Our new series of articles deals with interesting trends of photography and is supposed to provide some basic knowledge about the respective technique. We would like to enable you to try them out yourself – and maybe to become a professional photographer in no time ;-)
The third part of our photography special is about focus stacking.
What is Focus stacking?
This term of photography describes a way to enhance the depth of field of a photo. It is especially practical and often used for macro photography because the focus area is generally quite small. Even the best aperture setting cannot provide a picture that is shown completely sharp because if you fade out, your photo gets unfocussed. The solution is simple: Like HDR images, focus stacking works with several shots – but here you only need to manually (!) change the focus for each photo.
What do I need?
Once again you need a programme to edit the photos you have taken, and once again you can choose between a freeware and a software you need to pay for. Although the freeware Combine ZM is not that easy to use (at the beginning) as the commercial software Helicon Focus, you will get equal results. Theoretically you even have a third option because you might also use general image editing programmes like Photoshop to do focus stacking, but it is much easier, leads to greater results and saves a lot of time to use special programmes for this technique.
Which rules do I have to follow?
The most important condition for focus stacking is to choose an image that is static and to make sure your camera is placed on a steady ground or a tripod. Additionally, you can use a delayed-action shutter release or a remote-control release to be even more certain that the photo is taken without the slightest movement. Please make sure to take all photos with (more or less) the same exposure because if you use different ones, your final photo might show a nasty stripe.
How many photos do I have to take?
If you want to get a great result of an endless depth of field, the number of shots you have to take depends on the distance between the image (you want to take a photo of) and your camera as well as the aperture settings and lens you use. Roughly, you can distinguish between four groups of distance:
1. Average to long distances require one to three shots.
2. Short to average distances generally require up to five shots.
3. Close-ups are best taken with special equipment for macro photography and usually require four to ten shots.
4. “Real macro photos” require a great of number of shots that depend on the image you choose – the more detailed and focussed your final photo should be, the greater the number of shots you need to take!
Focus stacking – putting theory into practice
- Starting your series of shots
As mentioned above, the raw material you need for focus stacking consists of several shots of a single image that are taken with different focus settings. In order to visualize this process, you can imagine the focus area to move from one corner of your image to another – one step with every photo you take. This way you will cover the whole area and get suitable raw material that you can put together with the respective editing programme for focus stacking that you chose.
- Editing your raw material
Start the editing programme, open all photos together and let the software collect them to one picture that is “focus stacked”. Depending on the number of photos you took and the size they have, the process of combining all pictures to one result might take a few minutes. Please remember to save your final photo of an endless depth of field ;-).