Stacking by Hand

From a Flower to the Aurora

Spanning the size scale from a single flower to the entire galaxy, we encounter challenges with both edits. Because of breezy conditions, we ended up with only a handful of usable shots for our macro stack. Standard techniques for alignment were failing, but a little hand blending in the GIMP makes short work of the job.

In the Aurora shot, the Aurora is so bright that the stars are hard to pick out. The challenge here is to bring up the stars without excessive haloing. I use multiple instances of both the Highpass and Equalizer modules to add a starry-night feel to this spectacular viewer-contributed shot.

Thank you, Andreas, for your Edit my RAW submission!

This video builds on knowledge from previous videos, running full-tilt through tools and methods to achieve the edit. For fuller explanations, return to the Home Page and scroll down to Topics Discussed or Modules Used on the right-hand bar. Click on any of these, and we assemble a complete playlist of every instance for quick review right here on the site.

Stack RAW 1
Stack RAW 2
Stack RAW 3
Stack RAW 4
Stack RAW 5
Stack XMP

Aurora RAW
Aurora XMP 1
Aurora XMP 2

Complete Show Text

Download complete text here

(triangle palm flower)
(Carlsmith Beach Park, Hilo)
(Kapoho shoreline)
(Kapoho tide pools)
(Pahoa sunrise)


Welcome to Weekly Edit for January 11, 2016.

Hawaii is known for beautiful flowers.

We are also known for our ocean breezes.

These two factors combined to give us this week's inspiration.

Shooting this flower, we had to use a lower f-stop to get a fast enough shutter speed to compensate for the wind.

But that gave us a shallow depth of field.

No worries: just get lots of frames and focus-stack, right? Well, when we got back to the studio, that tricky wind left us with only a few usable shots.

We tried our faithful friends Hugin and Enfuse, but the parallax differences between the frames were too extreme.

When all else fails, hand-stack in the GIMP! (Harry's Voice) I took this macro stack, and it was windy.

I actually had to take around 30 shots, and only some of them came out.

Let's look at the ones that came out.

In this one, these parts of the flower are in focus.

I don't know that this one's really very useful.

It looks like these parts are in focus, but as I focus down further, it looks like it's better on the later ones.

This one looks like it gets parts of this.

Maybe that's helpful; maybe it isn't.

It looks like this part looks better.

And, on this last one, this back part looks great.

They're all in different locations and different magnifications.

I have tried this multiple ways.

I tried using Align Image Stack with various parameters; I tried setting control points with Hugin and having it do the alignment.

The problem is that the parallax view errors are so great because I'm so close to the subject matter and it's so deep from this point to the back, that this needs to be hand-stitched.

The best way to do that is in the GIMP.

Let's open the GIMP and open these as layers.

Let's see what we've got here.

This top one is focused closest to us.

This bottom one is focused farthest away from us.

This bottom one is going to have the smallest image, so we'll have it set the size.

So, let's come forward one.

Let's see where we stand with this.

Ah, look at the size difference.

We need to scale this down; it's too large.

The one beneath it is smaller.

Layer and Scale Layer.

We're at 6200; let's try 5600 and see what that looks like.

Okay, that looks better.

Let's move it and see how it lines up.

It looks a little too small now.

We'll work on that: Layer.

Scale Layer.

Instead of 5600, we'll go with 5700.

That still looks a little small.

Oh, that looks good.

Now I'll Add Layer Mask at (White) full opacity.

Then I'll take a pencil tool because it goes super fast, and make it nice and big.

Then I'll paint where I want the back to show through.

Over here, the back was much more in focus, so we definitely want that.

I can use that leaf as a dividing line.

If I let the back through here, it actually makes these parts larger.

I don't want them to be larger because when I paste them at the end, they'll be smaller.

So, I can go back and either Ctrl-z that, or I can use the Eraser tool and just remove the parts I don't want.

We'll go to Show Layer Mask and we can paint in all the areas we didn't catch.

Now what? Does that look pretty good? Are we lined up? Okay, but is it better here with the one behind it, or with this one? Oh, the one behind it looks better.

Okay, let's do this section too.

That looks nice.

So, it seems like we'll only use this second layer right up here.

