Bit of a correction. The f-stop is not the physical size of the aperture, but the size of the entrance pupil, which is the apparent size of the aperture when viewed through the front of the lens.
@@johndododoe1411 yes, the f-stop is the ratio between the focal length and the apparent size of the entrance pupil when viewed through the front of the lens.
Each stop doubles the area, so two stops double the diameter and thus the number . One stop is thus square root of 2 bigger . Hence the list 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32 .
@@reneeschke The iris covers the lens opening to reduce the amount of light that reaches the center . Lena manufacturers place the iris at a position where doing so has the traditional effect . The iris stop is the focal length divided by the hole diameter . So at F5.6, the hole leftover in a 56mm lens is 10mm in diameter . In a 280mm telephoto lens, F5.6 would open the iris to 50mm wide .
@@reneeschkeArea = (Diameter²)*π/4, which can be rearranged to Diameter = √(Area*4/π), meaning when you ×2 the Area (the goal of f-stops) then you only ×√2 the Diameter, so although the Area doubles per stop, the f-stop (based on the diameter of the iris(?)) only increases at the rate of the multiplicative half, which is √2.
Not to be a dh but there’s other people on this platform that have made videos about this. Anthony’s video is serving as a intro and hopefully this inspires you to go do more research 😁
I recommend reading about this sorta thing. Not just on forums. And if you want a video, then there are existing ones. I’m sure if you search ‘f stop explained’ you’ll get heaps of videos or ‘lens aperture explained photography’
There's a in-depth course called lectures in digital photography by Marc Levoy here in TH-cam. There's more in-depth explanations about these things in there. Check it out if you have the time and dedication
To be more precise, the number represents the size of 'entrance pupil' diameter, not the actual aperture size. Entrance pupil is the aperture when viewed from the front of the lens, which is different than the actual size of the aperture. This is the easiest to visualize in variable aperture zooms. When we zoom in, the aperture from the back doesn't actually change size, but when viewed from the front the entrance pupil looks like it become smaller because the optics moved, thus we have larger aperture number (smaller aperture).
I trained under a master photographer 30 years ago. I used to teach post-grad photography a long time back. You are the first person, apart from myself, who I have ever seen explain the incredibly basic mathematics of how the F-stops are just related to the diameter and surface area of the diaphragm. So simple, so useful to know, so neglected. Now, do you know why we had 8 bit colour channels? I’ll give you a clue. Humans can typically perceive 255 shades of grey between black and white. ;-)
Thank you for reminding me the formula for finding the diameter of the apertures and the area thereby of an aperture! If d is the diameter of an aperture then the radius of that aperture d/2 and the corresponding area would be π×d²/4 and we can easily find the each of the areas covered by each aperture! Therefore, f/2 for a 70mm lens would give 70/2mm Or 35mm diameter at f/2 and the area covering the almost circular aperture is about 22×17.5²/7 sq mm!
This guy is a legend. All this knowledge has leveled up my gear choices and general knowledge on camera bodies and the gears that works best for me, not every gear you recommend was for me, but there are some like the prograde card and the Rode wireless pro, then the knowledge on how to use ND filter and CPL filters. I just want to say a big thank you.
Insightful. Now what does a smaller aperture provide to a photo versus a larger aperture-50mm vs. 25mm (f/2)? Does it mean like letting in more or less light into photo?, Things like wider means more picture versus less opening of the lens?
@@elestudiodebuenavista628If you want to run a photography business, most of the time will not be spent on photographing people. It’s mostly paper work, networking, editing, etc. Making that art really needs to be a passion for you if you want to be successful.
@@Boris-dq3ub you probably already know this but generally gross profits will be relatively high and net profits low. The margin can vary based on experience, equipment costs, location, business expenses, business efficiency, etc. 🧸🧃
I need some advice! I currently have a Canon Rebel t3i (old I know but very reliable) paired with a 50mm lense 1.8 aperture I believe. What is another lense with low aperture but is more of a zoomed out/wide angle lense? I absolutely love the bokeh background blur
Is the ratio between the actual aperture opening and the diameter of the field lens behind the aperture opening. Unlike most people, I came to photography from astronomy. In astronomy, what is referred to as aperture in photography is referred to as focal ratio - which should be the term used.
