ISO Aperture and shutter speed: A basic guide


For all the newbies in photography..

One of the key concepts for getting a good pic is setting the correct exposure. Exposure is basically, the measuring and balancing of light

Too much light and the picture will be washed out. Not enough light and the picture will be too dark. A good pic depends on calculating the exposure settings that will give the film the "right" amount of light.

The photographer can control how much natural light reaches film by adjusting the camera's shutter, aperture, or film speed.

All cameras have an inbuilt light meter...
It looks similar to this...

-2...-1...0...1...2
^

In some cases, the numbers may be reversed, but they still have the same meaning. These numerical positions are called "stops". A 'stop' is a rough measurement of light being exposed in your picture.

If you start with a single lightbulb(assume at 0) and then add another bulb, the light intensity will increase by one stop (1)
To increase the light by another stop you would need to double the light for a total of 4 bulbs( 2) and so on..

For simplicity...
Double the light is one stop brighter (+1 stop)
Half the light is one stop darker (-1 stop)


While you may think that at "0" the exposure its perfect, that isn't technically the case. You have to experiment with the camera and find your own "sweet spot". In my camera its usually half stop behind 0. Basically, there is no general rule for a good picture...you have to experiment. Some guys like darker photos, some prefer brighter ones... try shooting the pics yourself and figure out your style.

We will get back to stops in a little while.

ISO
Don't ask me the full form of ISO..I haven't a clue. It isn't important anyway..just meaningless trivia. Basically, ISO describes how quickly the film reacts to light.
For example.
ISO 100 has medium sensitivity to light..its usually the lowest you can go on DSLRs. At ISO 100, you get a nice contrast, and virtually no grain in the pictures. IF you shoot a pic here with the right shutter speed and aperture, you will generally get a high contrast, colorful image.
Now if you jump to ISO 400, your light settings increase by 2 stops..soo, if you shoot the same picture, making no changes to shutter speed and aperture..your picture will be overexposed..and slightly grainy. To correct the lighting, you would have to adjust the shutter speed and aperture values.

Basically,
lower numbers = slower films = need more light = longer exposures
higher numbers = faster films = need less light = shorter exposures.


The higher you go, the grainier your picture gets. I can't speak for all cameras but I do know that for Nikon D80, if you go beyond ISO 800..there is just too much noise in the picture. For the Nikon D700, you can go up to ISO 3200 and manage to get a decent shot.
As a general rule I prefer always to use ISO 100, unless there is very low light, and I am not carrying a tripod. If you have a tripod then you could just keep your shutter open for a longer period of time :)



Shutter speeds and aperture.

The shutter blocks all light from exposing the film UNTIL you press the button. Then it quickly opens and closes, giving the film a brief flash of light.

You can control the length of time the shutter remains open by setting the SHUTTER SPEED.

So basically....
Longer shutter speeds = more light
shorter shutter speeds = less light


Its common sense..
if you keep your shutter open at say..1/30th of a second, you will capture more light than at 1/125th of a second.
Sometimes when you are shooting the sun directly, you may reach speeds upto 1/3000 to 1/4000 of a second..with the appropriate aperture setting..and it could still be slightly overexposed..depending on your lens. So even though the number may look bigger, don't be deceived!

Examples:

A half second exposure is ONE STOP darker than a one second exposure.
A 1/125 exposure is TWO STOPS brighter than a 1/500 exposure.
A 1/1000 exposure is THREE STOPS darker than a 1/125 exposure.

Confused?

Best way to learn shutter speed :-
Set your camera at ISO 100 and aperture f/2.8...or the lowest equivalent that your lens might have...generally kit lenses have f/3.5.
Now go to your window and look through your camera viewfinder.
Adjust the shutter speed until your light meter points at '0' Take a picture.
Now adjust it so the light meter reads at "-1" and take a pic...do it again for "+1" (incidentally, that's what you do for creating HDR pics...but that's a tutorial for another day :) )


Hopefully that will give you a better idea on shutter speeds.

As a general rule, the 'lower' you go..that is.. at 1/60 to 1/30 to 1/15 etc.. the more blurry your picture might get, either due to movement in the background, but mostly due to your own hands shaking.

A fast shutter speed will result in “freezing” a moving object and a slow shutter speed will let you capture the motion of a moving object.

For beginners, I prefer you not go below 1/125th of a second... at least not without a tripod. Once you learn to control your hands a bit better you can reach until 1/60th of a second.



Aperture
Like the pupil in a human eye, the aperture on a camera controls light.
It does so by closing up to restrict light, and opening up to let it through.


