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The Cognisys Stackshot automated macro rail is an electronically-controlled z-axis stage capable of 2µm steps designed for focus stacking. Stackshot is controlled through a separate electronic control box, and was the first such device available commercially. Stackshot is today one of various electronic stages available but is widely recognized as the class leader.

Cognisys Stackshot, the ultimate convenience in extreme macro stacking, capable of 2µm steps in its high precision mode. The bottom is a standard dovetail connection and the top is a standard tripod thread. Stackshot is a superb device and makes stacking easy and painless.

Stackshot does everything you need for stacking and a little bit more, and whilst it is an expensive investment costing roughly the same as a reasonable lens, I just wouldn't want to be without it. It's the ultimate automatic focus stacking apparatus for the extreme macro photographer.

Stackshot works directly with Zerene Stacker, Helicon Remote (Canon and Nikon only) and CamRanger, and is the only focusing rail that has a completely separate control box controlling stack parameters such things as step size, torque and so on. Stackshot allows for stack lengths from its full length of 100mm to 2µm, and has an auto return feature so as to be able to repeat the same run. Handy in case you want to try different step sizes for a different run. Stackshot does not have or need a mobile phone client as the unit and controller can be battery powered for field use. Stackshot also has a USB interface which allows the device to be controlled via a computer using Zerene or Helicon.

Stackshot Modes

Focus Stacking Walkthrough

1 ➤ The focus stacking workflow

2 ➤ How to prepare a focus stack

3 ➤ How to shoot a focus stack

4 ➤ Software tools for focus stacks

5 ➤ Postprocessing tools for focus stacking

One of the things that differentiates the Stackshot macro rail from other electronic rails such as the WeMacro rail, the MJKZZ conversion kit and all the others is the sheer amount of specialized modes that Stackshot has on its controller. Most other stages only let you control either step size or number of steps, but Stackshot has a huge number of options that the others don't. Once put in place and connected, the process for using Stackshot is incredibly simple - set a bunch of general parameters, choose a mode, set that mode's parameters, and off you go, with a nice handy countdown on the control screen showing how many shots are left until your stack is finished [ie 67/88].

Automatic Step Mode	Automatic Step mode allows the user to determine just the beginning and end position by using the fwd and back buttons, and also the number of steps desired. After that the stack run is started, the machine calculates the appropriate steps and does the rest.
Automatic Distance Mode	Automatic Distance mode is similar to Automatic Step mode. It allows the user to determine the beginning and end position exactly like Automatic Step mode but the user specifies the distance to travel for each step. Stackshot does everything else.
Manual Distance Mode	Identical to Automatic Distance mode except that each step must be manually advanced - useful for applications where the camera, subject, dye, or material may have a specific amount of time before the next picture is desired.
Total Travel Distance Mode	User selects the total distance, the rail will travel and the number of steps to use in that given distance.
Distance Per Step Mode	Distance Per Step Mode operating mode lets you specify the distance to travel per step.
Total Travel Distance Mode	Manual mode is similar to Distance Per Step mode in that it lets you specify the distance to travel per step, but it will only step the specified distance when a button is pressed. Lets you make small adjustments to camera settings between shots.
Continuous Movement Mode	Continuous Movement between user set points a and b, as opposed to take pic, start, stop, take pic, start, stop etc.

Stackshot Configurability

Stackshot specifications

• Highly configurable with down to 2 µm step size.
• Rail components made from T-6061 aluminium and stainless steel.
• Macro rail can lift a 10 lb (4.5 kg) load vertically at a torque setting of 5/10.
• Uses NEMA 17 stepper motor
• ACME Threaded Rod has 16 tpi, 1.59 mm of linear distance per motor revolution.

As mentioned, Stackshot is tremendously configurable. The global configuration options include: pictures per step, settle time, time between shots, load/save previous settings (10 can be saved), automatic return yes/no, motor speed, time lapse options, pulse time (length shutter output is active), ramp time (speed at which motor ramps up or down ie acceleration, units of measure, torque setting, high precision mode & LCD backlighting. Then each individual stack also has its own settings: mode, # of steps, start position, end position, change settings, run again and current step (ie 5/33). These will differ for each mode, as for example automatic distance mode requires the distance to be set rather than # of steps.

The huge benefit of this versatility recently came home to me when I bought a spare stepper motor from Cognysis in order to create a stepper unit for a new purchase, a laboratory compund microscope. With a few changes i the settings I was able to make the Stackshot rotate a fraction of a fraction of a turn each time, so that I can make a decent step sequence out of a stack using the fine focus knob of my microscope. Although wemacro now offers an all in one unit to do the same thing, it was nevertheless a real relief to be able to make such a unit a few months before wemacro came out with its version, especially one in which I could even configure a setting for backlash.

Summary: so why buy Stackshot?

