Beginner ISO and things like that.

Oldbones

Oldbones

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I am as green as grass about ISO and such, but I am learning a bit as time passes..
Just bought an issue of Amateur Photographer, just to see what photography is actually about, so far I have just flicked through it.
Noticing that most of the images have the camera setting printed on them.
This is a great help to me.
Its a steep learning curve, and already I feel like I have to put more thought into what I actually do with a camera, I think my point and shoot days are over now, so exciting.
Looking for good compositions and framings is also what I need to work on, its exciting and thought provoking, some of the images I see on here are amazing, and I want to achieve the same such things or at least get better than what I am now.
So ISO, it looks like a lot of the images have a low ISO 80, 100 most of the time, and a few have quite high settings, but I don't see what ISO actually is doing.
The good thing is I can take images as much as I want, simply because they are digital.
F stop is another thing I need to find out about, but ISO is what is on my mind right now.
 
Oldbones said:
F stop is another thing I need to find out about, but ISO is what is on my mind right now.
Click to expand...

The exposure triangle:

Shutter speed - how long the sensor is exposed to light.

Aperture - how much of the available light the lens is allowing through.

ISO - how sensitive the sensor is to light falling on it.

A balance of these 3 aspects controls the overall exposure. Many of us also tend to bias the balance in one direction to favour the kind of picture we're taking, often fixing 2 aspects and varying the 3rd. So:

Shutter speed - a short exposure can freeze movement, a long exposure can show movement. Think high-speed action or a waterfall:

Action! by Anton Ertl, on Flickr

Cascade de Brisecou by Anton Ertl, on Flickr

Aperture - at it's simplest this also controls how much of the image is in focus, so a very wide aperture means only parts of the image at the focus point are sharp, a small aperture means there is much deeper field of focus:

Spring - apple blossom 2 by Anton Ertl, on Flickr

London sky drama 2 by Anton Ertl, on Flickr

ISO-sensitivity - Low sensitivity such as 100 or less gives a finely detailed image with very little noise or grain. It may also give good recovery of underexposed shadows that can be brought up during processing. High sensitivity such as 6400 or now very much more often tends to result in noisy images with sensor artifacts readily visible, poor shadow/highlight detail and sometimes affected colours. HOWEVER modern sensors are VERY good about noise compared to those from 10 or 15 years ago.

An example of good shadow recovery, balancing intensely bright sunlight against shadows under the arch:
Waiting on the corner, Mogador by Toni Ertl, on Flickr
 
You've had some very helpful answers, which should help to get you started.
I've written a book for beginners, PM me your email address and I'll gladly send you a copy of it, which may help some more.
Oldbones said:
Just bought an issue of Amateur Photographer, just to see what photography is actually about, so far I have just flicked through it.
Noticing that most of the images have the camera setting printed on them.
This is a great help to me.
Click to expand...
I used to supply photography magazines with images, they always asked for the camera settings but, like most people (pre-digital at least) I never supplied them because they didn't matter, because I didn't remember what they were and because I never kept records.

So, what did (all) of the magazines do? They made them up. So, ignore, for example, 125th second at f/11. It may or may not be correct:)
 
Most D3*00s I see get used have the mode dial set on green. Which a lot of time means the pop up flash pops up. Pop up flash is as useful as a chocolate teapot in daylight unless you are taking portraits (fill-in).

Stick it on 'P', and then once you get the feel of how the camera selects its' settings start using 'A' if you are shooting landscape or 'S' for action.

Unfortunately, your camera doesn't support auto-ISO IIRC, so you do need to keep an eye on shutter speed and not let it too slow. The advice above is super, take heed! Hope to see some of your images on here.
 
If you change aperture or ISO to let more light in or make the sensor more sensitive, then you will have to adjust another setting to compensate and get the same exposure.

For example, if you leave your aperture alone, but increase your ISO by a whole stop, you'll need to adjust your shutter speed to double to get the sale exposure.

If you leave your ISO alone but increase your aperture, you'll also need to increase your shutter speed.

Handy things to know: when people say smaller aperture they mean that the hole in the lens is smaller, this is represented by a BIGGER F number. I have always thought of the F number as being 'one over F'. A half is bigger than an eighth, 1/2 is bigger than 1/8, so an aperture of f/2 is bigger than f/8.

A doubling of ISO number is a doubling of the sensitivity. ISO200 is half ISO400. But ISO 1600 is 4x ISO 200. ISO3200 is double ISO1600.