That looks pretty good.

I'll feather these edges now.

Show Layer Mask.

I'll get these areas.

What was right here? Nothing.


Then I'll feather this.

Let's see: this tool, and take our Size down, and take our Hardness down.

There we go.

Okay, our first two are done.

Let's go up one more.

Okay, what's useful in this? It looks like these parts of the center are useful.

Are they better on any of these others? Maybe.

That one looks better.

Maybe we don't need that one.

And then that one looks much better.

Well, let's just use this one and call it good.

Okay, I'll turn these two off.

So, we want to go to the left, and we need to be a little smaller.

Yeah, look; we're way down here.

Scale Layer.

Let's try 5000.

That looks pretty good.

Okay, what do we look like here? A little small.

Let's try 5300.

That looks pretty good.

I don't care about this over here; I'm just painting in the center.

Yeah, our lines lined up pretty well here.

Okay, we'll try that.

I don't want to mess with this part down here.

We'll Add Layer Mask.

White (full opacity).

We'll paint where we don't want the center now.

We'll start up here and work our way down, trying to get closer and closer to get our blend nice.

First off, I can see that this layer is not the same brightness as this layer.

I think a cloud may have gone in front of the sun.

So, let's get the exposure right.

We'll click on that and go up here to Colors and Curves.

We'll sample this area.

What's the greatest distance? Probably right there.

Oh, we're almost there.

Now we're getting brighter than the other one.

So we'll come down a little.

Oh, that's pretty close.

Now I want to feather in this edge.

We're on our Layer Mask, and we want this tool.

The Paintbrush instead of the Pencil.

Our Opacity is 100.0; that's good.

Hardness: that will give us a feathered edge.

We can go in and feather this in.

That's looking pretty good.

I can make it smaller and get in between these points.

Okay, let's make it smaller and get in between these little areas here a little more.

It's starting to look better.

This looks a little odd right in here.

And look, we're getting some yellow here and here.

We'll go back to the Eraser tool and fix these: kind of go back and forth a little bit.

Right there, and right there, and right there.

And right there.

How about here? Okay, I feel good about that.

Now I just want to quickly fill the rest of the area.

We'll zoom out and change our view to Show Layer Mask.

This is kind of crazy (laugh) It looks like we probably want to fill in this stuff.

Let's look and see what's behind those.

Yes, we definitely need to.

Let's see what that looks like.

Okay, now I want to fill in the rest.

We'll use this Fill tool.

Turn off our Show Layer Mask.


Export As.

We'll call this _gimp.tif Here we are in Darktable.

That turned out pretty sweet, actually.

I want to accentuate these large curves of these petals.

I don't want to get lost in the details.

That will give everything a little bit of a soft focus feel and a dreamlike look.

I want to sharpen this.

This looks a little jarring right now.

This area is so bright and this area is a little dark, or at least the stem is.

The whole thing looks a little jarring.

I want to make some tonal changes first, then we'll apply the shading.

Let's try this.

Where is it bright? It's bright here and here and here and here, and here and here.

We'll make that a little smaller, feather our edge.

What's bright? The brightest thing is right here.

Okay, that looks better.

Now, let's see: the stem looks so dark! Let's bring that up.

Oh, that looks better.

This looks a little too bright, though, right there.

Bring that down a little.

I only want to do that here on the stem.

And let's see if we can make that just a little smaller and feather that a little tighter.

Can I exclude the brighter parts with a Parametric Mask? I think so.

That might have worked just fine.

It might need a little Mask Blur there.

Mask Blur.

Then, maybe this is a bit much and we can come down a little.

That looks better.

Before, and after.

We don't even need as much as that.

There we go.

What else? I want the middle to look darker so it looks farther away.

Right there.

Maybe bring that down a little, and then feather this out.

And make these darkest points right there.

Right there.

Bring that down.

Oh, good.

Now I want to work on shading.

Take our Saturation down to zero and bring our Contrast down just a little.

I want larger-scale shading; I don't want to see these details.

So, I'll bring my Radius up.

Oh, yeah: like these large parts -- and bring my Brightness down a little.

Like that.

I might want to apply a Parametric Mask to exclude these darker areas, or minimize the effect.