I thought that was a fixed aperture. I get the same amount of light no matter if I'm on 180 mm or 70 mm in my lens. And I only get the same amount of light with the same size of the aperture opening open? Or am I completely wrong? But that would mean that I need to fill in 180 or 70 for the f and that gives me different results of course when using the same aperture. So now I'm completely confused
I didn’t know this 😅 but this does raise a question. If I wanted a 24mm with a 0.95 aperture. It’s just over a 21mm circumference. But 20mm f1.4 lenses are pretty huge. Do you think you can explain why these lenses have to actually be larger then with the formula suggests?
It's not the actual physical size of the actual physical aperture, it's the size that it appears to be when looking through the lens (which is a fucky concept to get you head around, but I think Gerald Undone has a good video about it). The smaller the focal length, the smaller the aperture appears to be when looking through the lens, so for f/0.95 @ 24mm, you would require a ludicrously large aperture if you wanted to cover full frame. f.95 lenses that wide do exist, but they're designed to cover m43 sensors.
its how open the front of the lens is, therefore how much light gets into the lens. but opening it more causes more of it to be out of focus, refered to as bokeh. if you open the lens to 1.8 the separation of the subject from the background will be more pronounced, and inversely if you step down to say f32 you will have the subject and the background in focus, but you will need to compensate for the lost light in other ways.
The highest iso I pretty much ever shoot at is iso 800 on my canon 70d Any higher and the noise starts to impact image quality more than I’d like due to the old and apsc sized sensor
So 50mm is the focal length...that means 50 mm is the focus distance where when an object is sharp beacuse the light rays converge at 50mm from focal plane of lens. So if f2 means 50/2 =25... then the aperture becomes double the 50 then light rays converge more nearer to focal plane that is 25mm.....is this correct?
+1 stop means 2x more light. Typical stop numbers are 1, 1.4, 2, 2.8, 4, 5.6, 8, and so on. Each one of those gaps is a "stop" different. Half of them are fractions because we're dealing with light as a 2d image, so opening the aperture 1.4 times more results in 1.4^2 (~2x) more light.
T-stops is more accurate for light gathering (in the center, it doesn't account for vignetting) but f-stops are the actual size of the entrance pupil. So two 50mm f1.4 lenses should have the same amount of background blur and the same depth to their field of focus, even if they transmit different amounts of light.
@@nedkelly2035 I realized I kinda forgot my point. Stills lenses will probably never use t-stops because it's not accurate for the look of the image. F-stops tell you how the image will look whereas t-stops are a technical exposure measurement.
If this formula is right, it still can't apply for all lenses. Example: A 600mm f4 lens would then have a 150mm (15cm) aperture diameter! The whole lens is not so fat! And: What about constant aperture zoom lenses? In a zoom lens, let's say a 24-70mm f2.8, where the aperture is the same in all focal lengths, this formula can't be relevant. 24/2.8 = 8.57mm, and 70/2.8 = 25mm.??? I hope someone has an explanation for this..
It is wrong, the actual aperture doesn't have to be that large, it only has to appear that large from the front of the lens. This is called the "Entrance Pupil". It does however mean the lens' front element has to be at least that size, but that's it. As for zoom lenses I got no idea those things are complicated. They still follow the rule but why the aperture remains constant is beyond me
@@ethan_webb Thanks for replying. Okay, so the size of the front element, and how big the aperture appears from it. Strange. In zoom lenses there are probably more factors, perhaps distance inside the lens or something. Thanks again for explaining 😊
I watch this dudes shorts solely out of anger. 😂 who is his target?? AFAICT its for people who can buy the higher end consumer level gear but have very little actual know-how and need the most basic photographic factoids.
