Astronomy stacker
Autopano Pro as an Astronomy Stacker
If you want to use Autopano Pro for stacking astrophoto images, you need to know a few things to get good result :
- When taking pictures of deep sky objects (galaxies, nebulae, etc.), you will need an equatorial mount with a clock drive. During the exposure, errors in the clock drive should be corrected using an auto-guider or by manually tracking a guide star.
- Always make and process photos in RAW or 16 bit TIFF for better dynamic range.
- Rotating the camera around its focus axis will reduce periodic error. For the best results, different frames of the same object should have different orientations.
- Use a linear type blending when stacking images together.
When taking astrophotos, there are two cases to consider:
- Photos of deep sky objects (nebulae, galaxies and so on)
- Photos of the Sun, Moon and planets.
Deep sky Images
Deep sky images are difficult because they often require multiple exposures made with exposure times measured not it seconds, but in minutes. Individual images can even be taken at different times and locations. For a good final image, each of the individual images need to be carefully aligned and stacked together.
| Open all RAW(16 bit TIFF) images. |
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| Check all settings as shown (check lens distortion) |
 
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| Set Planar projection |
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| Render this "panorama" into one stacked image, 16 bit TIFF. |
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| Results |
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Post Processing
We can correct the initial result using Photoshop (Image->Adjustments->Levels). Set the "black point" to get a dark sky background.
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| Here is the result with the black point adjusted. |
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| Моve the middle point to the left to bring out more detail. |
 
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| Here is the result with the black point set and the middle point adjusted. |
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| And here is the image after rotating and cropping. |
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| Result Image corrected and cropped Levels |
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| If you use Noise Reduction Software (like Neat Image) before setting the black point and adjusting the levels, you will get a better, cleaner result. If you don't want to use noise reduction software, you can use internal level correction in AutoPano Pro before rendering the stacked image. You can reduce noise either by increasing the number of frames or increasing frame quality. For better frame quality, you need a good clear, dark sky away from city lights (like in the mountains for instance). You can also try to use special filters that reduce the light pollution spectrum. My source images are really very average. They were made in an area with strong city light pollution and without any special filter. |
Final result
| M31 The Andromeda Galaxy. Noise reduction in NeatImage 5 |
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Sources for training
| M31_2006_09_20.zip | M31_2006_09_21.zip | M31_2006_09_22.zip |
Sun, Moon, planets
| Stacking photos of Sun Moon and planets usually need for avoid atmospheric turbulence(that blurring image) and get more details and sharpness on surface. |
Sun stacking
| WARNING you need a special SUN filter to make a photos of the SUN. If you don' have it DON NOT ever turn your telescope or camera direct to the SUN. It will damage your eyes, you can become a BLIND and your equipment will be burned up. |
| Special Sun filters you can make from BAADER Astrosolar Safety Film. |
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| Open all images, RAW is Really not necessary for SUN photos, because the SUN is very bright object. But if you want maximum quality you can make photos in RAW. |
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| Check all settings(uncheck lens distortion). |
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| Set Planar projection to correct perspective and geometric proportions. |
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| Render this "panorama" in one stacked image, 16 bit Tiff. |
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| Output result. |
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Post processing
| Rotate and crop image to make a right position and orientation of the Sun. |
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| For better resolution on surface you can use special Wavelet Sharp filter in asto software like Registax. Left - not sharped, Rigt - sharped with Wavelet filter in Registax |
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| Example of Registax Wavelet post processing. This program is FREE, you can get it from http://registax.astronomy.net/ |
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Final result
| Final result looks like that. Sun 2006/08/26.
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Moon stacking
| Open all images. There is one tip - if images stacking incorrectly(because of low contrast), just cut it for square proportions. |
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| Check all settings: Detection, Optimization - the like in Sun stacking. Projection set to Planar. |
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Post processing
| Stacked image looks like that. |
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| Crop it to square proportions, correct color (in Photoshop Image->Adjustments->AutoColor) and levels. |
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| Increase surface resolution by Registax Wavelet filter. Left - not sharped, Right - wavelet sharped in Registax. |
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Final result
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| All other planets processing is a similar, i don't have yet any source images for test this method on Jupiter or Saturn. For taking good pictures of far planets you'll need a really BIG telescope. If your telescope is small you can try to make a video of this planets and stack video frames in Registax. |
| That's all. |
| Sorry for grammar mistakes and hello from Russia :) |