You should use the exposure triangle for creative purposes and (typically) ISO is not used creatively. Most cameras can do Auto ISO as well as Shutter Priority, Aperture Priority and manual mode. These let you pick one setting and have the camera sort the rest out. Want to freeze action? Shutter Priority, speed set high, let the camera do the maths on the other settings. Want a small depth of field? Set the Aperture priority to a wide aperture and let the camera do the legwork on the others.

Personally I set the camera to manual mode with Auto ISO on. That way I can maintain control of the two creative corners of the triangle and let the ISO sort itself out. Just be semi mindful that the ISO doesn't get too out of hand for your usecase and for what your camera and editing software can handle. Grain can look good, but its often avoided.
 
The Amateur Photographer magazine has been going for well over 100 years now and when I first started buying it around 1963 it was informative and explained things very clearly the workings of ISO (Called ASA in those days) and how one of thee three factors inextricably affected the other two. Today the AP is a mere shadow of its former self because they no longer explain the workings and what could be done in the dark room (understandably) or how to improve their results by personal knowledge and use. They could get back to the essential basics by explaining how to use the various programmes like Photoshop which I suggest is learned by many (most) in a ' lets see what this button does' scenario

The relationship between ISO, shutter, and aperture, has not really changed since the days of William Henry Fox Talbot whether it is film+ darkroom or memory card + computer programme.

This has not been fully replaced by the finer workings of the digital and how to get the best out of you electronic masterpiece. The last copy I bought about a year, possibly a bit longer ago, to me seemed to be a free showcase of the next piece of equipment and how much easier it will make your photography. Not how to improve what you are doing with what you have got already. Perhaps that is what people want, I don't know. There was only a very, very brief mention of how to compose a picture, how light and shade can affect the final result, in fact it just seemed to gloss over everything fundamental, to glorifying technology, which is fine free advertising for the equipment manufacturers but of little practical use to the person wanting to learn about photography.
 
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Rodinal said:
The Amateur Photographer magazine has been going for well over 100 years now and when I first started buying it around 1963 it was informative and explained things very clearly the workings of ISO (Called ASA in those days) and how one of thee three factors inextricably affected the other two. Today the AP is a mere shadow of its former self because they no longer explain the workings and what could be done in the dark room (understandably) or how to improve their results by personal knowledge and use. They could get back to the essential basics by explaining how to use the various programmes like Photoshop which I suggest is learned by many (most) in a ' lets see what this button does' scenario

The relationship between ISO, shutter, and aperture, has not really changed since the days of William Henry Fox Talbot whether it is film+ darkroom or memory card + computer programme.

This has not been fully replaced by the finer workings of the digital and how to get the best out of you electronic masterpiece. The last copy I bought about a year, possibly a bit longer ago, to me seemed to be a free showcase of the next piece of equipment and how much easier it will make your photography. Not how to improve what you are doing with what you have got already. Perhaps that is what people want, I don't know. There was only a very, very brief mention of how to compose a picture, how light and shade can affect the final result, in fact it just seemed to gloss over everything fundamental, to glorifying technology, which is fine free advertising for the equipment manufacturers but of little practical use to the person wanting to learn about photography.
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Printed magagines have been wiped out by the internet, and are no longer relevant. AP used to be funded by the endless pages of camera shop adverts, which used to list every single item of stock.

Magazine staff used to have subjective interest and knowledge, that's also gone now, with magazines staffed by a tiny number of people who have to provide content for every one of the specialist magazines owned by the same group, for example someone who writes for a camera magazine also has to write for a motorbike magazine, a detectorist magazine, a boating magazine and so on.

A great deal of the techo stuff on the internet is just wrong, simply because literally anyone can publish, but the camera magazines had their fair share of wrong content too:(
 
I have an issue with most explanations of ISO for digital... ISO is not "sensitivity to light." The sensor only has one (or two in some cases) sensitivities/reactivities to light; and that is at the base ISO(s).

With digital ISO is simply a brightness adjustment... it is very much like the brightness adjustment for your monitor. Take a low light/noisy image and make it brighter and it will look worse (be more obviously noisy); make it darker and it will look "better." The same type of thing happens with audio and volume settings/adjustment during recording/playback.
 
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sk66 said:
I have an issue with most explanations of ISO for digital... ISO is not "sensitivity to light." The sensor only has one (or two in some cases) sensitivities/reactivities to light; and that is at the base ISO(s).

With digital ISO is simply a brightness adjustment... it is very much like the brightness adjustment for your monitor. Take a low light/noisy image and make it brighter and it will look worse (be more obviously noisy); make it darker and it will look "better." The same type of thing happens with audio and volume settings/adjustment during recording/playback.
Click to expand...


