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I recently had my first light with my new Mesu mount and aimed the Esprit 150 at NGC2903. Combined with the he ASI 071MC with its APS-C sized chip this gave me a rather large FOV and therefore a rather small galaxy.

1900857609_20190228NGC2903RGBPS47smallSign.thumb.jpg.80f31ff312179990dab4345fd96a1c62.jpg

I kind of like the small galaxy in a large space, but still I started playing with ways to crop the image, realizing that there are indeed many different ways to do this.

I first made a rather standard crop keeping approximately the same image dimensions and  the galaxy in the centre:

1556735591_20190228NGC2903RGBPS47Usualcrop.thumb.jpg.9fe4a2722bb4c1aaeff27cfe4af048b0.jpg

Then it struck me that it could look nice in a more panoramic view:

2062033306_20190228NGC2903RGBPS47Panoramacrop.thumb.jpg.ea446bfd5f1fced26ef47e9217b805e8.jpg

And finally, I started to think about the possibility to use the famous Golden Ratio (https://en.wikipedia.org/wiki/Golden_ratio) used by artists since Leonardo da Vinci. I first tried it in its simplest form by just placing the galaxy in the one-dimensional golden ratio position along the length of the image:

933510566_20190228NGC2903RGBPS47GoldenRatiocrop.thumb.jpg.c216c069069189982c65c0048c6b8ad2.jpg

But this could also be done in two dimensions using the Fibonacci spiral, and to get it there I felt it benifited from a 180° rotation of the image:

243449425_20190228NGC2903RGBPS47FullGoldenwithguide.thumb.jpg.4aa49f8ff3ceea38cc6c1ac355908240.jpg

132681306_20190228NGC2903RGBPS47FullGoldenRatiocrop.thumb.jpg.752edb07397b5d66c7f09972da2e9075.jpg

Any more suggestions? What looks best, if any? Feel free to play with different ways to crop my image.

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Personally I think whatever the crop they all look great images.

Where the main target is placed in the frame is very much up to the person doing the crop and I would say (only my take on this mind):

  • Not to put the target dead centre.
  • Not to crop too much, otherwise if the target fills the frame then can look too blurred and somehow is just not as interesting as some background included.
  • Not to keep huge areas with nothing to see but also not to crop areas of stars that do add interest to the frame.

All in all I would say it is your image and do what pleases you. Mostly people imaging never seem to be 100% happy with their work and always feel they can do better and always keep trying harder the net time.

Steve

Edited by teoria_del_big_bang
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2 hours ago, Scooot said:

I’d put the galaxy top right quarter with the brighter stars diagonally opposite. :) 

That is a good idea! I like the result:

20190228 NGC2903 RGB PS47Galaxy in top quarter.jpg

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Don't forget to look at different rotations when you crop. Although you may lose some of the image, a rotated image (particularly a non-orthogonal rotation) can give a fresh perspective. Rotating your image clockwise about 30 degrees  and cropping in about 40% makes the three (remaining) bright stars in the lower left look like they are "cradling" the galaxy and gives the image some support..

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9 minutes ago, Filroden said:

Don't forget to look at different rotations when you crop. Although you may lose some of the image, a rotated image (particularly a non-orthogonal rotation) can give a fresh perspective. Rotating your image clockwise about 30 degrees  and cropping in about 40% makes the three (remaining) bright stars in the lower left look like they are "cradling" the galaxy and gives the image some support..

Good point: I made two versions based on your suggestion since a full 30° rotation meant that the bright blue star was cut out I rotated the first one a bit less.

20190228 NGC2903 RGB PS47rotate+crop1.jpg

20190228 NGC2903 RGB PS47rotate+crop2.jpg

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Thanks for the input! I agree with the main message: NOT TO have the main object in the dead centre, which interestingly does not seem to be the norm, probably because our scope software puts it in the centre. This is the one I now settled for and posted on my Astrobin.

20190228 NGC2903 RGB PS51smallSign.jpg

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On 02/03/2019 at 11:30, gorann said:

this could also be done in two dimensions using the Fibonacci spiral, and to get it there I felt it benifited from a 180° rotation of the image:

 243449425_20190228NGC2903RGBPS47FullGoldenwithguide.thumb.jpg.4aa49f8ff3ceea38cc6c1ac355908240.jpg

If you use the golden ratio or rule of thirds, you need to have another, but minor, point of interest on the opposite side. In your final image the blue star provides that point of interest. Without it, the image isn't balanced. This is one reason why M81 and M82 make such a nice pair. Gendler dedicates one chapter of "Lessons from the Masters" to composition.

53 minutes ago, gorann said:

 

20190228 NGC2903 RGB PS51smallSign.jpg

Have you tried this with the bright star on the right cropped? Plus a little off the top.

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