Because if you multiply the diameter of the aperture with the square root of 2 (≈1.41) you get twice the area/ 2x the amount of light. This equals 1 stop. And 1.2 x 1.41 ≈ 1.8
Bit of a correction. The f-stop is not the physical size of the aperture, but the size of the entrance pupil, which is the apparent size of the aperture when viewed through the front of the lens.
I was wondering about that since some lenses have f0.8
It's diameter divided by focal length . An F/0.8 lens is short with a wide hole to let in more light to the sensor .
@@johndododoe1411 yes, the f-stop is the ratio between the focal length and the apparent size of the entrance pupil when viewed through the front of the lens.
😅
You kinda got it right
Each stop doubles the area, so two stops double the diameter and thus the number . One stop is thus square root of 2 bigger . Hence the list 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32 .
Oml that makes so much sense tysm
I see the numbers working out, but dont quite get it logically.
@@reneeschke The iris covers the lens opening to reduce the amount of light that reaches the center . Lena manufacturers place the iris at a position where doing so has the traditional effect . The iris stop is the focal length divided by the hole diameter . So at F5.6, the hole leftover in a 56mm lens is 10mm in diameter . In a 280mm telephoto lens, F5.6 would open the iris to 50mm wide .
@@johndododoe1411 what I see but dont get is the relation of "1 stop doubles area, so 2 stops double diameter of 'open iris'"
@@reneeschkeArea = (Diameter²)*π/4, which can be rearranged to Diameter = √(Area*4/π), meaning when you ×2 the Area (the goal of f-stops) then you only ×√2 the Diameter, so although the Area doubles per stop, the f-stop (based on the diameter of the iris(?)) only increases at the rate of the multiplicative half, which is √2.
I need a Detailed video on LENS covering the topics :
1. Technical terms
2. How they work
3. Types and varieties
4. tips and tricks
this dude isn’t the only source of info on the internet.. i understand recommending content but if you need it there is elsewhere
Second. This short barely makes any sense
Not to be a dh but there’s other people on this platform that have made videos about this. Anthony’s video is serving as a intro and hopefully this inspires you to go do more research 😁
I recommend reading about this sorta thing. Not just on forums. And if you want a video, then there are existing ones. I’m sure if you search ‘f stop explained’ you’ll get heaps of videos or ‘lens aperture explained photography’
There's a in-depth course called lectures in digital photography by Marc Levoy here in TH-cam. There's more in-depth explanations about these things in there. Check it out if you have the time and dedication
To be more precise, the number represents the size of 'entrance pupil' diameter, not the actual aperture size. Entrance pupil is the aperture when viewed from the front of the lens, which is different than the actual size of the aperture. This is the easiest to visualize in variable aperture zooms. When we zoom in, the aperture from the back doesn't actually change size, but when viewed from the front the entrance pupil looks like it become smaller because the optics moved, thus we have larger aperture number (smaller aperture).
I’m still processing this after the 3rd watch
My 3g brain 🫨
Me hear words. Me no understand words.
Basically aperture is how much light, so like he says f/2 of a 50mm lens is 25mm meaning you are getting 25mm of light 👍
but what does 25mm of light mean to us 😐
oh, it means it's brighter 😮
I trained under a master photographer 30 years ago. I used to teach post-grad photography a long time back. You are the first person, apart from myself, who I have ever seen explain the incredibly basic mathematics of how the F-stops are just related to the diameter and surface area of the diaphragm. So simple, so useful to know, so neglected. Now, do you know why we had 8 bit colour channels? I’ll give you a clue. Humans can typically perceive 255 shades of grey between black and white. ;-)
Damn, camera lenses are the beauty of science ❤
Thank you for reminding me the formula for finding the diameter of the apertures and the area thereby of an aperture!
