What is filmed with a fisheye lens. Fisheye lenses. What is distortion

Over the past three years, our team has filmed more than 10,000 spherical panoramas. With such volumes of work, we are constantly trying to develop the technique and technology of shooting. Saving time of one minute on each panorama allows us to save from one hour of time per shooting day. And getting high-quality original photos allows you to save a lot of time on processing and assembly. We have reached the limit of shooting productivity as a photographer: 40-110 points per day (depending on conditions). Further planned events could add, rather, the quality and comfort of shooting, but not increase labor productivity.

Initial data

The shoot place: large chemical production.
Manfrotto: tripods 190 and 055 models, tripod heads for spherical panoramas, level heads, tripod covers.
Cameras: full frame. The main ones are Nikon 750, Canon 5D-II (spare). In the future, we will completely switch to Nikon.
Lenses: Samyang 14mm f/2.8.
Shooting: to RAW format. Most of it is filmed in one pass (6 frames) with the top nadir. In some cases, when the equipment being filmed comes close to the shooting point, we shoot in two rows without nadir. Under contrasting shooting conditions, HDR is shot to cover the entire range of contrast from highlights to shadows. The image is transferred to the customer reduced to 10,000 points on the long side.

Assembly: Kolor Autopano Giga software. When shooting with a 14mm lens in 2 rows, there is good overlap between the two rows and there are no assembly problems. But when shooting "1 row + nadir", the nadir gives small gaps at the junctions with the row. To ensure minimal nadir overlap, we are forced to raise the horizontal row of the panorama by 5 degrees. So, we completely get rid of the "holes", however, several insufficient overlaps between the row and the nadir remain. Naturally, it is (almost) impossible to "sew" the series and the nadir qualitatively in this case. In addition, the Samyang 14mm, which has complex distortion, only exacerbates the problem. Therefore, in almost every panorama, we have places of inexact connection (“ghosts”), which we have to manually “finish” in Photoshop. These are the most significant labor costs at the post-processing stage.

What did you want

Expand the angle of view of the lens, that is, reduce its focal length. This will eliminate or at least reduce the number of two-row panoramas. The second reason to increase the FOV is to provide more nadir coverage and reduce post-processing time.

Initially, fisheye lenses were not considered at all due to the lack of experience in shooting with such a lens and prejudices regarding the quality of their image. Therefore, I was thinking in the direction of ultra wide-angle lenses with a focus of less than 14 mm. There were not many candidates at all, if you remove the optics with poor resolution, such as Sigma (photo on the left).

Laowa 12mm f/2.8- perhaps the best candidate to replace our Samyang 14 mm. Available for Nikon and Canon. Good resolution, with a record focal length (at the time of my reflection). Disadvantages: 1) high price of 1000 US$; b) is sold only by pre-order with an incomprehensible delivery time, because this is a new product and there are many people who want to buy it all over the world.

Canon lenses in their lineup had the Canon EF 11-24mm f/4L USM zoom. The resolution, judging by the tests, is superior to our Samyang fix. But the price of 2500 US$ is depressing. If this zoom were in operation for a long time, I would put up with it. But the conditions of our filming are so difficult that there is no guarantee that the equipment will not be fatally damaged on the first shooting. So, one day, my camera, along with a tripod, flew vertically down on the head of an engineer from our team. Sasha caught the falling "shell", first with a helmet, then with his hands.

Nikon could not offer me anything but two fisheyes. But at first I did not consider fisheye.

Doubts

The main doubts were that moving to a 12 or even 11 mm lens does not change the situation dramatically. Well, yes, it will be a little better, but I wanted a breakthrough. Doubts disappeared when I once again analyzed the values ​​of the angles of the field of view. In our 14 mm, it is equal to 115.7 degrees diagonally. Laowa 12 mm gives 122 degrees diagonally, that is, it will provide an increase of 6 degrees. This could save us from tilting the camera up while maintaining a small nadir overlap. Or increase the overlap, which may make post-processing easier, but still keep the row tilted up by 5 degrees.

The Canon EF 11-24 has 126 degrees diagonal (10 degree gain). It's already something. This angle of view will eliminate the upward tilt of the camera, in some cases reduce the number of two-row panoramas, and slightly increase the nadir overlap. However, I wanted to jump from Canon to Nikon for certain reasons.

Fisheye

Out of curiosity, I looked at the angle of view of the fish - 175-180 degrees. Wow! Exactly what is needed. It's even possible that with this angle of view we can cover a full turn in just 4 vertical shots. But what about the decline in quality? Will have to test. First I identified candidates for testing: Samyang 12mm F2.8 Fish-eye and Fisheye-Nikkor 16mm f/2.8. Fisheye-Nikkor 8-15mm f/3.5-4.5 at the time of my testing was not yet on sale. Canon also has a fisheye, but I did not consider it for the above reason.

