The Post Focus feature that can be used for focus stacking. Post Focus is a two-stage process. After placing the camera in Post Focus mode and pressing the shutter release the camera finds all the focus points in the image and then takes a 6K video of all those focus points. The process takes about 2 seconds after pressing the shutter release. The lens must be in autofocus mode.
You can stack images in-camera using the G9’s touch screen or use a program like Helicon Focus. I was going to publish some information and results after I concluded my tests, but now I will document the journey.
My Equipment
• Panasonic G9 (a Micro 4/3s camera);
• Olympus 60mm macro lens. That gives you 120mm, in 35mm speak;
• Raynox DCR150 and DCR250. Both Raynoxes can be attached to the Olympus using a Step-Down Ring 46-43mm; and
• Sokani X21 Compact LED Video Light mounted on the flash shoe for light. You cannot use flash with Post Focus, only continuous light.
Learn the camera & lens
I learnt how to focus stack in the wild manually, not with a rail, Helicon tube or the like. Your inclination is to use Post Focus straight away but you must take time to learn the camera and the new lens.
The G9 is highly configurable and can be challenging. I focused on the key aspects like AF modes, camera modes, etc and obviously the Post Focus mode on the camera, which is automated to the most part. PF only works if the lens is in autofocus mode.
Initial tests
I started indoors in low light. I figured if it works in low light, good light will not be an issue. I mounted a small flower on a specimen stand and the camera on a mini tripod. My observations were:
• getting your technique and process correct is important, using the camera is harder than watching a video! Practice, practice, practice…
• there is a learning curve when using a new macro lens, especially in autofocus mode (I mostly use MF for macro work);
• Post Focus takes about 2 seconds for each video clip, it has impressive speed compared to manual stacking. Multiple videos can be made in under a minute in the field;
• there was minor movement in the video, I am tracking down the source of this but I must buy a remote trigger to test one theory. Minor movement is having minimal effect on the image, just a few artefacts in Helicon Focus;
• I could not compare an in-camera stack to a Helicon Focus stack from the same video. I’ve not been able to save the stack damage in-camera, I can view it but not save it. Pretty sure it’s a user error;
• Post Focus works with the DCR150 and the DCR250 attached, even in low light. The whole process seems to take slightly longer by about ½ second, and there is softness the images around the edges. A lot more testing must be done before I can express a definitive view;
• To process the 6K video from the Panasonic G9 in Helicon Focus, you need version 6.8;
• In Helicon Focus Mode B creates artefacts visible at full resolution. No such problem exists with Mode C, except along the bottom of the frame. The artefacts were different between the two modes;
• I was able to do achieve a handheld Post Focus image outside, but this is not recommended. Use a tripod or a stick to support the camera.
Using the G9 and processing the 6K video in Helicon Focus gives you extraordinary speed and also great images, once you get the process and technique sorted. It is set to change in-field focus stacking once other camera makers follow Panasonic.
The G9 has a high resolution mode and I am thinking of using that feature to do a manual stack, in due course, that may give me Helicon Focus stack of over 200 meg. The camera also has a focus stacking mode using raw files, which I’m yet to explore.
I still have much to learn and refine, but the future looks promising. Here is an early test image with minimal post-processing, including the artefact along the bottom of the image.