If d is the diameter of an aperture then the radius of that aperture d/2 and the corresponding area would be π×d²/4 and we can easily find the each of the areas covered by each aperture! Therefore, f/2 for a 70mm lens would give 70/2mm Or 35mm diameter at f/2 and the area covering the almost circular aperture is about 22×17.5²/7 sq mm!
Remarkably informative!
Thanks very much, first time understanding this 😊
This guy is a legend. All this knowledge has leveled up my gear choices and general knowledge on camera bodies and the gears that works best for me, not every gear you recommend was for me, but there are some like the prograde card and the Rode wireless pro, then the knowledge on how to use ND filter and CPL filters.
I just want to say a big thank you.
Bloody brilliant, I’ve been doing fotografy for decades and never knew about this phormula
Time for me to sleep, but I'll definitely be watching the full video tomorrow after work!
Insightful. Now what does a smaller aperture provide to a photo versus a larger aperture-50mm vs. 25mm (f/2)? Does it mean like letting in more or less light into photo?, Things like wider means more picture versus less opening of the lens?
400 weddings and I just learnt how aperture stops calculated 😂love videos like this! ❤
@@Boris-dq3ubI want too to be photographer, I love spending my afternoon shooting in the beach. And making my passion into a job it would be a dream
Just goes to show that wedding photography is mostly an ability to handle stress 😂
I guess probably 100-200$ per wedding @@Boris-dq3ub
@@elestudiodebuenavista628If you want to run a photography business, most of the time will not be spent on photographing people. It’s mostly paper work, networking, editing, etc.
Making that art really needs to be a passion for you if you want to be successful.
@@Boris-dq3ub you probably already know this but generally gross profits will be relatively high and net profits low. The margin can vary based on experience, equipment costs, location, business expenses, business efficiency, etc. 🧸🧃
I need some advice! I currently have a Canon Rebel t3i (old I know but very reliable) paired with a 50mm lense 1.8 aperture I believe. What is another lense with low aperture but is more of a zoomed out/wide angle lense? I absolutely love the bokeh background blur
Can u explain what STOP is? And where to find them in the settings or understand them?
Fascinating videos. Please do them without the distracting music. Thank you.
Valuable information thanks
18-105 f4 or 17-70 f2.8 which will you prefer for a aps c body??
Not the best explanation lol, but i appreciate the try for sure. Needed to be broken down/simplified a little bit more/better
Is the ratio between the actual aperture opening and the diameter of the field lens behind the aperture opening. Unlike most people, I came to photography from astronomy. In astronomy, what is referred to as aperture in photography is referred to as focal ratio - which should be the term used.
So does it mean that if you have a cheap 120 mm lens with F 3.5 aperture give better bokeh than a 35 mm lens with F1.2, as the diameter is more?
Telephoto lenses usually give better Bokeh than wide lenses. But that 35mm f/1.2 will have better low light performance than that 120mm at f/3.5
120mm is Better for depth of field even tho it’s f/3.5 but f/1.2 is better for low low situations
120 / 3.5 = 34,3 Diameter ; 35 / 1.2 = 29,2 Diameter so u probably have slight more opening with the 120.
So 105mm at F4 lets in more light than 24mm at F4? Since the opening is larger ?
I thought that was a fixed aperture. I get the same amount of light no matter if I'm on 180 mm or 70 mm in my lens. And I only get the same amount of light with the same size of the aperture opening open? Or am I completely wrong?
But that would mean that I need to fill in 180 or 70 for the f and that gives me different results of course when using the same aperture. So now I'm completely confused
Now compare F stops to T stops 😎
Nice info 💯
Great! Insightful
I didn’t know this 😅 but this does raise a question. If I wanted a 24mm with a 0.95 aperture. It’s just over a 21mm circumference. But 20mm f1.4 lenses are pretty huge. Do you think you can explain why these lenses have to actually be larger then with the formula suggests?
