Hello!

Certainly, I'll search to activate the debug logs.

1. After a lot of tries and settings changes, I've pressed reset to default (guide-->option tab) and after a while, RMS went to 1-1.5.
2. SkyGuiderPro, so only RA
3. I've read about it and I have to try it.
4. My captures are great (for my taste), but I am trying to combat the walking noise, that's why I need it.

The thing is that I have also Stellarmate OS and with exactly the same settings dithering is working fine even with the max 10px. So I'm trying to understand why is it different.

Do you have a guiding deviation set in the capture module?

No, at least not in purpose. I'll check it.

But if it is ON, the captures should stop, correct? My captures are working properly.

Yes you are correct, just trying to think of anything else it could possibly be. Weird that it is happening regardless of your settings.

I noticed that SEP can have issues with color camera images. I'd try to use 2x2 binning and see if that improves things...

Dithering will try to move in a random direction, I'm wondering that if your Dec axis is fixed, whether dithering is going to help you, I think it will just give you oblong stars, as the dither can only move in a single axis.

No, why would it create oblong stars? It's not moving during the exposure....
But what usually happens is that RA-only dithering will not be able to remove the 'rain', the stripy appearance coming from fixed pattern noise of the camera. At least you'd need a stronger dithering (larger max), and much more images.

Well, because dithering normally moves one or two pixels across a 2D plane, but in your case it will move 1 or 2 pixels up and down a line, because that is all it can do.
I'm just not sure that it would be effective for you. I imagine it is failing because it is not taking into account your 1-axis guiding and still trying to dither both RA & DEC.

Let me add more Infos into this.

This is the stack with STF from the internal guider with the above settings and 10px. (1 day before this thread)


After creating this thread I've tried with the PHD2. This is the result with 4px into Ekos and 4.0 amount in PHD2 (So, 16px, am I correct?)



Clearly, I have an issue here..This is not by calibration files, those lines are visible after stack - probably will be at every single frame but I can't see them.

Here is also the PHD2 log file. I can see that dithering worked, but as I am a rookie, I can't be sure how to interpreter all those infos. Any tip will be more than welcome!

Hmm, I'd say this is the 'rain' I had been talking of. You can see that the 'stripes' are in RA direction.

The pattern is made from so-called FPN, fixed pattern noise. Think of it similar as hot pixels, just that their deviation is much less. So you do not see it in a single exposure, as they are randomly distributed. But if you start displacing it in only one direction those deviating pixels will start to form the lines you see there. This is why dithering isn't really effective in RA-only guiding.

If I understand correct, for the first image dithering failed. Would really be important to know if it only claims it failed, or if the dither really did not happen. As you say it works with Stellarmate - is that indeed also with SEP and multi-star guiding?

You might actually benefit from deliberately introducing a small error in your Polar Alignment, yes, your stack may have slight rotation in it, but you might also be able to address part of the rain effect in parts of your image. But I agree with the previous poster, I don't think Dithering in 1-axis guiding is going to be very effective.

It all began when I found those black patches on my images. Besides those patches walking noise was visible (tried to point it with those arrows)



www.cloudynights.com/topic/726700-does-t...-set-of-dslr-images/

This is also the result without even know what is dithering.



This is a result of Stellarmate and 5px dithering. I think it is an improvement. Then I've read that in fact with DSLR people go even further with 10-15px.


So the 1st M33 is with Stellarmate and 10px dithering, then I had all those issues with Astroberry and Internal Guider dithering and tried the M33 above with PHD2.