Elements+ question about noise stacking

I have brought this thread to Andrei's attention.  Hang in there!

Hi Peter
Sorry for the late response.
(I've been travelling without a computer.)

1. Wile experimenting with the noise stacking, I decided that a series of 10 snapshots is quite sufficient for my tasks.
After 15 snapshots, I can see any improvement at all.

2. Please, keep in mind that, even if you are using a tripod, the stacked photos are not identical. 
In your example, the moon is moving, there may be some changes in the atmospheric/light pollution, etc..

The more photos you stack, the more chances those mismatches can't be automatically fixed by the script.
Averaging the accumulated differences may worsen the image quality.

3. As for your experiment in general, it seems, the noise stacking technique just doesn't suite your task.
I believe, a single low ISO exposure always provides a better result than a stack of high ISO images.

4. Please, read this post on the purpose and the basic usage scenario of the tool:
photoshopelementsandmore.com/post/47687/thread

Kind regards,
Andrei

Pete,
I am a complete ignorant on astrophotography, so, I'm probably the wrong person to ask.

However, even in the burst mode, 15 snaps may take about 2-3 seconds.
This is, probably, already too much for the moving moon (just my unqualified guess, though).

Having very modest experience with astrolandscapes (which is a different story) I'm used to accept the noise as an inevitable evil.
I believe, for higher image quality we need some special equipment -- astronomical mount, modified camera, and dedicated software.

Kind regards,
Andrei

Hi Peter,

I feel Andrei's points 2 and 3 are the most pertinent wrt photographing the moon.



Photographing the full moon before it goes into the earth's shadow should be no problem with a low ISO. So noise removal without noise stacking should not be an issue.

When the moon is in total shadow, your exposure will need to be a huge ~6-8 stops greater (from my experience of photographing the eclipse in Jan 2018) because of the very low light. I would think your best option is to set maximum aperture (lowest f number) and the slowest shutter speed you can get away with to avoid motion blur of the moon. Then take many photos while increasing your ISO by the camera's minimum increment after each shot until you see an image on the camera's LCD screen while in LiveView that you are happy with. I don't know how long the moon will be in total shadow but hopefully it will be long enough to take many photos at certainly different ISO settings and perhaps even having to slow your shutter speed even further to get an acceptably bright image.    If you have a laptop with you at the time, reviewing images on a laptop screen is much better than on a camera's LCD screen.

After cleaning up the noise as much as possible in post processing and applying any other edits, especially in the total shadow shots, if you feel the images are still a bit soft, you could try applying drjoerogers' Detail Exraction, Sharpening with Surface Blur tutorial which works very well for full moon images and hopefully for moon in total shadow images as well.

Another option you might consider:

Soon after the eclipse in Jan. 2018 you posted -




Anyway, I'll stop rambling now. So as always, just some food for thought and good luck in Jan. 2019

Hi Peter,

How does the noise removal using stacking compare with using something like ACR to remove the noise from a single raw image?

The reason I ask is because depending on the length of time it takes your camera to take a 12 shot burst you will probably get some motion blur when you align the photos.

It's impossible to tell, with my eyes at least, whether there is any motion blur in your stacked image. It is too small. In my browser when I look at your image's info, I see it is only 1271px x 473px overall. The moons are obviously much smaller. The only way noise reduction can be evaluated properly is to look at the original image at 100%. Downsized images will always look sharper and with less noise on any screen.

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Assuming your F4 is wide open at 600mm, then at totality where you will need an exposure around 6-8 stops longer than for your full moon experiments, you will need a much, much slower shutter speed than the current 1/200 and/or higher ISO than your current 3200 to maximise the moon's detail at 600mm. If your shutter speed is too slow, you will definitely see motion blur as Andrei Doubrovski also alluded to earlier.



It would be a shame to possibly miss out on high quality "keepers" using noise stacking to reduce noise. I would strongly suggest you also take properly exposed single shots and process them as a Plan B.

ok, no problem Peter