I often just use star minimization in photoshop through the color range -> highlights -> filter minimum, but I find it leaves artefacts around star clusters and gives the overall image a smudgy look? curious to hear how all of you reduce your stars. CS, Max
Best Star Minimization Techniques?
Engaging
I don't do star minimization but keep them at a subjectively "nice" size by manually stretching them. I don't like any of the automated methods, I always extract them while the image is still on its linear state.
This is my current procedure:
. Run BlurXterminator. Usually, I don't like/need to sharpen the stars.
. Remove them (StarNet2) before stretching the image, on a linear state.
. Stretch the stars by using the Histogram Transformation, only moving the midpoint to the left. I usually do it in small increments, trying to barely bringing into visibility fainter/"invisible" stars one step at a time. Once I can barely see all the stars, I stop stretching them.
. Screen the stars back to the stretched starless image using the CombineImages script.
That's it. If I'd like smaller stars, I undo the last Histogram Transformation and re-screen them to the starless image. If I wanted them bigger, I stretch them a little more.
Lately, I've found that if I "sharpen" the stars with BlurX, they end up looking unnatural.
This is a crop at 100% of my last image:
And this is the same, on a more screen-friendly scale:
Hoping to see how others manage theirs!!
This is my current procedure:
. Run BlurXterminator. Usually, I don't like/need to sharpen the stars.
. Remove them (StarNet2) before stretching the image, on a linear state.
. Stretch the stars by using the Histogram Transformation, only moving the midpoint to the left. I usually do it in small increments, trying to barely bringing into visibility fainter/"invisible" stars one step at a time. Once I can barely see all the stars, I stop stretching them.
. Screen the stars back to the stretched starless image using the CombineImages script.
That's it. If I'd like smaller stars, I undo the last Histogram Transformation and re-screen them to the starless image. If I wanted them bigger, I stretch them a little more.
Lately, I've found that if I "sharpen" the stars with BlurX, they end up looking unnatural.
This is a crop at 100% of my last image:
And this is the same, on a more screen-friendly scale:
Hoping to see how others manage theirs!!
Well Written Helpful Insightful Engaging
1) Do a short stack based on the FWHM and roundness of your stars. It's up to you as to how aggressively you push this but stars don't need a lot of integration time unless you want to go deep. It also helps with clipping. This may be enough to reduce the size of your stars to your liking.
2) Remove the stars.
3) Process your starless image.
4) Stretch your star plate to get the star density and prominence that you want.
5) Add the stars to your finished starless plate. In most photo editors the screen function works best for this.
2) Remove the stars.
3) Process your starless image.
4) Stretch your star plate to get the star density and prominence that you want.
5) Add the stars to your finished starless plate. In most photo editors the screen function works best for this.
Helpful Concise
I do my processing in PixInsight.
If I shot my target using narrowband filters, I always shoot some RGB to capture natural-looking stars. Obviously, if I shot my target in RGB, I already have RGB star data.
I'll start by combining the R, G, and B into a color image, then run BlurX to sharpen the image. After that I use SPCC to calibrate color.
Then, if I need to do star reduction and/or process RGB stars separately (to add to an SHO image), I'll do the following:
1) While the image is still in the linear state, I use StarX (with Unscreen Stars checked) to create separate stars-only and starless images.
2) With the stars-only image, if it is really dense with stars, I use MMT to remove the smallest ones. If one gets too aggressive with star removal in MMT, the image starts to look unnatural.
3) I stretch the stars-only image to my liking with HistogramTransformation (sometimes I might use ArcsinhStretch a bit first to get a little more color in the stars). If needed, I might use CurvesTransformation to adjust colors and/or saturation.
4) After I stretch and process the starless image, I use PixelMath to recombine the images: combine(stars, starless, op_screen())
Often I will experiment by trying a few different star-only images (stretched to various degrees) to see which looks best when combined with the starless image.
If I shot my target using narrowband filters, I always shoot some RGB to capture natural-looking stars. Obviously, if I shot my target in RGB, I already have RGB star data.
I'll start by combining the R, G, and B into a color image, then run BlurX to sharpen the image. After that I use SPCC to calibrate color.
