My understanding is that shorter focal lengths lead to wider FOVs due to more light striking the lens. If so, why are the pictures not brighter then? (Unless other factors were adjusted before printing here)
kujjwal
I'm not 100% sure, but I believe that since the intensity would be the same, the smaller sensor in the camera due to a shorter focal length wouldn't be able to represent the image in as great quality causing the perception that the picture is less bright.
jayc809
I believe with a higher field of view there would be more distortion in the edges of the image. I think this might have something to do with the different ratios of world space units to the image space pixels at different parts of the scene. For example, an object that is 10 meters wide at the edge of the image will take up more pixels since its rays will intersect the image plane at an slanted angle. On the other hand, another object 10 meters wide in the center of the image will take up less pixels since its rays will be more incident to the image plane.
SuryaTalla22
One question I have is how does our phone focus on certain objects, causing objects at a different distance to be blurry. Is there a way for us to simulate this effect with computer graphics?
jerrymby
If the imaging sensor's size is fixed, I believe that shorter focal length & wider field of view is going to us brighter images. However, you won't see over exposure because of the shutter speed difference. The wide FOV & short focal length setting is compensated by a longer exposure time for instance.
aidangarde
What are the limits for focal length? It seems in these images that larger focal lengths produce better quality images and avoid the fisheye effect. My guess is that larger focal lengths require more sensitive equipment to capture a larger effect fov. Further more, longer focal lengths are bulky and hard to deal with. Proper focal length cameras are inconvenient to use and transfer, and embedding equipment lengths in smaller devices require smaller and more sensitive components to compensate.
sebzhao
I'm kind of curious how focusing works inside the camera. I looked into it, and interestingly, auto focus is actually enabled by small motors inside the lens itself that put the subject into focus.
el-refai
It is interesting how much FOV can impact fisheyeness and the distortion we see in images. This can have a substantial impact on computer vision algorithms since this distortion can be hard to correct with classical methods.
jacky-p
The shorter the focal length the larger the field of view, but I feel like at certain points it begins to distort the image, like that of 15mm/fisheye. It leads to more of following the shape of the lens and adds a curve, although I would like to say that recently fisheye style images have become very popular and quite interesting images to look at.
omijimo
Is the distortion by focal length fixed no matter what? would it be possible to reduce the distortion by using an already distorted lens, or something similar?
agao25
@omijimo I feel like camera companies are definitely designing newer lens with more unique shapes to combat fisheyeing for photographers who want the smaller focal length, but to @jacky-p's point, fisheyes images are definitely trending. I feel like if you could also put a filter on top of the lens or add another lens, and that might be able to reverse the effect of fisheyeing. I wonder if that picture would look even weirder or if it would like more normal like in 14 mm. I'm also curious why the 15 mm has the fisheye effect but the 14mm lens with an even shorter focal length is not fisheyeing? Maybe the photographer did add a corrective measure
yangbright-2001
I am also quite curious about the logic and implementation of macro shot in cameras or phones. For example, when we shift our lens closer to a flower or a person, the objects behind them will typically become blurry, making the flower or person more clear, as a contrast.
AbhiAlderman
It's interesting to see how the "fishbowl effect" comes from a shorter focal length. This makes sense intuitively, as the increase in FOV means more of the scene needs to be "rendered" into the camera. To fit the objects that are more "outside" the camera's range, the image itself ends up distorting into a bowl shape. Inversely, as the focal length is lengthened, we get more of a "point" effect. The FOV decreases and we zoom into the center of the image, almost like looking through a telescope or magnifying glass. In fact, this same principal, along with the help of mirrors/multiple lenses, is how telescopes and microscopes work.
My understanding is that shorter focal lengths lead to wider FOVs due to more light striking the lens. If so, why are the pictures not brighter then? (Unless other factors were adjusted before printing here)
I'm not 100% sure, but I believe that since the intensity would be the same, the smaller sensor in the camera due to a shorter focal length wouldn't be able to represent the image in as great quality causing the perception that the picture is less bright.
I believe with a higher field of view there would be more distortion in the edges of the image. I think this might have something to do with the different ratios of world space units to the image space pixels at different parts of the scene. For example, an object that is 10 meters wide at the edge of the image will take up more pixels since its rays will intersect the image plane at an slanted angle. On the other hand, another object 10 meters wide in the center of the image will take up less pixels since its rays will be more incident to the image plane.
One question I have is how does our phone focus on certain objects, causing objects at a different distance to be blurry. Is there a way for us to simulate this effect with computer graphics?
If the imaging sensor's size is fixed, I believe that shorter focal length & wider field of view is going to us brighter images. However, you won't see over exposure because of the shutter speed difference. The wide FOV & short focal length setting is compensated by a longer exposure time for instance.
What are the limits for focal length? It seems in these images that larger focal lengths produce better quality images and avoid the fisheye effect. My guess is that larger focal lengths require more sensitive equipment to capture a larger effect fov. Further more, longer focal lengths are bulky and hard to deal with. Proper focal length cameras are inconvenient to use and transfer, and embedding equipment lengths in smaller devices require smaller and more sensitive components to compensate.
I'm kind of curious how focusing works inside the camera. I looked into it, and interestingly, auto focus is actually enabled by small motors inside the lens itself that put the subject into focus.
It is interesting how much FOV can impact fisheyeness and the distortion we see in images. This can have a substantial impact on computer vision algorithms since this distortion can be hard to correct with classical methods.
The shorter the focal length the larger the field of view, but I feel like at certain points it begins to distort the image, like that of 15mm/fisheye. It leads to more of following the shape of the lens and adds a curve, although I would like to say that recently fisheye style images have become very popular and quite interesting images to look at.
Is the distortion by focal length fixed no matter what? would it be possible to reduce the distortion by using an already distorted lens, or something similar?
@omijimo I feel like camera companies are definitely designing newer lens with more unique shapes to combat fisheyeing for photographers who want the smaller focal length, but to @jacky-p's point, fisheyes images are definitely trending. I feel like if you could also put a filter on top of the lens or add another lens, and that might be able to reverse the effect of fisheyeing. I wonder if that picture would look even weirder or if it would like more normal like in 14 mm. I'm also curious why the 15 mm has the fisheye effect but the 14mm lens with an even shorter focal length is not fisheyeing? Maybe the photographer did add a corrective measure
I am also quite curious about the logic and implementation of macro shot in cameras or phones. For example, when we shift our lens closer to a flower or a person, the objects behind them will typically become blurry, making the flower or person more clear, as a contrast.
It's interesting to see how the "fishbowl effect" comes from a shorter focal length. This makes sense intuitively, as the increase in FOV means more of the scene needs to be "rendered" into the camera. To fit the objects that are more "outside" the camera's range, the image itself ends up distorting into a bowl shape. Inversely, as the focal length is lengthened, we get more of a "point" effect. The FOV decreases and we zoom into the center of the image, almost like looking through a telescope or magnifying glass. In fact, this same principal, along with the help of mirrors/multiple lenses, is how telescopes and microscopes work.