Lens design

It does change the angle of view

>>2987105
It changes depth of field.

Why would it? It just lets more or less light in depending on how far it is opened, but that doesn't really affect the angle now does it?

>>2987168
Yes but how?

>>2987169
h-how what?

On the subject of lens design

I've been googling, but I can't find any reading material about lens design. It's all lackluster wiki pages, which can only be found if I specifically search fro "Tessar" etc.

>>2987170
make a circle with your hand in front of your eye, now make it smaller, you see less! but this doesn't happen with apertures getting smaller

>>2987173
https://en.wikipedia.org/wiki/History_of_photographic_lens_design

Everything you need to know anon.

>>2987174
Poke a small hole in a piece of card with a drawing pin and hold it very close to your eye, whoa, you can now make things out clearer.

The main difference in a camera is the aperture is either behind or in the middle of the lens, so does not restrict the image circle.

>>2987169
light spreads out, it doesnt continue in a straight line when passed through a hole, it doesnt reduce the viewing area

>>2987182
This has nothing to do with lens design. You've just made a wide angle pinhole changing the focal lenght.

File: Capture d’écran 2016-12-21 à 15.34.47.png (24KB, 595x420px) Image search: [Google]

24KB, 595x420px

>>2987182
>>2987204

File: illustration-how-aperture-works-2.gif (25KB, 360x410px) Image search: [Google]

25KB, 360x410px

literally 10s in google

>>2987226

That does a terrible job of answering op's question though.

>>2987227
>>2987226

Also

>aperture in front of the lens

lol wut

File: DSF5994reg.jpg (217KB, 620x473px) Image search: [Google]

217KB, 620x473px

>>2987228
you can have the iris in the front depending on the lens

[EXIF data available. Click here to show/hide.]

Camera-Specific Properties:
Equipment Make	FUJIFILM
Camera Model	X-E1
Camera Software	Adobe Photoshop CC (Macintosh)
Maximum Lens Aperture	f/2.8
Sensing Method	One-Chip Color Area
Focal Length (35mm Equiv)	61 mm
Image-Specific Properties:
Image Width	4896
Image Height	3264
Number of Bits Per Component	8, 8, 8
Pixel Composition	RGB
Image Orientation	Top, Left-Hand
Horizontal Resolution	300 dpi
Vertical Resolution	300 dpi
Image Created	2014:06:30 21:24:13
Exposure Time	1/240 sec
F-Number	f/4.0
Exposure Program	Aperture Priority
ISO Speed Rating	500
Lens Aperture	f/4.0
Brightness	5.8 EV
Exposure Bias	1.3 EV
Metering Mode	Average
Light Source	Unknown
Flash	No Flash, Compulsory
Focal Length	40.70 mm
Color Space Information	Uncalibrated
Image Width	620
Image Height	473
Rendering	Normal
Exposure Mode	Auto
White Balance	Auto
Scene Capture Type	Standard
Sharpness	Normal
Subject Distance Range	Unknown

>>2987229

It's extremely uncommon (your lens is made by a single guy in japan) and that image is pretty misleading because of it. it's basically reversed.

>>2987231
I never said it was common or not just that it's not misleading because it can be done

It's also irrelevant to the image because its easy to imagine it on the other side as well as it's functionally the same

>>2987233

It's easy to imagine it on the other side if you understand aperture. if you're a newbie, it's only more confusing.

>>2987239
Yeah so you should definitely just teach people the basics so they never want to learn anymore so when they see a rudimentary image that explains how depth of field works they go

>aperture in front of lens lolwut

>>2987227
>>2987228
How do you manage to function as a living human being? Do you have breathing aids?

>>2987240

Or maybe you should teach people the basics simply and in a straightforward manner, so that they have a strong foundation to assess exotic situations later on in life when they encounter them.

don't be butthurt because of i disregarded your technicality and misleading image, kiddo. it's not your fault you can't explain things well. it's a natural byproduct of thinking you know more than you actually do.

>>2987242

No, I just have regular AIDs.

