Planetary Imaging

Sequence Generator
1

I can’t seem to find any planets in the framing and mosaic wizard…any help?

2

SGP doesn’t currently support planetary imaging.

Thanks,
Jared

3

You could easily link up with an ASCOM planetarium programme such as Cartes du Ciel to achieve the goto functionality, but I appreciate this is not the same and adds additional complexity.
Paul

4

Is there is any chance SGP developers plan to incorporate planet imaging in the future?

5

Previously Ken and Jared have understandably been reluctant to duplicate and incorporate functionality that is already very well covered by other applications for guiding (PHD2) and polar alignment. Presumably the same holds true for planetary imaging, which is covered in e.g. FireCapture.

Planetary Imaging requires such a different approach that it would be difficult to combine with DSO imaging in a single application without increasing complexity too much, or at least making the user interface too difficult. SGP developers have always done their best to maintain ease of use also for those without an engineering background (see also the requests for local horizon awareness and how to implement that in a user friendly way).

6

There is always a chance this will happen. We are certainly not opposed to it. The problem is mostly that we have a huge backlog of things to do that would be very popular and used by many and minimal resources with which to accomplish these features. Of course, as with all things, we keep track of threads like this and welcome being proved wrong.

It’s not that there is no desire for this feature. This is actually a reasonably popular thread. It’s really a good old-fashioned cost-benefit equation. This is a pretty massive undertaking…

7

I do both deep sky and planetary imaging. I use SGP for deep sky and find it to be very fit for purpose. I use Firecapture for planetary, which is a hugely functional piece of software for the acquisition of planetary data. I personally believe that there are not sufficient synergies nor benefits to justify the effort needed to incorporate planetary imaging into SGP. The extra programming complication is likely to be a significant disbenefit.
I was thinking about the things that SGP does very well and whether any of these would be of benefit to those who image the planets. Not in any particular order:

  • Plate Solving to accurately centre on designated RA & Dec coordinates…This is one of the biggest bugbears in planetary imaging…finding the planet. However, Plate Solving cannot in general be used because the focal lengths are so long and the FOV so small that no star pattern can be detected. Either the pointing accuracy of the telescope must be excellent or a finderscope is needed to find the planet.
  • Through the Autofocus function SGP can accurately determine the focus…this requires the PSF of a range of stars in the image to be measured to determine the HFR and by cycling through focus positions, find that which minimises the HFR. This is not practical for planetary imaging. Focus is achieved for each colour channel by eye and then that position reproduced at each filter change. There is no easily measurable parameter to tell one that a planet is in or out of focus.
  • Autoguiding is often required for deep sky to ensure round stars and sharp images…in planetary imaging autoguiding can be dispensed with since the exposures are so short. Guiding, where it is done, is carried out by ensuring the centroid of the planet holds its position and is usually done to ensure the planet doesn’t move out of the very small and cropped in FOV during capture.
  • Sequencing through different targets and filters, often on multiple nights, to gather sufficient data is the forté of SGP. Retaining information on where a sequence is up to so that it can be continued is an important feature. Conversely all planetary imaging is done in very short sequences usually of no more than an hour and must be performed on the one night.
    A cursory examination of the functionality available in Firecapture or Sharpcap will I think convince you that incorporating these into SGP would not be a trivial exercise and as noted above, not much if any benefit.
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