Capture time for Saturn

Hi all,

After seeing Jims image with a interseting white spot I got to wondering if it isn't better to keep capture times for Saturn on the short side. The rotational period for Saturn is only slightly longer than that of Jupiter so any fine details would be smeared by overall capture periods of longer than probably about 3 minutes (depending of course on what FL you're imaging at) maybe 4 if you don't mind a bit of smearing.
The whole trick is to get enough useable frames to beat down the noise, so I can understand why some people opt just to go for a more aesthetically pleasing image and therefore forego any possiblity of capturing fine details. Another factor if one has a colour camera its much easier than if you have a colour wheel. What are the capture times that are being used by most here? I know John B used about a 10 minute capture time for his amazing WSP Saturn image... and that image showed wonderful banding detail that could'nt probably be had with a short capture time. So perhaps its just a matter of a trade-off?

cheers

Mike

Hi Mike -

As long as you capture luminance data in short bursts (within two minutes or so) you have the option of preparing the data both for beauty and for analysis of saturn weather. I usually capture streams 1200 frames in length for saturn - and in a stretch of good seeing, collect a dozen or more of these. A spot such as the one in Jim's image will show up fine in an image made of 300 frames from one of these streams and a comparison of several over the course of a half hour will show some movement and confirm that the spot really exists.

Most of Saturn's features as observed from earth will be radial in nature and not harmed by averaging data over a longer period of good seeing. Averaging together a dozen 300 frame stacks captured over a half hour will still present a high resolution picture of the ring brightness variations, divisions and cloud belts.

Unlike with Jupiter, color data for saturn can be collected independently of luminance. To help the exposure, binning or imaging at a shorter FL can be used. You can even apply color data from a different imaging session within a week or so of the luminance without any noticeable effect on the final image.

best -
Alan