Purpose of testing: will it be possible to get a panorama shot by a fish, in quality no worse than that taken by Samyang 14mm. I will compare both the resolving power of lenses and the ability to keep backlight in high contrast conditions.

Next, I found a company that rents photographic equipment. Rentaphoto could provide me with both test lenses, but, unfortunately, the Samyang 12mm was only for Canon, also in the “video” version. However, in other companies, the situation with this fish was exactly the same. Therefore, I will compare lenses in pairs. For Nikon: Samyang 14mm and Fisheye-Nikkor 16mm. For Canon: Samyang 14mm and Samyang 12mm Fish-eye. Fish eyes were tested at aperture 8 as optimal. Focusing was carried out according to the text on the front desk.

Photo 1: Nikkor head rail in frame.
Photo 2: Overlap in 4-frame panorama.
Photo 3: "Ghosts" with insufficient overlap.
Photo 4: Small "ghosts"

Fisheye-Nikkor 16mm

Fisheye from Nikon was small in size and at first it pleased. I noticed that the lower and side rails of the head are included in the frame (photo 1). Hmm ... not critical, in extreme cases, this place can be cropped. In 4 vertical frames, the panorama, formally, can be filmed. But in the center of the vertical side, the overlap between shots is too small (photo 2). Just in case, I took a 4-frame panorama to see if it could be put together. Panoramas stitched with very strong mistakes, non-working option (photo 3). It is possible that sufficient overlap would be provided with a 5-frame panorama, but the Manfrotto head splitter does not have the possibility of such a division: only 4 or 6. I was forced to set the splitter to 6. This means that it will not be possible to reduce the number of frames even at 180- degree angle of view (with a vertical frame). It's a pity.

With manual focusing, we use two distances: 1.5 and 0.5 meters. The Nikon focus ring rotates too easily and it will easily go out of range during shooting. We will deal with this problem using paper masking tape. The picture, during the rotation of the ring, "walked" in all directions. There was a feeling that I was working with flimsy "glass" cheaper than $100. All in all, a bad experience. However, what is more important to me is what quality the panorama will be collected from this lens.

Photo 5: Backlight Nikkor holds better Samyang 14mm.
Photo 6: The resolution of the Nikkor is slightly higher than the Samyang 14mm.
Photo 7: Nikkor resolution fall islands.
Photo 8: Decrease in resolution in the corners of the Nikkor frame.

1) The planks included in the image are discarded by Autopano Giga during assembly, that is, they can not be cropped.

2) Small "ghosts" remained, despite the fact that the overlap zones increased significantly (photo 4).

3) The lens holds backlight a little better than the Samyang 14mm (photo 5).

4) The resolution of the Nikkor is slightly higher than the Samyang 14mm (photo 6). After reducing the size of the photo to 10,000 points, the difference is not visible.

5) There are "islands" of a strong drop in resolution (photo 7). I suspect that the reason for this is a strong drop in resolution in the corners of the frame (photo 8). This played a decisive role in making me decide - "not an option."

Samyang 12mm

The Samyang 12mm Fish-eye is well made, just like its 14mm brother. I immediately checked the alignment. For the 14 mm version, this sore spot- lenses are almost always misaligned after the factory, and when aiming at "infinity" on the distance scale, you can significantly miss sharpness. Everything is in order, "infinity" is in place.

Photo 9: Samyang, head slats stick out less.
Photo 10: Samyang in the corners is better than Nikkor.
Photo 11: Samyang is slightly less sharp than Nikkor.
Photo 12: Backlight Samyang holds the best.

The Manfrotto head rail also enters the frame, but much smaller (photo 9). I wondered why. As if the angle of view of this fish is less than that of Nikkor, which should not be. Ha, size matters! The Samyang lens is longer, its front lens is pushed forward relative to the head rail, so it hits the frame to a lesser extent.

The drop in resolution in the corners is not fatal, like in Nikkor (photo 10). In general, the resolution of this lens is slightly lower than that of the Nikkor (photo 11), but when the panorama is reduced to 10,000 points, the difference is insignificant. I fully admit that this can be explained by the fact that the Canon 5D-II, on which I tested this lens, has a 21 megapixel sensor on board, while Nikon has 24 megapixels.

Fisheye holds backlight better than Samyang 14mm and Nikkor (photo 12). Colors are transmitted brighter (find out later, when ordering). I believe that the reason for this is the better enlightenment of the front lens in fisheye.

