The 7artisans 25mm Lens: Resolution And Distortion

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

Bee Photographed On Corbett Avenue, San Francisco. Inset shows full frame. April 18, 2020

I added some photos to my morning walk oeuvre, and in doing so, I have found the lens to be worthy of the praise it has received.

7artisans 25mm F 1.8

Ready For Your Close Ups! The lens is capable of making reasonable closeups. Not at the true macro level, but certainly good enough to capture almost anything you might care to digitally immortalize. I found this bee on the street, and wanted to see what the lens was capable of doing. I photographed it by setting the lens at its closest focusing distance, moving the camera fore and aft until the bee was at its sharpest, and then gently pressing the shutter release. I'd repeat the process until I got an image that was sharp, or sharp enough.

If you look in the lower right hand corner of the lead image, you can see the relationship of the bee to the limits of the frame. The "big bee" is a cropping of the original image. I was impressed by the overall sharpness of the lens. The enlarged image is good enough for a normal computer display, and might even pass muster if printed as an 11x14 print. But for my purposes, this lens is totally adequate. Again, this isn't true macro performance, but if your subject is about the size of the palm of your hand, it can fill the frame. 

Barrel Distortion, 7artisans 25mm F 1.8 lens. 

Barrel Distortion: Barrel distortion is almost always present in wide angle lenses, and the less you pay, the more you get. You will notice how the ruler appears straight on its upper edge, but "curves" out noticeably the farther you get from the center of the frame. For the record, the optical center (red dot) is very close to the ruler's edge. Lines passing through the exact center will be straight, and those perpendicular to this line will exhibit mild to severe distortion based on the distance from the center. This can be a problem for architectural photographers, but is correctable in post production.

Garden, Corbett Avenue in San Francisco. April 18, 2020

Returning To The Scene Of The Crime: This is my second attempt for this crime scene photo from the Middle Earth. For this attempt, I overrode the auto-exposure setting by -2 stops so that the cyan LED eyes would appear brighter. The upside was the improved color saturation of the flamingo, which was too pale in my last effort. The overall darkness of the image added to its mystery, so this experiment was definitely to the good. See the original in this earlier posting.

San Francisco has a lot of creatives. I have no idea that plastic flamingos were targets for such wanton acts of violence.

Gratitude Bush, Corbett Avenue, San Francisco.  April 18, 2020

Since the Shelter In Place order, more and more children are left to find their own amusements, with parental supervision of course. Here, a tree was selected to carry messages of love and gratitude to the universe at large. Dozens of these laminated notes could be found hanging from the bush. Shot with the lens nearly wide open, the soft background has that smooth "bokeh" that everybody seems to want. 

Planter Box, Corbett Avenue, San Francisco. April 18, 2020

I think this image is a little hypnotic. All lines lead to the center, while the smaller plants stick to the viewer's eyes. Kidding aside, I've been looking for an image that would lend itself to a black and white rendering. 

Somehow, this image doesn't have that certain quality found in wet-processed black and white prints. It suspect it's due to the inability of a computer monitor to render a "true" black. But as a geometric study, it has its merits.

Flower Box, Corbett Avenue San Francisco. April 18, 2020.

Closeup Revelation: I just figured it out: When photographing a "bouquet", something must be in sharp focus. I chose the pistils of the center flower as my point of sharpness. Sadly, there are two factors working at cross purposes. First, you need to shoot at a relatively large aperture to minimize the depth of field. Unfortunately, lenses are seldom their sharpest when used wide open. I got the shallow depth, but not the super-sharpness that would have helped the photo work. 

Oh well. There's always tomorrow!

It All Depends On Where You Stand

Access Hatch, Corbett Avenue in San Francisco. April 20, 2020

I know this image isn't sharply focused. I wasn't paying attention to the focus peaking highlights on the back LCD. The camera was held unsupported at waist level. I had no idea it would be a Pulitzer Prize contender.

It's been about three weeks of attempting to make photographs while doing my sanity-maintaining morning walks. I think I've photographed every blooming flower and bush on Corbett Avenue, and today I had to look for something different.

Vine Cuttings, Romaine Street in San Francisco. April 20, 2020

For the moment, I was more interested in finding some interesting cloud patterns, which I found in the sky behind these clipped ivy vines entangled in the wire fence. I bracketed the shot (made several shots at different exposure times) for comparison during post production. In the end, I chose the first exposure because it revealed a tiny bit of magenta in the flowers at the base of the vine. A small amount of burning and dodging finished to photo. All of the shots I've made for this series of posts have been done in Aperture Priority. Variations were made using the Exposure Compensation dial conveniently located under my thumb when the camera is held at eye level.