Examples:
moving from f16 to f8 is: TWO STOPS brighter.
moving from f5.6 to f8 is: ONE STOP darker
moving from f4 to f2.8 is: ONE STOP brighter

Now, if the exposure is made with a wide aperture ( like f2.8 ), then objects farther away from the subject are thrown out of focus...which is why you see many macro shots with a blurry background. This effect is referred to as "depth of field"

So.. if the aperture is small (like f22) then objects in the background (and foreground ) will appear sharper. However, since less light is being taken in at f/22, you have to increase the shutter speed a lot..and it could result in blurring the image due to camera shaking.

Basically, you have balance it out using the "stops" in the light meter.
Since aperture and shutter are both measured in stops, keeping balance is easy. If you take away 2 stops from the aperture, you can give 2 stops back with the shutter and end up with the same exposure level.


Soooo, hope all you newbies learned something today.
A quick recap of everything.


Newbies can actually print the bottom part out, though I personally don't recommend it. The best way to learn all this is via direct experimentation. That's how I learned in the first place.

ISO
ISO 100 is always preferable unless you are in very low light conditions with no tripod.(unless you WANT noise in your picture)

Shutter speed
Try not going below 1/125th of a second without tripod, else it will result in camera shake and blurry pictures.

Aperture.
Pictures taken at f/22 will result in the background being much more clearer than at f/2.8...though most of the times you don't really want to show too many details in the background. However, f.2.8 will give you much more vivid photos and is thus extremely preferable around 80% of the time.



There is only so much one can learn from reading.
Get off your butts and go take some photos. I advise everyone to shoot in manual mode at all times. It will help you learn your camera settings faster.

Try different timings during the day and shoot different objects... landscape, portrait, bottlecaps, wall textures..virtually anything and everything. For the next week or two..just shoot everything while tinkering around with the settings. By the end of two weeks you will have fully understood this part of your camera.

We will carry on after that..

This is Hershey Desai, over and out.
 

Thanks for the efforts. There are already several newbies guides explaining these things. You may want to help the authors to improve these first. Secondly, many newbies cannot even read their manual, more guides here won't help them much ...
Also, check the accuracy of a couple of terms and similes you use. Some are misleading, sometimes important things are missing (e.g. Depth of Field for aperture). Keep out all personal preferences (e.g. shooting f/2.8 for "vivid pictures") and other, rather subjective statements.
 

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thanks. I'm sure there are several guides for this already. In fact, even a quick search from google will help you get this info from the pros. I just thought to give out my version of it. I'm not sure which terms are misleading here though, and I can't explain the basics without adding a personal touch. That's why people don't follow manuals, because its dull and boring. For nearly three years I've taken pictures, and have noticed they are more colorful if you take them at f/2.8. Just stating the facts I've gone through my friend.

Photography by definition itself, is only good when its personalized. Same goes for photography guides :)
 

Good! Another link to bookmark.
When people start asking questions when they are lazy to read the manual, i'll slam this on their face. :D
 

Good effort :thumbsup:, I appreciate it.
 

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Good! Another link to bookmark.
When people start asking questions when they are lazy to read the manual, i'll slam this on their face. :D

Dont so bad laa.. the manual only teach you how to use the camera, whereas here in clubsnap we show and demo how to use..clubsnap version more clear and easier to learn then the stupid manual :)
 

Just a few things to point out- there might have been some that I missed out. Reason for this is that I think newbies or novices (or whatever) should be taught the correct things from the start. This is my opinion anyways, feel free to disagree.

The higher you go, the grainier your picture gets.

It's not just increased image noise, but a decrease in dynamic range- but this opens up a whole new dimension to talk about.


For beginners, I prefer you not go below 1/125th of a second... at least not without a tripod. Once you learn to control your hands a bit better you can reach until 1/60th of a second.

It could be wiser to use the reciprocal rule, a general rule of thumb for a "safe" shutter speed to use without the resulting image suffering from visible camera shake is 1/focal length but not slower than 1/50.


objects farther away from the subject are thrown out of focus...which is why you see many macro shots with a blurry background. This effect is referred to as "depth of field"

Depth of field refers to how much or how little is in focus. It does not refer to the effect of a blur background. DOF is a physics concept, not an aesthetic effect. A blurry background is caused by shallow depth of field as opposed to shooting at a higher f number which results in a greater depth of field.


However, since less light is being taken in at f/22, you have to increase the shutter speed a lot..and it could result in blurring the image due to camera shaking.

Do you mean decrease the shutter speed and not increase?

Pictures taken at f/22 will result in the background being much more clearer than at f/2.8...though most of the times you don't really want to show too many details in the background.

Photos at f22 usually have very visible diffraction though. Hence, overall sharpness of the photo may be reduced.