Let's see what it looks like though.

We use the Softlight Blend Mode.

Let's bring this down a little.

It's not affecting this too badly; I think we can leave it.

I want to do that again, that same thing.

So, Saturation down to zero, and bring our Radius up, Brightness down.

I'm trying to show this shape, the larger shape of the flower.

Once again, Softlight Blend Mode.

There we go; it's kind of pulling you in here now, isn't it? How did that work here? Is that too much? It does look like it's a bit much, doesn't it? Let's apply this with a Parametric Mask and avoid some of these darker parts.

See how that looks.

Ah, like that.

Okay, there we go.

Now, I want to pick up some of this finer detail in here.

I'll use the Highpass Filter for that.

We'll do two passes: one for the contours and one for the edge detection.

This is nice; it's getting me these little stems here, and it's also getting me these veins in here.

I want to bring my Contrast up, but not to the point where I'm clipping either the dark or the light.

Then I'll apply this with a Parametric Mask based on the L Channel.

Softlight Blend Mode.

Bring down our Opacity.

That's with it full, and you can see it brings out a lot of the contours in the petals and it makes this look a little high-contrast.

So, we'll bring it down some.

Right about there.

Now I want to do something with edge detection.

That's another Highpass Filter instance, but this time we'll turn our Sharpness way down, and our Contrast Boost too.

This time I'll use the Overlay Blend Mode.

See how that brings this up? Before, and after.

It really gives us a lot of edge detection.

It's too much, so I'll change the Opacity down to around 50% That looks good.

Now we've got sharp edges everywhere and nice color.

I want to enhance the color just a little bit.

I'll do a gamma adjustment before the color, so I want to bring this up just a little bit.

And bring this down just a little.

Then, one last instance.

This time I'll add a little color with the Subtract Method based on the L Channel.

It's a little bit heavy; let's bring it back down to around 9%.

That looks good.

I think I'm liking it.

Do I need to apply an Unsharp Mask? At the very end here? Yeah, that helps.

Now, I would normally scale it first, and then apply an Unsharp Mask, so that's something I might do in the GIMP.

I still think this is a little bright, right here and in here.

Let's try a little Shadows and Highlights.

We'll switch this to Bilateral.

Okay, that certainly knocked down those highlights.

And it brought up the shadows a little too much.

Let's see what happens if we don't affect the shadows at all.

So, make that zero.

And it knocked down our highlights a little more than I wanted...

Oh, that looks better.

Okay, -28.67 That's it on this one; we're done.

(Mouse's Voice) Nice edit! I like the way the center of the flower darkens and draws you in.

I like that balance between detail and story that we achieved in this image.

Even more than that, I like the simplicity of this edit.

But we got great results without a lot of fuss.

(Harry's Voice) We have a guest edit this week.

Here we are.

This shot was taken by Andreas.

Thanks for sharing! This was on New Year's Eve.

It's really dark; it's the Aurora Borealis.

He lives in Sweden.

This looks beautiful.

I can see there's some foreground stuff going on here.

Let's take a look at what we can do.

Let's see: Base Curve.

What kind of camera was this? It is a Nikon D610.

Let's look at different Base Curves here.

There's Nikon LIke.

And this Nikon Like Alternate.

I'm not seeing much of a difference.


I want to see what's going on with the bottom.

Let's see: that really washes out our top end, doesn't it? Let's try just increasing the Exposure.


Can we set our White Balance by the snow? Let's see.

Now, I think some of the color in the sky is supposed to be reflected in the snow.

If I just take a White Balance from the snow, it won't be very accurate, so I'll take into account what these numbers are and try to meet them part way.

From the camera, we've got 0.97 and 3400.

Okay, 0.97 and 3400.

So, Temperature stays the same.

So, the distance between 0.69 and 0.97 -- well, we'll come up a little bit here and I think we'll have to split the difference.

There we go.

Now, how can I bring out the snow? Usually for really dark stuff like this, Tone Mapping is the way to go.

Yeah, look at that; that's: Kaboom! It's like daytime.

Obviously, it's too much; let's bring down our Spatial Extent.

Okay, and Contrast Compression.

Oh, that looks better.

The snow looks better now.

