First try at Moon HDR composite, pick it apart

[Stricnine]

I have little skill at compositing images together, and I find it giant pain in the *** to do.

Any way for images to start with I had one image exposed for the bright areas, and one that exposed for some detail in the dark areas (unfortunately clouds were streaming by for those, and it's picked up in the composited images). I hadn't planned to use the brighter exposures for anything, and only grabbed some images because "it looked cool" on the camera at the time.

I used gimp 2.10 for this as I don't have Photoshop/Lightroom.

I tried masks starting from the bright image, and tried fiddling with layer opacity, fiddling with mask brightness, fiddling with layer modes. I did the aforementioned in isolation and in various combinations. Never really got anything to look right along the terminator. I ended up fiddling with layer opacity, the bright image's curves to tone down the excessive brightness that was coming through, and set the bright images layer mode to "Addition" ("Screen" was decent as well. I tried the entire list of Layer Modes).

Anyway I did two versions, ignore the compression artifacts from the upload to this site, the JPEG and TIFF originals don't have that.

I'm not thrilled with the gray/wash out look in the center of the image due to the only way I could find to merge the images together along the bright/dark edge.

They're certainly darker than most HDR images of the Moon, I'm OK with that.

Yes, I didn't bother cropping the enlarged image down to remove the black border along the left and top.

This first composite is an attempt to recreate how it visually appears in the sky when Earthshine lights the dark side.

I'm sure masking works, I just don't know quite how to deal with the intense contrast. Maybe brighten the normal exposure more so it's terminator is closer to the bright image's?



This one has a brighter dark side, and some crushed stars show through as gray blobs instead of bright pin points. The curves I used were more or less a low and wide upside down U to keep the darker detail but bring down the brightness of the sunlit side (which crushed the stars at the same time) and I believe brought about the fuzzy grayness in the center of the image as the dark side approaches the terminator.



--
Stricnine

500px

500px.com

 

[W5JCK]

If you cannot find a decent HDR app at a decent price, or free, then you can do an HDR stack manually. A good method requires creating a separate layer in your composite image file for each of the bracketed photos. Starting at the bottom layer, number the bottom layer 1, then add 1 to each subsequent layer that you place on top of the stack. So for example, let us say you take 5 bracketed photos at 0.3 EV as follows:

• 4 sec (layer #5, top most layer)
• 5 sec (layer #4)
• 6 sec (layer #3)
• 8 sec (layer #2)
• 10 sec (layer #1, bottom most layer)

You stack each of those photos in a separate layer in the composite image file. The order in which you stack them is not important, but for this example we will stack them in the order listed above with 4 sec photo being the top layer of the stack and 10 sec photo being the bottom layer of the stack.

Now we use a simple formula to set the opacity level for each layer. The formula is:

opacity level = 100 / layer number

100% = 100 / 1 (example using bottom layer which is layer #1)

Thus we have a composite image file stack consisting of five layers, each layer with the following opacity levels:

• Layer 5: Opacity = 100 / 5 = 20%
• Layer 4: Opacity = 100 / 4 = 25%
• Layer 3: Opacity = 100 / 3 = 33%
• Layer 2: Opacity = 100 / 2 = 50%
• Layer 1: Opacity = 100 / 1 = 100%

You now have an HDR bracketed composite image.

You can save the composite image file to a separate TIF file as a single layer if you like, then post process it. Play around with different shutter speeds and see which ones combine to give you the effect(s) you desire. I usually take way more bracketed photos than I use in the final composite.

 

[W5JCK]

BTW, I really like your second image.

One thing to consider is that the larger the percentage of the Moon's surface that is illuminated by direct sunlight, the harder it is to show earthshine on the darker portions. The one I posted several days ago was actually pushing the limit of illumination percentage. I was surprised I still got that much earthshine to show. I find that earthshine images usually work best in the first 1 to 4 days after a new Moon when the illuminated crescent is still small enough to not overpower the image with bright sun reflection. The image I posted was 5 days after the new Moon, so I was lucky it came out okay. But it had been cloudy until that day, so I ha to wait longer than I preferred.

