Sunday, April 12, 2020

7artisans 55mm F 1.4 Lens - More Is Less (Useful)

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

Get your here.
The second 7artisans lens to arrive was the 55mm F 1.4 lens. I purchased this lens used, as I figured that of all the focal lengths, this would be the length I would use the least. I already have the autofocus Fuji 50mm F2.0 WR lens. To date, it's been used only a handful of times. 

Raison d'être: The 50mm-ish lens, when used in the APS format, has always held a special place in the photographic universe. Lenses with a focal length between 75mm and 85mm have long been considered the ideal lens for 35mm film portraiture. It's about the longest lens most people can hand-hold under low-light conditions.

Lens Topography: So far as I can tell, all of the 7artisan manual focus lens share the same general layout. That is to say that when mounted on the camera and seen from above, the aperture ring/focusing ring position and the largest aperture/shortest focusing distance are found on the left. At one time, this was a major selling point for purchasing OEM lenses to accompany one's film camera. When so equipped, you always knew that whichever direction you rotated these two control rings, the lens's response would be the same. 

Notice that the focusing ring  has been placed closer to the body than the aperture ring. The aperture blades are placed at distance equal to the focal length of the lens, or in this case, 2" away from the film plane. Since there are no mechanical linkages between the body and the lens, it stands to reason that controls be placed as close to this distance as is practical. Anyway, the wide focusing ring allows for plenty of room for my fingers to move about. I have to remind myself the the locations of the two controls are reversed.

Shot with the 55mm 7artisans lens. Not very sharp. I get it.
Magnification Ratio: This is a  term that doesn't come up often in digital circles, since so many cameras, even point-and-shoots, have a close-up setting. It's the ratio between width of the sensor and the width of the field of view when the lens is set to its closest focusing distance.

To calculate this ratio, I photographed this draftsman's ruler* with the 55mm lens at its closest focusing distance. As you can see, the width of the field would be 5.2", or 132mmSince the nominal width of an APS sensor is (nominally) 24mm, the ratio would be 1:5.5 (132/24). Obviously, this lens would not be a good choice for photographing small objects. Think of a 3 1/2" X 5" note card. This would approximate the smallest subject size you could photograph with this lens, or one with a comparable magnification ratio.  

A magnification ratio that approaches 1:1, while rare in all but true macro lenses, is often a selling point for longer-than-normal lenses, since it would possible to photograph creepy-crawlies from a greater distance, something to consider if your subject has claws, teeth, or a stinger.


Bike  Share, Roosevelt Way, San Francisco  March 31, 2020
Affordability: 5, Usefulness 1: The 55mm lens, used with an APS sensor, gives minimal foreground/background compression. In that respect, ti is marginally better than the 35mm lens I've been playing with. However, it would make a a good third lens if accompanied by a 12mm and a 25mm lens. This is very similar to focal lengths found in my basic light kit (18mm, 23mm, and a 50mm). It just doesn't provide the compression of the longer telephotos. But if I ever needed to make a great headshot, I'll have the perfect lens.

Easter Decoration, Roosevelt Way, San Francisco. March 31, 2020 

Easter. I Get It: Homeowners in my neighborhood sometimes go overboard on holiday decorations. I find it ironic that this festive bunny sadistically mocks what little joy we might find for ourselves during our "shelter in place" mandate.

So far as this lens is concerned, I think it is the ideal lens for use when a good head shot is called for. It just doesn't have the usefulness to be the lens I would chose to wander with, but certainly a nice one to stow away somewhere in my traveling kit. It would be more useful if it could focus closer than it can. It was certainly worth what I paid for it, but it probably won't be a daily carry.

*A draftman's ruler has 6 different scales to facilitate the rendering of properly scaled drawings. This particular edge is a standard inch-ruler with increments every 1/10". This predates AutoCad. The ruler was used because it was handy.

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