Focus stacking is a retouching / post production process that takes multipole copies of the same image, each with different areas in focus, and blends them together so that the the image is sharp and in focus throughout.
What does that mean?
When we take photographs there will always be areas that are out of focus no matter what aperture we use, however there are times when we might not want that to be the case. For example we might take a landscape photograph and want everything in focus from the foreground to the distant horizon line. It might be, as in my case more recently, when photographing the WW2 model aircraft I want it to be sharp and in focus from the propellers to the tail no matter what the angle I have the aircraft / model positioned in. To achieve this we use Focus Stacking.
How do I do it?
The process is actually really simple both with the photography side of things and then the post production.
For starters, when it comes to the photography you can make your life a whole lot easier by using a tripod. This way when you take the series of photographs they’ll line up perfectly.
For my example, when photographing the model aircraft I’m generally shooting at around f/8.0 and with a shutter speed of 1/60sec and an ISO no more than around 2500. This is because I’m photographing using ambient light be it from the window in my office, the daylight balanced video light or whatever. If I close down to f/11.0 or more the image will be too dark and I’ll gain nothing with regards to focus because of the closeness of the model to my camera.
So here’s what I do…
With camera on a tripod I choose Manual Focus and Focus Peaking on my Sony camera.
Focus Peaking shows me what will be sharp and in focus by highlighting those areas on my camera’s LCD with a bright yellow dots (I can change the colour of these if needed).
This then allows me to take around 3 photographs; the first where I use the focus ring on my lens so that the yellow focus peaking appears on the closest parts of the model…
Once I’ve taken the first picture I’ll then adjust the manul focus ring so that the Focus Peaking is visible around the middle section of the model and take a photograph. The to finish off I’ll adjust the manual focus ring so that the Focus Peaking is visible on the tail of the model.
If I were taking a landscape photograph this would equate to me focusing on the foreground and taking a photography, then the middle ground and the background (horizon).
Depending on what you’re reading this post on it might be difficult to see (unless you can pinch and zoom in) but the 3 pictures below are from when I photographed the HORSA Glider model. Three pictures were taken to ensure that the front, middle and back of the model were sharp and in focus…
Editing / Post Production
So now that we have the 3 pictures (or more) where each part is sharp and in focus, blending them together to make one image where it’s sharp from front to back is super easy.
Starting off in Lightroom, click on the first photograph in the filmstrip at the bottom of the screen and then whilst holding down the Shift Key click on the last photograph; this will then mean all 3 (or more) of the images are highlighted. Lightroom now knows you want to work with all of them.
Then go to the PHOTO menu and then EDIT IN > OPEN AS LAYERS IN PHOTOSHOP…
This will now open up all of the images in Photoshop but instwad of them being open in separate tabs, they are all in the same tab and one above the other in the layer stack.
Next thing to do is to make sure all of the images line up so highlight all of them in the layers panel by clicking on the bottom one, holding down the Shift Key and clicking on the uppermost one…
Then go to the IMAGE menu and then choose AUTO ALIGN LAYERS and when the dialog box appear simply click OK to use trhe default settings…
Finally to blend all of the images together, with them all highlighted in the layers panel go back to the EDIT menu and choose AUTO BLEND LAYERS… and choose the STACK IMAGES option.
Note: I tend to always tick the “Seamless Tones and Colours” checkbox. I don’t think it makes much of a difference with something like this but hey even if it makes a minor adjustment for the better I’m all for it.
Once you click OK just give it a short while (only a matter of seconds) and before you know it Photoshop has worked its magic and blended all of the images together to create one image that is sharp from front to back…
And that is all there is to it; I wish there was more I could say but there isn’t.
Nice and simple and works a treat! At this stage I can now crack on and have a bit of funwith the rest of the post production.
Catch you next time,