Can anyone explain, ISO, apature, shutter etc, all things I can change on my camera but I dont have a clue what they (really) are
can anyone explain...............
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I take it you're on about a film camera Pignut,
ISO is the sensitivity rating of the film itself or how quickly it reacts to light.
Aperture is the size of the hole in the lens, which dictates how much light reaches the chemicals on the film. It also has an effect on the resulting photograph - the smaller the aperture the greater the "depth of field" or, how much in front and behind the subject is in focus.
Shutter is how fast the hole is exposed and re-covered which also controls the amount of light reaching the film.
FIlms are very sensative to light so to get a good quality photo, you have to carefully control how much gets to the film, all done by adjusting the the things you mention.
This is very much in laymans terms as there'll be photographic gurus on here who could explain things better than I ever could. Your library might have some books on photographic techniques which would be worth a read.
HTH
Ogri the trog
This applies to DSLRs as well except that ISO refers to the "speed" at which the sensor records the light - thus, giving it more time (i.e. low number) means more sensitivity and less noise. ISO is simply a convenient way of expressing this for those used to film cameras and has now become a digital standard.
Basically:
Low ISO, slow shutter and narrow aperture for Landscapes (might need a tripod)
High ISO, fast shutter and wide aperture for Action
Depth of field is important to know about - basically, how much of the image is in sharp focus - narrower apertures give greater depth of field.
Hope it helps. The secret is to experiment - the "film" costs nothing!
My images (if you're interested):
http://www.accidentalimage.co.uk/
Have a read of this. It goes into a bit more detail than has already been said and may help you understand it a little more.
http://photographyjam.com/articles/29/camera-basics-shutter-speed-aperture-and-iso
Hope this helps.
http://photographyjam.com/articles/29/camera-basics-shutter-speed-aperture-and-iso
Hope this helps.
Washed out landscapes usually have more to do with the quality of the light when the photograph was taken rather then the photographer or the camera.
Slow speed and low ISO should give more detail and less noise. For saturation:
1. Try adding a polarising filter to the front of your lens - it cuts out reflection.
2. Under expose by half a stop or two thirds of a stop (i.e set a slightly faster shutter speed) This should saturate the colours more but you will lose shadow detail.
3. Increase saturation in you image software (easy in Photoshop or Elements)
4. Shoot early and late - low sun behind you makes the colours pop! And since the sun is so much lower in the winter sky, now is a good time to try.
5. Calibrate your monitor - There should be some applet hidden in Windows to do this. This way you get a more realistic view of what you took.
6. When you print, the image is usually darker (and therefore more saturated) than the backlit screen view. Getting the balance between screen and print can be an expensive business - I use trial and error.
Slow speed and low ISO should give more detail and less noise. For saturation:
1. Try adding a polarising filter to the front of your lens - it cuts out reflection.
2. Under expose by half a stop or two thirds of a stop (i.e set a slightly faster shutter speed) This should saturate the colours more but you will lose shadow detail.
3. Increase saturation in you image software (easy in Photoshop or Elements)
4. Shoot early and late - low sun behind you makes the colours pop! And since the sun is so much lower in the winter sky, now is a good time to try.
5. Calibrate your monitor - There should be some applet hidden in Windows to do this. This way you get a more realistic view of what you took.
6. When you print, the image is usually darker (and therefore more saturated) than the backlit screen view. Getting the balance between screen and print can be an expensive business - I use trial and error.
For your landscape photography Pignut, try to under expose a touch, ⅓ of a stop (eg, increase the shutter speed or lower the iso or close the aperture).
With it being washed out, it sounds like you are over-exposing, letting too much light in.
Have you got an example you could post, I do better troubleshooting with seeing
PS, I can write some tuts for you Tony, PM sent
With it being washed out, it sounds like you are over-exposing, letting too much light in.
Have you got an example you could post, I do better troubleshooting with seeing
PS, I can write some tuts for you Tony, PM sent
Hi Tony,
My original qualifications are in Photographic Science and Applied Sensitometry I could have a go if someone wants to give me a topic or two!
Andy
Pignut,
That’s a big question if you really want to know, but I’ll try and lay down the basics.
For this explanation I’ll regard film and digital as the same entity, although they have their own nuances. But in essence they are both a method of “capturing” light, focused by a lens on a receiver (a piece of film or a bank of charged coupled devices etc) to record an image.
ISO – international Standards Organisation
speed of 1 sec allows the “film” to be This is a numeric representation of the sensitivity of originally film, but has been adopted to represent the sensitivity of digital devices too, as photographers had already wrapped their heads around it, but I will refer to both capture mediums as “film” because I’m old fashioned. It replaces the older ASA/DIN measurements which I won’t bother boring you with.
A doubling of the ISO number signifies a doubling in the sensitivity of the “film” and vice versa. Therefore a “film” of 200 ISO is twice as sensitive as a “film” of 100 ISO. This doubling relationship is important in photography. And will become clear once we understand the term EXPOSURE.
