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Hi, I would like to try the very effective stacking tools in affinity photo to stack images from planets.

The first task would be to remove or rather reduce distortion due to the atmosphere. When I stack in affinity photo, it will already bend and twist images to make them align, so I hope that a reasonably large set of preselected images would reduce the distortion.

The second task is to realign RGB within each image to compensate for the atmospheric prism effect. I am sure this is possible if one has an infinitely long lifetime in which to do this, so my question is, how can such a process be automated to perform the two tasks above, or has someone already done something like this. If anyone has tried any of this I would be very interested in the experiences gathered.

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Have you tried loading the R, G and B images into a stack (File > New Stack) and  tick the Align Images box. For a planet with well-defined features, this should align it effectively. If the image is fuzzy, then it might not do so well! You can then crop the live stack and copy each layer into the R, G and B channels of a new RGB image.

John

 


Windows 10, Affinity Photo 1.6.5.123 and Designer 1.6.5.123, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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Hi John,

Thanks. First I would have to separate the layers, then stack them. Also, it would not be a small number of images, I think this would need to be several 100 images before one can select out the least distorted pictures. I will give it a try, when it stops raining, to get a good set of images to work with.

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Have a look at what people like Eric Ng and Damien Peach are doing - they're not using AP, but it's horses for courses!


AP user, running Win10

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2 hours ago, Anonymouse said:

Hi John,

Thanks. First I would have to separate the layers, then stack them. Also, it would not be a small number of images, I think this would need to be several 100 images before one can select out the least distorted pictures. I will give it a try, when it stops raining, to get a good set of images to work with.

I was assuming that you were taking images in the three separate colours as many astrophotographers do. If not, then what do you mean by 'realign within each image'?

John


Windows 10, Affinity Photo 1.6.5.123 and Designer 1.6.5.123, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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Hi,

I think I need to explain further. I don't have expensive equipment, I am using a cheap telescope someone gave me, a tracking tripod, and a sony alpha 6300. I have been reading articles about this, and what is often proposed is to record a movie, and then analyse the individual pictures of the movie. Many articles suggest working with datasets of 10,000 pictures or more, and lots of expensive equipment. Given that I will use a smaller number of individual shots to start with, and given that each colour picture from say 100 will need:

  1. To be separated into the three colour bands R, G, and B
  2. Each R, G, and B to be realigned to recreate a colour picture, where the colours actually line up
  3. All pictures to be averaged together to create a map of where the object (planet) is most likely to be
  4. Then filter out all the pictures that are too distorted
  5. Last, stack all the pictures to produce a clear single image (AP can definitely do that part)

The question is, can Affinity Photo be used to automate all the steps, or do I have to buy/build an image pre-processor for that. Further, has anybody ever tried something like this? I certainly don't want to perform all these steps by hand.

BTW. all of the free image stacking tools I have tried failed my simple test of stacking 3-4 nearly identical images, which is why I bought the Affinity Photo license in the first place. Because it worked!

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22 hours ago, Anonymouse said:
  • To be separated into the three colour bands R, G, and B
  • Each R, G, and B to be realigned to recreate a colour picture, where the colours actually line up

Surely, if you start with an RGB image, then separate it into three single-colour images/channels, then these will already be properly aligned (since they all came from the same original photo).

22 hours ago, Anonymouse said:

All pictures to be averaged together to create a map of where the object (planet) is most likely to be

Isn't this what you get when you stack the images using Align? If you use the median option, then it will ignore outliers.

As far as I can see, you have just a single step which, as you say, Affinity Photo can do.

John

 


Windows 10, Affinity Photo 1.6.5.123 and Designer 1.6.5.123, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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2 hours ago, John Rostron said:

Surely, if you start with an RGB image, then separate it into three single-colour images/channels, then these will already be properly aligned (since they all came from the same original photo).

I'm wondering if @Anonymouse is trying to remove chromatic abberation rather than dealing with atmospheric effects like scintillation.  It would be helpful to see a sample image.


AP user, running Win10

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