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| A sample image stack result |
I have been using the focus bracketing feature of the EM1 MK3 to photograph dragonflies with some good success. Here is what I have learned so far:
The lens
The Panasonic 100 to 400 zoom lens is one fantastic lens for this task. Currently Olympus does not have a lens like this. I started out with a fixed F7.1 aperture but have settled on using the variable aperture lens wide open. Depending on focal length the aperture changes on this lens. At 400mm (full frame effective 800mm) the lens is f6.3. Most images have been taken at 400mm as these skimmers are hard to get very close to. Using a largish aperture helps keep the background separate from the skimmer.
I am hand holding the lens and using the lens anti shake, not the camera body image stabilization. This is working far better than the monopod I previously used with full frame. You can hunt and frame the little beasts much quicker hand held. I have made a larger handle grip for the lens to help holding the lens steady. The lens IS is being used not the in body image stabilization (IBIS).
When using this lens on the Olympus body you cannot have the lens and body image stabilizations work together. This is a pity that Panasonic and Olympus don't 'cross' operate fully. Also the in camera focus stacking is not available. I don't find this an issue as I am using Photoshop to create the final merged image.
A high quality B&W polarizer is mounted on the lens to bring out colours and reduce reflections.
Camera Settings
I set the number of images to bracket to 5 and the focus differential to 2 (low). This covers the body of the larger dragonflies I have been photographing.
I am using aperture priority set at f6.3 You could use f7.1 but I have found this not necessary.
I'm using auto ISO with the maximum set to 1600 ISO. The shutter speed varies with the light available.
Technique
Use the smallest single focus point on the closest part of the dragonfly. This could be a wing tip or a tail end for example. The focus bracketing will move forward from that point and should cover the entire skimmer. The new toggle dial on the MK3 really helps with changing the focus spot quickly.
You will need to adjust the polarizing filter for vertical and horizontal orientations. The polarizer makes a significate difference in the final image.
The camera operates in high speed silent shutter mode when focus bracketing, and takes 5 images very quickly. You want the high speed shutter settings as fast as they can be set (60fps the camera default).
Image Processing
I use Adobe Lightroom to process the images and then Photoshop to align and create the stacked and merged final image. More on this in a later blog post.
