Guidelines and Tips and Tricks - Forums

Topic starter

May 5, 2021

This thread is to provide some guidelines, tips and tricks for a successful crowd imaging project. We've seen in the forums that some people have made some experience putting data from different observations together.

Maybe this thread can help to provide some Dos and Don'ts.

Björn Arnold

Topic starter

May 5, 2021

Let me just add/propose a few things ahead, maybe this helps to get a few things started. It's not only astronomy related but some general guidelines:

0. Keep in mind that I believe it should be a hobby after all and not running a profit-oriented business. People should have fun doing this and not stress because they have to deliver something in time.

1. If you have an imaging project in mind, I'd suggest to simply open a thread in this group, give it a clear title what the imaging project is about (e.g., target, spectrum (LRGB, NB, DSLR only) etc.). In the message body get into some details what equipment range you might want to use for your imaging.

2. As I've said in the forum already, a few technical things are likely relevant for a successful combination of (raw) data: image scales should be compatible. If angular resolution, FOV, image orientation etc. diverge, the stacked result might be a tiny intersection of the data and a lot of valuable data lost. However, experimentation is part of this hobby.

3. Agree on how you share the data. It may be quite a lot. Also keep in mind *PRIVACY*. If you share raw FITS files (and possibly other formats as well), it may contain location data of your scope etc.. Be aware of that. I recommend cleaning the meta data before it is shared.

4. *Share only*: if you want to exchange the data (e.g., through a cloud storage provider) don't allow uploads. Only upload your data and the others can pick it for processing. Most people are honest but you may meet people that might upload illegal content. Unfortunately one needs to keep these things in mind nowadays.

5. Every "member" of the project might have a different idea about the final result. Try to share the data amongst the group members so that everybody can (post) process the image in the way he/she likes.

These are a few items for the moment that I consider relevant. Please add or comment on them.

Clear skies!

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Björn Arnold

Topic starter

May 27, 2021

To publish an image created through crowd imaging, I'm proposing following procedure for publication (until there might be a dedicated release process for crowd images in AstroBin itself):

- Since each contributor may have created own version(s) of the final image, the group should select one image as the official "common" final image.
- Contributors, whose account allows the upload of more than one image version, would publish the common image as the original revision and can upload the own versions as revision(s).
- For capturing equipment, each contributor lists "only" his own equipment that he used to participate to the project.
- The same holds for the capturing details (filters, exposure times, # subs etc.). Each contributor lists only his contribution.
- In the description section, there could be a statement reading like this:
>> This image was created through a crowd imaging project. The imaging data above lists what I've been contributing to the final image. Other contributors are:
- [Name of contributor 1], [Link to AstroBin, the image of contributor 1]
- [Name of contributor 2], [Link to AstroBin, the image of contributor 2]
...
<<
- Of course, you need to agree on the common copyright.

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Doversole83

Aug 31, 2021

Hi Bjorn and all,

I am keen to experiment working on collaborative projects.
First reason would be the crap weather here in England doesn't allow to get long integration times all on myself !

But obviously I believe this is an interesting way to exchange wih people sharing the same interest.

I got a technical question. How do you use the frames that come from different scopes and sensors? Can you still align them in DSS? or do you have to manually align, resize and rotate in Photoshop? Is there some best practice in aquisition (someone takes Ha, some else takes OIII, etc, ?). I suppose as a minimum you have to provide some callibration frames along with your light frames.

Thanks!

Engaging Supportive

Björn Arnold

Topic starter

Sep 1, 2021

Hi,

I have to admit that I am not aware of some progress on this idea as for my side, weather has been the most serious issues here and I dealt with some equipment optimization.

To your question: if data is shared, then only calibrated lights. Anything else doesn’t make sense. Once the lights are calibrated, it wouldn’t make a difference for DSS or any other software if you have data from different sessions from your own equipment and from someone else.

However, there’s an open point in my opinion which needs some testing: data quality variance. If people use different scopes and imaging settings, optical aberrations will vary and SNR might be significantly different.
I don’t know yet if the integration process can handle this well.

Cheers,
Björn

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Doversole83

Sep 1, 2021

Bjorn,

Thanks. Indeed exchanging callibrated lights make sense.

In terms of image alignment, I did a bit of research yesterday and I believe DSS requires same sensor and scope. Other softwares like Registar can handle data from different sources but DSS can't. I understand APP can to a certain extend.

Otherwise, you can still align images in PS.

In terms of colaborative projects, this probably means it make more sense if someone can provide the complete set of data for one filter (H-alpha or Green for example) as you just have to combine the final image. If more people are collaborating together on H-Alpha data, this might be more complex to stack I suppose.

Regards

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