Most of the time you don't really want to show too many details? Not true. This is misleading, especially given that quite a number of CSers, including new learners, shoot landscape.

However, f.2.8 will give you much more vivid photos and is thus extremely preferable around 80% of the time.

What??? Really?

There is only so much one can learn from reading.
Get off your butts and go take some photos. I advise everyone to shoot in manual mode at all times. It will help you learn your camera settings faster.

But... it would be wiser to learn how to use A, S modes and then after a mastery of A and S, then a progression to M mode wouldn't it?


Yupp, that's all I picked out that I think could be improved upon. I appreciate that you made the time and effort to make this thread :)
 

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in the end depends on the beholder, some may say its too dark while others will say the same picture is too bright.
 

nope, imo i dont agree with the "shoot in manual mode at all times" part.

sometimes less is more but it really depends on the situation and there is no hard and fast rule as to how you should shoot a particular scene.

nevertheless, good effort for typing the long post out. :)
 

Shoot at f/2.8 for more vivid pictures???? What nonsense.

And yes, this is all covered, in great detail and with sample diagrams, in our newbies guides. So rather than continuing to re-hash what you learn in your courses and post your lessons here, please read up first.
 

Just a few things to point out- there might have been some that I missed out. Reason for this is that I think newbies or novices (or whatever) should be taught the correct things from the start. This is my opinion anyways, feel free to disagree.



It's not just increased image noise, but a decrease in dynamic range- but this opens up a whole new dimension to talk about.




It could be wiser to use the reciprocal rule, a general rule of thumb for a "safe" shutter speed to use without the resulting image suffering from visible camera shake is 1/focal length but not slower than 1/50.




Depth of field refers to how much or how little is in focus. It does not refer to the effect of a blur background. DOF is a physics concept, not an aesthetic effect. A blurry background is caused by shallow depth of field as opposed to shooting at a higher f number which results in a greater depth of field.




Do you mean decrease the shutter speed and not increase?



Photos at f22 usually have very visible diffraction though. Hence, overall sharpness of the photo may be reduced.

Most of the time you don't really want to show too many details? Not true. This is misleading, especially given that quite a number of CSers, including new learners, shoot landscape.



What??? Really?



But... it would be wiser to learn how to use A, S modes and then after a mastery of A and S, then a progression to M mode wouldn't it?


Yupp, that's all I picked out that I think could be improved upon. I appreciate that you made the time and effort to make this thread :)
Candycaine,
of course..novices should be taught correctly from the start. Else they end up like me :p

I have written this only according to my own observations. For me, I was never interested in the technical details of everything as long as I knew how it functioned and how I could tweak the settings.

Have no idea what the reciprocal rule is, but I know that I haven't met anyone besides Stevewhy who can shoot sharp images at speeds around 1/30th of a second without a tripod.

You got me on the DOF thing, I was just trying to explain it more simply..keeping the science part of it out.

And it is infact quite true that most of the times you don't want to show too many details in the background...but then again, I should have mentioned that its specifically for portraits. For landscapes of course you want everything as crisp as possible.

And again with the f.28 thing.
Yes. Really. Its what I've observed happening with the D80, and the D700 too, specially when I use a 50mm prime lens. The colors are a LOT more vivid.
I don't how how or why it happens...it just does. I'm merely stating my own observations.

And, well, everyone has their own learning curve. I used aperture and shutter priority modes after I was well versed with the M mode. It helped understand more quickly when to use the former two modes. There is no specific progression for that as such. To each their own though.


I'm glad you read through this in such detail to pick out the errors. I appreciate it, but please try to understand, this is just a rough guide..not a literal fact sheet. I try to keep things as simple as possible without going into the details of it only because I wasn't taught all these myself :p
My stuff was mostly through trial and error. Picked up stuff a lot faster than actually reading up all the technical details.
 

in the end depends on the beholder, some may say its too dark while others will say the same picture is too bright.
So true.
Some say its too colorful, some say its too dull.
There will always be critics for your work..whether it be in pictures or writing guides and articles ;)

The only thing that matters is whether you yourself feel the picture to be perfect or not.
 

nope, imo i dont agree with the "shoot in manual mode at all times" part.

sometimes less is more but it really depends on the situation and there is no hard and fast rule as to how you should shoot a particular scene.

nevertheless, good effort for typing the long post out. :)
well yes, technically it does depend on the situation. There will be times when the photographic opportunity is one of those split second moments.. You don't want to fiddle with the settings then.. just rush to shutter priority and snap.
But in general, when you go to basic outings like landscape or macro...times when you are relaxed and taking pictures at your own leisure...I strongly recommend to use full manual mode.
The reason is simple.
manual mode does fail at times and it is definitely better to shoot in A or S modes, but there are many instances when those fail too. At that time, only manual mode can save you...and considering it is technically the hardest mode to get used to...an early beginning helps out a lot.
For those who are used to it, its quite easy to quickly adjust the shutter and aperture to get the right shot, but for beginners, it takes time for them to get used to their camera's light settings. Manual mode makes them more familiar with the camera's internal metering simply by forcing them to finetune their own settings for that 'ideal' exposure.


