Easy to use software to merge foreground with tracked milky way?

Started 2 months ago | Discussions
allematic Regular Member • Posts: 145
Easy to use software to merge foreground with tracked milky way?

Milky way season is about to begin and I plan to use a tracker this year. My plan is to take separate images of the same scene, one for the milky way on the tracker and another one of the foreground, then merge them.

What could I use to merge them? I use Luminar 4, can it do this job with its sky replacement tool? I'm not interested in a subscription so phtoshop is ruled out.

Alen K
Alen K Senior Member • Posts: 1,278
Re: Easy to use software to merge foreground with tracked milky way?

I have never used it myself, but this article claims it works well for that:

https://fstoppers.com/astrophotography/quick-tips-luminar-4-night-sky-replacements-430192

OP allematic Regular Member • Posts: 145
Re: Easy to use software to merge foreground with tracked milky way?

Alen K wrote:

I have never used it myself, but this article claims it works well for that:

https://fstoppers.com/astrophotography/quick-tips-luminar-4-night-sky-replacements-430192

Seems like it's going to work for what I need!

nighthiker Contributing Member • Posts: 525
Re: Easy to use software to merge foreground with tracked milky way?

Hi!

Mmmmmh, the image example from Luminar is looking total realistic to me and absolutely no Kitsch ... or so 

OP allematic Regular Member • Posts: 145
Re: Easy to use software to merge foreground with tracked milky way?

nighthiker wrote:

Hi!

Mmmmmh, the image example from Luminar is looking total realistic to me and absolutely no Kitsch ... or so

Because they chose a daytime foreground which is irrelevant to my goal. I'm looking to merge separately shot foreground and  sky of the exact same scene.

nighthiker Contributing Member • Posts: 525
Re: Easy to use software to merge foreground with tracked milky way?

allematic wrote:

nighthiker wrote:

Hi!

Mmmmmh, the image example from Luminar is looking total realistic to me and absolutely no Kitsch ... or so

Because they chose a daytime foreground which is irrelevant to my goal. I'm looking to merge separately shot foreground and sky of the exact same scene.

It's OK allematic. I believe that you will use it for a realistic picture (background and foreground from the same location within a short time interval). I worry that we already have many Beth Moon's out there (https://petapixel.com/2019/05/07/this-milky-way-photo-on-nat-geo-is-raising-eyebrows/).

I would also put some other points of the Luminar picture into question: The horizon line is relatively simple with only a small tree on the left side. Trees with branches are a complex issue. On all of my pictures I have a transition along the horizon with light pollution and haze/clouds. This abrupt change from the foreground to a perfect MW is pretty unrealistic. I also have to fight against light pollution on the whole image, often very irregular with several gradients. PixInsight has a nice gradient removal tool, but that isn't cheap ...

I have my doubts that you will get happy with Luminar as the problems I have with merging background and foreground are complex, but give it a try if you think that it works and come back later with your experience. I'm always happy to learn new stuff and will change my opinion if the is strong evidence that I'm wrong

primeshooter
primeshooter Veteran Member • Posts: 6,174
Re: Easy to use software to merge foreground with tracked milky way?

nighthiker wrote:

allematic wrote:

nighthiker wrote:

Hi!

Mmmmmh, the image example from Luminar is looking total realistic to me and absolutely no Kitsch ... or so

Because they chose a daytime foreground which is irrelevant to my goal. I'm looking to merge separately shot foreground and sky of the exact same scene.

It's OK allematic. I believe that you will use it for a realistic picture (background and foreground from the same location within a short time interval). I worry that we already have many Beth Moon's out there (https://petapixel.com/2019/05/07/this-milky-way-photo-on-nat-geo-is-raising-eyebrows/).

I would also put some other points of the Luminar picture into question: The horizon line is relatively simple with only a small tree on the left side. Trees with branches are a complex issue. On all of my pictures I have a transition along the horizon with light pollution and haze/clouds. This abrupt change from the foreground to a perfect MW is pretty unrealistic. I also have to fight against light pollution on the whole image, often very irregular with several gradients. PixInsight has a nice gradient removal tool, but that isn't cheap ...

