Proof of concept.
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In Part I I detailed the hardware requirements to use an ancient Leica Bellows II for the M mount with a 135mm Elmar lens head and a variety of extension tubes, all used with an LED ring light.
I just ran a first test, using a pine cone as the subject.
Here’s the setting:

The LED light is some 24″ from the pine cone.
The Leica SL2-S’s exposure mode was set to Manual so that the same exposure would be used for the multiple images required for focus stacking in Helicon Focus. I set the LED ring light to maximum brightness and, after establishing critical focus at f/4 on the base of the pine cone using the handy magnification feature of the camera’s EVF, I proceeded to take 17 images of the pine cone. The focus for each was varied a small amount using the secondary rack and pinion rail of the Focusing Bellows II. This has a handy tightening lever which was set part way to prevent the lens assembly from drifting on the lower rack. While the sweet spot for the 135mm Elmar if f/8 to f/11 I used the maximum aperture of f/4. This would constitute a critical test of the focus stacking software. The shutter speed was 1/250th and IBIS was turned on. ISO was 2200. Though I used Auto ISO it is better practice to use manual ISO to ensure constant exposure across the range of constituent images.
The images were imported to Helicon Focus (v 9.0.2) and combined into one image, sharp overall.
Here is the result in LR Classic, top left, followed by the 17 constituent images:

The images and result in LRc.
Here is the final result.
Click the image for a larger version.
Check the large version and you can see that my focus on the base of the cone was incorrect, denying optimum results from Helicon Focus, but as a proof of concept for the rig and the application this is a promising start.
How to change focus when taking multiple images for focus stacking:
Changing focus using the extension of the focusing bellows is decidedly sub-par. A minuscule change in the bellows extension results in a large change in the plane of focus. By contrast using the lower rack of the Focusing Bellows II to move the camera/bellows/lens assembly nearer to – or further from – the subject is relatively insensitive to the change in the plane of focus. As an example, a subject depth of one inch at life size may require three to four dozen changes in the position of the camera, meaning three to four dozen exposures, easily done with the lower rack, where changes of as little as one millimeter are easy to accomplish. This is virtually impossible to achieve using the variable extension of the bellows itself.
If you are using a bellows without a lower focus rack, Novoflex makes one but as with most of their products the pricing is plain silly. The sole advantage I can see is that the rack range is 14.8″, which is large. Instead, check eBay searching for ‘Macro Focusing Rack’ and you will find many choices for under $50. But better yet spring for a Leitz Focusing Bellows II and experience the ne plus ultra of German mechanical engineering for a modest outlay.



