Okay, I just want to apply this to the snow, not to the sky.

We'll use a combination of a Drawn & Parametric Mask and use this ridge line.

We'll have to turn this around because we want the lower part.

Here's our Mask Indicator.

Now it looks like we need more here on the sides and less in the middle because the sides are darker.

Let's add a mask here and feather the edges.

Okay, turn on our Mask Indicator.

I want to exclude this second one.

So, Tone Group, the first one we'll do Union and the second one we'll do Intersection, and then the second one we'll do Use Inverted Shape.

There we go.

Now it's applying more of it over here and none in the middle.

Now we can turn this down until it's even and apply it to the whole instance.

See, now this area is a little too bright.

We'll have to bring that down on our first one.

Adjust Opacity until we match better.

There we go: Opacity 15% Now on this second one.

And bring our Contrast Compression down.

Once again, use a Drawn Mask.

We will combine it with a Parametric Mask in just a second.

And exclude these darker areas.

There we go.

Give it a little Mask Blur on both of these.

Okay, now we've got a little foreground information; that helps.

This looks like it's greatly skewed.

I'll increase the Brightness so I can see what's going on.

Yeah, we've got trees pointed this way and trees pointed this way.

So: Keystoning.



I love Keystone.

It's so easy to use.

Just pick a couple of straight lines, like I want this one to be straight right here, on that tree.

See? And I want this one to be straight on this tree.

Then I try and get my horizon level too.

It looks like there's a greater distance here than here, so I'll bring this one up a little.

There we go.

Then click Okay.

Now we have a straight horizon and our trees are straight on both sides.

Now we can crop it.

Oh, nice.

Okay, I'm happier with that perspective.

Get rid of our brightness here.

Now let's see what we can do.

I want to bring out the shapes in the Aurora and I want to bring out the stars.

If I look at the image information here, the Aurora must be incredibly bright because this is only a 3-second exposure, so the stars are kind of dim.

We'll have to bring up the stars and we'll have to bring up the Aurora.

I think there's more of the Aurora in here too, look.

Yeah, there's stuff in here.

Let's see if we can bring that out.

Where is that? Oh, yeah; that brings up this whole curtain here.

Now, these darker parts here: do we need to worry about them? Oh, nice.

This looks a little bright right in here.

Right from here to here, like that.

Now, we just want to bring down this high end a little.

That looks better.

I want to make the snow whiter and bring up the stars.

The snow: whiter.

Oh, yeah; that's a lot of green.

And a little bit of yellow.

That snow is looking better.

Denoise (profiled): what does that look like? Oh, that does a pretty nice job.

Look at that.

We've still got some fringing up here.

Can I change this patch size and get even better? Ah, yes; that is even better And, it's possible that when we turn on Chromatic Aberrations, that will get rid of some of this fringing too.

Okay: Equalizer.

Let's see what we can do.

Different sizes.

That looks pretty interesting.

So does that.

That's a little small.

Now let's try the same thing with the Lowpass Filter and see what it looks like.

Oh, that gives nice edges, doesn't it? Okay, that's probably the way to go.

Let's see: bring our Brightness down a little.

Contrast up.

Okay, let's try that again.

I want to bring out more detail in the middle here and more down here.

Let's see if we can do that with the Equalizer.

Try and stay away from these edges so I don't get halos.

Now I'm going to go with Darken only.

There we go.

Oh, yeah, that brought up a lot.

And then let's see if we can do the same thing down here.

We'll start another instance.

Same thing: Darken only.

Ah, that looks better.

I'd like to bring this up over here, and also some of this over here and over here.

How can we do that? I want to brighten that up, but I don't want to brighten it up and add a bunch of noise.

I'm afraid that I will.

Let's try it with just the Tone Curve first.

Right there.

No, it doesn't bring up a lot of noise.

That looks fine.

Oh, yeah; that opened that up.

This looks a little bright right here.

And I definitely don't want it up here.

Okay, just a little bit of a gamma adjustment here.

Bring this down.

That's starting to look pretty good.

What can I do in here? It seems like there should be more information, doesn't it? It looks like my best bet is this Highpass Filter.

Yeah, right in here.

So: Drawn Mask.

We'll go like this.