 

[bmike]

If you cannot find a decent HDR app at a decent price, or free, then you can do an HDR stack manually. A good method requires creating a separate layer in your composite image file for each of the bracketed photos. Starting at the bottom layer, number the bottom layer 1, then add 1 to each subsequent layer that you place on top of the stack. So for example, let us say you take 5 bracketed photos at 0.3 EV as follows:

• 4 sec (layer #5, top most layer)
• 5 sec (layer #4)
• 6 sec (layer #3)
• 8 sec (layer #2)
• 10 sec (layer #1, bottom most layer)

You stack each of those photos in a separate layer in the composite image file. The order in which you stack them is not important, but for this example we will stack them in the order listed above with 4 sec photo being the top layer of the stack and 10 sec photo being the bottom layer of the stack.

Now we use a simple formula to set the opacity level for each layer. The formula is:

opacity level = 100 / layer number

100% = 100 / 1 (example using bottom layer which is layer #1)

Thus we have a composite image file stack consisting of five layers, each layer with the following opacity levels:

• Layer 5: Opacity = 100 / 5 = 20%
• Layer 4: Opacity = 100 / 4 = 25%
• Layer 3: Opacity = 100 / 3 = 33%
• Layer 2: Opacity = 100 / 2 = 50%
• Layer 1: Opacity = 100 / 1 = 100%

You now have an HDR bracketed composite image.

You can save the composite image file to a separate TIF file as a single layer if you like, then post process it. Play around with different shutter speeds and see which ones combine to give you the effect(s) you desire. I usually take way more bracketed photos than I use in the final composite.

 

[W5JCK]

Maybe you should just try it before having a brain meltdown. I think you are confusing HDR and post processing. Those are two different things. If you need to do extensive masking and what not after creating the HDR, then you probably shanked the bracketed photos. You can only adjust the high contrast between the sunshine illuminated portion of the Moon and the earthshine illuminated portion so much without it looking bad. Try to push it too much and it will look like garbage. As we used to say in the software industry--garbage in equals garbage out. So you need reasonably good photos for the layers to begin with. This takes practice of course. And you have to understand that there are instances when nothing you do will work because the Moon phase already has too much of the surface illuminated with sunshine.

 

[Stricnine]

If you cannot find a decent HDR app at a decent price, or free, then you can do an HDR stack manually. A good method requires creating a separate layer in your composite image file for each of the bracketed photos. Starting at the bottom layer, number the bottom layer 1, then add 1 to each subsequent layer that you place on top of the stack. So for example, let us say you take 5 bracketed photos at 0.3 EV as follows:

• 4 sec (layer #5, top most layer)
• 5 sec (layer #4)
• 6 sec (layer #3)
• 8 sec (layer #2)
• 10 sec (layer #1, bottom most layer)

You stack each of those photos in a separate layer in the composite image file. The order in which you stack them is not important, but for this example we will stack them in the order listed above with 4 sec photo being the top layer of the stack and 10 sec photo being the bottom layer of the stack.

Now we use a simple formula to set the opacity level for each layer. The formula is:

opacity level = 100 / layer number

100% = 100 / 1 (example using bottom layer which is layer #1)

Thus we have a composite image file stack consisting of five layers, each layer with the following opacity levels:

• Layer 5: Opacity = 100 / 5 = 20%
• Layer 4: Opacity = 100 / 4 = 25%
• Layer 3: Opacity = 100 / 3 = 33%
• Layer 2: Opacity = 100 / 2 = 50%
• Layer 1: Opacity = 100 / 1 = 100%

You now have an HDR bracketed composite image.

You can save the composite image file to a separate TIF file as a single layer if you like, then post process it. Play around with different shutter speeds and see which ones combine to give you the effect(s) you desire. I usually take way more bracketed photos than I use in the final composite.

I had only two exposure levels to work with, and I used a mix of that above with curve adjustments to the bright Moon layer.

The next time I try I'll capture more exposure levels to make it easier as you suggest.