Landscape astrophotography

[Matt S]

Hi all

I recently took a short break under dark skies and captured an image of the Milky Way with an uninspiring collection of tree tops for context. The waxing gibbous Moon had just set.

I used an untracked D5300 DSLR and Samyang 14mm lens (at f2.8) combo and captured: 20x lights (10sec subs, ISO 1600); 20x darks; and 20x flats. Stacking was achieved using Sequator and its TIF output was converted to FTS for processing in StarTools. My final image (JPEG format, due to size) is attached.

I followed tips regarding the proper masking of the tree tops in Wipe. My question is, how can I preserve the little detail (ie colour and texture) that is visible in the tree tops in the post-stacked image, rather than end up with a silhouette?

Thanks for your time in reading this.

Clear skies
Matt S

[Mike in Rancho]

Hi Matt, cool stuff!

I don't know my way around landscape + Milky Way very well, but I did try to stretch out your jpg and couldn't find any texture or color in the trees. Just...all black pretty much.

I generally think masking of often used for this sort of thing. Good news is that your current image is so black down there that ST's mask should be able to select it quite easily, perhaps using Select by Brightness, and then maybe one or two grows if needed.

The question then is what to blend into that using Layer (with a little fuzz). You could process another version, same binning and cropping if used, but that stretches out whatever you got in the trees. Ignore the sky. You might even be able to throw a bit of wavelet sharpening at it?

Save that separately, and then I would take both images into Layer, using that mask, and try to get the right blending algorithm and percentages that look best.

Aside from that, there may be other things that you would need to do during the acquisition. So, perhaps one exposure at high gain, maybe even with focus adjusted for the foreground. That wouldn't be stacked but again would be layered in. I know I have read that some will also "paint" the foreground with a bright light for such an exposure, but I really don't know more about how to do that.

[Matt S]

Hi Mike

Thanks for taking the time to pen some insights, which are all gratefully received. The unprocessed, but stacked, image does contain some tree detail, but it’s either during Wipe, or subsequently, that I lose it all. That said, it probably looks better without.

I’ll certainly give the Layer idea a go, if I can draw more detail out of the trees. My skills using modules like Layer and Mask are still fairly basic and I would benefit from a masterclass on both: maybe Ivo is reading…?

Thanks again for your support.

Clear skies
Matt

[hixx]

Hi Matt,
great shot! To split the image, You may use "flood darker pixels" or "similar brightness" options in ST mask tool. You'd need cut out the trees and save them for individual processing. Then process the "stars part as normal. Not sure if Star Tools would be the best tool for the foreground though, You might try GIMP, DXO PhotoLab or some Adobe stuff or whatever. After these were processed as well both parts would need to be married again using LAYER module - Just load stars and trees in foreground / background and use a mask fuzz of some 1-5 Pixels here to avoid border artefacts.
I'm sure in the Manual and user Notes are lots of "Special techniques" for Layer Module which might add here

regards,
Jochen

[Matt S]

Hi Jochen
Thanks for your support and advice, both of which are greatly appreciated.
I just increased the RAM in my laptop to 32Gb and will give your suggestion a go. V1.8 really pushed my laptop and I found that I was spending as much time waiting for changes to happen, rather than actually processing. Hopefully the upgrade will help.
Thanks again-if I have any joy I’ll upload the ‘layered’ image on this thread.
Best and clear skies
Matt

[Mike in Rancho]

Hi Matt, let us know how any layering tricks go!

You could always link your original stack to let the crowd have a go at it and see what tricks they come up with.

Also Ivo makes the best mini-tutorials when he has data to work with and can show us the steps.

But for the future, I do think burning a separate exposure optimized for the landscape might be the best option.