We'll apply that with a Parametric Mask based on the L Channel and we'll change the Blend Mode to Softlight.

There's our before and there's our after.

Oh, that added a lot of detail.

Now, I want to bring out the stars and I'd like to enhance the colors a little more.

I'm just wondering if I can get a little bit more right here in the middle.

Is there anything in there? Is it our Denoising that's getting rid of any detail? No, it isn't.

We might be able to bring down the Strength a little bit though.



Here we go.

Right here in the middle, let's see what we can do.

We'll leave these ones where they are.

And we want the difference between here and here.

So, bring this down a little bit.


And bring that back up a little bit.

Okay, good: now I can see some more information in there.

I want these colors to be more intense up here.

How about right in here.

What have we got? Okay, greens.

Ah, there we go.

And our yellows.

First off, I've got all this crazy fringing here.

And I don't know if my Chromatic Aberration control is going to get rid of it.

Let's turn on our correction for our lens; maybe that will get rid of it.

Where's a bad fringe? There's one.

Okay, let's see: Lens Correction.


Nope; that didn't do it.

It says Corrections: All.

TCA was part of it.

Okay, well, let's do it manually.

Using the Chromaticity Channel, I'm going to try and isolate these areas that have this blue right there.

Give it a little Mask Blur.

Give it a little bit more.

Okay, and is that hitting any area we don't want? It is, right in here.

So, I will draw those out.

Right there.

Okay, invert that.

And now, hopefully it's just our stars here that have fringing going on.

Yeah, there are our yellow spots.

Turn off our Mask Indicator and take our Saturation way down.

Almost gone.

And take our Radius down to just a couple of pixels.

Take our Saturation down to zero.

And take it negative.

Okay, that looks a lot better.

Now to bring out these stars.

Highpass Filter.

I really want to bring out the stars a lot, so we might have to do this a couple times.

So, I just want the stars; I don't want anything else.

I'm bringing down my Sharpness until I only have the stars.

Like that.

Bring my Contrast Boost down.

Oh, bring it up just a little.

Okay, there we go.

And then we just want it on the stars.

Can we do that with an L Mask to some extent? Parametric.

Okay, that's mostly just getting the stars, and it's not going to really affect the Aurora up here.

So I will combine this with a Drawn Mask so it doesn't affect this lower part of the image, because there are no stars down there anyway.

And then we want to apply this with an Overlay Blend Mode.

Did that mess up our Aurora? No, it didn't.

It definitely brought out the stars, though.

Okay, let's just Duplicate that a couple of times.

There we go; now we've got some stars going on.

These halos are a little tough, eh? So, let's bring our Opacity down on each of these.

There we go.

Alright, now we've got stars with a lot less halos.

Maybe we can do that a little more in these darker areas.

It seems like we've got stars in these lighter areas now.

So, I'll Duplicate Instance this again, except on my Parametric Mask I just want it on these darker areas.

And I don't want it to exclude the stars, so I'm going to make my Mask much bigger.

Now, I don't need to change my Opacity, because when I Mask Blur it, it doesn't apply it fully.

There we go.

And then we'll Duplicate Instance that one more time.

There we go.

Now we've got stars, and we've got the Aurora, and we've got our colors looking better.

(Mouse's Voice) While Harry grabs a cup of coffee, I just want to go over how to create Playlists on our website.

Let's go to Weekly Edit.

When you get there, this is what you see.

Our most recent post is right up in front.

On the right-hand side is a list of all the recent posts.

You can just click on any one of those episodes; it takes you straight to it.

When you do that, you can watch this; obviously you can watch this, and you can go to Full Screen...

But, if you scroll down here, you see that we've cataloged all of the Topics Discussed and the Modules Discussed, with their times.

So, you can jump to wherever you want to in the video based on what Topic or Module you want to look at.

But the really cool thing, if we go back to the Home Page, and you scroll down again on that right-hand sidebar past Resources, you see that same list of Topics discussed.

Now, this is every Topic and every Module from the beginning.

So, if you were to click on one of these, it takes you to the Playlist Page.

On the Playlist Page, we've composed a playlist, chronologically, of all of the times we've used Denoise Profiled, in this example, from the beginning of time.

