Jupiter learning curve pictures

Jupiter webcam learning curve pictures

All these pictures of Mars were taken at prime focus with a 10 inch Meade LX200 GPS telescope and a Logitech Quickcam Pro 4000.

These prime focus (f/10) pictures were all created from 60 seconds long AVIs. The top 90 percent images were stacked - based on the quality as determined by the Registax freeware. Wavelet processing in Registax were also used. The pictures were then processed in Photoshop: contrast and cropping.


7 June 2003 at 19:29	14 June 2003 at ?:

Jupiter's apparent diameter: 16.6"


15 June 2003 at 18:12	15 June 2003 at 18:14	15 June 2003 at 18:15

Jupiter's apparent diameter: 16.6"

Struggling efforts in getting good quality pictures of Jupiter - at higher than f/10.

The picture on the left was taken on 18 June 2003 at 18:58 - the picture on the right on 18 June 2003 at 18:38.

I used a 2x Barlow for the picture on the left (f/20) and the picture on the right was at prime focus (f/10).

At this point I must still figure out how to get more detail on my higher magnification pictures.

Both pictures were generated by processing 60 seconds of AVI and selecting only the top 90 percent quality frames - using Registax.

Jupiter's apparent diameter: 16.6"

Prime focus (f/10) pictures of Jupiter taken on 27 June 2003 between 18:14 and 18:27.

A - 10 percent gain; 1/30s exposure per frame
B - zero gain; 1/30s exposure per frame
C - zero gain; 1/10s exposure per frame
D - 10 percent gain; 1/25s exposure per frame

Looking at these results now, I could have taken pictures of other combinations too, since the results is not clearly obvious, but here are my conclusions anyway:

1/30s is too short an exposure time to gather meaningful detail. (Images A and B) Image D has more detail.
1/10s is too long an exposure time - brighter details drown in white (Image C)
1/25s seems to be the best exposure time (Image D)

Jupiter's apparent diameter: 16.5"

Lessons learned

During the first week I struggled with focussing. I took one picture, refocussed somewhat and took another picture and so on. This meant that most of the pictures were not in focus. I was in too much of a hurry to take many pictures. TIP: Take your time before taking any pictures to ensure your telescope and camera is in focus. Then, any pictures you take for the next hour will all be in focus. It wastes a LOT of time to refocus for every picture you take.
Initially I only used the fast and medium speeds of the Meade focusser to focus with. I thought that was good enough. It was not :-( TIP. Take time to focus using the slow and fine settings of the electric focusser as well. Pictures reveal MUCH more detail if they are in focus. You CANNOT focus your pictures afterwards in any image processing package.
The pictures of Jupiter when it was further from the horizon reveal more detail than the pictures taken later at night when Jupiter was relatively low on the horizon.

This comment below was added on 2 July 2003

For the next around 3 months I am 'giving up' capturing AVIs of the planet Jupiter

There are many reasons for this:

I am having GREAT success with the planet Mars and would like to concentrate on it.
Mars is closest to Earth in 70,000 years. I would like to take advantage of that and take as many webcam AVIs of it as possible.
During this month my success with Mars let me realize the reasons for my disappointing results with the planet Jupiter.
- Jupiter is currently (July 2003) too low on the horizon to be able to take GREAT images.
- Jupiter is only visible just after sunset. The ground has not cooled down sufficiently yet to enable great images to be taken through calmer air.
- I spend an hour of astrophotography on Mars a night before I start getting acceptable images for it. With Jupiter, it sets below the horizon every night and then I am still struggling to find the webcam camera settings that will work well with it for the night. Every night, just as I figured out what settings will work on Jupiter, it sets.

So I will continue with webcam astrophotography of the planet Jupiter but only when it starts rising in the morning again as well as rises much higher above the horizon.

Jupiter and its changing clouds and satellite events is an ideal target for webcam astrophotography. I am eagerly waiting to get started to take pictures of all that.