House Number, Grand View Terrace. April 20, 2020

The Value Of Shadows: I walked past this carved wood house number, and despite the near lack of detail, made a quick photograph. The sky was clouded over, any light that was available would be extremely diffuse. At first glance, the image should have been shadowless, or nearly so.

When I previewed the image, I could see that there were indeed shadows, and to top it off, I could easily see that it was coming from high above. Curious, I approached the number from the opposite side, just to see I the numbers could be rendered in greater depth.

As you can see from the second image, changing position allowed me photograph the very shadows that I couldn't see from my previous shooting position. 

House Number, Grand View Terrace. April 20, 2020

Having seen the difference in the two positions, I'll remember that a change in position can often change the appearance of the final image, especially when shadows are involved. I could have played with the exposure in post production if I needed the numbers to really "pop", but I found that this simple experiment was a real eye-opener, so far as observing the effects of existing light was concerned. While the number "277" has no special significance to me, the photographic process that brought me to this point does.

Garden Statue, Corbin Stairs in San Francisco. April 17, 2020

It turns out that this was not my first opportunity to work with subtle shadows created by large, diffuse light sources like those I encounter on my morning walks. The Garden Statue taken days before would have no detail whatsoever unless something, in this case the dark soil foreground, prevented light from flooding the shadows. In this case, the shadows were enhanced by the reduction of light, courtesy of those dark surroundings.

The 7artisans 25mm Lens: Well Worth The Wait!

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

Place your order here.

Christmas In April: Ever since the shelter in place started on March 16, we've all been struggling to find something to keep our minds off the situation, provided we washed our hands and kept ourselves at an appropriate social distance.  Thursday, April 16, was the high point, when not one, but two lenses finally arrived. Here's the long story made short. 

On January 27, 2020, a Youtube post appeared singing the praises of a manual focus lens made for the X-mount Fuji camera that costs less than $80.00, and in many cases, for much less. It was made by a company called Pergear, and was sold under several different names, including 7artisans. Coincidentally, I wanted to experiment with the manual "focus peaking" feature made available with the introduction of the Fuji X-Pro1. Up until then, I hadn't thought of when focusing manually would ever be something I wanted to do. But at the low price point and the high on-line praise, I was ready to try. This lens was to become the gateway drug in my quest to create a compact prime-lens (fixed focal length) system to use when I wasn't up against a deadline, or when I wanted to make images just for fun.

My first attempt to purchase the lens was on February 18, 2020. B&H carried the 7artisans version. At the time it was on back-order, and I assumed that their inventory would be quickly replenished. Then the Corona virus brought China to a halt, so the actual delivery date was anybody's guess.

On March 31, I found an EBay re-seller (notice I didn't say "dealer") that claimed to have the 7artisans lens, in black and in stock, already in the United States. This was a clear case of a bird in the hand, so I cancelled my B&H order and placed my EBay order*. While I was at it, I also ordered the 12mm F 2.8 7artisans lens from a re-seller who also claimed to have this lens in stock. Both dealers projected a delivery date of April 9, which was slightly more than a week after purchase. I really felt I had beat the system, and that I'd shortly be in lens heaven.

The two lenses finally arrived on April 16, one week after they were promised. OK, I was too optimistic in the delivery projections, although they had been fairly accurate in the past. It was interesting that they were sent from the same facility in Los Angeles. Strange doings, but after all that waiting, I was just glad they arrived.

Mural on 18th Street, San Francisco. April 17, 2020

I mounted the 25mm lens on an X-E1 body and took it with me while I mailed a letter at the Castro post office. As I walked home, I looked for things to photograph. The Castro is full of creatives, and art can be found almost anywhere you look. This whimsical mural was found on 18th Street. Using the new lens was a refreshing change when compared to the 35mm lens that up until now, I had used almost exclusively. The new lens gave me a wider field of view. I made this shot without having to back up into the street.

Succulent, Community Garden on Storrie Street in San Francisco, April 17, 2020

Closer Closeups: The 25mm lens focuses closer than the 35mm. If you believe the distance markings on the lens barrels, the minimum film-plane to subject distances are 0.6' to 1.2', respectively. This is an apples to oranges comparison because the different focal lengths, along with their different magnifications, challenge the relevance of any conclusions you might draw. 

