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Thursday, March 4, 2021

Nebulae of Auriga and how my mosaic images are done.

I'll like to show the actual resolution of this and other of my large mosaic images by posting a close up from this panorama. Since there are data from so many years (2009 -2021) and it has been shot with various optical configurations, I had to develop a new method to combine frames for a mosaic image.

A closeup from the panorama
Click for a large image

This closeup is reduced about 80% from the original resolution

In my last blog post I published a panoramic mosaic image showing the sky between taurus and Perseus.

The Mosaic Work

Up to 2014 I was using an old Meade LX200 GPS 12" scope, QHY9 astrocam, Canon EF 200mm f1.8 camera optics and baader narrowband filter set. After 2014 I have had 10-micron 1000 equatorial mount, Apogee Alta U16 astro camera, Tokina AT-x 200mm f2.8 camera lens and the Astrodon 50mm square narrowband filter set. I have shot many details with a longer focal length, before 2014 by using Meade 12" scope with reducer and after 2014 Celestron EDGE 11" and reducer. Quider camera has been Lodestar and Lodestar II.

I took my current toolset as a base tool since it has a relatively high resolution combined to a very large field of view. Also it collects photons very quickly since it's undersampled and I can have very dim background nebulosity visible in very short time (many times 30 min frame is enough)

I do all my mosaic work under the PhotoShop, Matching the separate panels by using stars as an indicator is kind of straight forward work. My processing has become so constant, that very little tweaking is needed between separate frames, just some minor levels, curves and color balance. 

I have used lots of longer focal length frames in my mosaic to boost details. To match them with shorter focal length shots I developed a new method.

Firstly I upscale the short focal length frames about 25% to have more room for high resolution images.Then I match the high res photo to a mosaic by using the stars as an indicator. After that I remove all the tiny stars from the high res image. Next I separate stars from low res photo and merge the starless high res data to a starless low res frame. And finally I place the removed low res stars back at top of everything with zero data lost. Usually there are some optical distortions and it's seen especially in a star field. Now all my stars are coming from a same optical setup and I don't have any problems with distortions. (I'm using the same star removal technique as in my Tone Mapping Work Flow)


Unknown said...

Incredible work by Astroimaging Guru

Unknown said...

What a beauty!! Proud of you!

Unknown said...

Absolutely fantastic! I am blown away at the sheer beauty of the galaxy you have revealed to us. Thank you! Few people would have had the patience to pursue this task.

Anonymous said...

Amazing photos... Thanks for all your time and for sharing them!

O LORD, our Lord, How excellent is Your name in all the earth, Who have set Your glory above the heavens! Out of the mouth of babes and nursing infants You have ordained strength, Because of Your enemies, That You may silence the enemy and the avenger. When I consider Your heavens, the work of Your fingers, The moon and the stars, which You have ordained, What is man that You are mindful of him, And the son of man that You visit him? For You have made him a little lower than the angels, And You have crowned him with glory and honor. You have made him to have dominion over the works of Your hands; You have put all things under his feet, All sheep and oxen— Even the beasts of the field, The birds of the air, And the fish of the sea That pass through the paths of the seas. O LORD, our Lord, How excellent is Your name in all the earth! ~Psalm 8

Korki Bucheck said...

�� WoW!!! Thanks

Unknown said...

To jest piękne..

Unknown said...

Wow! Stunning! Well done.

Unknown said...

An amazing achievement! Thank you!