Merging two images to retain sky detail, Photoshop CC

[gad-westy]

Are there any simple tutorials for photoshop thickos like myself for simply blending two exposures of the same scene, one for a dark foreground and one for a brighter sky (I'm thinking particularly sunset/sunrise with the sun in front of the camera). I'm familiar with HDR in photoshop and lightroom but that's not really what I'm after. Not having much luck finding what I'm after on youtube.

On a vaguely related note, I'd also like to be able to preserve some moon detail when doing long exposures at night. Whenever I've played around with this, I always end up with massive halos around the moon if I manage to retain any detail at all. I guess I'm looking for a merging technique for that as well.

 

[Deleted member 34016]

Are there any simple tutorials for photoshop thickos like myself for simply blending two exposures of the same scene, one for a dark foreground and one for a brighter sky (I'm thinking particularly sunset/sunrise with the sun in front of the camera). I'm familiar with HDR in photoshop and lightroom but that's not really what I'm after. Not having much luck finding what I'm after on youtube.

On a vaguely related note, I'd also like to be able to preserve some moon detail when doing long exposures at night. Whenever I've played around with this, I always end up with massive halos around the moon if I manage to retain any detail at all. I guess I'm looking for a merging technique for that as well.

have look here Graham -

View: https://www.youtube.com/watch?v=AnVgcud_q-o


plenty more on good old YouTube and they are free too

Les

 

[gad-westy]

Thanks Les. I'll take a look this evening.

 

[Brian G]

On a vaguely related note, I'd also like to be able to preserve some moon detail when doing long exposures at night. Whenever I've played around with this, I always end up with massive halos around the moon if I manage to retain any detail at all. I guess I'm looking for a merging technique for that as well.

Yes, exposure blending is the only way you'll retain detail on the moon's surface, but I don't know how to handle the halos.

Consider this:
What is the source of illumination for the moon?
Answer - the Sun!
The correct exposure to reveal surface detail on the moon is roughly the same as for a terrestrial photo taken on a sunny day.
It's amazing how many people seem to think that, because it's a night time object, the moon requires a long exposure.

 

[gad-westy]

Yes, exposure blending is the only way you'll retain detail on the moon's surface, but I don't know how to handle the halos.

Consider this:
What is the source of illumination for the moon?
Answer - the Sun!
The correct exposure to reveal surface detail on the moon is roughly the same as for a terrestrial photo taken on a sunny day.
It's amazing how many people seem to think that, because it's a night time object, the moon requires a long exposure.

Thanks Brian, appreciate it. The correct exposure of the moon is not really the bit I'm struggling with. I understand it's far, far brighter and so if I take a normal exposure for everything else, the moon will appear as bright blob but will also have a bit of spill out brightness around it (flare maybe?). so if I were to simply take another exposure correctly exposed for the moon (where everything else is black) and the moon is a nice neat detailed circle, and layer them on top of each other and then mask everything else, I end up with a very untidy bright halo around the moon and it looks very unnatural. I'm maybe not explaining it all that well, will try to dig out an example tonight.

 

[orangeframestudio]

and layer them on top of each other and then mask everything else,

Rather than mask everything else, can you not just mask the land (or everything that's not sky?) Therefore the halo would also be hidden.
Depends a lot the content of your pic obviously, If you need the sky from your first shot (with the blown out moon) removing the halo will involve some good photo shopping, matching radial gradients of a moonlit sky. (again depends on your actual shot)
You may find the end results are just too odd - You take a picture of a huge bright light source and the scene it lights up, then replace the light source with one that apparently is much much dimmer, it may be too unnatural on the eye to work.
Be good to see the actual shot you are trying to change.

 

[gad-westy]

Rather than mask everything else, can you not just mask the land (or everything that's not sky?) Therefore the halo would also be hidden.
Depends a lot the content of your pic obviously, If you need the sky from your first shot (with the blown out moon) removing the halo will involve some good photo shopping, matching radial gradients of a moonlit sky. (again depends on your actual shot)
You may find the end results are just too odd - You take a picture of a huge bright light source and the scene it lights up, then replace the light source with one that apparently is much much dimmer, it may be too unnatural on the eye to work.
Be good to see the actual shot you are trying to change.

Cheers Ben. I think you've summarised it in the first instance. I typically encounter this problem in the post sunset blue hour. To the naked eye, I can see detail in the sky, foreground and indeed I can see detail in the moon (or at least a clearly defined shape rather than just bright blob). The sky and foreground are fine in one exposure as it's not truly dark at that sort of time so the camera's DR covers everything within reason but if the moon is creeping into shot, I'm guaranteed to have a big bright blob and any highlight recovery in that area looks weird. If I replaced the whole sky with one that is exposed 'correctly' for the moon' the sky would be way too dark. I'm not necessarily chasing a look of perfectly exposed moon and foreground, more just trying to create the same sort of appearance the human eye sees where the moon's shape is well defined.

No specific shot I'm looking to sort, it's more of a recurring problem that I have put off learning about until raising this thread.

 

[CraigDHD]

for a basic way to blend two images using a quick cheat similar to luminosity masking add the two images as layers in photoshop, add a mask to the top image and select it. go to the image menu and choose apply image, you may want to play about with what layer you apply for best result i think generally bottom layer is best option but not got PS at moment to remind myself.

You will now get a black and white version of the image on the mask so the bright parts show and the dark are masked but in a much more graduated way than selection or painting masks will make. If you want to change what shows hit ctrl+i to invert the mask. If you want to change the intensity of the masked areas hit ctrl+l to adjust the levels of the mask. to refine the mask further group the layer with itself using ctrl+g then add a mask to the group and you can paint on it to select which parts of your masked image appear.

You can do more in depth stuff with luminocity and channel masks but this is usually a pretty effective way to tackle this type of issue quickly.

 

[gad-westy]

for a basic way to blend two images using a quick cheat similar to luminosity masking add the two images as layers in photoshop, add a mask to the top image and select it. go to the image menu and choose apply image, you may want to play about with what layer you apply for best result i think generally bottom layer is best option but not got PS at moment to remind myself.

You will now get a black and white version of the image so the bright parts show and the dark are masked but in a much more graduated way than selection or painting masks will make. If you want to change what shows hit ctrl+i to invert the mask. If you want to change the intensity of the masked areas hit ctrl+l to adjust the levels of the mask. to refine the mask further group the layer with itself using ctrl+g then add a mask to the group abd you can pain on it to show which parts of your masked image appear.

You can do more in depth stuff with luminocity and channel masks but this is usually a pretty effective way to tackle this type of issue quickly.

That's great thanks. I'll have a play with that method.