Uranus
Imaging Uranus is particularly challenging due to the small apparent size of its disk and low brightness. Atmospheric detail is more difficult to capture on Uranus than on Neptune because Uranus has a less dynamic and less active atmosphere. Try to use filters which pass light of wavelengths longer than 600 nm. Keep the capture framerate low since you don’t want to use a high gain (high gain will increase noise). Capture a long video. You won’t get significant rotational smearing since Uranus rotates in a little over 17 hours. Use a 10 minute recording with a 70 -100 ms exposure (about 10-15 fps capture framerate) with a 610 or 685 nm filter. Try to avoid colour cameras and use instead a monochrome camera like an ASI290M.
When stacking with Autostakkert, try 1.5X dithering and use a single alignment point rather than multiple alignment points.
This image shows the brighter polar region of Uranus which is currently turned towards the Sun.
Neptune
Imaging Neptune is particularly challening due to the small apparent size of its disk and low brightness. Most atmospheric detail is best captured using near-infrared filters which pass light of wavelengths between 600 – 800 nm. Keep the capture framerate low since you don’t want to use a high gain (high gain will increase noise). Capture a long video. You won’t get significant rotational smearing since Neptune rotates in a little over 16 hours. A 10 minute recording with a 70-100 ms exposure speed (about 10 – 15 fps capture framerate) with a 610 or 785 nm filter is a good starting point.
When stacking with Autostakkert, try 1.5X dithering and use a single alignment point rather than multiple alignment points.
The image below shows a bright spot near the limb. I took four images in succession and combined them into a short movie. The movie shows the same bright limb feature. This suggests it is not stochastic imaging noise. It also shows the feature move, likely due to rotation of the planet.
