#M45 from B4

151 messages · Page 1 of 1 (latest)

rancid apex
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It is cropped because RGB and Lum was taken at different angels.

Lum 32 minutes, RGB 2h 20m.

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brazen gorge
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Nice detail and excellent colors

ebon turret
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Cleaaan

harsh hull
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damn

willow vapor
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diffraction spikes 😍

naive iron
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I really like the sharp diffraction spikes! Id love to get some like that myself. I am curious, how do you process your stars?

rancid apex
naive iron
rancid apex
naive iron
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My secondary holder vanes are quite thin so I think they have a hard time showing up in my images.

naive iron
rancid apex
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They need to be very precisely aligned to give good sharp spikes.

rancid apex
naive iron
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yours versus mine

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naive iron
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I know the background is noisey compared to yours. I think I add too much noise back in after I use deepsnr

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noisy^

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the only star ive ever done that even remotely looks good like yours is the extremely bright Alnitak

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see how it looks like its a glowing radiance

naive iron
rancid apex
naive iron
rancid apex
rancid apex
naive iron
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Agena astro mirror

rancid apex
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And my collimation is a bit off. I can get a OSC image to compare. Hang on...

naive iron
naive iron
naive iron
rancid apex
rancid apex
naive iron
# rancid apex Try to do both ways and compare.

I have. The issue I have is with noise level in the image. Each image is different. I use pixel math to add noise back in and I do it by a certain percentage, usually 10%. If I have an image that is virtually no noise because its really well sampled then 10% proportionally isnt much, but if the image isnt sampled well then 10% is a lot more so I have to play with the values.

rancid apex
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In this OSC of M45, the spikes are terrible because I do not have my spider vanes paralell...

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THis is after BXT btw.

naive iron
rancid apex
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I only sharpen stars 0.2. I dont like the tiny star thing.

naive iron
rancid apex
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Here is another one more recent, Bright star:

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All OSC data.

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Star not centered in halo because of collimation error.

naive iron
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I think it may be a sharpening error

rancid apex
# naive iron yours versus mine

I looked at your star again, I can see you used SCNR on the image - I only do that before adding stars back. I never use it on stars. It creates brownish hue to the spikes that I dont like.

naive iron
rancid apex
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THis is another bright star just next to M31. Notice the green in the rainbow. I have SCNR on the background, not star image.

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naive iron
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heres a star thats been corrected and nothing else. I am going to sharpen it like how you do it

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rancid apex
naive iron
naive iron
rancid apex
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Yeah, star luminance 🙂

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And yes, use as a mask. It will help to get that green tint that sometimes follow the star at the separation.

naive iron
naive iron
rancid apex
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for comparison

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naive iron
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its definitely better but Im still curious about the spikyness between the diffraction spikes

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They are like rays

rancid apex
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Do you have an mask over your mirror clips for the primary?

naive iron
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thats my primary'

rancid apex
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Ok, you do not.

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That is part of the issue.

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THe mirror clips that keep the mirror to the mirror cell will give you diffractions and more importantly dark shadows.

naive iron
rancid apex
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THis is because the very outside edge of the mirror is not optically sound (usually) it has a slight curve.

rancid apex
naive iron
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so there would be no solution to make it more even?

naive iron
# rancid apex Yes, precicely

I still dont understand how theres many dark shadows if theres only 3 mirror clips, maybe I should clean my mirror haha

rancid apex
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If you have a 3D printer, you can print a circle that covers the clips and simplu use the same or longer screws to hold it in place.

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I did the easier thing and used a black marker.

naive iron
rancid apex
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I simply drew a black line on the mirror that goes as far inside as the clips.

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Several you tube tutorials on this.

naive iron
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or at least hide them

rancid apex
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My stars improved drastically.

naive iron
naive iron
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I was like, what the heck am I doing wrong!

rancid apex
naive iron
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I got an old Meade 10" SCT that suffers from mirror tilt so I've been waiting on parts to correct it so I can start doing photography.

rancid apex
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Nice!

naive iron
rancid apex
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Very nice galaxy/planetary scope!

naive iron
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for this image I 2x drizzled it so thats why the star looks weird, I also sharpened it too much.

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but look at how the diffraction spike is wavy!

naive iron
rancid apex
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Yeah. It is field curvature and BXT trying to fix it.

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I have a feeling DSNR also can be involved. I try to go backwards in the editing history to see where the problem occurs.

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Sometimes it is enough to use DSNR before BXT or the opposite.

naive iron
rancid apex
naive iron
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I do deepsnr right before I stretch

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denoise, star removal, then stretch individually]

rancid apex
naive iron
rancid apex
naive iron
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but then I show them what I stay up all night for and they are like whatttt

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I am working on an image for the competition. Its NGC 4236

rancid apex
naive iron
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This is the first 10h roughly processed

rancid apex
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Awesome image!!

naive iron
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this is a crop of the nebulae

rancid apex
naive iron
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I think it will make for a very unique, uncommon image. Although I still am not entirely sure on how to combine the channels into a regular broadband image.

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This was my first attempt but I feel like I didnt do it very well, they look like red blobs with no detail or anything.

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naive iron
rancid apex
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Another great image! I would be happy with that. You might tune it down if you don’t like it, but there is not one way that works every time. Some times I simply use Ha as a mask and increase red in the curves tool, or increase saturation to show the Ha emissions in the main image.

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Other times I have to go all the way and use continuum subtraction on Ha and then add it in one of the scripts.

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Sometimes I add it in linear mode, sometimes after the stretch.

PI has a series of videos on the subject though.

naive iron
rancid apex
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My take away on M81. Not unlike yours.

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naive iron
# rancid apex My take away on M81. Not unlike yours.

fair enough! that looks great! This actually reminds me of another annoyoing issue that I have had to deal with. How do you prevent star exterminator from taking the nebulae out of the galaxy! the only way Ive figured out how to do it is by using a mask over the galaxy and doing two separate star removals, one of the stars on the outside of the galaxy and one on the inside with all the nebulae. Ill then duplicate the galaxy one and use clone stamp to remove all the stars from one and have that be the nebulae image and remove the nebulae from the other image and have that be the star image. I then recombine the nebulae with the background and add the galaxy stars with the background stars and then I can start processing them.

rancid apex
naive iron
rancid apex
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That will move the nebula from the NB stars and place it in the broadband stars data so you can add them back.

naive iron
rancid apex
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I dont think I’ve seen a video on that but it simply compares the images listed between ( and ) and uses the brightest pixel from them. I always create a new Image. The formula is exactly the same as Avg, Med and Min (Average, Median an Minimal)

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If your rgb_stars and Ha_stars images are named like that , you open Pixelmath and type

Max(rgb_stars,Ha_stars)

And create the image, voila, star image with nebulas to add back.

naive iron
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haha

rancid apex
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Yeah. Beats manual work 😅

naive iron
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should I stretch them first? when should I combine them in the work flow, that was another thing I was wondering. I combined them after they were stretched already

rancid apex
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I think it works both ways.

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Important to match their brightness before hand though. I usually put the two on top of each other and blink untill they are stretched equally bright (compare the stars as reference).

naive iron
rancid apex
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I sometimes use the process Linear fit, sometimes the script DNAunlinear fit.

rancid apex
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It switches between last and present image back and forth

naive iron
rancid apex
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But I did notice that it might be problematic, so I sometimes use Background neutralization on the image first.

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The color calibration tools only ”bend” the colors into submission, so the closer they are to begin with, the better result

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I am off to grab some sleep now 😅. I will check in tomorrow.

naive iron
brazen gorge
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Curious to know what newt you are using there too

rancid apex
harsh hull
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damn