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Tuesday, August 8, 2023

Grand Mosaic of the Milky Way is now large than ever

Last Spring I published a large mosaic photo of the Milky Way and it went viral!
I have now even a large version of it, the mosaic spans 145 degrees of sky from Orion to Cygnus, the previous version showed 120 degrees of sky.

The new panorama image was published today in Finnish Tähdet ja Avaruus Magazine 
at first time in the World.

This and other of my astronomical photographs can be seen in my NIGHT FEVER exhibition in Helsinki.


The Grand Mosaic of the Milky Way Galaxy II
 This is the only photo in the World showing the Northern Milky Way so deep and detailed, now it's large than ever!

Click for a large image, 7000 x 1150 pixels

Over a decade, 1500 exposure hours and 301 individual frames visible in one image
NOTE, image of the Full Moon as a scale in lover left corner.

23.000 x 3500 pixels

You can now pan and zoom around the large image. Photo size is reduced to 40.000 x 6000 pixels from original 120.000 x 18.000 pixels to save some bandwidth.
NOTE, all material in this blog is under copyright, any kind of usage without authors permission is forbidden.

  • Panorama spans 145 x 22 degrees of sky (Full Moon covers 0,5 degrees of sky)
  • Resolution 120.000 x 18.000 pixels
  • Photos has 2.2 gigapixels in it, the spatial resolution is equal to 8.8 gigapixel image from color camera since all the channels are in native resolution.
  • There are least nine confirmed supernova remnants in this panorama
  • About 25 million stars are visible in the photo
  • Distance to the nebulae in the image between 350 to 20.000 light years
  • Exposure time over 1500 hours between 2009 - 2021
  • 301 individual images are stitched together seamlessly 
  • It took about 12 years to finalize this photo
  • Narrowband image from light of ionized elements,    hydrogen = green, sulfur = red and oxygen = blue
  • Processing time for the whole panorama, way too large part of my life


Click for a large image

The high-resolution panoramic photo spans 145 degrees of the Northern milky way

Click for the large images, it's worth it!

A zoom in series from upper left of the large panorama image above to gives an idea about the overall resolution of the large mosaic image.

All the dots are stars, not the noise!

Closeup of the supernova remnant IC 443


Click for a large image, 5000 x 1500 pixels

There are several very dim and practically unimaged supernova remnants in this panorama.
NOTE, all material in this blog is under copyright, any kind of usage without authors permission is forbidden.


11500 x 3400 pixels


The reason I keep doing my slow work is an endless curiosity, I love to show how wonderful our world really is. That's how I feel at front of everything I'm able to see through my photography. This is my purpose as an artist. I have to fulfil the demands of my passion – and I have done so for about 25 years.

Photographed area of sky is showing a large part of Northern Milky Way in high resolution. Beside the size, it's very deep, meaning that it shows extremely dim and unimaged nebulae across the galaxy plane. One of the reasons for this massive panorama project was a fact, that there was no such an image anywhere in the world.  I had personal need for the photo like this since I wanted to use it as a map to the new adventures.

Revealing the hidden beauty of our universe is my passion. I stand in rapt adoration before all that I see. When art meets science, the results can be quite mind-blowing.


Step 1, 


Astronomical photography is a very time-consuming process. If I want to have a color image, I have to shoot each target least three times through a different filter to have all three-color channels needed for color image. Also, the exposure times can be very long, in my case even hundreds of hours for some very dim objects. An average exposure time is around 25 hours per image. Also everything has to be carefully pre planned.

I made imaging plans over ten years ago, I wrote first ideas about this imaging project to my little black Moleskin notebook. I was aware at the time, that it will take a decade to be finalized but it doesn't bother me since I love long projects, they are giving a purpose and the goal to my work as an artist. 

My little black notebook and first plans for the project at 2008

A notebook page opening from Autumn 2008

I needed to develop many new working methods to be able to control this massive project. I needed to get them ready first since ones started, the project can't be changed anymore without canceling it. Everything needs to be spot on, the planning of composition and its relation to the Milky Way objects, many technical aspects, like how to handle a data from different optics with a different spatial resolution etc. I won't go very deep into technical details, since the complex technique needed is just a tool to make my art.  

A notebook pages from 2009

I like to compare my long imaging projects to a relationship. This project was like that too but not just between two entities. This is like a relationship with the whole family, a large Klan. There might be a nasty drunk uncle or other difficult persons in a family but
you must be able to get along with them too. I felt like that, when I was stitching pieces
together and some of them didn't fit the way I wanted and I had to reshoot them. That easily took months, or years. but at the end, everything slides together smoothly without any visible seams.

I'm a perfectionist, when dealing with my photography. This feature is essential for the great results but it also can cause problems. This photo could be ready maybe five years earlier, if I could leave some extremely dim targets out or leave them less detailed but I simply couldn't do that. When the photo was ready, I didn't remember all of those sleepless cold nights, I remembered the joy I felt when the most difficult parts got ready.

Step 2, 


2009 - 2021


Each photo in the posters is a slow and complex battle of its own

Click for a large image

Some of my individual photos shot between 2009 and 2021 are collected here. Most of them are now part of the Large Mosaic Image of the Milky Way galaxy.
NOTE, all material in this blog is under copyright, any kind of usage without authors permission is forbidden.

Step 3, 


Finally at 2019, after so many years, I had enough material to start working with the final mosaic image. The work took about two years due to complex mosaic structure and massive amount of image material. I also needed to shoot lots of missing material for the mosaic at the same time

I used the Cartes du Ciel, a star map software, for planning and a preliminary fit the individual frames.


BETWEEN 2009-2021

Click for a large image

This image collection show the evolution of my Large Mosaic of the Milky Way Galaxy.

Step 4,



Click for a large image

The final photo is over 120 000 pixels wide and it has 301 individual mosaic panel. Most of the objects are originally shot as a self-standing artworks, due to that, they are in various positions and angles to each other. This is the reason, why the final mosaic structure looks so complicated, as can be seen in this image.


At October 2021, after 12 years, 1500 hours of exposures and countless hours of work

The Grand Mosaic of the Milky Way Galaxy II

Click for a full size image, 7000 x 4300 pixels
NOTE, all material in this blog is under copyright, any kind of usage without authors permission is forbidden.

Getting to a last piece of the puzzle is always a thrilling process. Many of us know, how frustrating it can be to notice, that one piece is missing. That's happened to me too. I was sure that I shot the piece about three years ago but couldn't find it anywhere from my hard drives. As a result, I had to wait several extremely long weeks to be able to reshoot the missing piece to get this massive puzzle finalized. 

The Mosaic Work, technical info

I have used several optical configurations for this mosaic image during the years. Up to 2014 I was using an old Meade LX200 GPS 12" scope, QHY9 astrocam, Canon E200mmf1.8 camera optics and baader 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 was needed between separate frames, just some minor levels, curves and color balance. 

I have used lots of longer focal length sub-frames in my mosaic to boost details. (See the mosaic map at top of the page) 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 Workflow)