Using the AstrHori 18mm f/8 Low-Cost Shift Lens
Low-cost lenses started appearing in the market in the last twenty years or so, with prices coming down steadily. When I saw another inexpensive lens in an article a couple of months ago, it grabbed my attention not with its price but with its core feature. It was a shift lens. An 18mm, fixed-aperture at f/8, shift lens at $119 was worth trying.
Before Reading Further
While reading the rest of the article, you may want to know that:
- My Canon R7 has a native resolution of 34 megapixels with an APS-C sensor.
- The lens I will talk about works fine on this size sensor but is unsuitable for full-frame cameras.
- I mention a small amount of barrel distortion, but it may be more noticeable at closer distances or straight lines close to the edges.
- The images you will see are minimally edited for exposure correction, sharpening, or noise reduction.
- All the images below are clickable for solo viewing with captions below them.
- And, this is not a lens quality review but a lens use exploration. Everything mentioned here can be done with any shift lens.
Astrhori Shift Lens
I have had a Canon 24 mm tilt-shift lens for quite some time and enjoyed creating panoramas (I shared some in a post on my blog titled “Ordinary Places“). But the AstrHori 18mm f/8 shift lens, with its diminutive size and an equally small price, was noteworthy. I followed the link from the article and ended up at a Chinese vendor’s site, and looked at the lens. No, I don’t get any referral credits!
It was available in a few mounts, and Canon RF was among them. I exchanged a few e-mails about the lens, shipping, and return policies. Shipping from China in two weeks was free to boot. I ordered one on December 15, 2022, hoping to get it by the year’s end. A few weeks passed, and I wrote to Pergear twice about the delayed delivery. The last message finally triggered the shipping, and the lens arrived on January 19, 2023. Covid-19 slowed the process, they said, as half of their staff were sick at home.
A Small Package
I opened the package with curiosity. The exterior was a plastic bag tightly wrapped and taped around foam padding. Inside was a firm square box with more padding inside where the lens was safely ensconced. For its size, it felt hefty. Unlike my Canon TS lens, there were no knobs to shift the lens. All happened with sufficient friction. In addition to the shifting to either side of the center position, the lens also rotates in 45-degree steps with click stops. That allows you to shift the lens in different directions depending on the need.
A winter cold spell with rain and a tiny bit of snow forced me to play with the lens indoors. I discovered that the shutter would not release with the AstrHori shift lens mounted on the Canon R7. Searching through the menu options, I found a setting that turned on the shutter to release when no lens was mounted on the camera. Since this lens has no electronics, the camera does not know it has a lens mounted. After I turned that feature on, the shutter started working.
What Does a Shift Lens Do?
These lenses emerged as the view cameras lost their footing. They had shifting and tilting fronts and backs, giving the photographers control of vertical lines in architecture with their shift feature. When you set up your tripod to photograph a building, you may realize that the angle of coverage may not be sufficient to include the top of the building unless you angled the camera upwards. That results in converging verticals which is generally not good practice.
The camera on a tripod, shifting the lens up would have more coverage at the top, bringing the entire building into the frame. Another use is to take several photographs with the lens in different shifted positions and stitch them into a panorama. This results in a greater angle of view and provides easy stitching. I am mainly interested in using a shift lens to create stitched panoramas.
First Experiments and Impressions
With the camera mounted on my tripod, I took a few frames to see the results. Today, I repeated the experiment with a little more attention as the weather was much more pleasant.
Plain Vertical Panorama
With the camera roughly framing the house, I took one shot. Then shifted the lens up for another, and shifting it to the bottom, I took the third frame. Although the full swings in both directions create sufficiently overlapping frames, I included the center position for the record. In Lightroom, I reviewed the three images for stitching into a panorama. There was a small amount of barrel distortion, most noticeable on the slightly curved gutter.
I selected the three images and instructed Lightroom to stitch them into a panorama. You can see the three separate images and their stitched version below. I corrected the barrel distortion and other perspective issues in Lightroom. If you like, you can try those corrections in Photoshop which has a few more tools to deal with distortions.
The resulting stitched panorama has a greater angle of coverage and is a much bigger image. Full size, it has the dimensions of 6986 x 8477 pixels – a 59-megapixel image. But wait, there’s more!
The shift axis can be rotated 360 degrees, with 45-degree click stops. That makes it relatively simple to further increase the angle of view and the final megapixels by using diagonal axis shifting. Making sure the lens is at a 45-degree stop and shifted in one direction take one picture, and shift the lens to the end in the other direction and take another shot. After that, rotate the lens two click stops and repeat the above. You will end up with four frames.
The generous overlaps between the frames make stitching easier and with little or no distortion. In the stitching stage, there may be small areas on the edges missed by the frames that can either be fixed using the “Fill edges” option in the panorama stitching panel or cropped later.
The stitched panorama dimensions are 9528 x 7212 pixels, or about 69 megapixels, covering a greater angle horizontally.
Combined Axis Stitching May Be Possible
In these two panoramas, I used a vertical axis and two diagonal axes for taking the photographs for stitching. What if I combined all those into one? Here are three axes and their combined result.
The blank corners can be content-aware filled in the stitching stage or later in Photoshop. I let Lightroom fill the edges while stitching and ended up with the last image in the above gallery. The finished image is about 83 megapixels with 9761 x 8455 pixels dimensions.
Let us not ignore the final axis and create a horizontal-shift stitched image. That will have wider horizontal coverage but lack the vertical angle. Below is a stitched image using two frames taken at two extremes of the shift on the horizontal axis.
Is That All?
Of course not! There are other possibilities for combined axis stitching if the subject is suitable. Instead of using the vertical frames in the combined axis example, we can use the horizontal axis shifted panorama. That will yield a wider image instead of a taller one.
Again, if the subject and its surroundings are suitable, we can combine all four axes with very large images, covering greater angles. That all depends on what kind of detail may need to be matched in the content-aware filling.
One Last Thing
All the above photographs were taken with the camera mounted in the landscape position on the tripod. If you were to mount it vertically and repeat all the above, you will end up with a new set of stitched images. These lenses and techniques can be useful in architectural, landscape, seascape, and other photographic genres.
Try them all, but beware: it can be addictive!
About the author: A. Cemal Ekin is a photographer based in Warwick, Rhode Island who has been shooting for roughly 60 years. The opinions expressed in this article are solely those of the author. Ekin retired as a professor of marketing emeritus from Providence College in 2012 after 36 years of service there. Visit his website here. This article was also published here.