Have a close look at the following two photographs. What do you notice?
Three gum caps, some seeds and the gum nut. The two photos are equally sharp in some of the central areas, but the first photograph is significantly sharper all over. This is not an example of using aperture to increase depth of field. This kind of depth of field is nigh on impossible to achieve with this standard approach. It was achieved by using focus stacking. I took 12 exposures of the nuts and combined them using CombineZM software. The program selected the sharpest portions of each photo and created a seamless composite. This software is free.
Normally the images would be taken by mounting your camera and macro lens onto a motorized stage and progressing the camera just a few millimeters at a time to build up your bank of images.
I however used a different approach. My camera was on a standard tripod. I tethered my camera to a laptop and used the Digicam Control software (see article by Eric Budworth) to create the sequence of 12 images. This is achieved by the computer adjusting the focus of the lens by small increments. This software is also free.
All of my previous focus stacking attempts have been done with hand held images stacks. These are uneven in many ways, in the alignment, rotation, the gaps between focussing points. This often gave an uneven patchy result. The Digicam images are however smooth and convincing. This is obviously a superior method, and certainly cheaper than buying a motorized stage (providing you already have a laptop).
Here are a few more examples of my first attempt at this approach.
The images are so crisp. It is magical what you can achieve. The only downside to this new technology is that it might make it impossible to put a standard macro shot into competition. The judges expectations of sharpness are going to go through the roof.
Post Script: How to make a stack with Digicam Control software.
- Set up still life, lighting and place camera on a tripod.
- Connect camera to laptop with a cable.
- Turn on Camera – place into Aperture priority
- Open Digicam Control
- Select your brand of camera from the list of cameras
- Open Live view
- Adjust f stop and ISO to desired level in the software
- Double click on the displayed image to select an auto focus point and focus. Chose the closest point you want to be in focus.
- Open Focus stacking dialog – select number of images (12) and direction of capture (near to far). Chose how big you would like the steps (medium). Press start
- After the camera has finished taking photos you can find the images in My computer>[C]>User>Username>My pictures>Digicam Control.
- Open Combine ZM and create a new stack from these images.
- In the Macro Menu select – Do stack
- Once the stack has been assembled save the result and then open it in Adobe Photoshop for final editing, curves, sharpness, cropping etc.