Jump to content
You must now use your email address to sign in [click for more info] ×

Recommended Posts

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.

Link to comment
Share on other sites

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 1.10.5 Designer 1.10.5 and Publisher 1.10.5 (mainly Photo), now ex-Adobe CC

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

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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 1.10.5 Designer 1.10.5 and Publisher 1.10.5 (mainly Photo), now ex-Adobe CC

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

Link to comment
Share on other sites

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!

Link to comment
Share on other sites

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 1.10.5 Designer 1.10.5 and Publisher 1.10.5 (mainly Photo), now ex-Adobe CC

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

Link to comment
Share on other sites

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, AD & APub user, running Win10

Link to comment
Share on other sites

  • 4 weeks later...

As far as samples go:

Here a 5 image stack from Jupiter, showing massive distortion in shape, colour shift (orange on the left, blue on the right) effects, and so on. As Jupiter was low on the horizon, I only got around 36 x 36 pixels, but it does give a nice indication of the issues involved.

The image quality gets much better when the planet is close by, and you are shooting almost vertically, but that is seldom the case.

The second image is a 3 image stack of the moon, almost directly overhead, but there is still considerable blurring. This is a really difficult form of photography, and any automation of post processing would be helpful.

Jupiter

 

Moon

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Terms of Use | Privacy Policy | Guidelines | We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.