Unleash the Power of Curves Transformation: Literally The Most Powerful Editing Tool You Have

[@nikaxstrophotography]

The stars look funky and unreal, the nebula itself is excellent

[@SKYST0RY]

I think you're referring to the star-like objects in the working images. Those are artifacts leftover from running StarXTerminator. They are a common issue with star removal apps. They are easy to remove but the process is not covered here as it's another topic entirely.

[@protonx7722]

ive freshly bump into your channel, newbie here in astrophotography... happy new year and thanks for your sharing your work.

[@SKYST0RY]

Welcome to this art and science.

[@markalot]

Very nice explanation of the curves tool. Love the results, love the explanations. I've used large overlap on star x which should not make a difference but seems to have less artifacts. Different algo maybe? This video popped up in my feed, I assumed it was recent, just noticed it was 7 months ago. :)

[@SKYST0RY]

I always use the "large overlap" option in SXT. I consistently see fewer artifacts. Still get them but fewer than before.

[@jims9982]

Great video. Using curves properly is still a work in process for me, but this video is helping alot.

[@SKYST0RY]

It takes some practice. You need to get a sense of what part where to drag the curve to affect what luminance range, and the most challenging thing is probably getting a sense of how adjusting one color channel will affect the others. It takes practice, but if you become adept at curves you soon realize it is your best photo developer, contrast enhance, star sharpener, and even color filter.

[@Tony-Elliott]

Another excellent tutorial thanks for taking the time to make these video

[@SKYST0RY]

You're very welcome! Thanks for watching, and I hope it helps!

[@mupangamwanakatwe1300]

Great stuff and do keep it up!! 👍🏾

[@SKYST0RY]

Thank you for watching!

[@richardshagam8608]

Your videos are great. Before latching on to them, I had been spending what I now consider to be a waste of time working with that supposedly new hot tool, the Generalized Hyperbolic Stretch to bring out contrast within various brightness levels. But what is GHS?--Just a mathematical formalism trying to accomplish what you've been showing can be done with the curves tool empirically.

[@SKYST0RY]

Fundamentally, yes, that's what GHS is. I don't really understand how or why astrophotography latched onto the idea of fine manipulation of the light curves by way of a histogram stretch tool. To me, it's like trying to do fine wood carving with a Bowie knife. Theoretically possible, but a histogram TF tool is primarily a way of making large changes to the light curve, and the curves transformation tool is fundamentally a way to make fine changes to the light curve.

[@grahamprescott9426]

Is this function in Siril? Ive have a go in GIMP under "curves" where you also see the histogram. Still not sure ive mastered this. Currently trying to bring up the shadows in the heart nebula. From what ive seen i need to drag top quarter up? And lower quarter down?

[@SKYST0RY]

It's been a while since I've used Siril, but I don't think Siril has a curves tool. I don't use GIMP , but I've read it has a very sophisticated and excellent curves tool.

[@magedsyehia]

Just wanted to confirm if you did any gradient removal before processing this image?

[@SamStars8811]

I was wondering the same thing but in a previous video he said he was in a dark sky site so I'm guessing there was no need (unlike for most of us).

[@SKYST0RY]

Sorry, the channel is getting so busy I find myself missing replies though I try to get back to everyone. I live in a dark sky area. I never have to deal with gradient issues except in the case of moonlight. Even with moonlight, I tend to shun gradient removal tools and handle gradients manually.

[@jesuschrist2284]

I assume this applies to curves in gimp too? Any fellow gimps got suggestions?

[@SKYST0RY]

I would assume it does, though GIMP probably has its own quirks, like all software. I haven't used GIMP in ages but I hear it has really developed into a powerful editor.

[@jesuschrist2284]

@@SKYST0RY just trying to transpose your processes into the free tools i use until i get pixinsight. Thankyou :)

[@SKYST0RY]

@@jesuschrist2284 I really don't recommend PixInsight for editing. I find it essential, but only because it's the only platform that runs the RC Astro tools, which is ridiculous. PixInsight does have a good stacking script, however, and the SubFrameSelector is very useful. Also, you can try the full version of Affinity Photo for six months for free.

[@neilhankey2514]

What is wrong with the stars in these images??? The nebula is sharp but the stars look to big and soft!!! In the bubble image they don't even look focused. Like small donuts? Otherwise a nice tutorial.

[@SKYST0RY]

I think what you're referring to is artifacting left after StarXTerminator and/or Starnet is run. I did not show star extraction because it takes a while and isn't really relevant to curves themselves. Those artifacts are easily removed, something I tend to do at the end of the development process. I wait till the end because they are handy color references, and sometimes they fit in to an image's motif well when the stars are restored. But we can only cover so much ground in a video and that's another topic entirely.