky but at the Moment I am happy being able to Focus. Yesterday I even saw a M shaped prominence but still bad sky conditions. I also saw some Details on the Sun surface as some Filaments but of course not the same as with my Observatory set up.

[rsfoto]

Hello Rainer,

electric focusers are not that difficult to build, and there are plenty of good designs to make a controller (inlcuded ascom) using arduinos with motorshields or steppermotor driver. The most difficult thing for me was making an attachment to the focuser. (I am a software man, not very handy in building stuff, maybe I need a 3D printer). I have used https://sourceforge.net/projects/arduin ... erpro2diy/ There is now also a version if you prefer DC motors https://sourceforge.net/projects/mydcfo ... dcfocuser/ (these work better than some crap I bought to automate my C8 with Crayford focuser)

The newton rings are easy to deal with. What I found is the higher the f/num the more chance of Newton rings. So a reducer after the Quark sometimes helps. Or just a little tilt. And there is also a software solution using Fast Fourier Transforms in Photoshop, Gimp or AstroImageJ.

To focus in difficult conditions I use the histogram. Aim at the solar limb, and you see a dip in the histogram. Then change focus and the dip will go up/down. When it is at its lowest point, you should be in focus.

But: was your Quark heated? Even wih bad atmosphere, there should be some detail visible. The image looks very pale.

Regards,

Paul

Hi Paul,

Yes the QUARK was heated and yes, yesterday I started to see Details on the suns surface and also at the limb some hints of Spicules. The weather is really not cooperating and when I ahve Chance to get the into into the QUARK it starts at an altitude of about 29° so I know those are also not the best conditions as poiunting onto the zenith as I can in my Observatory.

On Thursday 17th I will be in the Observatory for a few days and test it on my FSQ 85 up to the zenith.

Fast Fourier Transforms in Photoshop

¿ where do I find that and how does that work in Photoshop ? I have PS CS6

The image acquisition Software i have Lucam Recorder has a function where I can use the contrast for focusing. I choose a window and there I look at the highest value and there it should be in focus.

Rainer

[PDB]

Hi Rainer,

here is a thread on CN https://www.cloudynights.com/topic/5944 ... om-images/

I find this one very detailed but complicated

In another thread (unfortunately in Dutch) you can see it can be done simpler https://www.astroforum.nl/forum/astrofo ... -oplossing just look at the pictures of the FFT and invere FFT

So you need a Fast Fourier Transformation filter
-> do the de FFT on the image -> search for the errors usually seen fairly clear as defaults in the pattern.
Just wipe them out an do an inverse FFT. After some training you can obtain very good results.

P.

[rsfoto]

Hi Rainer,

here is a thread on CN https://www.cloudynights.com/topic/5944 ... om-images/

I find this one very detailed but complicated

In another thread (unfortunately in Dutch) you can see it can be done simpler https://www.astroforum.nl/forum/astrofo ... -oplossing just look at the pictures of the FFT and invere FFT

So you need a Fast Fourier Transformation filter
-> do the de FFT on the image -> search for the errors usually seen fairly clear as defaults in the pattern.
Just wipe them out an do an inverse FFT. After some training you can obtain very good results.

P.

Hi Paul,

Will try to replicate it.

Question, would something like a little optical window with a tilt in the optical path take away the Newton Rings ?

Just guessing

[rsfoto]

Wat works is a prism in the optical path (that is also mentioned in the Dutch explanation). I did some tests with a ZWO ADC and that also works. Actually what that does, since you only work in 1 frequency) it tilts the focal plane instead of the camera. Same effect.

P

Hi Paul,

AH, I understand and so a parallell optical surface would only shift the rings a bit to the side.

I will test if the thread of the C-Mount Adapter allows a tiny tilt by putting a shim on one side and tightening it and so the camera is tilted. Hopefully I get some Sun today

That ZWO ADC is quite big, I have 3 ZWO cameras on the way to me. I guess I will get them in a few weeks.

Rainer

[PDB]

Wat works is a prism in the optical path (that is also mentioned in the Dutch explanation). I did some tests with a ZWO ADC and that also works. Actually what that does, since you only work in 1 frequency) it tilts the focal plane instead of the camera. Same effect.

P

[rsfoto]

Hi,

Yesterday 14th I got this with this skies. I think I am getting closer

2018-05-14_18-30-06-1f_500.jpg (792.49 KiB) Viewed 1753 times

IMG_3671_C1.jpg (120.35 KiB) Viewed 1753 times

Today's forecast looks good but this can change quickly in Mexico City

SunForecast_15052018.JPG (171.85 KiB) Viewed 1753 times

[rsfoto]

Hi Paul,

I downloaded Fiji and tried on an image but I just can not get the rings out of it. Quite difficult.

Look at the screen shot of the test image and the FFT result. I do not know where to exactly mark the lines. I did take the 2 little slightly diagonal lines but no, does not work

FFT_Fiji.JPG (302.52 KiB) Viewed 1741 times

and here the original image in TIF

2018-05-15_15-04-28-1f_500_BW.tif (2.76 MiB) Viewed 1740 times

[PDB]

Hi Rainer,

took the liberty to download your image with the NR's

Tried to do it in GIMP (Fiji can sometimes be cumbersome to do something) and had some problems too. The image was saved in RGB (could be because of the dowload) When I converted it to grey it worked better. (Never had good results with color images, I only used it on monochrome)

So this is what I did and the result. Not perfect yet (still some issues in the bacground, but the disc looks ok. Probably a spike still needs to get blackened)

Test.png (135.1 KiB) Viewed 1704 times

Regards,

Paul

[rsfoto]

Thank you Paul,

Yhe attached Image is a bit small and I cant see the difference between my original and the FFT processed Image.

Today afternoon I will show you what Fiji ImageJ makes. Also will download GIMP and see how it works,

About the Image being colour yes you are right. The fact is that I am applying a false colur mask in realtime when streaming my videos and it is saved as an RGB Image. I noticed that when ImageJ gave me some advice about processing colour channel 1. I then converted the image into B&W and it ran but with weird results.

I will post one later on.

Rainer

[MalVeauX]

Hi,

Yesterday 14th I got this with this skies. I think I am getting closer

Today's forecast looks good but this can change quickly in Mexico City

Just a thought, but if you're shooting through window glass, I'm wondering if that will play a role in this?

Very best,