With Stackshot costing significantly more than the other focus stacking rails on the market, the question needs to be asked what is it that makes stackshot a good buy? For me the answer to this question really comes down to two factors, its operation features and the external control box. In operation, Stackshot has all the modes that anybody could possibly want, so that it's ever so easy to choose the one that suits you. Ie go to start and end and set number of steps. Or go to start and end and make each step 7 µm. Having access to such a wide variety of modes complemented by a wide range of settings gives you the widest configurability and means you're likely to be able to execute a successful stack, regardless of how unusual your particular project may be. Secondly, and almost as importantly, the external control box. I can't put my finger on exactly why, but having this external control unit as opposed to bluetooth phone app or desktop application adds a level of convenience and ease of use in terms of the apparatus setup that the other stacking apparatus companies have difficulty matching. On a practical front it also means that you don't need to have your stacking apparatus right next to a PC.

Using Stackshot

Stackshot controller

• 12VDC, Reverse battery protected.
• Stepper motor controller run in 1/16th step micro stepping mode.
• Controller has a durable extruded aluminium housing.
• Open drain output configuration on Shutter output.
• Shutter output can switch up to 1A of continuous current.
• System can be battery powered with Li-Ion Battery Kit.

This device is a pleasure to use and gives me reliable results 99.999% of the time. It has its foibles that you need to watch out for though. Be aware of the remote control, it comes set for Canon users but if you use it on a different brand you will need to re calibrate the remote control for your brand, otherwise it doesn't get picked up. One of the very few gotchas with this tool.

Are You Missing Shots With Stackshot?

Working with Stackshot is nearly always a pleasure but like anything there are occasional mysteries. For example, if you have your camera in liveview mode and set off on a stack using Stackshot and the remote IR unit, the camera sometimes won't register the instruction to make a photo so Stackshot can miss out shots during a stack. This is a camera problem rather than a Stackshot problem as the buffer fills up on the camera and it takes a different time to process various images in Liveview. This has happened to me using Pentax, and has also been reported with Canon EOS Utility Live View and ControlMyNikon. It transpires that if a camera is in Live View mode but is not displaying the actual Live View image, then the camera can ignore shutter commands coming from the StackShot. In my case the Live View process overrides the remote process, so whilst transitioning to and from liveview, remote control instructions are not read by the camera. My recommendation is simply to avoid using liveview whilst a stack run is in progress. Another thing to be aware of is that with Nikon, when the lens is set to manual focus, the body also needs to be set to the same - otherwise the shot won't be taken. An easy thing to forget, but tricky to identify.

Stackshot with In-Camera Delay

amazing customer support offered by Cognisys, the company that produces the Stackshot device

Many cameras, mine included, come with an optional in-camera delay for remote activated shots. This can cause confusions, because you need to make sure that you account for this in your settings. Ie you want the sum of your tPulse and tOff settings to be longer than that delay, otherwise the Stackshot will already have moved before the in-cam delay has run its course.

Stackshot Support

A final extra note about the superb customer support offered by Cognisys, the company that produces the Stackshot device. It's excellent, and they're more than happy to fix your device when something happens. I had issues with the first version of the power lead which kept switching off in the middle of a stack. I sent the whole thing back to them and they upgraded it to a better cable-locked version all within two weeks, free of charge. Good people.

Stackshot Alternatives

Although Stackshot has more or less held a monopoly of stacking devices in this particular range, other electronic focus stacking rails do exist. There is a comparison of electronic stages on my blog. The MacroRail. The MacroRail package is more expensive but is a more complete package so includes components that Stackshot doesn't such as the vertical rail and a specimen base. likewise Rainer Ernst's Stackmaster. Electronically controlled stages have always been available for the microscopy world but they tend to operate at a micron range rather than being suitable for 1:1 to 20:1, and they are generally out of budget for amateur photographers, and more in budget for organizations like NASA that use them on the Mars Rover.

updates - 2 new companies making electronic stages: Wemacro with the wemacro focus rail and MJKZZ with the DIY rail package Both excellent products.

Stackshot In The Field

Stackshot can be taken outside as well! The stackshot rechargeable battery is 4x18650 rechargeable battery @2.6-4A in plastic with a ziptie covering them, and jack to recharge/go into stackshot. Ie 4x3.7V = 14.8V. This is an unusual battery, but I recognized these as they happen to be the same that I have in some of my UV torches, and for which I have some ultrafire rechargeable batteries and charger bought from eBay. With a bit of jack welding and a £1 18650 battery container unit holding 4 batteries, this really would be trivial to DIY.

Stackshot in Europe

Stackshot can be purchased directly in Europe and the UK from photospecialist, from their .co.uk webstore which has the item in The Netherlands. VAT is inclusive and being in Europe there is no need to pay import duty (Thanks to Michael Brian for this information). At the time of writing (Summer 2014) the extended rail package comes in at £559.83 and comes supplied with a European plug via this route.

However, buying the exact same extended rail package directly from Cognisys with $57 postage (that's what it cost me) costs a total of £407, which comes to £489 with import duty with the option to choose a UK plug. So, once again, buying in Europe from a European distributor is more expensive than buying straight from the US.

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