About the Image(s)

I thought I would challenge myself to shoot some higher magnification images of some watch parts that I had. The actual size of these parts was between 3-5 mms (see the additional image in which the gears were shot against a ruler with millimeter gradations). Being so small, I was shooting at 2X magnification of the actual size (as my camera sensor saw it), and as such I needed to be aware of the aperture and diffraction. When one shoots at 2X the “effective aperture” is really 3X the camera setting. So, an f/5.8 setting is effectively an f/16.8 aperture. This is significant in that effective apertures greater than f/18 begin to exhibit diffraction and yield soft images (regardless of how to collect the images). Note that when I shoot at 1X (1:1 reproduction) or less (like most flowers), this is generally not an issue, so I generally collect my focus slices at apertures of f/8 to f/10, settings that my Canon Macro f/2.8 100 mm lens is sharpest. The bottom line here is that diffraction only really comes into play at magnifications of 2X or greater.

This image was captured using my tripod mounted Canon R5 Mark II body with Canon MP-E 65mm f/2.8 1-5x Macro Photo Manual Focus Telephoto Lens at 2X. Here I collected 87 ‘focus slices’ (0.8 sec, f/5.6, ISO 2,000), using natural light and an automated focus rail. The focus rail I used was the Cognisys StackShot Automated Macro Rail. I used this system since the focus travel distance between each focus slice was 0.2 mm, something I would be hard pressed to accomplish with manual adjustments. The camera shots and focus rail movements were both controlled using a laptop computer, so I could see what the camera saw on the laptop screen and set up the shot using the computer. One press of a button, and the system automatically collects all of the slices. Pretty Cool ! I have included an image of the actual set-up (shooting gains of rice pilaf) to show you this system in action.
Now, typically I use the automated focus slice collection system within my camera or use a manual focus rail for most of my collection efforts. It’s only when I delve into the more extreme magnifications, do I use the automated rail system. This is not something one generally needs unless you are really into your subject (and is crazy enough to give it a try).

In this case I used Helicon Focus to stack the 87 images, and Photoshop to bring out the detail, color and texture while removing the odd distractions that often accompany stacked images.

This was a fun challenge and allowed me the opportunity to discuss some topics that we normally don’t get into much. What do you all think?