>>2987243
>it's not your fault you can't explain things well. it's a natural byproduct of thinking you know more than you actually do.
>don't be butthurt because of i disregarded your technicality and misleading image, kiddo

You sure I'm the one that's butthurt

>>2987249

Yes.

introducing the aperture behind or in front of the entire lens assembly causes, respectively, pincushion or barrel distortion - exactly because of "changing the angle of view" - to dumb it down - and of course only at very small apertures - which is exactly why aperture assemblies are always, preferrably (cutting costs or simplifying design aside), in between optical elements of the lens - so that the distortions caused by the aperture being, respectively, behind the front element(s) and in front of the rear element(s) effectively cancel eachother out.
This is applied in the early double meniscus or, regretably called - "periscope lens"(the term was overtaken by the other more famous periscope so google wont help) design.

I wish I was less of a fag to fit this in fewer simpler words.

It does. However the effect is one of restricting the angles from which light is permitted to reach the focal plane, thereby increasing the range of depths at which the resulting image is in acceptable focus. Think of it as a smaller aperture causing less blur to reach the focal plane.

This is also the reason why large-aperture prestige lenses (f/1.4 and bigger on 35mm eqv.) tend to be softer and have less edge contrast wide open regardless of focus; the brighter areas leak in more.

>>2987263
reminder that this slav is the giannis of misinformation

ITT: millenials not being able to understand a simple image depicting a natural phenomenon

>>2987394
You don't know what the fuck you're talking about. You think you're answering the question, but you're nowhere near. UR TOO INTELLIGENT FOR THIS THREAD XDDDD

>>2987366
That's pretty annoying with older lenses like my 1.4 non-AI nikkor from the 60's.

File: Peacockingmini.jpg (261KB, 1151x800px) Image search: [Google]

261KB, 1151x800px

>>2987078
Hey OP, the optical stop is normally placed in the middle of the lense to restrict any mechanical vignetting it might introduce.
The light travelling through the lense is inverted and spat out the other end upside down and back to front, so they stop down the crossover point. If you take a lense and stop it down, holding it in front of your face, looking from the front, you can still see a clear path through the lense as you move it around within the lenses' angle of view, it's just a smaller path.
What the stop does is filter the light coming through the lense, so that progressively, as you stop down, only light pointing directly from your subject straight at your imaging plane straight through the centre of the lense is permitted to pass.
Think about the way light operates; it bounces in all directions off almost everything. The exception is a mirror, for example, which bounces light off it in a very orderly fashion.
If you look at something across the room, and then move your head 3cm to one side, you can still see it. That 3cm represents the distance from the middle of your 85/1.2 to the outer periphery of its wide open aperture.
That means your very expensive f/1.2 lense will take that entire, 6cm wide wedge of light emanating from that point object, and converge it back into a point (relatively) at the focal plane. When you stop down to f/5.6, it's only converging a 1cm wedge now, and accordingly, it's a shitload sharper, but also a lot less light, so your exposure time increases.
>>2987226 is a useful diagram, because it shows why you get more blur as you open the stop; because it's letting such a wide beam of light through the lense, it reconverges at wildly different points relative to the imaging sensor/film. All of those narrow, in focus beams are also getting through of course, but they're swamped by the massive amount of outof focus light in your final exposure.

[EXIF data available. Click here to show/hide.]

Camera-Specific Properties:
Equipment Make	Canon
Camera Model	Canon EOS 550D
Camera Software	GIMP 2.8.14
Image-Specific Properties:
Horizontal Resolution	72 dpi
Vertical Resolution	72 dpi
Comment
Projection	Rectilinear (0)
FOV	9 x 6
Ev	13.25
Color Space Information	sRGB

>>2987452
I didn't understand a word you said

>>2987452
>EOS 550D
lol faggot

>>2987452
Not OP but actually that makes sense, thanks.

>>2987452
Sweet blow out sky

>>2987263
pretending to know what you're talking about while asking for attention about your sexual orientation that no one asked about

>>2987452
based anonymous providing actual explanation with facts and science and reasonable and responsible language choices

tripfags are such scum