A panorama of 4 images is assembled, but the stitching errors are very strong, even without nadir. The miracle didn't happen.

conclusions

We bought two Samyang 12mm and were not disappointed. Fisheye perfectly holds the backlight and the sun, allows you to shoot a spherical panorama (from the tripod legs) in 7 frames. So 12-frame panoramas are a thing of the past for us. This will reduce the time of shooting and processing, all panoramas will be visually of the same type, and not in 1 and 2 passes. The cost of lenses, the purchase of which was paid by the customer, will be returned to him, due to savings, on a couple of productions, and, in the future, will give the customer significant savings in the cost of shooting and processing. We are satisfied.

PS: thanks to Andrey, Rentaphoto employee, for help with lens testing and amazing Buddhist calmness.

To create interesting effects in the pictures and make them more expressive, different means are used. For example, unusual lenses. A fisheye, or fisheye, is a type of short-throw ultra-wide-angle lens with barrel distortion.

What is distortion?

These are geometric distortions that can occur in a photograph, curvature of lines and objects. The most common option is barrel-shaped, the lines seem to curve outward, while objects become convex. Pincushion distortion is the opposite effect, objects begin to appear concave.

Otherwise, barrel distortion is also called positive, and pincushion distortion is called negative. In classical photography, distortion is a defect, so photographers try to prevent it from occurring. Special corrective lenses are built into wide-angle lenses in order to avoid this effect.

However, if distortion works for the photographer, then it can be an interesting artistic technique, a way to get unusual, bright pictures.

Fisheye (lens) specifications

The main difference of this lens is the angle of view. It is at least 180 degrees, so it becomes possible to fit half the space in one frame. It is believed that the fish sees objects in this way, which is why the name has taken root - "fisheye effect".

The next characteristic is the focal length. It is short, 6-15 mm.

Hoods for such lenses are very small or not used at all. This is due to the fact that due to the huge angle of view of the lens, the hood can get into the frame. Also, the traditional installation of a light filter on a fisheye is impossible.

Lens Varieties

There are two types: circular and diagonal. A circular fisheye (lens) gives a circular perspective, but the image does not completely fill the frame. At the edges of the frame on a full-frame camera, you can see that part of the image is missing and replaced with black corners. This type of lens is used only in applied areas of photography (for example, meteorology).

Diagonal type is otherwise called full frame. The image from such a lens fills the entire frame, this is achieved by slightly reducing the viewing angle. This type of lens is also the most popular.

The history of the lens

The term "fisheye" was introduced by the American physicist Robert Wilms Wood, who was the first to think about how a fish can see the world around it. He speculated and performed an experiment involving a sealed box filled with water and containing a small hole. The first photographs taken with such a box were published in 1906.

The fisheye lens has been used since the 1920s and has been used in meteorology to capture clouds. Lenses were also needed for astronomical surveys.

To date, there are already dozens of such lenses, the viewing angle of individual models reaches 220 degrees, and the scope of their use has expanded significantly. In addition to the lens, there is also a fisheye camera. These are panoramic models with a viewing angle of 360 degrees.

In the USSR, the first photographer who used such a lens for his work was L. A. Borodulin, a master of sports photography.

What is the fisheye effect used for?

Lenses with this effect are often used for filming extreme sports, this makes it possible to show not only the athlete himself, but the whole stunt in the frame. In this case, you can shoot from a short distance.

The lens is good for shooting spherical panoramas. You can find the use of such a lens for interior shooting, especially when it comes to small and narrow spaces (corridors, bathrooms). If you need to create a virtual 3D panorama, you can't do without fisheye either.

To achieve a comedic effect when shooting portraits of people or animals, such lenses are also used. It turns out funny and bright shots.

In general, this lens gives you the opportunity to see ordinary things from an unusual point of view, and this can be very interesting. You can shoot architecture, landscape, trees from unusual angles. strange shots cause a very lively and emotional reaction from the audience.

You can also shoot people, for this person you need to place in the center of the frame and move away from him. The human figure will turn out in this case in full height, small in size and without distortion, but the space around the subject is very interestingly curved.

How to choose the right lens

If you decide you need a fisheye lens, here are a few tips to help you avoid disappointment after your purchase.

Consider the size of the matrix of your camera when purchasing a lens. For a full-frame camera, a focal length of 15-16 mm will suffice, for a crop sensor camera, a lens with focal length 8-11 mm.

Of the two types of lenses available - diagonal and circular - the first is the most preferred. Examples suitable lenses: Canon EF 15mm F/2.8 Fish-eye, MS Zenitar-M.

This lens is unlikely to become your main working lens, the scope of its use is too narrow. But for replenishing the arsenal of means of artistic expression, it is really good and worthy of taking its place in the photographer's bag.

The Fisheye lens is not often seen as an essential tool among professional landscapers and urban landscapers. People see them as little more than a wide-angle effect with specific distortion. Many don't even like this species lenses due to this distortion.

You can change your mind after working with fisheye optics for a while. For example, the Samyang 12mm F/2.8 Fisheye lens offers a lot of new possibilities, and most importantly, it's fun to work with.