I have my doubts that you will get happy with Luminar as the problems I have with merging background and foreground are complex, but give it a try if you think that it works and come back later with your experience. I'm always happy to learn new stuff and will change my opinion if the is strong evidence that I'm wrong

Agreed. Better to get PS, learn how to lum mask and then all scenes become possible to blend with time and effort. There is an easy way and a hard way in life, the easy way can cause problems down the line. Lum masking and select and mask workflow are the ways to have control in making an accurate mask. Even with all that control we still need to do manual work from time to time I find, esp at night.

indigoshrine Forum Member • Posts: 74
Re: Easy to use software to merge foreground with tracked milky way?

Being a beginner in post processing and especially blending myself, I have tried out many methods and tools last MW season. See also https://www.dpreview.com/forums/thread/4488468

Meanwhile I also gave a shot at a trial version of Luminar but was not happy with the results, so did not buy it (note that I am not an expert in PP Software handling and did not invest a lot of time into this - it might work better for others).

For me personally the best results could be achieved with either cloning around horizon line or - as already mentioned by others above - luminosity masks. It is more manual work, but at present I do not see any SW which can replace this properly. LR's 'select&mask' and 'color decontamination' are powerful tools which are a great help, so at least there is some kind of AI support.

I'll be more than happy to be proven wrong, so if you find an easier workflow that offers reasonable output, please share.

 indigoshrine's gear list:indigoshrine's gear list
Sony a7 III Zeiss Batis 18mm F2.8 Sony FE 85mm F1.8 +1 more
Lyle Aldridge Senior Member • Posts: 1,207
Re: Easy to use software to merge foreground with tracked milky way?
1

This isn't always easy, but it's also usually not outrageously difficult, and GIMP (freeware) can accomplish this task just as Photoshop would, possibly even better. Most nighttime MW images show the sky lighter than the foreground, and that makes it pretty simple to create an operative layer mask using the "Levels" and  "Threshold" adjustments on the "Color" menu. The process, as usual, takes almost infinitely longer to describe than it does to actually perform.

At its simplest, you start with foreground as a layer on top of your sky image. When you create a layer mask in GIMP, one of the options on the menu is to use the image on that layer as the layer mask, and another option is to invert it. (I haven't used newer versions of Photoshop, but the older versions I have used didn't have this nice option.)

So if you check both those options, and create a inverted layer mask of the foreground image, that lighter sky will be darker on the mask. After making the mask visible (right-click on the layer dock and check "Show layer mask"), do a "Levels" adjustment of it, pulling the middle slider right to enhance the sky-foreground contrast. Here, I've taken the fair use liberty of using the Milky Way image from that Luminar demo (linked in Alen K's reply post) as an instructive example:

With the contrast of the mask thus amplified, the next step is to apply a "Threshold" adjustment to it, pulling the black slider to the right. there will almost always be a point where the adjustment will produce a distinct, detailed black-white transition between foreground and sky.

As you can see, there are some areas in the sky that haven't yet turned black. If I pulled the slider a bit farther right those would also be black, but in this instance, it also blackened more of the foreground than I wanted. There are also some small parts of the foreground that are black, but after clicking the "OK" button to make the layer mask look like this, I just used the paintbrush tool to make the sky parts completely black, and the foreground completely white, while preserving the detailed transition between the two.

While using that MW image on top, I had a cobbled-together moon and sky image on the background layer, so the two layers together look like this:

Yes, I know, the moon looks, strangely oriented, but you get the point, I hope. This works better on larger images, in which details are not as pixelated as the trees on the left were. As an impulsive exercise of personal taste, I've also eliminated the messy-looking branches that were extending into the sky on the left. That's just done by painting black on that part of the layer mask.

OP allematic Regular Member • Posts: 145
Re: Easy to use software to merge foreground with tracked milky way?

Thanks for the detailed explanation. Very helpful and it doesn't seem too difficult, if the Luminar 4 sky replacement doesn't work.

chris gunn
chris gunn Veteran Member • Posts: 9,425
Re: Easy to use software to merge foreground with tracked milky way?

They use daytime imaged foreground? Sounds fake.

-- hide signature --

cheers!
Gunn
-- Get a big lens and get closer™.

 chris gunn's gear list:chris gunn's gear list
Pentax K-1 II
nighthiker Contributing Member • Posts: 525
Re: Easy to use software to merge foreground with tracked milky way?

chris gunn wrote:

They use daytime imaged foreground? Sounds fake.

Luminar IS fake. Isn't that the strong point of that 'enhancement' software ?

It's probably founded by Beth Moon or a spin-off from her work 

Keyboard shortcuts:
FForum MMy threads