In-Camera Focus Bracketing
Yesterday I shared info on in-camera focus stacking of images captured with the Post Focus Photo Mode in the Lumix GX85. The PFPM is a great feature for getting images from moving objects, quick captures and times where you won’t need to crop into the image very much because the still frames pulled from the video are eight megapixels. Eight megapixels can get you to a twenty-inch print with no problem but when you want to go big it’s time for a new feature built into the camera.
Focus Bracketing is different than the Post Focus Photo Mode in that the camera will be making image captures using the full-size files and changing the focus between each shot automatically. Here’s the screen you will see to set up the capture of multiple images with one push of the button.
Each one of the menus adds choices. You’ll need to experiment and ‘bracket’ your choices as you learn the results. Step – is the distance that the focus will move on each exposure. Image Count – will be the number of frames made with a single push of the shutter button. You’ll want to ensure there’s enough to cover the scene. Sequence – is the order the images are taken in. Choices are 0/+ to start close and go far (I recommend) or 0/-/+ which will alternate how the bracket is accomplished. I found that Photoshop tends to choke when creating the focus stack using this setting.
Here’s an example of a completed capture and focus stack using Adobe Photoshop taken at Horseshoe Bend just outside Page, Arizona. The Focus Bracketing allowed for a much deeper depth of field in the final image.
People ask why do you want to go to all this work? I just set my camera to a smaller aperture like f16 or f22 for deeper depth of field. There is some science that will come into play here. When you use smaller apertures, you will introduce diffraction into your image which will soften the image. There is a sweet spot in lenses between f5.6 and f10, depending upon the lens, that is the absolute best quality the lens can produce. That is the f stop to use when focus stacking. All the sharp areas will be the sharpest and highest quality when combined.
I’ll look at the actual focus stacking technique in a future post using Adobe Photoshop. There are also automatic software solutions like Helicon Focus, Zyrene Stacker, and possibly others for you to check out if you plan to do a lot of stacking.
Yours in Creative Photography, Bob