StackShot - Automated Macro Rail for Focus Stacking

Macro-photography is a fascinating sub-set of the photographic world. It brings to life detail that the human eye all too often misses. Unfortunately macro photographs often suffer from a narrow depth of field. How do photographers capture that stunning shot at high magnification and still have great depth of field? Enter focus stacking. Focus stacking is the art of digitally combining a series of images with a narrow depth of field into a single image with an extended depth. The images are usually collected with a macro rail and combined using a software program such as Zerene Stacker or Helicon Focus. Ideally each of these images is taken at a fixed distance interval.

Most macro photographers are familiar with using a macro rail to adjust the camera’s position relative to the subject of interest. These macro rails allow the distance to be adjusted and provide a crude manual method for taking the series of shots required for focus stacking. Unfortunately there are several drawbacks. There is a lack of accuracy, reproducibility, speed, and precision. Additionally, sub-millimeter steps are difficult at best. This is where StackShot comes in, it is an automated focusing rail for repeatably collecting images for focus stacking.

If you want to take your focus stacking to the next level by adding a touch screen interface or two additional axis' of automated motion (subject rotation for example) check out the latest version of StackShot - the StackShot 3X, we also have a comparison of the two controllers.

Repeatable Collection of Images for Focus Stacking - StackShot

StackShot is an electronically controlled macro rail system that coordinates the movement of the macro rail and the triggering of the camera. StackShot’s simple user-interface makes the automation of the entire image collecting process for focus stacking very easy.

What are the advantages of StackShot?

Accuracy: Step size adjustment from full length of the rail 100 mm down to 2 um.

Repeatability: The “automatic return” feature allows adjustments to the exposure settings between stacks captured with the same position and step size as the previous run with a single button press.

Speed: No more manually adjusting the rail position, pressing the shutter button, and hoping you didn’t bump the camera. Everything is automated and fast. This enables focus-stacking for critters that may not be willing to stay in the same position for very long. See Scott Linstead's guest post on the stacking of live spiders for an example.

Completely Configurable: The StackShot is completely user configurable. Timing (both on, off and settle), number of pictures per step (useful for HDR –, maximum speed, ramp time, camera settle time, etc. All the flexibility you will ever need for focus stacking.

Can be battery powered for use in the field. Check out our Li-Ion Battery Kit.

StackShot and the Extended Macro Rail

While the standard rail will fit the vast majority of focus stacking applications, you may want more length for your larger subjects or just more working distance. The extended length rail will give you 200 mm (8 in) of movement from one end to the other, this is double the 100 mm provided by standard macro length travel. If you plan to only do high magnification (>10X) stacks of small subjects you might want to stick with the standard rail as its shorter length makes for a slightly more rigid system. But, if you want to capture larger subjects or want more working distance then this is the longer rail is likely the better choice. Even with its extended length this rail still maintains the same linear accuracy as its shorter cousin. The image below gives an idea of what is possible.

Orchid Stack

The large Orchid image is a focus stack of 48 combined images. It was captured using the Extended Length Macro rail and StackShot controller.

The small image is the first image in the stack. As you can see the depth of field for a single image is very limited.

Many thanks to Bob Coates for the use of his images.

The Extended Rail

If you are already a StackShot user you can use your existing StackShot controller with the StackShot Extended Macro Rail - no software updates or modifications are required. The extended rail will work with either the single axis StackShot or the StackShot 3X. If you already have a StackShot the StackShot Extended Macro Rail. is available without the StackShot controller.

Keep in mind when creating a focus stack that is the full 200 mm that you will loose the periphery of the image as the rail moves from back to front.

The extended rail, like its shorter cousin is made from black anodized aluminum and stainless steel rails and fasteners.

Focus Stacking Modes:

Automatic: (Auto-Dist)
Use the FWD and BACK buttons to adjust the rail's start/stop position. Enter the distance of each step. Then go!

Total Distance:
Select the total distance you want the rail to travel along with the number of steps desired in that distance.

Manual Step:
A button press is required to move the rail the specified distance. Only one step occurs for each button press. Useful for cameras with no electronic shutter release.

Distance Per Step:
Similar to Total Distance, except that you enter the distance desired for each step, and then the number of steps.

Continuous:
Move the camera the specified distance without stopping in steps.