aster94

Hello,

 

I finally bought an astro tracker (the star adventurer 2i) and a few nights ago I shoot my really first session during a bad night (I just wanted to test the equipment): I shoot almost against the full moon and I took only 30 lights.

 

So the result is quite good considering the conditions:

Stacked with siril with 20 darks, 80 flats and 80 bias, then little corrections in darktable

 

This is one of the lights that I used for the final image above:

120s, ISO 100

IMG_5440.CR2

 

And I took a few 60s, ISO 100

IMG_5439.CR2

 

So I would like to ask advices mainly to the RAW lights files

1) Do you think the 60s would have been better?

2) How do you understand when it's the "perfect" settings (ISO, exposure, ecc) for your sessions?

 

Best

I am not sure if ephemeris is what I am looking for, my question is indeed how ephemeris are calculated?

I am very curios of how this site made this previsions: https://www.calsky.com/map.php?lang=en&isstransit=&lunar=

hello,

I am wondering how is possible to express the orbit of an object and where, if possible, can I find it?

for example if I go to the ISS website I can see that they have a map (https://spotthestation.nasa.gov/tracking_map.cfm) that shows the position of the ISS second by second and it's future position. How is it calculated? Is this mathematical formula somwehere?

Also before I wrote "position" how it it expressed? I guess it is the https://en.wikipedia.org/wiki/Equatorial_coordinate_system so it will use a declination and right ascension but how can I translate these to a https://en.wikipedia.org/wiki/Horizontal_coordinate_system so to azimuth and altitude?

 

Edit: for the second part of the question it is just a bit of math: https://astronomy.stackexchange.com/questions/13067/conversion-from-equatorial-coordinate-to-horizon-coordinates and http://www.zafzaf.it/coordinate/chapter7.htm

Hello,

In a few days I am going to do my first startrail, so yesterday I made some software's test, someone may find this topic with google and may be interested.

I compared these software:

StarTrails: https://www.startrails.de/

StarStarX: https://markus-enzweiler.de/software/starstax/

Gimp + plugin: https://github.com/themaninthesuitcase/gimp-startrail-compositor

Siril: https://www.siril.org/

 

I used a canon 600D with samyang 8mm 3.5f and I shoot in RAW. The environment is not perfect with street lights. I converted the RAW to jpg with darktable without any processing step, in average a single jpg pic was aroung 500kb.

I made around 340 shoots and from these I made two datasets of images

1) with all of them

2) with only the first 140 pics because after some nasty clouds appeared

 

 

About the software:

1) startrails (version 2.3) - velocity medium - image size -60%

2) starstax (version 0.71) - velocity fast - image size +76%

3) gimp (version 2.10.18) + plugin (version 1.8) - velocity slow - image size -30%

4 Siril (version 0.9.12) - velocity fast - image size +100%

 

Here the visual comparison:

1) All pictures (with clouds)

Startrail:

with dark:

 

without dark:

StarStaX

with dark:

 

without dark:

 

Gimp + plugin:

with dark:

 

without dark:

 

with dark + removing skyglow "light":

 

Siril

(without dark)

 

2) only first 140 pictures - always without dark

Startrails:

 

StarStaX

 

gimp + plugin (png, not jpg):

 

with removing skyglow "heavy"

 

with removing skyglow "full"

 

Siril:

 

Even if gimp was the slowest it is the one i enjoyed most for the "removing skyglob" mode

 

 

 

Thanks I already know it, even if i never used none of them. I may try to use the same jpg/tiff images for making a comparison between the three software

https://markus-enzweiler.de/software/starstax/

https://www.startrails.de/

I wanted to avoid the overload of memory usage, my SD are not that big and I don't wish to wake up at 3am to change it. Is there a common practise for this? I have been googling around for it but i wasn't able to find anything

Hello,

Tomorrow I am going to do my first star trail experiment. I am going to use a GIMP plugin (https://github.com/themaninthesuitcase/gimp-startrail-compositor). Since it accept only not-RAW files, I have a doubt about what should I do to:

1) shoot in jpg then stacking then post processing

2) shoot in raw then post processing then staking and finally little adjustment with post processing again

 

I guess I would get better results with the second option but is it really necessary?

Would would you do?