Closest Focus: 35mm lens                                                                    Closest Focus: 25mm lens

Put in practical terms, the horizontal field widths of the 35mm and the 25mm lens are (approximately) 8.1" and 4.2", respectively. I'll have a more detailed post on the subject and will include some images of the practical implications for all of the 7artisans lenses I purchased.

Gardens Of Fancy: The Corbin Stairs connect Corbett Avenue and 17th Street between Ord and Mars Streets. It's where I caught the 37 Corbett bus that would take me to Twin Peaks School until I was old enough to make the mile-long walk on my own. Over the years, neighbors have  taken to turning its borders into a whimsical garden with lights, gnomes, and statuary. With the close focusing capabilities of new lens, I made these images of some of the garden's permanent residents.

Garden Statue, Corbin Stairs in San Francisco. April 17, 2020

Subtractive Lighting: I learned about this from an article written, I believe, by Dean Collins in Petersen's Photographic Magazine. To create better modelling, Mr. Collins suggests that the subject might be surrounded by non-reflective black panels to prevent the key light from bouncing back into the shadows. In this case, the dark, light-robbing dark soil prevented light from filling the side of the porcelain statue's face. This allows the viewer to see the shadows beneath the eyes and beside the nose.

Flamingo Killer, Corbin Stairs in San Francisco. April 17, 2020

I suspect there are some things we were never meant to fully understand, and the lives of the residents of a fantasy garden are probably among them. I can only wonder if the victim of this forest denizen was headed to flamingo heaven, or a pre-heated oven.

I'll report on the 12mm F 2.8 lens after I've had a chance to play with it.

*Incidentally, on April 19, the black version of the Fuji-mount 7artisans 25mm lens became available for purchase through B & H.

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 132mm. Since 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.

A Bloke Mucking About The Castro

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

The Village: I decided to mail a letter at the Castro post office and to enjoy the welcomed appearance of the sun at the end of a dark and dreary morning. My 35mm 7artisans 35mm was the lens of choice, and since it had already proven its penchant for slight color shifts, decided to just play with different levels of color saturation and create some images that might be a little more "festive".

Dinosaurs In The Window: I made this photo of a infant-friendly plush animal mobile in a window of a shuttered specialty store. I have a soft spot for dinosaurs and frogs, and love them as much as I love puppies and birdies, and yes, sometimes kitties too. I can't help but grin at this comic representation of a baby Tyrannosaurus Rex. If I was a little plush Brontosaurus, I'd be really scared.

I was curious to see if this lens was indeed sharp, so I zoomed in on the eye, which was my point of focus. I was amazed that this shot, made through the glass windows, showed the lens to be sharper than I had expected, and more than adequate for its role as a leisure lens on a leisure body.

I'm still not wild about the 50mm equivalent focal length, and still think its field of view is too narrow for my tastes. Alas, the 25mm lens hasn't made it across the Pacific Ocean yet, and since I was late to the purchasing party, got stuck at the very end of the customer line. Based on this particular photo, I hope all the 7artisans lenses are equally sharp, as they are certainly handy and inexpensive.

Harvey: Reminders of Supervisor Harvey Milk (1930-1978) are everywhere in the Castro, and this mural, painted on the side of the restaurant I knew as the Cafe San Marco, shows him as a cross between Mario Savio and George Washington. I mentioned in a earlier post that I knew Harvey and frequented his camera store. I sensed his greatness even then.

Bokeh To You Too, Bud! Bokeh is a term often used in the evaluations of these manual-focus wonders. It is the umami of the photography, a difficult-to-define quality, something you recognize but cannot accurately describe. In short, it's a way to value the rendition of the out-of-focus backgrounds using words like creamy, smooth, and blurry. This lens does a good job in the background department.

Just so you know: SFUSD stands for San Francisco Unified School District. The historic street lamp globe belongs to the school district and not to the city proper. I'm not sure why they felt the need to identify it so, but there you have it.

From the Web. Citations will follow

A contributing factor to quality bokeh is the lens's 9-bladeed diaphragm, which gives an aperture that is more circular than polygonal. This tends to enhance this desired blurry effect. Automated lens often reduce the number of aperture blades to decrease the time it takes for the lens to transition from a "open aperture" to the smaller "shooting aperture" just prior to exposure.

You can see in this illustration a lens with six aperture blades (left) and one with eight blades (right) By all rights the eight-bladed lens would produce better bokeh, and has contributed to the popularity of the 7artisans manual lenses which have nine to fourteen.

While on my walk, I found out that my 55mm 1.4 lens had just been delivered, so I will comment on it as soon as I get a chance.