It's not the actual physical size of the actual physical aperture, it's the size that it appears to be when looking through the lens (which is a fucky concept to get you head around, but I think Gerald Undone has a good video about it). The smaller the focal length, the smaller the aperture appears to be when looking through the lens, so for f/0.95 @ 24mm, you would require a ludicrously large aperture if you wanted to cover full frame. f.95 lenses that wide do exist, but they're designed to cover m43 sensors.
@@patrickmeyer2802 okay thanks. I’ll try to check out that video.
This earnt a sub
Today I learned something new
It would be cool to see a graph of diameter against f stop
Does it mean that 50mm f/1.2 and 85mm f/2 gets the same amount of light?
Using the same formula and a 24-70mm f2.8 lens, is the diameter of 24mm/2.8 the same as 70/2.8?
Thank you 😊
So I’m just about to start out with DSLR. I’m getting a couple of lenses. This just has me baffled. What is the effect of different F’s?
its how open the front of the lens is, therefore how much light gets into the lens. but opening it more causes more of it to be out of focus, refered to as bokeh. if you open the lens to 1.8 the separation of the subject from the background will be more pronounced, and inversely if you step down to say f32 you will have the subject and the background in focus, but you will need to compensate for the lost light in other ways.
Holy heck. Never would’ve known that. Thanks!
Great, now i also need math for photography... 💀
You need math in life kid
@@coin777 What kid lmaoo 😭💀
@@coin777not everyone is amused by math and calculations like you
So, how does the famous f/0.98 lens work?
The highest iso I pretty much ever shoot at is iso 800 on my canon 70d
Any higher and the noise starts to impact image quality more than I’d like due to the old and apsc sized sensor
Can we use Tstops
Anyone who engages in visual astronomy nose this is the focal ratio. The follicle ratio in photography perhaps people would understand it better
For m43 lenses would you use the m43 numbers or the full frame equivalent
The f stop of mft is doubled just as focal length is, so i imagine just use full frame equivalent
So 50mm is the focal length...that means 50 mm is the focus distance where when an object is sharp beacuse the light rays converge at 50mm from focal plane of lens.
So if f2 means 50/2 =25... then the aperture becomes double the 50 then light rays converge more nearer to focal plane that is 25mm.....is this correct?
Aperture science! For the good of all of us, apart from those that are dead 🎂
What camera and lens did you use for this video?
How this helps me to take better photos?
wait so does that mean that 2.8 on a 24-70 is different than the 2.8 on my 70-200?
What does "One full stop" means? Can someone explain, please?
+1 stop means 2x more light. Typical stop numbers are 1, 1.4, 2, 2.8, 4, 5.6, 8, and so on. Each one of those gaps is a "stop" different. Half of them are fractions because we're dealing with light as a 2d image, so opening the aperture 1.4 times more results in 1.4^2 (~2x) more light.
What's better a cheap second hand camera for 300 or a phone
Cheap second hand camera for sure
my math teacher after saying today will be a fun lesson
I need another video explaining this video
Actually, use of T-stops would be more accurate, but that has never been adopted and probably never will be in still photography.
T-stops is more accurate for light gathering (in the center, it doesn't account for vignetting) but f-stops are the actual size of the entrance pupil.
So two 50mm f1.4 lenses should have the same amount of background blur and the same depth to their field of focus, even if they transmit different amounts of light.
@@TechnoBabble Correct. Optics 101.
@@nedkelly2035 I realized I kinda forgot my point. Stills lenses will probably never use t-stops because it's not accurate for the look of the image.
F-stops tell you how the image will look whereas t-stops are a technical exposure measurement.
Been wanting a 24mm 1.2......need to win a small lottery 😭😭😭😭
What's the stop
What is a stop though
All you need to know is it's half the area. F2 = 1/2 the area. Nothing to do with diameter. It's area.
It's actually the inverse square. 1.4 ² is 2. 2² is 4. 2.8² is 8
Oh my… took me a few attempts to understand but… does that mean that a 24-70 f/2.8 is lighter than the 14-24 f/2.8?🤨
So do.... aperture reduces on APS C ?
