Stacker manual
Welcome
SpikerSoft Stacker turns a set of photographs, each focused a little deeper than the last, into one photograph that is sharp from front to back. It is built for close-up and macro work, where a lens at a useful aperture holds only a sliver of the subject in focus at once: an insect’s eye but not its antennae, the near petal but not the far one. You shoot the sliver many times, moving the focus between shots, and Stacker finds the sharp part of every shot and assembles them.
This manual walks the program in the order you use it. Each chapter is one step of the ribbon across the top of the window, and each section of a chapter is one section of the panel on the right. Read it front to back once, then keep it for the chapter you are on.
How a focus stack works
A camera lens focuses on one distance. Everything nearer or farther is blurred, and the blur grows with distance from that plane. At the magnifications of macro photography the zone of acceptable sharpness, the depth of field, can be a fraction of a millimetre.
A focus bracket is a run of photographs that steps the focus from the nearest point of the subject to the farthest, with the steps close enough that every part of the subject is sharp in at least one of them. The camera’s own focus-bracketing drive can shoot such a run in a second or two; a focus rail or the focus ring does it by hand.
Stacking is the second half. For every point in the picture the program looks at the same point in every photograph, measures how sharp it is in each, and takes the colour from the photograph where it was sharpest. Done well, the result looks like a photograph taken with a lens that has no depth-of-field limit at all.
Three things make that harder than it sounds, and they are what most of this program is for:
- The photographs do not line up. Changing focus changes magnification a little, a rail moves the camera, a hand-held camera moves a lot. Before the sharp parts can be combined, every photograph has to be warped onto one of them. That is Align.
- Deciding which photograph is sharpest at a point is a judgment, and different ways of judging suit different subjects. Fine hairs against a smooth background want one kind of judge; a flat, textured surface wants another. Stacker ships thirteen of these judges, called engines, and lets you run several and compare. That is Stack.
- The real world does not hold still. A leg twitches between frames, a breeze moves a stem, and the program sees two sharp versions of the same thing in different places. Catching that early is Images › Curate; fixing what slips through is Touch up.
The seven steps
The ribbon shows the steps in order. Each one hands its result to the next, and a step is dark until the one before it has given it something to work on.
| Step | What it does | What it hands on |
|---|---|---|
| Capture | Drives a connected OM System camera: focus, exposure, the bracket itself. Optional; you can shoot without the program and import the files. | A folder of RAW files, imported automatically |
| Images | The list of photographs. Shows what the camera recorded, checks the bracket for gaps and problem frames, and decides how the RAW files are converted. | Developed, neutral images in a fixed order with one reference |
| Align | Warps every image onto the reference so the only thing that changes through the stack is focus. | Aligned images and a report of what each one needed |
| Crop | Trims the border where the aligned images no longer overlap, and bakes the alignment in. | A set of identical-sized images every engine works on |
| Stack | Runs the engines you pick and shows their results side by side. | One or more fused results |
| Touch up | Paints detail from a chosen source image onto the result where an engine got it wrong. | The retouched result |
| Finish | The creative part: the look, the print chain, a photographer’s stamp, share sets for Instagram, QR codes, species identification, export and publishing. | TIFF, JPEG, PNG, AVIF, a pan video, a share set, or a published page |
The step cards also carry a running status, a Pause and Stop while something runs, and a short note on what each step is waiting for. Hover a dark step to read why it is not available yet.
Where editing happens
If you have read advice about focus stacking you have probably read that you should not edit your photographs before stacking. That advice is right, and Stacker is built around it. It helps to know exactly what that means here, because two sections of the program have “develop” in their name.
Nothing creative happens before Stack. The RAW files are converted into neutral, linear images: values in proportion to the light that reached the sensor, with no tone curve, no contrast, no brightening. That is what the alignment and every engine were designed and tuned against. Even the picture you see on screen during Images, Align and Crop is a faithful rendering made only for display; the underlying pixels are untouched.
Images › Camera develop is colour science, not editing. It decides four facts the conversion needs: which white balance every frame shares, which colour matrix the camera’s colours go through, whether the lens’s vignetting is removed, and whether colour fringing at the edges is corrected. These must be settled before stacking, because they are exactly the things that go wrong if left until after: a colour fringe would be stacked as if it were detail, and a white balance that differs between frames would leave colour seams in the result. Changing them later re-converts the images but keeps your alignment, crop and touch-up strokes.
Touch up repairs. It copies real pixels from one of your photographs onto the result. It never invents detail and it has no colour controls.
Finish is where the look lives. Exposure, contrast, highlights and shadows, curves, colour grading, vignettes: all of it is in Finish › Develop, and all of it is applied only when the picture is shown or exported. It never changes the stacked pixels, so you can set a look early, keep working, and adjust it at the end as often as you like. A science export skips it entirely.
Why. Keeping the creative decisions at the end means every engine sees the same honest data, a stack can be compared fairly against another program’s, and a photograph can carry a record of exactly what was done to it.
Reading this manual
- Words that appear on screen are in bold, exactly as the program spells them.
- A box like the one above explains a reason or offers a tip. You can skip them on a first read.
- Every chapter ends with the shortcuts and the status messages that belong to its step.
- Hover almost anything in the program for a sentence about it, and click the ? at the right of any section title for a short guided tour of that section. The manual says the same things at more length and in order.
Before you begin
The quickest way to learn is on a bracket that is known to work. Help ▸ Practice Stacks… downloads a real focus bracket shot on an OM System camera; the figures in this manual were made from it. Import it, press Align, then Stack, and come back to the chapters with a result on screen.
Stacker runs on macOS, Windows and Linux and reads RAW files from Olympus and OM System cameras and from other makers, as well as DNG, TIFF, PNG and JPEG. A free trial runs for 30 days with no limits. After it, free mode stacks up to 15 images at a time and marks exports with a small SpikerSoft QR code; a one-time licence lifts both. The Settings chapter has the details.