×

INDI Library v2.0.6 is Released (02 Feb 2024)

Bi-monthly release with minor bug fixes and improvements

New Bahtinov Mask Assistant Tool

  • Posts: 1309
  • Thank you received: 226
Fantastic! I have been hoping to see this one day. I have a number of bahtinov examples to share since I've been producing masks made from acrylic for people. I will also point you to this tool Maskulator To simulate bahtinov masks.

Here are a bunch of assorted bahtinov mask samples.
Dropbox Samples

Hope these help.

Andrew.
The following user(s) said Thank You: Sebastian Neubert
5 years 1 month ago #34600

Please Log in or Create an account to join the conversation.

  • Posts: 14
  • Thank you received: 15
Dear Andrew,

This is exactly what I was looking for. Many thanks!!

Sebastian
5 years 1 month ago #34605

Please Log in or Create an account to join the conversation.

  • Posts: 15
  • Thank you received: 3
note that APT has already built in this module: ideiki.com/astro/usersguide/bahtinov_aid.htm maybe this iswhere the idea iscoming from
5 years 1 month ago #34630

Please Log in or Create an account to join the conversation.

  • Posts: 14
  • Thank you received: 15
Indeed as I wrote above APT is one of the inspirations for this.
I'd be curious for suggestions how we can be better than APT. E.g. the two circles that indicate the Focus error in APT.. are they really useful? Why use circles here? What is measured is just a single number.
Instead what I want to provide is an uncertainty of the measurement, so that the user sees when they have reached the sensitivity of the method and further tuning becomes pointless.
This can be expressed visually through a "Focus achieved" message.

BTW: is color vision deficiency (CVD) a design consideration in KStars? Might be an issue when we use differently colored indicators.

Cheers, Sebastian
5 years 1 month ago #34633

Please Log in or Create an account to join the conversation.

  • Posts: 1309
  • Thank you received: 226
I believe the circles in Bahtinov Grabber / APT implementation show a scaled up magnitude of error and whether it is inside or outside focus. It's intuitive enough to get the circles to overlap as much as possible. The software is also capable of averaging over a number of frames to combat seeing conditions.
5 years 1 month ago #34651

Please Log in or Create an account to join the conversation.

  • Posts: 1309
  • Thank you received: 226
How feasible is it to integrate with the liveview/video stream? That would be ideal.
5 years 1 month ago #34736

Please Log in or Create an account to join the conversation.

  • Posts: 1119
  • Thank you received: 182

Please don't give up on the autofocuser. That works fantastically and is indispensable when running an automated image acquisition sequence.

Both have their place, but I don't see how a Bahtinov mask focusing mode could be integrated into the scheduler.
5 years 1 month ago #34772

Please Log in or Create an account to join the conversation.

  • Posts: 1309
  • Thank you received: 226

Autofocus is great, but not everybody is setup with a motorized focuser. A bahtinov mask is a quick and reliable manual method. It works well by eye, and better with computer guidance.
5 years 1 month ago #34773

Please Log in or Create an account to join the conversation.

  • Posts: 14
  • Thank you received: 15
Hey,

the autofocuser based on HFR will not be affected by this and stay the default option.
In fact it would be possible to use the offset calculated by the Bahtinov fitter to drive the autofocuser.
In a fully automatic setup this could be combined with a mechanics that places the mask onto the scope (similar to what some people have for flatfield caps). But we are digressing.

For the streaming mode we have to see. The fitter works on the image frames, so in principle it can be done. The question is performance, i.e. at which framerate can we produce the solutions. It definitely will work in a frameing mode.

Short status report: the algorithm that extracts the diffraction pattern and fits the Bahtinov lines to it, thereby measuring the offset of the center line is implemented in my local copy of EKOS.
Since I had to switch to GSL for the numerical libraries, I am working some convergence issues. Next will be work on the graphics (plotting the lines corresponding to the found solution).

I'll post pictures as soon as I have something presentable.

Cheers, Sebastian
The following user(s) said Thank You: Jasem Mutlaq, Alfred
5 years 1 month ago #34783

Please Log in or Create an account to join the conversation.

  • Posts: 106
  • Thank you received: 11
Just a thought; as an interim feature, could it be possible to select an overlay (akin to cross hairs and guidelines) and centre a Bahtinov mask directly on the selected star in the acquisition images. The selected star will still be auto focused as usual but the viewer will see the Bahtinov mask pattern results as the focus becomes more accurate. We are talking about a pretty bright star for Bahtinov therefore the pattern can be proportionate to the corresponding HFR .

Note: should this be an existing feature on other applications I was truly not aware. I only use Ekos.
Skywatcher 190MN - EQ6 Pro (with Belt Mod) - ASI1600MM-Cooled - ASI EFW7 - ASI120MM - WO f4 Guide Scope - Rigel nStep - KStars/Ekos - KDE - PixInsight
5 years 1 month ago #34874

Please Log in or Create an account to join the conversation.

  • Posts: 969
  • Thank you received: 94
Hi.
It would be totally awesome if you could give us the real time streaming view at 5x and 10x, as in APT.
Cheers
5 years 1 month ago #34894

Please Log in or Create an account to join the conversation.

  • Posts: 1119
  • Thank you received: 182
Just thought I share my experience with Jasem's autofocus tool, using a very simple home-built autofocuser with a timed motor (not a stepper motor) and Shoestring Astronomy FCUSB as the driver. I focused using Jasem's tool and then checked using a Bahtinov mask. Here is the result:



Couldn't me more perfect, I would say.

PLEASE, Jasem, do NOT give up on the autofocuser. It is (almost) PERFECT as is!
5 years 1 month ago #34955
Attachments:

Please Log in or Create an account to join the conversation.

Time to create page: 1.497 seconds