But it is turning up the gain of the amplifiers to give the effect of raising the sensitivity to that ISO number, so as it is on a camera, it is more useful to have the level displayed in ISO numbers than numbers 1-11.

The resultant signal to noise ratio depends on a number of factors and really none of the technicalities around using ISO and what it really means have much relevance to the average camera user.
 
sk66 said:
I have an issue with most explanations of ISO for digital... ISO is not "sensitivity to light." The sensor only has one (or two in some cases) sensitivities/reactivities to light; and that is at the base ISO(s).

With digital ISO is simply a brightness adjustment... it is very much like the brightness adjustment for your monitor. Take a low light/noisy image and make it brighter and it will look worse (be more obviously noisy); make it darker and it will look "better." The same type of thing happens with audio and volume settings/adjustment during recording/playback.
Click to expand...
I read somewhere they called it gain.
 
Sangoma said:
But it is turning up the gain of the amplifiers to give the effect of raising the sensitivity to that ISO number, so as it is on a camera, it is more useful to have the level displayed in ISO numbers than numbers 1-11.
Click to expand...
The only real benefit of calling it ISO and using ISO numbering (rather than 1-11) is just convention and not confusing old photographers coming over from film. In the CIPA standard it does state that the REI ISO value should approximately equate to the value a handheld light meter would give; so it provides some "backwards compatibility" with previous knowledge/understanding/equipment.

SsSsSsSsSnake said:
I read somewhere they called it gain.
Click to expand...
Yes, it is analog (op amp) gain; just as it is with an audio signal (ignoring digital ISO values).
 
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ancient_mariner said:
Your technical explanation is spot on, of course Steven, but it's much easier to explain the simple effect of variable ISO by presenting it as sensitivity.
Click to expand...
Why is that easier than "brightness setting" (or analog gain)? When, in fact, "brightness setting" is much more accurate and more correctly explains the effects of changing the ISO.

It is certainly simpler to understand for anyone coming from film due to the rough correlation. But as with most over-simplifications; it is also prone to error/confusion. I.e. increasing ISO does not increase image noise; if anything it decreases recorded image noise (non-invariant cameras). And understanding the difference between actual sensitivity and analog gain allows one to understand the advantages that dual ISO sensors and ISO invariant cameras have.

I would even argue that ISO is not, and never was, an exposure variable. The exposure triangle actually *is/was aperture, shutter speed, and light. The choice of ISO is simply a compensation for the amount of light. And with film, once you loaded the film it was no longer a variable.
It is only that, for some reason, very few consider(ed) changing the light (direction, time, source, weather, etc,); when in fact that is a much more significant factor. And ISO has only become "a variable" to change per image/exposure with the advent of digital.

(*or, if you prefer; the exposure factors do not create a triangle; it is a polygon...)
 
Oldbones said:
So ISO, it looks like a lot of the images have a low ISO 80, 100 most of the time, and a few have quite high settings, but I don't see what ISO actually is doing.
The good thing is I can take images as much as I want, simply because they are digital.
F stop is another thing I need to find out about, but ISO is what is on my mind right now.
Click to expand...

I think a good experiment could be to take a series of pictures at increasing ISO's and to repeat this exercise in different lighting and see if any are too bad for you to look at and enjoy. I'd recommend taking pictures in different lighting as some artificial lighting can make things look worse at relatively low ISO's or at least that's been the case for me.

Given the choice between reducing shutter speed and possibly ending up with blur or widening the aperture and reducing depth of field increasing the ISO and having some noise but having the shutter speed and depth of field you want may be a better option, sometimes.
 
sk66 said:
Yes, it is analog (op amp) gain; just as it is with an audio signal (ignoring digital ISO values).
Click to expand...
Not for long, class D opamps will soon be common place, and lower noise, with much lower heat dissipation.
 
Oldbones said:
So ISO, it looks like a lot of the images have a low ISO 80, 100 most of the time, and a few have quite high settings, but I don't see what ISO actually is doing.
Click to expand...

It doesn't really matter what ISO is called, or how it actually works in the camera, it's a term that is universally understood and allow photographers to converse and advise etc

If you leave the shutter speed and aperture the same, and increase the ISO, the picture gets brighter.
If you leave the ISO and aperture the same and decrease the shutter speed (ie so that it is open for longer) the picture gets brighter.
If you leave the ISO and shutter speed the same and reduce the f number (making the iris wider) the picture gets brighter..




The only problem with increasing the ISO is that after passing through the electronics, the "picture" signal has some "noise" added to it, and the more you boost the "picture" the worse the ratio of "picture" to "noise" becomes.

