Saturday, September 12, 2020

Filter Holder For The 7artisans 12mm Lens

For a compilation of the morning walk images, click here.

7artisans 12mm lens without (left) and with (right) the filter adapter.
My enthusiasm for creating a manual focus lens kit resulted in the assembly of a collection of compact lenses and bodies that would duplicate the minimum equipage for a rangefinder-toting photojournalist in the post WWII years. As a child of the Single Lens Reflex era, I never experienced any attachment to rangefinder cameras. However, I used an Olympus 35SP as my everyday camera during my years playing the part of the 70's Concerned Young Photographer, but have come to associate the "Kah-Clunk" of the SLR as the sound of an image being captured.

The 7artisans 12mm lens has become the shiny new object in my life, although it is neither my most recent photographic purchase, nor my most used lens. I've been very pleased with the results thus far, although it hasn't been taken on any assignments, primarily because there haven't been any since the Pandemic. I've taken it with me on my morning walks, but only when I had something specific in mind. 

One initial concern was the inability to attach a filter to protect the bulbous front lens element. I personally install filters on all of my lenses, and remove them only when I'm working indoors in a "clean" environment. The purchase of the 7artisans dedicated filter adapter, available from eBay and from B&H Camera, might eliminate my concerns for protecting the lens. I included links to a video describing the adapter in an earlier post. Having owned the adapter for several weeks, I discovered some design features that you might find interesting, if you're thinking about purchasing it.


The adapter is held in place by a strip of felt on the inner surface of the bezel, a method long used to provides a snug fit between the lens and traditional metal lens caps. It is threaded to accept a standard 77mm filter, which is the standard thread size for my larger Nikkors. To their credit, the designers provide recesses on the lens that correspond to alignment tabs on the adapter itself. I have noticed that the felt itself is starting to work free from adapter, the I've resorted to cutting off that little loose bit from time to time. Also noteworthy is the small thumbscrew that provides some additional retention. It is small, and easily lost if allowed to unscrew itself from the adapter. Because of this, I will probably store the adapter off camera and in a sealed pouch so the screw won't get lost.

In closing, the adapter does exactly what was designed to to, but may detract from the compactness of the lens when installed. If you decide to buy the lens, order the adapter at the same time. Better to have it and not need it, especially at its $10.00 price tag.

Double Exposure? No, actually. Since I don't own two lenses, I relied on the same programmed interval exposure technique from last week. Basically, I shot a series of photos with the lens in my left hand, followed by a series with the lens in my right. I check the viewfinder to be sure that the images didn't overlap, and layered the two images together.


I set up the camera to make a series of exposures at 5 second intervals. It took three exposures to get a shot where the highlights were reasonably placed. Since I was using bounce flash, it was helpful to preview the image immediately after the shot was made.

This second series shows the same lens, held in my right hand, and positioned in the right half of the frame. You'll notice that the background remains constant throughout the procedure. The selected images, #3 and #4, were then layered, on on top of the other, and the excess background erased. I discuss the technique in an earlier postHaving the camera mounted on a rigid tripod is essential for this technique to work properly.

Once again, here's the final image. A word of caution: The backgrounds of the two merged halves must match exactly. It's amazing at how easily the human eye can detect slight variations in the background. You need a sturdy tripod to support the camera. In addition, it is important the exposure settings for the left and right hand images be identical, as exposure variations are equally obvious. I normally make any post production tweaks after the two images have been joined and flattened into a  single layer. This helps to make the seam between the two images impossible to detect.