and here I thought the rectal linear lens was used in a colonoscopy.

Fisheye lenses have lower focal lengths the further you get from the centre. So in your example the focal length at the centre may be 12 but it will get to 8 or 9 by the edge of the frame. Hence the distortion and the wider effective view. I think!

Great video, very informative. Never knew that the Rectilinear lens existed. Learn something new everyday.

never used a fisheye before but I've had my temperature taken the rectilinear way before

good comparision in field of view between 11mm Rectilinear and 12mm Fisheye!

Nice explanation . Recently purchased a Rokinon 14mm 2.8 and an 8mm 3.5 .Waiting for the ice age to end to use them LOL . I always enjoy your videos . Great content .

@dwightlooi

4 ай бұрын

A simpler way to explain the difference is that in a perfect rectilinear lens, light entering further from the center of the lens is rendered on the focal plane proportionally from center of the image. In a fish eye, light entering further from the center is rendered progressively less far from the center of the image. Imagine a rectangle, the corners are further away from the center than the middle of the sides, however they are rendered closer from the center than they should be hence everything is distorted like a barrel. However, any line going through the dead center of the image will appear straight because all the compression as you move further out is also along the same line. A fisheye captures more imagery because while the focal length is specific to the center, the progressive compression pulls in more imagery.

The rect type will enlarge things toward the edges. A standing person would appear to have large head and legs.

Great channel Dave Sir. I think the etymology of the tetm "fisheye" comes ftom the 180 degree FOV that some of those lenses have. A fish perhaps has similar FOV with eyes both sides of its head. This is merely my view. Perhaps i am wholly incorrect! 🎊👌🎉👍🎊

@Appletank8

Жыл бұрын

So, if you could somehow tape two lenses onto the sensor…

Come for debunking, stay for learning about lenses. High end photography is black magic. At least for now. Lots to learn

Rectalliner lenses are so cool

Dave, when are you going to fix the cables in the background? The cable there on the left is very distracting. Can't you just put an extension on it and route it above the field of view? And the same on the shelving on the right. I think if you use those cable channels with about the same width as the shelving frame then it could look as an extension to it if you put two of them right below the frame. Other than that, great video, I had no idea these lenses even existed.

@DaveMcKeegan

Жыл бұрын

It's on my to-do list 😁 I've a few changes planned to address these but i'm waiting on some stuff becoming available in the next few weeks

Good video, What is the difference between the different degree angles of the fisheye lenses, for example 180° or 220, 250°? I hardly see any difference when I watch videos. And what I would also be interested in is how you get that peephole look with it?

i have question so i was planning to move tp new system canon r ,and i have 3rd party lenses.. while my tamron 24-70 g1 and canon 135 f2 work great on new system my sigma ex DG 85 1.4 creates circles when shoot wide open..at f2 works, great but on wide open every pic have circles, y? and is there solution for this without selling my fast lenses and buying new

Re-upload?

I'd like to use a fish eye, but knowing it will eventually get damaged as you can't protect the main element I just can't justify buying one, that and not being able use any filter on it whatsoever lol.

So then what is even the point of a fisheye lens? Like why would you ever want to use it practically? Why is it used today at all?

@chickenspaceprogram

Жыл бұрын

Probably for certain shots, or for creative effect.

@widicamdotnet

Жыл бұрын

One way to put it: a rectilinear lens "expects" to be looking at a flat surface, while a fisheye lens expects to be looking at the curved surface of the inside of a sphere. Shooting a flat surface with a fisheye lens artificially enlarges the center, but shooting the inside of a sphere with a fisheye lens gives you a balanced representation of that object over the entire image. Extremely wide-angle rectilinear lenses overemphasize the edges while shrinking down the center, this can lead to "tunnel vision" with some scenes. Same problem as projecting the earth onto a flat map - different projections are useful for different purposes.

@0LoneTech

Жыл бұрын

A fisheye lens may for instance give a much easier field of view for stitching a panorama, with less uneven resolution. It's impossible to take a rectilinear image 180 degrees or wider, and you would rarely even want to get close to that limit. For instance IMAX Dome uses fisheye imagery, without distorting because they display it through a fisheye projector on a curved screen, 180 by 125 degrees.

@okaro6595

9 ай бұрын

With a fisheye you get 180 degree view. That can be quite dramatic. There actually are two types of fisheyes full frame (not to be confused to full frame in the sensor size, completely different) and circular. A circular fisheye provides 180 degrees to any direction. A full frame fisheye has 180 degrees from corner to corner only. Not with APS.-C lenses the angel of view can be somewhat different from 180 degrees because of different sensor sizes.