Focus Stack Preparation
by Johan J Ingles-Le Nobel
Last updated August 31, 2017
Like anything, there's a certain amount of preparation that's done before shooting a focus stack, but of course you can skip many of these steps if you're just starting out and keen to get on with it.
For more experienced stackers though, preparation is as important as the execution of the stack and good preparation will save you time in postprocessing your stacked shot.
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
Field Preparation
Depending on the depth of your stack, stacks can take anywhere up to hundreds of images to complete, so both flash and DSLR batteries should be fully charged with spares available onhand. Also, don't forget spares for the remote control.
Focus stacking in the field is best done early in the morning when there isn't too much wind about and it's too cold for the insects to move. I also use a large light tent with some panels removed to create a very large wind shield - this improves the light and also stops the wind.
Field Stacking
- Use a strong no-wobble tripod
- Set camera to manual focus
- Keep lighting consistent
- Use liveview
Alternatively, go towards water or lure insects to your garden using entomology lures.
Depending on the depth of your stack you may need to spend 30 minutes taking images so ideally you want a subject that is stationary and likely to remain so.
Choose and test out the background before setting up the diffusion. Nothing more is more annoying than setting up perfect diffusion but having a crummy background which can be radically improved by moving round a few degrees.
Studio Preparation
Many of the points for field preparation are true in studio work as well, although studio work tends to be more at your own leisure as the specimens are usually caught and preserved. But there are a few points worthy of note:
- If you're using continuous or ambient light, let your lights warm up for 15 minutes before starting the stack to assure better colour temperature consistency.
- Keep your specimens covered until the very last minute to prevent dust landing on your beautifully cleaned and pinned specimen. I keep mine covered with the plastic from a 5l large plastic car wash fluid container, with one end cut off.
- Decide and test out your diffusion and backgrounds together before uncovering any specimen, as diffusion and background might get in each other's way and you'll need to make that decision before starting the stack. Bear in mind that as you change distance to your specimen during the stack this may also change the flash intensity if that moves as well.
Specimen Preparation
Preparing a preserved specimen for photography can be a challenge, and there are a number of techniques from the entomology world that can help with this process.
- Freezing is the most common manner to dispatch insects, but chemical means are also available.
- Insects need to be cleaned and pinned for studio work, and carding makes them look nice.
- If it is a staged or studio photo, then it should be declared as such, as per normal photography etiquette.
Imaging Preparation
I usually create a new directory for each stack that I do, and import the JPEGs straight from the camera. TIFFs are also used, but the filesize is too large for my system to cope with and I don't find that they give anything over a JPEG. That said if you're printing large or want more colour bits TIFFs might be your friend. Alternatively, use RAW and apply correction to the files once they're on the PC but I tend to get them right in-camera anyway so that's not something I do.
Next: Shooting The Focus Stack
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