You click on one of those and it takes you to that video.

That was an early one; you can hear the frogs in the background.

We started recording in the daytime so you didn't hear that as much.

Or, in 'Let's Add Grain'...

Well, that's what I wanted to show you.

I'll let Harry get back to his Aurora Borealis shot.

(Harry's Voice) So, Crop and Rotate...

Let's see now.

I want to bring this in.

I want to feel like we're tight in on this action.

And I'm not a big fan of this upright stem right here, so I'm going to try and bring it in just before that.

There we go.

Oh, that's kind of nice.

How does that look? I feel like we're tilted a tiny bit to the right.

Okay, that looks better.

I like it.

Now I feel like I'm in the action.

So, what do we have here? Hot Pixels: Detect by 3 Neighbors.

I don't know if we'll find many with a 3-second...

Oh, 59.

And correct for Chromatic Aberrations.

Then export this as a TIFF.

When it's done, I'll open it up.

Alright, here we are.

Let's see what we've got.

Oh, not too bad.

I wonder if we can get rid of some of this with the Defringing Tool.


Maybe not.



I'm not going to worry about it.

I would like to bring out these stars even more, though.

I'll try the Equalizer, bring it up at the right size for stars.

That looks good, like that.

And then set this to Lighten only.

That made a big difference.

Let's try that one more time.

We've got a sky full of stars now! Wonderful.

They look pretty good, too.

I want to add some color to the Aurora.

We'll use a Subtract Method to do this.

This adds more intense colors to the brighter parts of the image because I used an L Mask.

Oh, that's starting to look pretty good, except that this looks terrible down here.

Probably the Equalizers.

Yes, okay, so we'll have to put Drawn Masks with those.

We don't need them any lower than the stars.

There we go.

Okay, so there's one.

And there's a second one.

Now the snow looks better.

The snow still looks a little bright to me right here.

Final touches.

That looks about right.

Okay, ...and, Gradient.

It makes it easier to grab it when it's behind another shape.

Okay, there we go.

Turn on our Mask Indicator.

We want Union and Intersection.

There we go.

So, it will tone it down the most right here.

Then we want this right here.

I want to bring down both sides of this.

That looks a little more like night time.


Just a little more color? I think the color is a little intense down here, and it could be more up here.

So, I'll add a Drawn Mask to this.

Here we go.

Then I can turn this up a little more.

There we go; that looks good.

Thanks Andreas.

What a beautiful shot! That was so much fun.

I got a lot of wonderful RAW contributions.

I cannot wait to go through them! I just had to do this one today, though, because I love the Aurora Borealis.

I'll have more to do next week.

Now I'll hand you over to Mouse.

She wants to tell you a little bit about our website.

(Mouse's Voice) Harry's right; I do have a couple more things to show you about the website, so let's go there.

Here we are, on an episode.

I already showed you about the Topics and watching it, so let's scroll down a little bit.

You'll see we've got show notes on every episode.

Then we get to the fun part.

You can download the RAW files so that you can play along at home.

Right here, from our Google drive to you.

But, in addition, we give you all the sidecar files.

Keep on going down and you see we've included the complete text from when I transcribe the show.

You can also download that, just that easily.

Let's go back to the Home Page and I'll show you how Andreas got us that beautiful RAW shot that we edited in today's episode.

If you scroll down past all those posts, you get to Resources.

Towards the bottom of Resources: Edit my RAW.

That's the segment of the show.

Click right there and there's a place where you can upload your file.

Send us your RAW files.

Each week we select one.

We edit it on the show, and if yours is the winning one, we'll print it out and send you a signed, matted copy of it as a souvenir of the show, with our undying thanks.

And one more thing: Patreon! Go to and become a patron.

Support us in what we do.

If you choose $10 a month, you can choose any of these rewards.

There is a bunch of them.

Or, you can choose 'No Reward' and put in whatever amount you want here.

$5, or $50 or $500...

whatever you want to do.

Just click 'Continue' and it's super-easy.

Thank you for supporting us.

Thank you for watching.

We'll see you again here next week.

A hui hou.

2 thoughts on “Stacking by Hand

  1. Pingback: Weekly Edit 23: Stacking manuel – darktable FR

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