Jupiter 21 September

[michael.h.f.wilkinson]

Finally some half clear skies. Through distinct haze I managed to capture a decent avi with my SPC900NC, Meade 2x TeleXtender and C8. Quickly processed 675 images from 1105 stacked in Registax, colour processing in Gimp. Nice to get two moons and descent detail on the planet. I might get a better result with more processing, but this will have to do for now. Thicker cloud is coming in, so I am calling it quits for now.

[michael.h.f.wilkinson]

I got a better colour balance using some ImageJ trickery. I think the first reprocess is slightly better, though it depends a bit on which monitor you view them. The moons are Ganymede (closest to Jupiter) and Europa.

[michael.h.f.wilkinson]

Third attempt at colour balance.

[Clayton]

Not bad Michael.

It looks like Your avi was under exposed, and stretched later to bring it up a bit??

If so does your capture program have a histogram display to guide you in this respect?

[michael.h.f.wilkinson]

The initial frames were properly exposed, but through the capture the haze thickened quite a bit, reducing the effective exposure, requiring some stretching. Once I had packed everything in the skies cleared up of course. I hope this evening will be better. I also want to play with white balance during capture a bit more. The blue channel is not well exposed at all in the original.

[jgs001]

It's a nice result Michael, the colour balance is better later on.

[DarkerSky]

Nice one Michael. Corresponds to what we saw on the Bedford Astro 16" SCT last night. I was watching that white streak in the NEB. Saw it about the same time when it was central across the disc

[michael.h.f.wilkinson]

Nice one Michael. Corresponds to what we saw on the Bedford Astro 16" SCT last night. I was watching that white streak in the NEB. Saw it about the same time when it was central across the disc

I would love to use an instrument like that! We have a 16" RC on our building, but I do not have regular access to that (anyway, the dome seeing is awful until about 2 am, I hear).

They really should have put that thing in my back garden:D

[AztecastroMcJ]

hey Michael nice pics

as others have said colour balance is bit off

maybe due to white balance on capture

looks slightly overexposed too

did quick auto rgb on ur pic

hope u dont mind

James

[michael.h.f.wilkinson]

I find your version a bit on the blue side, and the overexposure of the equatorial zone is more profound. I find that the whole business varies a lot with the monitor you work on. Settings that look fine on my laptop look WAY to red on my desktop monitor. The same holds for contrast stretching: what looks fine on one monitor looks too dark or too bright on another.

Actually, I often capture with "daylight" settings which objectively speaking should be right. This is confirmed by daylight film shots I took in the past, in that I get the same kind of yellowish cast in the equatorial zone, as can be seen below. The exposure time was way too short to show up serious differential Schwartzschild effect between the colour layers of the film.

What we often do is try to match the perceived colour, based on what we saw with our dark (and possible incandescent-light) adapted eye, which is much more blue sensitive. In this case it is down to aesthetics. During capture however, the blue channel's dynamic range ought to be used properly, so a "blue-biased" capture should be better.

Things are looking good weather-wise here, so I will have a go tonight.