Great video Bruce, I have a Startravel 120 on order and this will help me as I didn't realize you could fix CA in software. I would be pleased if my image turns out as good as your original image.
I can confirm this worked for both my Sony 85mm and Sigma 16mm lenses on a Sony A6400 APS-C camera. Removed all purple fringing on the stars in my astrophotos.
Well whoever told you that is completely wrong.There are even filters that allow you to kill most of your chromatic abberation. The real statment is that you will have to work a lot harder to get an acceptable image. Again, a better telescope will have even less Coma at the corners also. Thats what I am, and many other are willing to pay for. Your image is also suffering from some guiding errors. These can also be reduced using Photoshop. make a separate dark layer and use to arrow keys to move it slightly around to correct the stars etc... You can do a lot with Photoshop to make pretty astro pictures.
Shooting RAW can three sets of exposures be made focused for each colour/color channel? The RGB images could be combined in a panorama tools program like (free) Hugin perhaps. Infrared and ultraviolet could be filtered out. With RAW there wouldn’t even need to be red, green and blue filters. The panorama software could correct for lens distortions and change the _projection_ of the final image.
Hi Bruce, Thanks for the video. Question: The same people who can't afford an APO, are people who can't afford the more expensive astronomy programs. Are there similar tricks that can be used with free programs? I use Star Tools. I came into AP from visual and like using my ES152. Blue halos drive me nuts! :-) Thanks, Tom, Tucson
I'm not sure. I have only tried this trick on Adobe Lightroom. There are free programs for Astrophotography ... but I don't know of any that can remove chromatic aberration.
Your reaction to the purple fringing is a learnt response from the elitists in the astro community. It' isn't anywhere near as abhorrent as you are making it out to be. In the history of astronomy achromatic telescopes were a major invention. Prior to that lenses with no correction at all were used and the chromatic aberration from those was astonishing forcing astronomers to use crazy long telescopes with tiny lenses. The invention of the achromat was game changing allowing tons of real science to be done (not taking pretty photos of the sky). Achromats were where it was at in science until the issues with reflecting telescopes were corrected in the early 1900's (poor % of light reflected and surfaces tarnishing). Apochromatic telescopes only focus the three wavelengths of light we see with our eyes on the same spot, the other wavelengths are still aberrated that along with the warp field and stupid prices and it's crazy anyone buys them. The aberration means they aren't used and have never been used for real science. If you care about chromatic aberration then use a Schmidt-Cass. They produce perfect images in all wavelengths and perfect flat fields. But it's not really about that is it...it's about buying expensive toys that look like "real" telescopes (which scientist astronomers don't use).
Plank, how about you posting a scientific paper peer reviewed by real scientists in a real professional journal. I have one posted using a 80mm TASCO refractor on a EQ mount with no motors or auto guiding using a calibrated reticle. If you care or can even read it is still on the internet. Look up in the Journal of double stars under first author Darrell Grisham 3 inch TASCO, 2008 I did, and published for a Physics class took in 2007. to pass the class .The instructor is Russell Genet sitting scientist at the University Cal Poly San Luis Obispo CA. A lot of science can be done with small telescopes. I am a college of the Naval observatory here in Arizona. Still doing research only with a 120mmx1000f/l Celestron OMNI XLT on a Meade XL70 mount with only a motor on the RA axis. On double stars that have not been measured for separation in a 100 years. Useful information in that some may be stars that appear to be doubles and are not. Others that are. Have a good night observing and quit putting down those who actually do.
Have you tried a field flattener with it? I found the Evostar 80ED flattener worked great on the 120mm achromat that Skywatcher makes. Did a video on it here. ruclips.net/video/4nB79t998s4/видео.html
Phographing galaxies is not taking photos of cat. You have to use at least RGBL filters (and refocus) or narrowband to get decent results out of achromat. What you have shown in this video is not decent, looks crappy like andromeda i took with my vintage pentacon 135/2.8 M42 lens...
come on man, that's a pretty good picture. It seems that many are infected by astrophotography elitists who will not accept an image unless it is taken with a 10,000 telescope. besides, it is one more trick, just like the thousands of tricks for image processing and arrangement used by astrophotographers, or tell me, do the natural photos, recently taken, even look similar to this one? Another thing, what would be the image standard for galaxies? who is the creator of that standard? any reliable source?
The original picture itself with all its flaws is already great !
I think the purple fringing looks cool! Keep it.
someone gives this guy a medal.
I like the purple, I think it's more beautiful with it.
Great video Bruce, I have a Startravel 120 on order and this will help me as I didn't realize you could fix CA in software. I would be pleased if my image turns out as good as your original image.
Very helpful. Thanks! You’ve got a new subscriber.
Hi!! You get the Baader Contrast Booster Filter! Regards!
I can confirm this worked for both my Sony 85mm and Sigma 16mm lenses on a Sony A6400 APS-C camera. Removed all purple fringing on the stars in my astrophotos.