Maybe an easy way to observe this is to have a room very quiet, and turn the hifi volume (with nothing playing) right up. Unless it is a top end hifi, you will hear some sound from the speakers, maybe a bit of white noise (hiss) and or a bit of hum. That noise would not be audible with the volume control at a lower level.
Now, play a loud piece of music (bright light for a photo) and you would need to turn the volume control down, to a point where the hiss/hum would not be audible if the music was not playing. When you listen to that piece of music, the comparative levels of the music to the noise is great, so the noise does not impact on the music.
Then play and extremely quiet passage (low light for the camera), and you need to turn the volume control right up. Now the noise would become audible, and the music would be polluted by the noise, as the comparative levels of the music and noise would be small.
The volume control controls the gain (degree of amplification) of the amplifier.


The camera has a ISO control that does the same as the volume control on the hifi, it controls the gain of the amplifiers in the picture line in the camera.
The camera has several sources of noise, like the sensor and the amplifier electronics, but the end result is the same as the hifi, the higher the ISO (gain) the worse the ration between the picture and the noise is.

(This is not intended to be a technical explanation, but just intended to help explain the effects to the OP)


As suggested by WW experiment with your camera (might make things easier if you let us know what it is, unless I missed that) to see what the effects are. (Actual numbers vary from camera to camera)

Don't worry about the exposure triangle if it confuses more than helps you, it is not intuitive!

I will post a link to some useful bite size guides later. There is a lot on the internet, unfortunately many are so full of personal experiences and gumph that the facts you want are hidden amongst them, and are hard going to read.
 
Hi @Oldbones and welcome to TP and the world of photography.

Whilst the exposure triangle is important to understand it’s just maths and you really should keep an eye on what you start to obsess over.

Photography is about making pictures, and along with the technical recording of the light (exposure triangle), other major considerations are focus, depth of field, composition, timing and crucially the quality of light.

In fact for most professional photographers, most of the time, the exposure calculations are left to the camera. Because it’s just maths, and the calculator in the camera can do maths easily. But no camera can decide where to go, what to shoot and when.

The biggest mistake made by new photographers is putting too much attention on the maths cos it appears complicated (it’s not) rather than the important stuff, which is not really complicated but will take you a lifetime to get good at. And that’s ’making interesting pictures’.

I suggest you start with Aperture priority mode, if you can set Auto ISO, then the only decisions you have to make are:
Aperture (determines how much of the image is in focus)
Focus on your chosen subject
Frame your photograph to create a pleasing image
Choose the point to press the shutter.

If your camera doesn’t have auto iso, pick 100 in summer, 400 in winter and higher if the light is lower.
 
Some knowledgeable people have made some very good technical points here, but let's not overcomplicate matters.

My own general rule is to use the lowest ISO setting that will do the job. For example, if I'm in the studio and want ultimate image quality and have plenty of light, my default setting is ISO 200 (which is also the native setting on my cameras). If I need a high ISO setting for, say, an action shot in poor lighting conditions, I'll use a much higher setting, on the basis that it's better to get a shot that may have some noise than a blurred shot or no shot at all.

We also need to understand that advances in technology have made the "problem" far easier. About 25 years ago I bought what was a top-end camera at the time, a Kodak DCS14-N (I think) that produced superb image quality at ISO 80 but the noise was terrible, and unusable, at ISO200. Those days are, thankfully, long gone and although not all cameras are the same, all modern cameras are now great at ISO settings that didn't even exist a few years ago.

And there's another factor too, photographer skill and experience. One of the few things that I'm good at is holding the camera still, and avoiding camera shake. That's possibly because I've been shooting rifles all my life, and rifles have to be held correctly and discharged very carefully, to get the shot on target. That transferable skill allows me to take shots with a camera with minimal risk of camera shake, but many people just can't do it and need to increase the ISO so that they can use a fairly high shutter speed.

So, to the OP - Don't worry too much about the ISO setting, it's just one of the tools in your toolbox, and far less important, most of the time, than the correct choice of lens aperture or shutter speed.

EDIT: Crossed with @Phil V , but he said it better:)
 
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Oldbones said:
I am as green as grass about ISO and such, but I am learning a bit as time passes..
Just bought an issue of Amateur Photographer, just to see what photography is actually about, so far I have just flicked through it.
Noticing that most of the images have the camera setting printed on them.
This is a great help to me.
Its a steep learning curve, and already I feel like I have to put more thought into what I actually do with a camera, I think my point and shoot days are over now, so exciting.
Looking for good compositions and framings is also what I need to work on, its exciting and thought provoking, some of the images I see on here are amazing, and I want to achieve the same such things or at least get better than what I am now.
So ISO, it looks like a lot of the images have a low ISO 80, 100 most of the time, and a few have quite high settings, but I don't see what ISO actually is doing.
The good thing is I can take images as much as I want, simply because they are digital.
F stop is another thing I need to find out about, but ISO is what is on my mind right now.
Click to expand...


