Mitakon 20mm lens – Initial test results.
Mitakon 20mm lens – Initial test results
A few weeks ago I posted information about the New Super Macro Lens 4.5x.
I was very curious about this lens. The company Zhongyi Optics (ZY Optics) claimed high-quality compact lens to be the solutions for photographers to capture extremely fine details or patterns with ease. The official price 199$ was attractive enough to order this lens directly from China. I worked with high magnification lenses with Canon and Nikon cameras, and I wanted to check how this lens works with my Nikon DSLR camera.
I received the lens in the second week of January and immediately started to use it in the dental world.
After two weeks of using this lens with my Nikon D3X, I can share my initial impressions.
Construction:
The lens is solid and made of metal. The finishing is good but not the high-end standard. The general opinion – it looks like 20mm lens reversed mounted, with an additional manual aperture ring. The ring allows setting aperture from 2.8 to f/16. The marks are clear, and you will have no difficulty to set it correctly. By rotating the barrel of the lens, you can shift in between 4x and 4.5x magnification.
Focus and Minimum working distance:
The lens is manual type. No Auto Focus. There is short working distance, just a few centimeters (approx. 4cm) from the object. You have to be very close to the object to get focus.
With high magnification shots, the image in the viewfinder is very dark, making it very difficult to focus. I recommend an additional light, to support focusing. It may be the chair light.
Depth of Field
Images have a tiny depth of field. It’s just a fraction of the millimeter with maximum aperture f/16 (range 0.3-0.4mm). The diffraction will soften the result, but you can improve the photo in the sharpening process in the postproduction.
The Chairside test.
For test purpose, I used my Nikon D3X. For focusing illumination, I used the dental chair light with clinical photos. To get correct lighting, I used an additional flash Yongnuo YN-560IV triggered with RF-603N and Lastolite Ezybox Speed-Lite 2 softbox.
Photo 1: Tooth texture. Aperture f/16; Shutter speed 1/200; ISO 200; Manual Focus; 1 Flash was used YN-560IV with Manual power 1/2.
Photo 2: Iris of the eye. Aperture f/16. Refraction and difficulty to find the correct focus point creates very soft picture.
The Stack Photography
For stack photography, I used my set with StackShot automated macro rail for focus stacking and 2 Speedlites Yongnuo YN-560IV triggered with RF-603N and Lastolite Ezybox Speed-Lite 2 softboxes. As the object, natural wisdom tooth was used. After setting the exposure (Manual Mode; f/5.6; Shutter Speed 1/200; ISO 100; Manual Focus; WB 5500.) I set the initial starting point and the end point of the rails. The step was set to 50mikrons. In total 700 to 800 shots were taken. The postproduction with Zerene Stacker Software was performed at the end.
Photo 3: Single, unprocessed photo with aperture f/5.6. Very shallow depth of field (approx: 0.1mm).
Photo 4: Final photography of the molar tooth with 4.5x magnification. A total number of photographs stacked in the photo: 700.
Conclusions:
– The lens is difficult to work with. For the handheld use, you need to be very close to the object and additional support with the dental chair or patient’s shoulder will be beneficial to avoid the shake.
– To maximize the DOF, you need to close down the aperture to f/16, but the consequence is softer image and dark picture in the viewfinder, which’s hard to see the sharp focus. Use additional light to support focusing.
– For focus stacking, it works good, but you need a sturdy tripod and macro rails.
– The price of 199$ is worth considering to get this high magnification (4-4.5x).
– Canon EF, Nikon F, Sony FE, Sony Alpha, Pentax K, Sony E, Micro Four Thirds, Fuji X mounts are available.
