Charles Ginsburgh  

Salt by Charles Ginsburgh

July 2021 - Salt

About the Image(s)

Since we are talking about MACRO Photography I thought I would challenge myself and see how clearly defined I could capture a few grains of salt right out of the salt-shaker.

To get an idea as to how small these subjects are, sprinkle some salt onto the tabletop and explore this subject some.
Here I used my Canon 5d Mark IV camera with an Canon MP-E 65mm f/2.8 1-5x Macro Photo Manual Focus Telephoto Lens with the following settings; f/4.5, 2.5 sec, ISO 600 to collect 76 slices at 5X. As the magnification was so great in this shot, I needed to be aware of possible diffraction issues, so I chose here a wide aperture of f 4/5. The wider the aperture the less the probability that defection will inhibit obtaining a sharp image. This seems like a lot of slices, but since the magnification was so great, (five times the normal 1:1 magnification), the depth of field was very small and I needed more slices at very small intervals. Each slice was taken about 0.075 mm form the next. To do this is used a Cognisys StackShot automated focusing rail. If you wish to shoot these very small subjects then you often need an automated rail since one normally can’t make the fine adjustments (small focus adjustments) that are often required.

After stacking in Zerene Stacker, I edited the image in Photoshop to highlight the subjects and to add a different background.

This round’s discussion is now closed!
5 comments posted

Peter Newman   Peter Newman
Charlie, Very interesting result. Thank you for the detailed explanation of your process. I would never have thought of making those small grains look like jewelry. That certainly shows that you are worth your salt. (Sorry, I couldn't resist.)

Your discussions and showing of stacked images piqued my curiosity, and I have started looking into it. Below is a link to a basic discussion of FS, which contains many additional links.

I see auto stacking rails vary in price. Am I correct in thinking that it should be able to focus in steps of 1 micron? I imagine that the number of slices would vary with the number of steps and length of the rails.   Posted: 07/16/2021 15:22:21

Judith Lesnaw   Judith Lesnaw
(Groups 52 & 79)
Charles, I am visiting from Group 79. Your salt grain images are terrific. I have been attempting photomicroscopy using an iphone and Fold scope, as well as a digital Qx5 microscope--all with disappointing results. I was not familiar with the lens you used. AND you method of 75 slices with the photorail is great. Thank you for posting. Judith   Posted: 07/24/2021 18:02:08

Jeff Fleisher   Jeff Fleisher
Very nice image Charles. This image really supports the concept that common things look so different when viewed at the macro scale and beyond. I was really taken by the geometric shapes, especially the square one in the center of the image. I am a little surprised there is not more uniformity among the various salt crystals.

The exposure is excellent. Very nice!   Posted: 07/28/2021 21:08:56
Charles Ginsburgh   Charles Ginsburgh
Salt crystals normally form the cube type of structures. Here though the edges have rounded off from most of these grains due to the gains rubbing against each other in the processing of the salt   Posted: 07/29/2021 10:52:25

Bev Caine   Bev Caine
(Groups 48 & 80)
And my first impression was, I'd never dream of shooting ice cubes. Very well done and obviously a study as to how a picture doesn't always tell the truth.   Posted: 07/31/2021 09:19:57