This is the most useful collection I have found

shotkit.com

Learn Photography for free from Pro Photographers

Check out the easiest and most enjoyable way to learn photography with these free, in-depth guides written by professional photographers.
shotkit.com shotkit.com

I spent hours editing an making booklets for my son, and he finds it easy to read and follow (he was 11 when he started with it)
He started photography GCSE this year, and his teacher commented that he had a proper understanding of the topics they have covered so far, not just a learn the answers for the test understanding.

There are of course some things that are of no interest at all, and a very few that are poorly written or illustrated, but on the whole, easy to read concise facts with no unwanted padding.

There are of course many more, and many articles on youtube as well.
 
The pedant in me dislikes ISO being refered to as part of the exposure (Triangle)...Though I can see why it's regarded as such.
If I may liken it to getting a sun tan (Stay with me. :cool:) the "exposure" is how "bright" the sun is and how long you are exposed to it. How brown you get then depends on how sensitive your skin is.
Back to cameras. The exposure refers to how much light your sensor / film is "Exposed" to and that is controlled by how much light you let in (Aperture) and how long for (Shutter).
So sensitivity plays no part in "Exposure"...the image you get is a result of the exposure to light your sensor receives and how sensitive your sensor is.


Now let that be an end to it! :D
 
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The technicalities are fine, but they don't help the newcomer trying to understand what the setting does on the camera, and how to use it to their advantage to get photos, which is the point of a camera.




From https://shotkit.com/what-is-iso/


"There is a lot of misinformation on the internet about ISO. For the purposes of this article, I’m not going to going to get into debates about what is technically wrong or right.


(More often than not, all it does is give you bragging rights in a forum with people you don’t know!)


Instead, I thought it would be better to focus on understanding what is ISO, how it impacts your photos, and how you can leverage it to make your photos better."
 
Garry Edwards said:
My own general rule is to use the lowest ISO setting that will do the job.
Click to expand...
And depending on the equipment/camera in use, that could be a flawed approach. With most of my cameras it makes (effectively) no difference what ISO I use; the image quality will be the same. And with my Z9 the image quality may be marginally worse if I use a lower ISO when I could have used a higher one... i.e. ISO 500 is cleaner than ISOs 250-400; because the camera is actually more sensitive to light at ISOs 500+ as compared to ISO's 64-400.

I.e. the first question should be "do I have, or can I get/add, enough light"; not what ISO should I use... and that's always been the case. When creating images the quality of light should be the first concern; not something you work around.

Dave Goodier said:
This forum is 'Talk Beginners' after all :)
Click to expand...
Oops; I didn't notice that...
In my defense, I was willing to leave it as "it's actually brightness and not sensitivity; but the effect is basically the same"... at least that is what I meant to convey with my first post...

I'll step away now...:exit:
 
I'll stick to my pie chart :D

www.talkphotography.co.uk

Beginner - Exposure Triangle?

This post is meant for beginners and gives an alternative to the Exposure Triangle. Experienced photographers, especially those who grew up using film, no longer need to think about how to set or change exposure and more recent photographers have probably understood and accepted the Exposure...
www.talkphotography.co.uk www.talkphotography.co.uk
 
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sk66 said:
And depending on the equipment/camera in use, that could be a flawed approach. With most of my cameras it makes (effectively) no difference what ISO I use; the image quality will be the same. And with my Z9 the image quality may be marginally worse if I use a lower ISO when I could have used a higher one... i.e. ISO 500 is cleaner than ISOs 250-400; because the camera is actually more sensitive to light at ISOs 500+ as compared to ISO's 64-400.
Click to expand...
With respect, although you're right, I don't think that that's the point.
I say this because we all use different cameras, and one size doesn't fit all because of that. It's far easier, and far more intuitive, simply to say that we should use the default setting on our camera in good light conditions and a higher setting only when necessary, let's not complicate things for people who are just starting out . . .
sk66 said:
I.e. the first question should be "do I have, or can I get/add, enough light"; not what ISO should I use... and that's always been the case. When creating images the quality of light should be the first concern; not something you work around.
Click to expand...
The quality of light should be the first concern, whether we find it (find the best shooting position relative to the light source) or create it. But, when making decisions about ISO, it's the quantity of light that informs the decision.
 
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