I, uh… I’m gonna sit in the back now

Sometimes you wonder about your own mind. Or at least I do…

Here’s the story: My primary macro lens, for many years now, is a Mamiya-Sekor 80mm f4 Macro that was designed and intended for the Mamiya M645 series of medium-format cameras; I couldn’t tell you exactly when my lens was made, but the system ran from the mid-seventies to the mid-eighties. I had purchased it for my Mamiya body, oh, eleven, twelve years ago? And when my Sigma 105 Macro got balky and I couldn’t afford to get it repaired or replaced, I made a quick and dirty adapter for the Mamiya lens and began using it on the Canon DSLR bodies. It is a testament to the quality of the lens that I’m still using it because nothing has ever beaten its performance.

Mamiya-Sekor 80mm f4 Macro lens
It came with a matched extension tube, essentially a spacer between lens and body which magnifies the image even further – sometimes I use this, sometimes I don’t, so it necessitates switching the tube on and off. This can be slightly fussy, especially when juggling the lens and camera body out in the field where I don’t want to drop anything. The lens has a slotted tab at the base where it engages the Mamiya bodies, directly linked to the aperture ring; this tells the body what aperture the lens is set at, because there is no electronic communication between body and lens while aperture is set on the lens itself. This way, the exposure meter in the medium-format body knows what aperture the photo will be taken with (even though it has not closed down yet – that will be done when the shutter trips) and can set exposure correctly. The tab can just be made out edge-on in these photos, the small brassy bit just below the aperture numbers at the bottom of the lens.

Mamiya-Sekor 80mm f4 Macro lens with affixed extension tube
When the extension tube is affixed as seen here, it has a tab of its own that will engage the slot in the tab on the lens. It is part of a free-spinning collar around the entire tube, and duplicates the slotted aperture tab down at its own base, to once again engage with the camera body and continue communication with the exposure meter.

The big bit is, that tab-and-collar has a tendency to slip around when the extension tube isn’t attached, and usually requires a bit of fumbling to get it to fit into the slot at the same time that the extension tube is lining up with the mounting ring at the base of the lens – especially since I want to hold the tube by the very collar that encircles it, which prevents the collar from moving easily to the slot. The knurled/ridged portions at the top and bottom of the tube are the fixed bits, what I should be grabbing, but obviously they’re not as easy to latch onto, especially when I’m endeavoring not to drop anything.

Now here’s the part that just occurred to me: the tab on the extension tube doesn’t have to engage anything at all. It’s intended solely to communicate with the Mamiya bodies, and I haven’t been using this lens on them. The aperture ring does nothing at all to communicate with the Canon bodies; instead, I have to meter exposure (when everything is not set manually, as it usually is with the flash rig,) with the lens manually stopped down so it is transmitting the proper amount of light. I could just slap the extension tube on without worrying about the little tab, as long as it’s out of the way.

Mamiya-Sekor 80mm f4 Macro lens with disengaged extension tube
I want you to understand, I’ve been messing with this damn thing for years, close to a decade I believe, and it never once occurred to me that I was wasting time screwing with having that tab aligned. I’m not proud…

To offset this chagrin, I will point out that, with this very post, I have surpassed the previous record for number of images uploaded in the year; that was 706 photos for 2015. And lest you think this post was simply to break that mark, I will point out that despite the yucky conditions, I have more photos coming very soon (they’re already shot.) Besides, it’s not like I never do frivolous nonsense posts anyway…

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