There have never been any rules for photography. All the notes, all the guides, all the 'rules' are merely tips...little guidelines which you should, at first, learn and follow until you reach a point where you know when to break the 'rules' once in a while. :)
 

Shoot at f/2.8 for more vivid pictures???? What nonsense.

And yes, this is all covered, in great detail and with sample diagrams, in our newbies guides. So rather than continuing to re-hash what you learn in your courses and post your lessons here, please read up first.
RAshkae,
Yet again I say this.
f/2.8 gives more vivid pictures. Yes. No nonsense. Just my own observation. If you or anyone disagrees, its your problem. Everything varies on a person's camera and/or lens.
I have shot with the 50mm at f/2.8 countless times, and the picture HAS MORE VIBRANCE than when I shoot it at f/8 keeping the light metered exactly the same. I don't know how, I never bothered to ask why..and to be honest, I wouldn't even want to know why.


And yes, all this IS covered in extreme detail with, as you said, sample diagrams and images etc. Its written in great length in ANY photography beginners book.
But why read my humble guide? Because I am not beating around the bush.
Photography for me is about the moment, not the technical details. Shutter speed, ISO and aperture...there is a science to it.

Science is often boring and scary for novices, which is why I explained my stuff in the most basic way possible. Now I agree there may be some factual errors that the 'pros' may have a major issue with, and I can understand their frustration. My goal here is not to point out the facts via actual numbers or via picture examples...its simply to explain, 'my own personal view' of shooting pictures.

Yea sure, my 'methods' might be questionable for some of the pros...but my photographs speak for themselves.
I can go talk more on this in great lengths, but lets just move on.
After all, this is just a guide :)

There will be many more to come and I'm sure I'll have to face quite a lot of critics ahead ;)
 

I wasn't taught any of these either. That doesn't make it any less important to get the facts right because the title of this thread already implies that the information here is more or less correct. After all, it is a "basic guide". Basic does not = incorrect.

Wrt DOF, it's not whether you left the science part of it out! You misunderstood me, DOF is not the name of the effect but the concept behind the effect. You are simply using the wrong term.

Lastly, I don't believe f2.8 gives you more vivid colours. That has to do with your in-camera processing as well as your post processing. Nothing to do with f number.

Really, some of us here appreciate the effort. But if you write guides based on your observations then the least you could to was check for the factual accuracy of your observations. If not, soon you'd be writing weather reports that Singapore's weather is nice and foggy when in fact it's Sumatran haze.
 

Well, I finally understood what you were trying to say about the DoF... sooo..is there any name for the actual effect produced by the concept?
I'm not having the f/2.8 conversation again.

I'll keep in mind about cross checking some of the facts.
For the ones I miss, I have experts like you to correct my mistakes :)

An HDR tut is coming up in a short while.. hope I get it right this time
 

Well, I finally understood what you were trying to say about the DoF... sooo..is there any name for the actual effect produced by the concept?
I'm not having the f/2.8 conversation again.

I'll keep in mind about cross checking some of the facts.
For the ones I miss, I have experts like you to correct my mistakes :)

An HDR tut is coming up in a short while.. hope I get it right this time


I am curious. I'd like to see a photo at f8 and a photo a f2.8, no processing done. Really. If there is a visible difference in vibrancy of colours, then I concede with apologies. No processing done.

The out of focus parts of a photo is known as bokeh.
 

i'll post the difference here tomorrow itself. No editing whatsoever.
I thought bokeh is the thing that happens to point sources of light when they get blurred..usually when the lens is out of focus(for the background) causing mostly a ring if your aperture is at f/2.8, or a more hexagon or octagon shape depending on the flaps inside the lens???
 

i'll post the difference here tomorrow itself. No editing whatsoever.
I thought bokeh is the thing that happens to point sources of light when they get blurred..usually when the lens is out of focus(for the background) causing mostly a ring if your aperture is at f/2.8, or a more hexagon or octagon shape depending on the flaps inside the lens???

From Wikipedia,
"In photography, bokeh (pronounced /boʊ'kɛ/) is the blur, or the aesthetic quality of the blur, in out-of-focus areas of an image..."

Point sources of light become star-like at higher f numbers, under which the number of points in the "star" depends on the number of aperture blades. As far as I know, most people just call it the "star effect".