Attach a fisheye optic and study your surroundings through the viewfinder. You will see the world in a completely new way, which will open up scope for creativity. And that is not all. The fisheye can also be very useful in taking pictures that would normally require a lot of effort or are not possible at all with other optics. Think of shots from above, the code that distorts the lines actually gives meaning to the image.

Here are a few reasons why you should consider using ultra wide angle lenses.

1 Distortion

The distortion can be annoying. But don't be so critical of him. Use the ultra-wide lens distortion to your advantage. Find scenes where the fisheye effect adds something interesting. Try using this effect to work with leading lines.

The following shot of Hong Kong with slightly distorted buildings works well with the curved road shapes:

2 Alignment capability

Sometimes fisheye lenses can be used as wide angle lenses. By placing the horizon in the middle, you will usually get an almost straight line. Some tools in image editors will help straighten out the distortion to get super wide-angle images with straight lines.

3 Use with round shapes

A fisheye usually curves straight lines. So if you're photographing curved shapes, the curvature becomes less noticeable. Try to photograph pipes, round stairs, intersections, etc.

The curved horizon completes this frame by making a full circle.

4 Angles

You can get incredible lines by tilting the lens up. Using different tilt angles, you can get incredible shots.

5 Great for backstage

This lens is good for capturing what's going on behind the scenes during photo shoots, video shoots, hikes and trips, etc.

6 Creative portraits

Try taking wide-angle selfies or portraits. Don't put people too close to the edge or you'll get a lot of distortion.

7 Creativity

Fisheye can create shots that would not be possible with normal lenses. Try to keep the ultra-wide lens on the camera for a longer period of time, and study your surroundings through the viewfinder. You will be amazed at how much you can see on the camera screen compared to what you see with your own eyes.

Using wide-angle lenses opens up a whole world of possibilities. Get creative and have fun!

Lenses are divided by viewing angle. In addition, each type of optics can be divided into more precise categories. Wide-angle optics can be divided into ultra-wide-angle and fisheye (fisheye). When developing wide-angle optics, developers try to correct all distortions as much as possible. In the case of the fish eye, everything is different. These lenses have the strongest distortion.

How can a photographer use fisheye lens distortion?

AT real life building lines are straight. The wide-angle lens tried its best to make them look like they are in the photo, and it succeeded. The fisheye did not overwork much and bent all the lines in a way that was more convenient for him. That's the kind of design he has. The center of the fisheye frame keeps the lines straight. They are rounded only to the edge of the image.

Fisheye is great for artistic photography. It is often used in architectural and landscape photography. Shooting people with such optics is a bit comical. Faces and body proportions are greatly distorted.

If your goal is to convey maximum realism in your photo, then fisheye is not for you. Now virtual reality systems are becoming more widespread, and a fisheye lens can be useful for shooting spherical panoramas. Creating curved lines at the edge of the frame is the price to pay for a very wide viewing angle. Fisheye can accommodate an image almost 180 degrees from all sides.

Fishies are different. There are optics that provide a viewing angle of 180 degrees diagonally. Some lenses produce a round image that accommodates a 180-degree view in all directions, but these lenses are rare because they produce very unusual round shots on a rectangular sensor. Because of this, the corners are black.

If you have a camera with an APS-C sensor, then you need to take fisheye specifically for this sensor format. If you use optics from a full-frame camera, then due to the crop factor, all the charm of a wide viewing angle will be lost. Fisheye lenses allow you to create images with very unusual geometries. Flat squares are distorted, and buildings, poles and trees whirl intricately. If you change the angle of the camera, you can get completely new types of familiar places.

Conventional wide-angle lenses create smooth horizontal and vertical lines. These pictures look very familiar.

Don't think that buying a fish eye will allow you to experiment endlessly. In fact, the functionality of such optics is limited. It will make all your frames look the same. Even if the plot changes, all of them will be similar to each other, so such shooting must be done in a dosed manner and create really interesting plots.

Fisheye is a bulge effect in the central part of the image. It is achieved by using special lenses or manipulations in photo editors, in our case - in Photoshop. It is also worth noting that some modern action cameras create this effect without any additional actions.

First, let's select the source image for the lesson. Today we will work with a snapshot of one of the districts of Tokyo.

Image distortion

The fisheye effect is created in just a few steps.

After clicking, we will see just such an already distorted frame with a single central point. By moving this point in the vertical plane, you can change the strength of the image distortion. If the effect suits, then press the key Input on keyboard.

We could stop there, but the best solution would be to emphasize the central part of the photo a little more and toned it.

Adding a vignette

As a result, we get the following vignette:

Toning

Toning, although not a mandatory step, will add more mystery to the picture.

 

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