Exposure
Exposure is the total amount of energy, to be absorbed by the “film”, that is required to accurately record a scene. It is an absolute amount, more or less delivers an over or underexposed image and this impinges on the quality of the recorded image. For any situation there is only one correct exposure value but you can arrive at this in a number of ways.
Exposure is governed by film speed (or the sensitivity of your digital camera) represented in ISO, shutter speed and aperture and each one of these variables can have an effect on the result.
“Film” speed
As already stated is measure in ISO, the bigger the number the more sensitive it is and therefore the LESS ENERGY (light) it will require to record your image. The down side of this is that with both film and digital the higher the ISO, the lower the quality the final image will be, I won’t go into the reasons for this here. So, in a low light situation, to put a “fast” film in or wind up the ISO on your digital camera is not always the solution if you want quality images.
Shutter speed
Once you have chosen the sensitivity of your “film”, that defines how much energy must pass through the lens – not much for a high ISO much more for a low ISO – to accurately record it, but for every scene there is one discrete amount of light required. The passage of light through the lens is controlled by both the shutter speed and the aperture. The “shutter speed” is actually the length of time the “film” is exposed to the light coming through the lens, only when you press the shutter release is the light reflected from the subject allowed to act on the “film”. So a shutter exposed to light for 1 sec, a shutter speed of half a sec... yep I know I’m labouring the point but it highlights the fact that your shutter speed settings half or double depending which way you are going up the scale (with a few minor mathematical corrections that I won’t go into here)
So if you had a perfect exposure with a shutter speed of half a second at an aperture of X and an ISO of 100, then changed the shutter speed to 1 sec but didn’t change the aperture, suddenly you would have twice as much energy acting on the “film” – you’ve doubled the time the light hits the “film” - result – over exposure. BUT because of this doubling relationship, you could change your film (or reset your digital camera) to 50 ISO (half as sensitive) and you now have a perfect exposure again for the same scene.
As mentioned there are drawbacks to all things, the issues with shutter speed are to do with the extremes of the range and the subject matter. I won’t go too much into the issues at the extremes of the range but you can enter an area where the linear relationship between shutter speed and aperture breaks down, this is called low and high intensity reciprocity law failure but probably won’t be encountered in the vast majority or normal photographic situations, but it’s good to tell the truth The other issue with shutter speed is how it captures the image if the image is moving. Imagine the effect of a very slow shutter speed on a fast moving racing car – blurred with a capital B (there are ways around this if for some reason you with to use a slow shutter speed – panning, ask if you want to know). BUT as with all things, you can use this issue as an advantage if you wish, just look at some of Wayland’s lovely images of moving water to see it in practice. Conversely, a very fast shutter speed used to capture a dramatically fast subject can freeze the action too much resulting in a “sterile” image that looses all its excitement. Also there can be issues with the effect of a second shutter curtain especially when using flash – but again this is something for another day.
Aperture
The aperture is the “size” of the whole that light travels through before it strikes the “film”. It’s an adjustable baffle and its “size” is expressed in f-numbers or f-stops (don’t ask – you thought you were bored already) and, slightly counter-intuitively, the smaller the number the bigger the hole the more light it can let through (the more expensive the lens) – so f.32 is a pin *****, f.1.4 is, well it lets loads of light through. You will notice again that these numbers more or less double again (with mathematical anomalies) and their effect does double. So f.8 lets through twice as much light as f.16 which lets through twice as much light as f.32.
So back to the example, this time not changing the film speed (ISO). A perfect exposure for a scene is say f32 at 1 sec, this is exactly the same exposure as f16 for half a sec, as f8 for one eighth of a sec, as f5.6 (one of those anomalies) for one sixteenth of a sec... All of these give the same EXPOSURE! Not much light for a long time to lots of light for a short time.
So why bother having all these options? Similar issues, anomalies and effects apply as with shutter speed. With very small and very large apertures there can be anomalies due to issues with the optics of the lens, which I won’t discuss now. Using the extremes can push the shutter speed into areas of reciprocity law failure – on rare occasions. The most useable effect to bear in mind is that as the aperture gets smaller the depth of field becomes greater, but this and use of the hyperfocal distance are topics for another thread if anyone’s interested. As is assessing the correct exposure which is a whole other huge can of worms and probably one of the most common errors encountered.
Hope that is of some help, if it’s way off the mark let me know and I’ll spend more than a few minutes trying to explain.
That’s a big question if you really want to know, but I’ll try and lay down the basics.
For this explanation I’ll regard film and digital as the same entity, although they have their own nuances. But in essence they are both a method of “capturing” light, focused by a lens on a receiver (a piece of film or a bank of charged coupled devices etc) to record an image.
ISO – international Standards Organisation
speed of 1 sec allows the “film” to be This is a numeric representation of the sensitivity of originally film, but has been adopted to represent the sensitivity of digital devices too, as photographers had already wrapped their heads around it, but I will refer to both capture mediums as “film” because I’m old fashioned. It replaces the older ASA/DIN measurements which I won’t bother boring you with.
