Jupiter from recent days

[rcj]

Hi all,

Here are some sample images of the Jovian giant from recent days. Still getting a hang on planetary processing and experimenting with various methods, so some of the Jupiters will not have a similar look. Let me know if u have any comments, or favourites too. Some processing has been delibrately done to look "natural" and some have high contrast and saturation. At this time, it was worth playing around with different settings during the capture sessions as well. But nothing beats having excellent seeing and stable conditions while imaging. The second set was taken last night in East Coast under windy conditions, but think the seeing then was better as compared to the first set. All were taken through the refractor and a Phillips Toucam Pro II web-camera. IRIS was used to capture. Last night's session was interesting too, because some of the students who were present during Jupiter Watch, helped to see to achieving good consistent focus as well and at the same time, savour the fundamental techniques of web-cam planetary imaging. BTW, sorry for not having more details on CM, UT information for these sessions, they were treated as trial learning sessions on Jupiter imaging for now, until I find a consistent way of processing and perhaps a more suitable tube.

[VinSnr]

I like the last one (on the right) on the last row.. Very nice.

[Tachyon]

I'm still trying to figure out how to brighten the edges of the disk...

[Meng Lee]

you can try to use Curves to brighten the edges of the planet. Do a super gentle stetch on the shadows region on the curves. That's my own opinion.

[rcj]

Hi Tachyon,

Do you have a sample at hand that has limb-darkening? will illustrate. it is a different method and preserves details on the globe.

[aquillae]

Hi Tachyon, try unsharp mask with "small" amount and "big" radius and play around with the slider.

The most important thing is the data though, if the center is too bright, could be too much gamma on the capture setting (I shot 0-10% gamma range).

[Tachyon]

Ok, thanks for all the suggestions! I will be very busy trying out all the different methods!

[rcj]

Here's another way of removing limb darkening:

I have exaggerated the limb darkening on a sample grayscaled Jupiter taken recently for reference.

You can see in the image below that there is pronounced limb darkening. One thing to note, this technique can remove this effect, but it is advisable not to remove it completely otherwise it will not look natural and has a "flat" appearance. Everything is done in Photoshop.



Here is an attempt to remove the limb darkening effect at 100%. You can verify the degree. It might be suitable to have it at around 75-90% instead. Please experiment.



Method:
1) Open the image in Photoshop.
2) Press CTRL-A to select the image, and then CTRL-C to copy the image
3) Press CTRL-V to paste the image over (i.e. to create a duplicate copy of the original image)
4) Press CTRL-I to invert the duplicated image.
5) From the FILTER menu, select the BLUR->Gaussian Blur. Set radius to 40. Note that the radius value will vary according to your jupiter size. You may experiment on the radius size and see the outcome.
6) Again, from the FILTER menu, select the BLUR->Radial Blur. This time, set the radial blur value to 100. Note that the default value may be 10.
7) You will now see an inverted circular haze which gets gradually lighter in shade from the center to the outermost portions.
8) Now, for this duplicated "blur" layer, from the LAYER dialog menu, set the BLENDING MODE to OVERLAY. This effect will mix both the "blur" layer and the original image layer together according to the degree of "blurness" we applied earlier. You will now notice that the limb darkening effect is less pronounced. You can vary the opacity of this "blur" layer to your own preference in taste. This is the value that I'd mentioned earlier, where we could use values ranging from 75-90% instead of 100%.
9) Lastly, you can flatten the image (combine both layers together) from the Flatten command in LAYERS menu. Save the image.

Notes: Thus, from above, one can get effective limb-darkening removal by playing around with the following parameters:
a) Gaussian radius blur value
b) "Blur" layer opacity

You may like to play around with the Radial Blur value as well instead of setting it to 100 but the overal effect may not be as worthy in spending time as compared to (a) and (b).

Good luck!

[mrngbss]

Good tips!! Thanks!!

[chrisyeo]

Thanks for the tips Remus! Someone add to the wiki?