One of the most difficult challenge of macro photography is shallow depth of field. And when we get into extreme macro photography territory where depth of field is measured in sub-millimeters, it is even more challenging.
Focus stacking is a powerful method to extend depth of field by taking a series of images at different focal plane and use computer software to pick the sharpest part of each image for the final result. One way to acquire such series of images is by moving the camera towards or away from the subject (or by moving subject towards or away from the camera) so that different part of the subject will be in focus in each image. Then by applying computer algorithm, these images will be combined into one sharp image.
In order to move the camera (or the subject for that matter) and automate the process of image captures, an automated rail system is preferred method.
However, current products on the market are extremely expensive and many macro photographers have to do it manually which is a tedious work to do. Besides expensive rail system, good stacking software are either expensive (but really good) or difficult to use (though free).
The goal of this project is to offer macro photographers with three solid solutions for focus stacking at affordable prices and ease of use.
Stacking and Motor Control System
Stacking and Motor control system consists of two components -- hardware controller and PC software application. The software application communicates with hardware controller via USB port that emulates a serial port.
The hardware controller allows motor power to be set digitally. Along with lead screw pitch information, a motor profile can be set up for any rail system. By default, all of our rails systems are there (total of four), but custom profile can be set up by user so that other rails system can be supported.
Motor control hardware also has limit switch input so that motor can be stopped automatically when slider reaches either end of rail when limit switches are installed.
Another key feature is the hardware controller can be easily expanded to use wireless technology, such as Bluetooth. As matter of fact, a prototype is already being used, but its case design is not done yet. With this Bluetooth technology, mobile phones are also potential controllers. You can download Stacking and Motor software application for PC and PDF manual.
Standard Rail SR-90
The standard rail system has minimum 80mm travel distance. The key component of this rail is the linear guide rail used in industrial automation. This linear guide rail makes overall system design much simpler yet it ensures smooth and precise operation.
Motor is NEMA 17, 1A per phase, 200 steps per revolution step motor. Pitch of lead screw is 2mm, with motor set to 1/8 microstep, minimum step size is 1.25um, at 1/32 step size, minimum step size is 0.3125um. This rail is a versatile rail and can be used in many situations, in studio or in field due to its compact size and light weight. It has been routinely used for 5x magnification work with great results.
Its base actually is a standard 38mm quick release plate, it can be quickly mounted on a tripod with such system. It can also be bolted down on a piece of T-slot board with M5 screws.
Precision Rail PR-18
This is a precision rail with 18mm travel distance. It is driven by a NEMA 14 motor with 200 steps per revolution and 0.75A current per phase. It has fine pitch of 0.5mm and a dovetail construction to ensure stable and smooth operation at higher tightness.
With fine pitch of 0.5mm, even motor is set at 1/4 microstep, the minimum step size is 0.625um. It can also be mounted on a tripod and used in the field though its intended use is indoor studio because often it is used with microscope objectives at 10x or higher magnification where wind alone in the field can make it impossible to stack.
The bottom of this rail has 5 1/4-20 threaded holes so that a tripod plate can be attached to it and then mounted on a tripod or other fixtures.
High Precision Rail PR-110
This is a high precision rail with almost industrial automation specifications. It has travel distance of 110mm. The motor used is a NEMA 17, 1.25A per phase, and 400 steps per revolution. The lead screw is a ballscrew of 12mm in diameter and 4mm pitch. At 1/32 microstep mode, the minimum step size is 0.3125um.
It is very heavy due to its high precision construction, weighing 1.5kg by itself without motor. This rail is intended for indoor use for professional macro photographers.
Last but not least, the Specimen Holder. This is designed to hold subject on a swiveling base with rotating arm for increased degree of freedom when manipulating and posing the subject. It is an essential tool that is often forgotten or omitted.
When mounted on a T-slot board, it has two thumb screws that make it much easier to slide along the T-slot, making another dimension adjustment much easier.
SnapFuse Focus Stacking Software For PC
This is one of our proudest piece of technology. It is easy to use, just drag and drop files over it. We have been using it for many of our focus stacking works. You can download a copy of it for trial use. Note, this application needs a lot of memory to run and it is better to have 64bit Windows.
Currently, only English and simplified Chinese are supported and user can select either one. We do not have the resources to localize it to support other languages, but user can customize it themselves.
The following images were created while developing these rails.
EB SMCTRL and SMCTRL
This is the reward for backers who wish to use our control hardware and software combination to control their existing rail (either commercial or DIY'ed) because our solution is very flexible (motor power control, for example) and economical. Backers can enjoy future updates of our software.
Backer will receive stack and motor control hardware - controller box, camera cable of choice, and a 4-wire cable with a connector that fits into our controller so that backer can wire their own rail to fit our hardware. The PC software can be downloaded online.
EB SR-90 and SR-90 Rail System
This is our standard rail system as described in Technology section. This reward is for those who want to get into focus stacking but kept away by the high price of current rail system. It is the most affordable solution on the market as of now.
EB PR-18 and PR-18 Rail System
This is our precision rail system as described in Technology section. This reward is for those who want to do higher magnification work at affordable price.
PR-110 Rail System
This is our high precision rail system, there is no early bird option for this rail because of it high cost. The rail is specified at industrial automation standard and it is the preferred tool we use for any work.
Round Quick Release
All rail system rewards (exclude SMCTL and EB SMCTRL) will come with ONE round quick release system as shown below.
All shipping will be via DHL. In case locations considered as remote area by DHL, EMS will be used except Stack and Motor Controller which will be shipped by Hong Kong Post.
For backers who does not want to use DHL, please contact us BEFORE funding finishes so that we can find out costs.
As explained and disclosed in Risk and Challenges section of this project, we are a bunch of risk aversion people, we do not like unfinished prototype. Current status is that we are ready to make large orders of each system, but for to happen, we need initial funding for tooling setup, manufacturing, and packaging material.
All manufacturing will be done in Shenzhen, China by our trusted contractors and ourselves.
For the first batch, packaging will be off the shelf boxes and material if minimum funding is met.
Risks and challenges
In any project, there will be unseen risks, no matter how sure we can be. For example, our last project, SnapPal, we ran into trouble with OLED display supply RIGHT after we were about to do manufacturing. Fortunately, we located another supplier, though at much higher price and redesign of PCB, we secured enough displays to fulfill our obligations for that project.
For motor control hardware, all components are off the shelf and easily obtainable in Shenzhen, China. However, we do not manufacture the USB to serial conversion part. It is available in large quantities, however. Even if not, it is not something that is not replaceable, we can even design our own.
For SR-90 and part of PR-18, we have a factory that we have worked with for long time and their workmanship is excellent. They are sometimes very busy with other orders of their own, so to avoid delays, we can put in our order as soon as this project is funded.
For the high precision rail, PR-110, we have a new supplier and we have only been dealing with them in past few months. Though all parts are off the shelf, we do have limited resources to find another supplier who can assemble it at strict specification and at negotiated price.
All software were tested for about 3 months and they seem to be very stable. These software can be downloaded online, so the risk is very little.Learn about accountability on Kickstarter
- (42 days)