Point image formation is good at the center of the frame and little flare is visible. However, points closer to frame peripheries tend to exhibit slight flare in the sagittal direction. Though the amount of flare is low for a fisheye lens, I think that better results would be achieved with astrophotography by stopping down the aperture one or two stops. V. Considering the relationship between the object plane and the image plane The red box added to the table shows the angles that correspond with each half-millimeter as counted away from the zenith (0.0). High School Math Is Useful Now let's look at the unique characteristics of this lens in terms of design. First, I think you'll notice that the structure of the entire optical system is incredibly simple. The first and second lens elements are concave to generate excessive negative distortion. This structure offers strong negative refractive power, while the use of only concave lens elements and adoption of the optimal meniscus shape ensures the proper passage of light through the lens and suppresses aberration generation. The doublet behind these provides compensation for spherical aberration, coma, and chromatic aberration. The aperture is inserted, and the structure of the rear group is also simple. With two sets of doublets, aberrations generated both on- and off-axis are suppressed for consistent rendering performance to the edges of the frame.

The majority of buyers were impressed with the sharpness and image quality the Sigma 15mm offered. They loved its high-quality build and the colors it captured. Customers found it to be quiet and fast and stated that they had a lot of fun shooting with this lens. However, users were disappointed with the fact that the lens cover did not fasten to the unit. The chart on the left provides data at a glance. The table on the right provides more data accuracy.Lens design also had to assure that the image resolution performance would not be degraded even if the aspherical surface was imperfect. Aspherical lens mass production technology, while productivity was much lower than it is today, still existed.

Fisheye lenses are of two types – circular fisheyes and full-field diagonal fisheyes. Diagonal fisheyes create an image circle that covers the image sensor completely, resulting in an image that has a full-sized, regular, rectangular shape. Vignetting is present in the corners of the frame, resulting in a tunnel vision effect that makes the scene appear to be confined inside a round circle.Since years have passed since the lens was manufactured, colors are slightly yellowish, but as you can see from the samples, not severely. There should be no practical problems with used with reversal film. Hill called this type of lens a whole-sky lens, and is known as the father of whole-sky cameras. However, the name is mysterious. Why was "fish-eye" not used? For a time, "whole-sky camera" and "whole-sky lens" were the names commonly used in the industry. So what was the first lens to be named a "fisheye lens"? After looking into the matter fully, it seems likely that the name originated with Nikkor lenses manufactured by Nippon Kogaku K. K. (now Nikon). It seems that the term "fisheye lens" has been used by Nippon Kogaku K. K. (now Nikon) since before WWII. "Fisheye lens" is noted on design blueprints produced in 1938. In addition, "FISH-EYE NIKKOR" is stamped on a whole-sky camera lens released in 1958. Based on these records, it seems highly likely that the name "fisheye lens", which is now recognized around the world, originated in Japan. II. Circular fisheye and full-frame fisheye

It was at that moment that a fisheye lens with which emphasis was placed on performance at close distances was born. VI. Actual performance with sample images The maximum aperture is f/5.6, which is a rather small aperture, but the image resolution is extremely sharp even to image corners. It has no focusing mechanism, and the focal length is a short 10mm, so there is no out-of-focus even with close objects. The image will be adequately sharp up through about 50cm (1.6 ft.) from the lens even at maximum aperture. Nikon doesn’t have any dedicated Z-mount fisheyes yet. Presumably, you could use an FTZ mount adapter, but it’s not a combination I’ve experimented with personally. [ ↩] An ultra-wide-angle lens that creates an extremely wide panoramic view, fisheyes have plenty of visual distortion. To put this unit to good use, it’s essential that you fully understand its strengths and weaknesses. ProsThe Rokinon FE8M-N 8mm boasts truly exceptional image quality. The unit distorts lines in such a way that makes the captured scene look very intriguing and interesting. Since it distorts the plane of the image completely, it enables photographers to be incredibly creative. In fact, the best results are achieved in manual mode when images are underexposed a bit. Lenses – The lens has dust inside that may affect images. The rubber zoom/focus ring is coming away from the barrel of the lens.

Here are some shots I’ve taken with this lens, and you can find my detailed hands-on review here. I took this photo with a Nikon AF-S 8-15mm f/3.5-4.5E ED fisheye zoom lens on a Nikon D850 @ 15 mm and ƒ / 4.5. I took this photo with a Nikon AF-S 8-15mm f/3.5-4.5E ED fisheye zoom lens on a Nikon D850 @ 8 mm and ƒ / 5.6. I took this photo with a Nikon AF-S 8-15mm f/3.5-4.5E ED fisheye zoom lens on a Nikon D850 @ 15 mm and ƒ / 4.5. I took this photo with a Nikon AF-S 8-15mm f/3.5-4.5E ED fisheye zoom lens on a Nikon D850 @ 15 mm and ƒ / 5.6. Now let's consider angle of view for a moment. You may be interested in knowing just how wide a photographic lens's angle of view can extend. As the subject interested me very much, I examined records and patents. I discovered the answer in a book titled, Kameraman no tameno shashin renzu no kagaku (in English, The Science of Photographic Lenses for Photographers), by Shotaro Yoshida. Records show that the widest angle of view was achieved with a 12.3mm f/10 medium-format fisheye lens invented by three people including A. C. S. V. Heel from The Netherlands' National Defense Research Committee (NDRC). It offered an incredible 2ω = 270° angle of view. We do not know whether this lens was actually made, or whether it was simply invented on paper, but it seems to be the lens with the world's widest angle of view. In the age of rangefinder cameras, the refractive power arrangement of lenses utilized a "symmetrical lens" structure that was nearly symmetrical. This symmetrical lens structure provides better compensation for distortion and curvature of field than does the retrofocus structure. However, if we consider the common projection formula (y=f·tan θ) with fisheye lenses, excessive negative distortion is generated. Therefore, it can be said that the retrofocus structure is the optimal structure for fisheye lenses.

Consistent rendering is achieved throughout the entire frame, but the effects of diffraction cause resolution to appear somewhat reduced.