Then, if I need to do star reduction and/or process RGB stars separately (to add to an SHO image), I'll do the following:
1) While the image is still in the linear state, I use StarX (with Unscreen Stars checked) to create separate stars-only and starless images.
2) With the stars-only image, if it is really dense with stars, I use MMT to remove the smallest ones. If one gets too aggressive with star removal in MMT, the image starts to look unnatural.
3) I stretch the stars-only image to my liking with HistogramTransformation (sometimes I might use ArcsinhStretch a bit first to get a little more color in the stars). If needed, I might use CurvesTransformation to adjust colors and/or saturation.
4) After I stretch and process the starless image, I use PixelMath to recombine the images: combine(stars, starless, op_screen())
Often I will experiment by trying a few different star-only images (stretched to various degrees) to see which looks best when combined with the starless image.
Well Written Helpful
I use StarXterminator in pixinsight. It's easy, but I know there are free tools like starnet2+ that are just as good.
I'm not a Photoshop expert at all, and every time I tried stat reduction in Photoshop it left weird artifacts, that's actually what pushed me into pixinsight. Well, that and Blurxterinator.
I'm not a Photoshop expert at all, and every time I tried stat reduction in Photoshop it left weird artifacts, that's actually what pushed me into pixinsight. Well, that and Blurxterinator.
I find that the best star reducing technique is to do only a partial stretch of the stars after extracting the stars from the background.
Then there is not much need for additional star reduction.
I use Pixinsight to most of the processing job and Photoshop to fine tune the colors at the end of the processing
Then there is not much need for additional star reduction.
I use Pixinsight to most of the processing job and Photoshop to fine tune the colors at the end of the processing
Roy Hagen:
I find that the best star reducing technique is to do only a partial stretch of the stars after extracting the stars from the background.
Then there is not much need for additional star reduction.
I use Pixinsight to most of the processing job and Photoshop to fine tune the colors at the end of the processing
I agree. To that I would add that shorter subs help as well.
Well Written Respectful
The newest SetiAstro tools (CosmicClarity Suite) do a nice job and they're free
Not sure why you need to make stars smaller as it looks like you only use camera lens to image, but I have brought this up before.
Since you use Photoshop, you should look into this software from Pro- Digitial, it's an action set they sell for photoshop, photoshop calls them Actions, PI calls them scripts.
This action set has many different actions and one of them is *make stars smaller* it works great without artifacts and if running once is not enough, run it again. Check it out.
Astronomy Tools Actions Set by ProDigital Software
Since you use Photoshop, you should look into this software from Pro- Digitial, it's an action set they sell for photoshop, photoshop calls them Actions, PI calls them scripts.
This action set has many different actions and one of them is *make stars smaller* it works great without artifacts and if running once is not enough, run it again. Check it out.
Astronomy Tools Actions Set by ProDigital Software
Concise
You guys minimize stars?
NOTE: The following applies to "stars only" component of images.
1) Duplicate and stretch duplicate so the duplicate is totally black
2) Lightly Stretch the Starry Image (any process you want to use)
3) Use Bill Blanhsan/Mike Cranfield Star Reduction Script with the black image selected as the starless image - adjust size and appearance as desired.
1) Duplicate and stretch duplicate so the duplicate is totally black
2) Lightly Stretch the Starry Image (any process you want to use)
3) Use Bill Blanhsan/Mike Cranfield Star Reduction Script with the black image selected as the starless image - adjust size and appearance as desired.
Bill has a bunch of every effective star reduction scripts: https://www.youtube.com/watch?v=ofGt0Fk51h4
I spend time getting my focus perfect, polar aligned precisely and guiding at the .4" range. Smallest hfd possible.
When performing panoramic projections the stars at the edge of the field get quite bloated from the projection distortion so i use Russell Cromans StarShrink to normalise them.
https://www.rc-astro.com/software/ss/
https://www.rc-astro.com/software/ss/
Chris Beere:
When performing panoramic projections the stars at the edge of the field get quite bloated from the projection distortion so i use Russell Cromans StarShrink to normalise them.
https://www.rc-astro.com/software/ss/
This is a great program and I have used it in Photoshop and Affinity Photo, I wish it worked in PixInsight.