I’ve written before about computational photography and focus bracketing / stacking.    And if you’re curious, you can find much more info on the web.

Today’s post is inspired by a gift the Olympus Camera Company has just given to owners of their OM-D E-M5 Mark II and E-M1 cameras.  They’ve issued free firmware updates that add new capabilities, one of which is focus bracketing.  Here’s an example image I made while learning about the new features.  I wanted all the orchids sharp and the background to stay blurry.

Orchid – a focus stacked image processed in Photoshop from 14 frames made with the new focus bracketing feature in the E-M5 Mark II.  Individual frames are at ISO 200, f/4, 1/25 second, 60mm (120mm eq.).

You can read about the firmware updates at this link on the Olympus website (sorry – no longer available).

There are several camera companies providing new features in firmware updates to existing cameras.  The Olympus engineering team is exceedingly clever and seem to really enjoy exploiting their hardware to come up with novel features, many of which are computational in nature.    Focus bracketing is the latest example.  Here are my first thoughts about this mode:

• Of course, you can focus bracket manually, but having the camera do it for you is a big help.
• When you frame your composition, leave room to crop.  The stacking process can introduce anomalies at the edges.
• Your starting focus point should be on the closest area.  The bracketing function will step the focus away from the camera.
• You control the number of exposures and relative step size.  The step size you use depends on the situation and you’ll have to use trial and error to set it until you gain some experience.  If your step size is too great, it’ll leave blurred areas in the processed image.
• Set the number of exposures greater than you think you’ll need.  Once you look at them on the computer you can discard any unnecessary ones.  You can get very good control of depth of field and background blur by selecting which frames to use when post processing.
• Focus bracketing uses the camera’s electronic shutter, so there are some limitations from that (e.g. flickering / banding due to fluorescent lights;  An 8 sec. longest shutter speed limit; others?)
• As with many kinds of multi-frame computational images, subject or camera motion will introduce artifacts.  Focus bracketing works best for stationary subjects with your camera on a tripod

Here’s another example.  And yes, including this may give you some idea of how old I am – I’m old enough not to care about that.

My engineering school calculator – a focus stacked image processed in Photoshop from 21 frames.  Individual frames are at ISO 200, f/4, 1/40 second, 60mm (120mm eq.).

For comparison purposes, here is a single frame from the series.  You can see the tremendous difference in depth of field.

I have more focus stacked images in this album on Flickr.

I’m very pleased with how well this works.  Olympus deserves a big thumbs up for putting out this update for free.  Doing things like this can earn a lot of customer loyalty.

Now if we could only combine it in camera with other computational photography tricks:  focus stacking, plus high res mode, plus HDR, plus … maybe next time.

Thanks for stopping by and reading my blog.  Now – go compute some photos!

©2015, Ed Rosack. All rights reserved.