A doubling of the ISO number signifies a doubling in the sensitivity of the “film” and vice versa. Therefore a “film” of 200 ISO is twice as sensitive as a “film” of 100 ISO. This doubling relationship is important in photography. And will become clear once we understand the term EXPOSURE.
Exposure
Exposure is the total amount of energy, to be absorbed by the “film”, that is required to accurately record a scene. It is an absolute amount, more or less delivers an over or underexposed image and this impinges on the quality of the recorded image. For any situation there is only one correct exposure value but you can arrive at this in a number of ways.
Exposure is governed by film speed (or the sensitivity of your digital camera) represented in ISO, shutter speed and aperture and each one of these variables can have an effect on the result.
“Film” speed
As already stated is measure in ISO, the bigger the number the more sensitive it is and therefore the LESS ENERGY (light) it will require to record your image. The down side of this is that with both film and digital the higher the ISO, the lower the quality the final image will be, I won’t go into the reasons for this here. So, in a low light situation, to put a “fast” film in or wind up the ISO on your digital camera is not always the solution if you want quality images.
Shutter speed
Once you have chosen the sensitivity of your “film”, that defines how much energy must pass through the lens – not much for a high ISO much more for a low ISO – to accurately record it, but for every scene there is one discrete amount of light required. The passage of light through the lens is controlled by both the shutter speed and the aperture. The “shutter speed” is actually the length of time the “film” is exposed to the light coming through the lens, only when you press the shutter release is the light reflected from the subject allowed to act on the “film”. So a shutter exposed to light for 1 sec, a shutter speed of half a sec... yep I know I’m labouring the point but it highlights the fact that your shutter speed settings half or double depending which way you are going up the scale (with a few minor mathematical corrections that I won’t go into here)
So if you had a perfect exposure with a shutter speed of half a second at an aperture of X and an ISO of 100, then changed the shutter speed to 1 sec but didn’t change the aperture, suddenly you would have twice as much energy acting on the “film” – you’ve doubled the time the light hits the “film” - result – over exposure. BUT because of this doubling relationship, you could change your film (or reset your digital camera) to 50 ISO (half as sensitive) and you now have a perfect exposure again for the same scene.
As mentioned there are drawbacks to all things, the issues with shutter speed are to do with the extremes of the range and the subject matter. I won’t go too much into the issues at the extremes of the range but you can enter an area where the linear relationship between shutter speed and aperture breaks down, this is called low and high intensity reciprocity law failure but probably won’t be encountered in the vast majority or normal photographic situations, but it’s good to tell the truth
The other issue with shutter speed is how it captures the image if the image is moving. Imagine the effect of a very slow shutter speed on a fast moving racing car – blurred with a capital B (there are ways around this if for some reason you with to use a slow shutter speed – panning, ask if you want to know). BUT as with all things, you can use this issue as an advantage if you wish, just look at some of Wayland’s lovely images of moving water to see it in practice. Conversely, a very fast shutter speed used to capture a dramatically fast subject can freeze the action too much resulting in a “sterile” image that looses all its excitement. Also there can be issues with the effect of a second shutter curtain especially when using flash – but again this is something for another day.Aperture
The aperture is the “size” of the whole that light travels through before it strikes the “film”. It’s an adjustable baffle and its “size” is expressed in f-numbers or f-stops (don’t ask – you thought you were bored already) and, slightly counter-intuitively, the smaller the number the bigger the hole the more light it can let through (the more expensive the lens) – so f.32 is a pin *****, f.1.4 is, well it lets loads of light through. You will notice again that these numbers more or less double again (with mathematical anomalies) and their effect does double. So f.8 lets through twice as much light as f.16 which lets through twice as much light as f.32.
So back to the example, this time not changing the film speed (ISO). A perfect exposure for a scene is say f32 at 1 sec, this is exactly the same exposure as f16 for half a sec, as f8 for one eighth of a sec, as f5.6 (one of those anomalies) for one sixteenth of a sec... All of these give the same EXPOSURE! Not much light for a long time to lots of light for a short time.
So why bother having all these options? Similar issues, anomalies and effects apply as with shutter speed. With very small and very large apertures there can be anomalies due to issues with the optics of the lens, which I won’t discuss now. Using the extremes can push the shutter speed into areas of reciprocity law failure – on rare occasions. The most useable effect to bear in mind is that as the aperture gets smaller the depth of field becomes greater, but this and use of the hyperfocal distance are topics for another thread if anyone’s interested. As is assessing the correct exposure which is a whole other huge can of worms and probably one of the most common errors encountered.
Hope that is of some help, if it’s way off the mark let me know and I’ll spend more than a few minutes trying to explain.
So we have
This was taken with the "Auto" setting
ISO 400
S 1/400
App F5.6
ISO 200
S 1/60
App F36
ISO 200
S 1/160
App F6.3
ISO 200
S 1/500
App F5.6
ISO 200
S 1/16
App F36
This was taken with the "Auto" setting
ISO 400
S 1/400
App F5.6
ISO 200
S 1/60
App F36
ISO 200
S 1/160
App F6.3
ISO 200
S 1/500
App F5.6
ISO 200
S 1/16
App F36
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