June 2013 - Check out the StopShot Studio - a 12 channel computer controlled version of StopShot
April 2013, Capture insects in flight with our new portable Insect Rig.
January 2013 - Check out our new Water Valve Mounting Bracket for multiple colored collisions
December 2012 - Introducing the Shutter Support System. Completely portable high speed.
October 2012 - Check out our latest one of a kind product - the High Speed Shutter - finally you can capture insects in flight.
August 2012 - Take your StackShot into the field with our new Controller Carrier Also works great with StopShot.
February 2012 - See our new web page on creating Three Drop Collisions with StopShot.
January 2012 - Check out our latest sensor the RangeIR. Designed for birds and wildlife.
November 2011 - Power your StackShot or StopShot longer in the field with our new Li-Ion Battery Pack
Focus Stacking How To:
The Overview. There are several different ways to create a stack of photos. You can move the camera, the subject, or change the distance between the lens and the camera. Typically the camera's position is adjusted in relation to the subject of interest by using a macro-rail. It allows finely controlled movement of the camera to change the distance between the camera and the subject. This movement slides the in-focus part of the image through the subject. There are more educational links about focus stacking at the bottom of the page. If you've done this before you know it can be a slow and tedious task. Take picture, move rail slightly, take picture (ugh! Did I just bump the camera?), move the rail a little more, and then as if fate knew you hauled out ten pounds of camera gear, the insect you were photographing flies away. So what does Cognisys have to offer the world of focus stacking? StackShot. automates the movement of the rail and the triggering of the camera's shutter. This precision controlled rail will take as many pictures you want at whatever step size you'd like (down to 0.01mm). So how does it work? Let's first start off with the connections involved.
Connecting StackShot is very simple. First connect the macro rail to the controller with the supplied 4 conductor cable. Next, StackShot requires power. This can be accomplished with the supplied AC adapter or an optional Li-Ion Battery. Finally connect the shutter release of the camera to StackShot. This is the mechanism StackShot uses to control the camera. The cable that goes between the camera and StackShot needs to be purchased separately. If your camera does not have an external wired shutter release we do offer a universal IR remote that works with most cameras.
The Equipment. There are plenty of options in the photographic world for taking macro photographs; macro lenses, microscope objectives, bellows, inverted lenses, extension tubes, etc. Use whatever lens and camera setup you are comfortable with. Regardless of the setup you choose you will want to have a feel for the depth-of-field (DOF) of your lens and aperture setting. Consult your lens manual as this information is often published there. In the ant example below the manual states the depth of field for the Canon MP-E 65mm, at 3x magnification and f/8 is 0.249mm. Three is an excellent discussion on depth of field and focus stacking here, Rik Littlefield of Zerene Stacker does a great job of explaining the subject in the fourth post down.
Flash Canon MT-24
Shutter Speed: 1/60
Camera Mode: Manual
Flash Mode: Manual 1/32 power
StackShot Mode: Auto-Distance
Stacking Step Size: 0.15mm
Settling Time: 3sec
Images in Stack: 38
Software for Stacking: Helicon
The Process. The first step in the stacking process is to adjust you camera and flash settings to get proper exposure. The one difference for focus stacking is that you will want to use full manual mode for both the flash, shutter and aperture. The auto exposure modes tend to meter the scene a bit inconsistently causing a significant variation in brightness of the photographs over the range of images in the stack.
In this example we're going to use the "Auto-Distance" mode in StackShot. Since the DOF is 0.249mm, the "Distance per Step" variable in the controller is adjusted to 0.150 mm. It is desirable to have some overlap of in focus depth between photographs. Using the FWD and BACK buttons the position of the camera is adjusted to the initial starting point for the first picture in the stack. StackShot will travel in both directions so it can stack from the foreground to the background or visa versa. Pressing the Up/Down button sets the starting point for the stack. Then the position of the camera is adjusted to the final position of the stack. One more button press initiates the capturing process and the camera is moved by the distance entered (0.150 mm) with a picture taken at each step. After the rail takes a step there may be some unintended motion in the camera due to the setup. A configurable "settle" time may be adjusted to meet the specific needs of the shooting environment. What about exposure bracketing? StackShot can be configured to generate multiple shutter pulses (exposures) per step. This feature may also be useful for cameras that require a preliminary shutter press to activate mirror lock-up. A configurable delay between pulses allows additional fine-tuning. At the end of the process StackShot defaults to returning to the starting position. This lets you experiment with different camera and/or flash settings for subsequent runs. You might want to shoot a place holder shot of your hand between runs to act as a book-mark.
The stack of images has been created. Now what?
Software. Now it is time to use the software of your choice to combine the images. There are several possibilities including Helicon Focus, Zerene Stacker, Photoshop, or Combine ZM. Both Helicon Soft and Zerene Stacker offer 30-day evaluation versions, they can be downloaded here:
Other Resources.Here are a few web sites that go into more detail about the Focus Stacking process:
Focus Stacking Articles - Laurie Knight does an excellent job explaining the in's and out's of focus stacking including tips and tricks as well as common problems.
Photomacrography Forum - Great forum for anything related to macro photography
Focus Stacking Video - You-tube video by ePhotoZine.tv
The Results.This is a picture of a Maple Stamen. The picture was taken with StackShot and a 4X microscope objective. It contains 26 frames separated by 50um. Click on the image to see a movie made up of the individual frames. The movie shows the very shallow depth of field in the individual frames. Thanks again to Linden for the use of his pictures.
This picture of the Cithaerias Aurorina butterfly wing was taken with a 10X microscope objective. The image is the compilation of 39 individual pictures collected with the help of StackShot and then merged together. Each image was taken at a step size of 0.01mm.
The moth above was taken using a 100mm f/2.8 Canon Macro Lens and StackShot. This moth was hanging on our glass sliding door. The smaller pictures below are the first and last images from the stack. You can see in the first shot, the legs in focus and in the last shot the antennae are in focus. This gives you an idea of the depth of field you would be restricted to without focus stacking.