Fixing Stars in Linear Data with Siril

Рет қаралды 1,873

9 ай бұрын

Using Sirils Star Processing Tools. I will show you how to fix your bad stars in your linear data. The technique is very similar to how you do it with non-linear data but different enough that it requires another video.

Пікірлер: 12

@pman3349 6 ай бұрын

I really needed this video! Well done! Thank you!

@jeffrh 6 ай бұрын

Glad it helped...

@earthling8635 3 ай бұрын

Hi Jeff, this was a nice, detailed run-through and exactly what I was looking for regarding fixing stars (although I have used the Siril approach but not exactly successfully). When I've used it, I tend to find the stars (particularly bright ones) look fake and have awful halos afterward and, where my starless may have left overs of the star "spikes" (due to brightness not a reflector secondary spider), the resynthesises star then looks dull and lifeless within the "spike" (if you understand what I mean). I then also find, in addition, that I can't get good colour in the stars so your steps re using Asinh may be helpful there. There's one other thing though. I tried fixing the stars with a capture of M3 and the roundness and resynthesis steps ended up removing a whole bunch of stars in the cluster so I simply couldn't use it in that case at all. Any suggestions? Thanks.

@jeffrh 2 ай бұрын

I assume you have a refractor or a scope with spiders... Spiders can give spikes with a little extra punch if you are using longer exposers... like anything over 3 minutes. This can make StarNet++ work a little harder and it will sometimes fail. This is what it is sounding like from here. If you are using a refractor, you will need at a minimum a UV/IR Cut filter. That will help with star halos. Gobs are the hardest thing to fix using these tools. There can be too many stars too close together for the routines to work correctly and thus it will fail. Hope this helps and Clear Skies... which I haven't had since October of last year. 😞

@earthling8635 2 ай бұрын

@@jeffrh Just got notified of your comment Jeff. 4 weeks it took! I was using an SCT for M3 while I also have a refractor. The star spikes though, happen with my Samyang 85mm lens. Great lens but the spikes are produced by the blades. Anyhow, just the way it is. I'll work with it.

@jeffrh 2 ай бұрын

@@earthling8635 KZfaq can be like that... ;-) The spikes you see in this image are from the brightness of the stars. The C14 which made this image usually doesn't have spikes unless there is something bright in the FOV. I don't mind them very much and if I really wanted to spend the time. I could easily remove them. The colimation was off a tiny bit so that might contribute to some of the length to one side... The Samyang 85 might be more susessable to spkies when it is wide open. Try going a stop or two up and see if that helps the cause... if anything it should help the edges of the image...

@afryhover 8 ай бұрын

It's pronounced "ark sign" stretch. But, other than that well done 👍 You made me want to try Siril and see how it compares to Pixinsight/Photoshop workflow.

@jeffrh 8 ай бұрын

Thanks, I've heard it said the way I try to pronounce it... not saying it's right or wrong... ;-) I have never tried Pix and from what I've seen of it. It has much more than I'll ever use which is one of the reason I went with Siril. Siril is a better fit for my workflow which includes Photoshop. I also don't like paying for the same tools twice. I also love GraXpert. Both Siril and Pix backround extraction tools don't compare to GraXpert in my book... I also like the way Siril handle large Deep Sky Lucky Imaging runs. I flys through the data pretty quick. It would be hard giving up the cost you already paid for using Pix... Siril is Open Source and free. They have been updating it fairly quickly of late. another reason I like Siril...

@MyOuterSpacePlace 7 ай бұрын

Hey Jeff, excellent video. I'm trying to learn Siril to help deal with stars and have a question: Around the 12:30 mark you first do an arcsinh stretch on the star layer then switch to linear mode and do a general hyperbolic stretch. What's the point in doing both? Post processing has always been my nemesis and I'm just trying to understand the process here. Thanks.

@jeffrh 7 ай бұрын

I think I say that I do this to enforce the colors of the stars. Then after stretching in the GHS, I also use the color saturation to bring the colors up. Hope this helps...