No
@@AndriiDibrova thankiiiiiiiii
@@AndriiDibrova so.... In reality... APS-C never have same perspective of lens as written on lens (even if it's made for APS-S itself) ? 😀
@@Work-Horse focal distance (mm) for aps-c if you use full frame lens is always 1.5 times more, but aperture and other specs stay the same
@@AndriiDibrova many many thanks Brother 😀😀🌝😁🌝🌝
This is why t-stop is better
Me with no camera no lens 🥲
Still confusing 😕 i need full video on it
Example for nikon z 50/f2.0 z 50 /f1.8
Sorry it’s 1.25 stops.
Dude ... 1.4 is a stop ... no need to complicate it to get views 1. 1.4. 2. 2.8 .... etc.
How is f0.95 possible then?
Waiting for him to start talking about the physics of optics. Hopefully next video…😂
F4 vs F16 ?
F/1.4 when?
Or you could just go with the smaller the number the blurrier the background 😅
1.8 is 1,5 times smaller than 1.2
Seven times Four equals splevndyfour.
Please explain again
1/1.2 is not twice as big as 1/1.8 😂😂😂
If this formula is right, it still can't apply for all lenses. Example: A 600mm f4 lens would then have a 150mm (15cm) aperture diameter! The whole lens is not so fat! And: What about constant aperture zoom lenses? In a zoom lens, let's say a 24-70mm f2.8, where the aperture is the same in all focal lengths, this formula can't be relevant. 24/2.8 = 8.57mm, and 70/2.8 = 25mm.??? I hope someone has an explanation for this..
It is wrong, the actual aperture doesn't have to be that large, it only has to appear that large from the front of the lens. This is called the "Entrance Pupil". It does however mean the lens' front element has to be at least that size, but that's it. As for zoom lenses I got no idea those things are complicated. They still follow the rule but why the aperture remains constant is beyond me
@@ethan_webb Thanks for replying. Okay, so the size of the front element, and how big the aperture appears from it. Strange. In zoom lenses there are probably more factors, perhaps distance inside the lens or something. Thanks again for explaining 😊
Asks question A.. Answers question B...
Naw. It’s inversely proportional price. F1 costs a lot more than f4.
Me on f4: 😢
Homie is the reason why the community is in gear shambles shoot stop worrying about gear this content is toxic
I'm here to take pictures not do math :(
😂😂😂😂😂 he is so convinced of what he's saying 😂😂
But you didn't explain f1.2 and f1.8.
Ok, now do this math with a 600mm F4 and come back with the correct explanation after you realize a 5.9" physical aperture opening ain't it bruh
The math is literally just (1.8/1.2)²
And the end of the day we just wanna shoot in f8,f4 and f2 Lol!
I'm kinda confused 😂
I watch this dudes shorts solely out of anger. 😂 who is his target?? AFAICT its for people who can buy the higher end consumer level gear but have very little actual know-how and need the most basic photographic factoids.
Its 2 stop of difference
How did you get wildly high areas? The area should be pi×d. Your first number should be slightly higher than 155 mm^2
π*d is the perimeter not the area, the area is π*(r^2) or π*[(d/2)^2]
@@hungjuryadept3363 you're right. I was foolish and spoke without confirming.
Still don't quite get it
So how's it one stop?
Because if you multiply the diameter of the aperture with the square root of 2 (≈1.41) you get twice the area/ 2x the amount of light. This equals 1 stop. And 1.2 x 1.41 ≈ 1.8
Actually... it doesnt matter, as long as you get the shoot and is sharp ( usually two steps down) you will be ok.... or not,.. lol ,,,, ha...!!!
It’s 1.5 stops.
Stop. Just stop. Stop. It’s all about the extra stop. 😂
So show me your 180mm lens at f2 😂
You lost me at “Math”. 😂
... Ok. I'm lost. ...
I already make my life 100x harder to make a cup of coffee (coffee nerd), now even photography... nah uh uh ahhahahah
Just get 50mm f1.0