The first step in planetary imaging is making a video file of the planet. The goal is to collect as many frames as possible in a limited amount of time. The time is limited because the planet rotates. Christophe Pellier did some experiments that he published here:
He has lots of other good material for us so I recommend spending some time checking out his site.
The most critical step in planetary imaging is capture. You can screw up everything else and then later be able to get a good picture from your video file when you learn what you did wrong. Happiness is getting a good video file.
iCap is the capture software that comes with the NexImage 5 webcam. This camera takes excellent pictures and is priced under $200 so it is very popular. iCap is filled with landmines that I warn you about in this video. I will mention a few here but you really need to watch the whole video before you go out in the dark with it.
iCap requires you to select a frames per second (FPS) setting. This can only cause problems as I explain in the video. Also, the FPS setting will change to something you don’t want when you’re not looking. Always check the FPS setting just before hitting record.
iCap is capable of creating a worthless .avi file due to allowing you to mix codecs between two drop-down menus.
Once you get used to iCap it is actually pretty good. This is like fire. It is wonderful but if you’re not careful it will burn you.
FireCapture is the most popular capture software and it supports many cameras. You can see which cameras it supports and also download the software here. Note that to use FireCapture with the NexImage 5 you want to select The Imaging Source camera.
This video shows how to use FireCapture version 2.3 which is no longer the latest version. The latest version has changed in appearance, a lot. Still, the video should at least tell you what capabilities to look for when you use the latest version.
Histograms are powerful tools for planetary imaging. Without using histograms you’re flying blind. This video tells you what histograms are and how they’re used for planetary imaging.
Exposure, Gain, etc.
Getting the right capture settings can be tricky. In this video I start with not knowing how to set brightness, contrast, exposure time (length of video), exposure time (shutter speed), gain, gamma, focal ratio, frames per second (frame rate), histogram, saturation, and total number of frames to collect. There are too many combinations to experiment with. In the video I get it down to just exposure (shutter speed), gain, and histogram.
The histogram is not something we set but is a function of gain and exposure time. If we decide we want to attempt to get a 40% histogram then the gain becomes a function of the exposure time and we only have one variable to experiment with. We want to use an exposure time that will allow the maximum frame rate. For a bright planet the camera’s max frame rate may be the limiting factor. For a dim planet we end up setting the gain to 100% and then adjust the exposure time to get 40%.