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Easy Astrophotography Mosaic: Using Photoshop's Photomerge
Easy Astrophotography Mosaic: Using Photoshop's Photomerge at US Store

Often times you'll see these wide field photos of astrophotography images. One way to obtain a wide field photo of the night sky is to create a mosaic of smaller images. Adobe Photoshop has a tool called "Photomerge" and it's very easy to use to create wide field images of the night sky.

To get started, you first must take "overlapping" images so Photoshop will know how to stitch the mosaic together. Ideally, try to get approximately 20-25% overlap on each photo.

The example I have is NGC 2264. Here's the top image:

NGC 226-a
NGC 226 Image 1

And here's the bottom image:

NGC 226-b
NGC 226 Image 2


Before you merge your photos, crop any "stacking feathers" from your image. When you "stack" your image you typically see feathered edges and if you try to merge these feathered edges your merged photo will show a seam or line where the images overlap.

Remember, you shouldn't start processing your image before you merge the photo. After you've merged the photo then you can start processing your image. If you process each panel separately you will see differences and the mosaic will look like a bunch of stitched together patches.

In Photoshop simply select FILE'AUTOMATE'PHOTOMERGE, this will bring up a dialog box like this:



Click the BROWSE button and select your 16 bit TIFF files. I leave the layout to "Auto" and Check blend images together. Then press "OK" and let Photoshop do its magic! Now you may think it doesn't matter which order you select your files, but it does make a difference! In this example I selected the Bottom FIRST:



The results when selecting Bottom FIRST:

Bottom First


When I selected the "Bottom" first, it didn't give me the best crop results. I really would like to keep the bottom part of the image "square" because there are more important details on the bottom.

However, if I select TOP First:

Top First


The results when selecting TOP FIRST:

Top First Results


Now when I crop the image the bottom details will be square and I will have a nice mosaic.

Here are the results after I merged the photos and then processed the image:

Results - NGC226 Mosaic


If you would like to view this tutorial in a video, please visit Astrophotography Tutorials by Doug Hubbell on YouTube:

Astrophotography Tutorials by Doug Hubbell on YouTube
Astrophotography Tutorials by Doug Hubbell on YouTube:





Doug Hubbell is a Systems Manager by day and an astrophotographer by night. Doug is an avid fan of astrophotography and enjoys creating astrophotography video tutorials. As Doug says, "The great outdoors and astrophotography are perfect for camping trips." He's been an Orion Customer since 10/2007. In 3/2008 Doug started contributing to the Orion Community, and he became an Orion beta tester in 2/2010. Follow Doug Hubbell on Facebook, at Astrophotography Tutorials.

Date Taken: 02/19/2014
Author: Doug Hubbell
Category: Astrophotography

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