4 image mosaic Moon 08-02-09

I think that looks much better James!

The Moon is surprisingly difficult to get a "perfect" image of. One would think that an object as bright and large as the Moon would be easy to image. While an image is relatively easy to capture, to get a truly great image is very difficult as it involves tweaking levels of brightness, contrast and sharpness until it is "just right" - not easy.

In terms of sharpening, I find that if you apply any "reasonable" amount of sharpening to the image to improve the craters, the edge of the Moon becomes overly sharp and shows a sharp white line. To overcome this, I draw a lasoo in Photoshop around 95% of the Moon, but excluding the bright "edge" in the direction of the Sun. I then apply a small amount of shaprening. This will allow you to sharen up the craters nicely but avoid the dreaded white-line-effect on the Moon edge.

Also, sharepning should only be applied to the image *after* it is resized. So, if you are planning to keep the image size down to say, 800 x 600, then you should save a copy at the size first, and then apply the sharpening.

Brightness and contrast look fine.

Hope this helps. Keep up the good work!

Michael.

Thank you for the advice Michael.I'll give that a try when I get home from work. It's great to have such a helpful support network from all you folks on the forum. Thanks again. It's really appreciated.

Hi James,

That image looks a lot better. Michael gave some great advice keep on posting your results.

Carl.

Ps,
Are you going to try image Saturn It's becoming a very good object at the moment. And of course don't forget Comet Lulin passed about 4 degrees north of Spica.

Much better James.
Just on the sizes etc..


michaeloconnell wrote:

Also, sharepning should only be applied to the image *after* it is resized. So, if you are planning to keep the image size down to say, 800 x 600, then you should save a copy at the size first, and then apply the sharpening.

Out of genuine curiosity why should you do this?
Would resizing first not reduce the amount of
information & detail in the image?

I've read that you should always work with the full size image,
do your adjustments, then resize.

Moreover, Do all your adjustments in seperate layers.
e.g.
In photoshop.
If you want to lighten it - create a layer copy
name it 'light adjust' and then make your adjustment.
Then if you want to sharpen it, again - create a layer copy,
name it 'sharpen' and tewak away.
In the layers box you would then have 3 layers,
The main image (background)
The Light Adjustment
&
The Sharpening adjustment.
You can then always go back and change a seperate effect
in its own layer.
Once you are happy. Flatten the image and then
save it to the size you want.

Hi Carl, I'm looking forward to getting a good evening of imaging Saturn. I've haven't tried imaging a comet yet. If the weather plays ball I'd love to have a bash at it.

Michael, Tried using the Lasso tool. It worked really well. Thanks for the tip! Here's another image taken the same night with the Nikon D200 attached to the Megrez. The bottom link is my reprocessed attempt at the mosaic.

farm4.static.flickr.com/3425/3288861012_70b3dbc89d_o.jpg

farm4.static.flickr.com/3642/3288921910_78da1b0e2f_o.jpg

Thanks for the great advice Frank. I'm trying to learn all I can at the mo about photoshop.