Lucky imaging with Siril

I am new to Siril (version 0.99-4), and I am still confused by the options for stacking.

Living in polluted Rio de Janeiro, I would like to try some planetary/moon lucky imaging. However, I am not sure which would be the best algorithms/configurations for this. I am not happy with the final result

What I have tried is to take around 200 pictures and do this in Siril:

  1. Delete the poor images just by eye.
  2. Process lights, darks, bias, flats in a standard way.
  3. Register all images in the sequence with “Image pattern alignment”.
  4. Stack with “Average stacking with rejection”, “Winsorized Sigma clipping” (low = 3.2, high = 3.3). I am not using any Normalization, since I get errors with it in version 99.4 (Normalization failed. Check image NN).

Is this OK for lucky imaging?


Siril only supports registration on the entire image, or on one part or it. For planetary or moon imaging with a large focal length, you need multi-point registration in general, which siril does not do yet. Look at PlanetarySystemStacker for that in the free software side of things.

If you still want to use Siril, you can use the planetary registration, it will give you a quality indicator for images, and you can filter the best images given by this indicator in stacking. Normalization is probably not important for planetary images, and if you are stacking 8 bit images, you must use the sum stacking anyway.

I guess by “planetary registration” you mean what Siril’s call “Image pattern Alignment”, right?

Which “quality indicator” you are referring to? Is this what is controlled in the “Sigma low/high” in the Stacking tab, or in the “all” drop down menu? For some reason, if I select “quality” in the latter, the “start stacking” button gets unclickable. In the Sequence tab, if I open the frame list, I see “N/A” in the quality of all images.

About normalization, I am using DSLR RAW images, probably 12 bits, converted by Siril into 32 bits I guess.


When registering with Siril, one result is that Siril can then align images, the other is that it can also sort them using some criterion. For deep-sky type registration methods, the criterion is FWHM but there are a few others like star roundness; for planetary type registration methods (yes image pattern alignment, but also the enhanced correlation coefficient), the criterion is an image quality. If it’s not available in stacking in the filters, yes the “all” drop down, it means that you are not opening the registered sequence or possibly that there is a bug, we almost never use that.

I tried both. I am opening the registered images, and also re-registering the images. In both cases, no quality appears in the “Open frame list”.

Another strange thing is the “Plot” tab. It shows nothing.

Maybe these are bugs in the devel 0.99.4 version that I use (same for normalization problem).

Ok that does not appear to be normal, we’ll check. Thanks

I just noticed that in the frame list window, data only appear if you select another channel and go back to the channel that has data, in green by default. You may check with that if you see the registration shifts and quality.

The Green channel has the shifts (the -1 in the other channels is a bit misleading…). Yet, in the 3 channels I see “N/A” in quality. Seems like a bug?

I just tested on a video.
No problem. Registration data are well saved.

I only tested at DSLR RAW images. No quality.

Maybe I have some wrong config?

Lucky imaging with DSLR? it is not really possible :).

That’s what I have… :’(

So “Quality” only appears for Video??

No This is not what I’m saying. You can process with Siril. But this is not lucky imaging.

What I meant is to take 300-500 pictures of a planet and align the best ones. Isn’t that “lucky imaging”?


Lucky imaging is recording at high speed (generally a video with some ms for each frame).
Doing that you can have some picture not destroyed by seeing.

In general I shoot at 50ms. I thought anything faster than 100ms was lucky imaging (that is what Wikipedia says).

Anyway, not relevant. The crucial thing here is that quality is not evaluated for pictures, unless I am doing something wrong.

A planetary camera shoot every 50ms. A DSLR cannot.
This is a big difference!!

I tried planetary algorithm on DSLR images. It works as expected.

Sorry, I don’t understand. DSLR shoots 4k movies at 30, 60, 120fps, that is one picture every 8ms. And still photograph bursts at 15-20 each second, or 50ms. My camera takes full resolution RAW bursts at 60fps, or 16ms (then needs 6 seconds to clear the buffer).

Can you filter them by quality?? If I choose “quality” instead of “all” in the stacking tab, the “start stacking” big button is disabled. I can surely stack them all… no luck!