I have many great clients, including Gene Kozak. Gene’s
company is Kozak Micro Adjusters www.kozakmicro.com.
He sells high quality micro adjusting screws, bushings & gauges for a
variety of industries. Gene is a brilliant guy and designs all his products
himself. He came to me at the end of last year to shoot some of his products.
The catch is most of them are quite small - less than one (1) inch long and very
thin. The threads on the screws are also very fine - some of the finest in the
industry.
A. Depth of Field
Photographing tiny objects presents some unique challenges. The biggest challenge is getting the entire object in sharp focus.
This is because the combination of close shooting distances and high magnification
results in very shallow “depth of field.” Depth of field is a fancy way of
saying how much of an image is in focus.
Sometimes we want shallow depth of field. We’ve all seen
(and I have done) photos where the main part of the image is sharp and the rest
of the image falls into soft focus. Using shallow depth of field is a way to
increase drama, and if you’ve read some of my prior blog posts, you know
increased drama = increased interest = increase sales. But just as often, especially for
technically precise products like Gene’s, you want deep depth of field so the
entire image is in clear focus. This allows potential customers to see the quality
and detail of what you’re photographing.
There are three common ways to increase the depth of field
in a photo:
1) Close down the aperture (F-stop) of the camera. The
smaller the aperture (higher F-stop) the greater the area in focus.
2) Manipulate the focus plane to increase the apparent depth
of field of the image. This can be done either with a “tilt-shift” lens or a “view”
camera. Both tilt-shift lenses and view cameras allow you to tilt the focus
plane parallel to the subject matter allowing it to appear that more of the
image is in focus.
3) Use focus stacking.
Focus stacking uses several photos of the same object taken at different focus
points. Those multiple photos are then combined in Photoshop to create one
image where everything is in sharp focus.
B. Focus Stacking
With regard to very small objects, the first two methods of
increasing depth of field - shooting at small apertures, or using a tilt-shift
lens or view camera - usually come up short. Thus, focus stacking is the only
way to get everything in sharp focus.
Below is an example of a group of Gene’s products. The first
shot is the final image after focus stacking is applied. The individual shots I
used to create the final image are below it.
There is no set formula for number of photos you’ll need to
do focus stacking. The general rule is the smaller the object and/or higher the
magnification, the more photos will be required. There is specialty software that
automates the focus stacking process but I prefer to use Photoshop. Photoshop
can automatically stack and align the individual images. Then I mask off the
unsharp portions of each image by hand. This tends to be more time consuming,
but I feel it yields better results.
A final side note: the higher the magnification the easier
it is to see dirt, dust, dings and other imperfections in the product itself.
This is true whether it’s an expensive piece of jewelry or a precision
adjusting screw. So the better the condition of the samples when they arrive at
my studio, the easier it is to get great product shots. That said, even the best samples usually require a fair amount of retouching when shooting at
high magnifications.
So there it is: focus stacking to create deep depth of field
in your micro precision product photos.
As always please contact me with questions or
leave comments in the space below.