Well whoever told you that is completely wrong.There are even filters that allow you to kill most of your chromatic abberation. The real statment is that you will have to work a lot harder to get an acceptable image. Again, a better telescope will have even less Coma at the corners also. Thats what I am, and many other are willing to pay for. Your image is also suffering from some guiding errors. These can also be reduced using Photoshop. make a separate dark layer and use to arrow keys to move it slightly around to correct the stars etc... You can do a lot with Photoshop to make pretty astro pictures.
What filter can I get for my celestron to kill more of the ca?
Shooting RAW can three sets of exposures be made focused for each colour/color channel? The RGB images could be combined in a panorama tools program like (free) Hugin perhaps. Infrared and ultraviolet could be filtered out. With RAW there wouldn’t even need to be red, green and blue filters.
The panorama software could correct for lens distortions and change the _projection_ of the final image.
Hi Bruce,
Thanks for the video.
Question: The same people who can't afford an APO, are people who can't afford the more expensive astronomy programs. Are there similar tricks that can be used with free programs?
I use Star Tools. I came into AP from visual and like using my ES152. Blue halos drive me nuts! :-)
Thanks,
Tom,
Tucson
Registax for stacking
And nexstudio for image processing
I'm not sure. I have only tried this trick on Adobe Lightroom. There are free programs for Astrophotography ... but I don't know of any that can remove chromatic aberration.
instead use the free versions like GIMP, Sharpcap, Registack 6, and others, they work.
Your reaction to the purple fringing is a learnt response from the elitists in the astro community. It' isn't anywhere near as abhorrent as you are making it out to be.
In the history of astronomy achromatic telescopes were a major invention. Prior to that lenses with no correction at all were used and the chromatic aberration from those was astonishing forcing astronomers to use crazy long telescopes with tiny lenses. The invention of the achromat was game changing allowing tons of real science to be done (not taking pretty photos of the sky). Achromats were where it was at in science until the issues with reflecting telescopes were corrected in the early 1900's (poor % of light reflected and surfaces tarnishing). Apochromatic telescopes only focus the three wavelengths of light we see with our eyes on the same spot, the other wavelengths are still aberrated that along with the warp field and stupid prices and it's crazy anyone buys them. The aberration means they aren't used and have never been used for real science.
If you care about chromatic aberration then use a Schmidt-Cass. They produce perfect images in all wavelengths and perfect flat fields. But it's not really about that is it...it's about buying expensive toys that look like "real" telescopes (which scientist astronomers don't use).
Plank, how about you posting a scientific paper peer reviewed by real scientists in a real professional journal. I have one posted using a 80mm TASCO refractor on a EQ mount with no motors or auto guiding using a calibrated reticle. If you care or can even read it is still on the internet. Look up in the Journal of double stars under first author Darrell Grisham 3 inch TASCO, 2008 I did, and published for a Physics class took in 2007. to pass the class .The instructor is Russell Genet sitting scientist at the University Cal Poly San Luis Obispo CA. A lot of science can be done with small telescopes. I am a college of the Naval observatory here in Arizona. Still doing research only with a 120mmx1000f/l Celestron OMNI XLT on a Meade XL70 mount with only a motor on the RA axis. On double stars that have not been measured for separation in a 100 years. Useful information in that some may be stars that appear to be doubles and are not. Others that are. Have a good night observing and quit putting down those who actually do.
My god man! I was about to write something very similar. Glad I read the comments first.
Thank you sir
Extremely helpful video. What were your camera settings for taking this? How many subs and exposure time length?
I have same problem, even good stretch of M31 doesnt look that well, i just want to remove purple color with some stars.
you can with long focal length
Wow ! 👍🏻
Um hello how do I fix the rainbow coloring around my telescopes
Thanks!!
Did you just use a DSLR?
Everyone can shoot Andromeda galaxy with everything that can take photos. Thanks
Have you tried a field flattener with it? I found the Evostar 80ED flattener worked great on the 120mm achromat that Skywatcher makes. Did a video on it here. ruclips.net/video/4nB79t998s4/видео.html
I like all that purple fringing in my images.
There is an immense amount of snobbery in youtube astrophotography. It's more about their new toys rather than the actual astronomy.
Is there a.i that can remove the purple automatically?
There might be ... but I don't know of any.
so you got rid of all of the blue stars, including the naturally blue stars that wasn't color aberration!.
Phographing galaxies is not taking photos of cat. You have to use at least RGBL filters (and refocus) or narrowband to get decent results out of achromat. What you have shown in this video is not decent, looks crappy like andromeda i took with my vintage pentacon 135/2.8 M42 lens...
come on man, that's a pretty good picture. It seems that many are infected by astrophotography elitists who will not accept an image unless it is taken with a 10,000 telescope. besides, it is one more trick, just like the thousands of tricks for image processing and arrangement used by astrophotographers, or tell me, do the natural photos, recently taken, even look similar to this one? Another thing, what would be the image standard for galaxies? who is the creator of that standard? any reliable source?