Words of the photography world

Chris989

Chris989

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Christopher
Edit My Images
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As I'm a beginner can I check that I understand some of the meanings of words in the photography world?
Aperture: (f-stop number) The aperture is the size of the lens hole, the smaller the number the wider the lens hole is.
Shutter Speed: How long the shutter is open for. The higher the number the faster the shutter.
ISO: The lower the number the darker the image. (Don't know how it works, please explain)
Af modes: Af: Automatic Focus MF: Manual Focus
WB: I know what it does but don't know how to explain. (Also don't know how it works, please explain)
Photo metering: No idea, please explain again

That's the main stuff! If I've got something wrong please correct me, I'm a beginner!
 
ISO is basically sensitivity to light. In easier words for you to understand, it helps you get photo in the dark. The more the ISO, the brighter image you get. It works similar to the way the Aperture and shutter speed works. Hope it makes some sense to you.
 
Hi Chris

Get out there and take some photos! Especially if you can move the dial away from the program/auto mode to one of the priority modes (where you set shutter speed or aperture and the camera sets the other).

You can do all the reading and watching of youtube, but there is no substitute for the experience of actually taking photographs. BUT... you also need to be able to review the photos yourself and start to build an understanding of why that photo looked the way it did - over exposed, under exposed, camera or subject movement (too slow a shutter speed - either the wrong settings or too low an ISO used), the wrong part of the picture in focus (focusing problem), not enough of the picture in focus (too big an aperture = too low an f-number), bright white patches of sky etc. (need to reduce the exposure), big black patches with no detail (need to increase the exposure), grainy picture (high ISO used)...

As you can see (and I did it deliberately), there is a huge amount to think about when taking a photo when the camera is not set to "auto". I am of the view - and I'll concede it's not a view held by all - that you need to be able to do this instinctively in order to be able to capture scenes you want consistently and in the way you want. If you can master all of that, then the camera becomes a tool which you use in the way you want. Will it take good photos? No... it will take the photos you tell it... YOU take the photos (whether they are good or otherwise!)

And that's where the real fun starts - allowing the photographer in you to come out and see the right image, knowing you'll be able to capture it with your camera precisely how you want.

But for now it's about building that instinctive relationship between you and your camera's controls, so get out there take photos. Don't expect them to be perfect (you may well end up with some real crackers though) but be critical of your shots and spend more time reviewing them than you do taking them :)

Enjoy!
 
ISO is, as Shakil has said, relates to the sensitivity to light.

This may not be exactly correct but I think it is pretty much right.

Light hitting the sensor creates a small electrical output.
This is amplified and is sent to card.
If the amplifier is turned up then the data sent to the card is increased and produces a brighter image.
Turning up the amplifier in a camera is achieved by increasing the ISO and it allows you to get a photo in darker conditions - there is a small amount of light hitting the sensor but this is amplified to give a brighter image.
However, turning up the amplifier in a camera is a bit like doing the same in a hifi. At first the sound gets louder but still sounds good, but eventually the greater amplification causes distortion.
In a camera this distortion is called noise. Going from a base ISO of 200 to 400, 800 or 1600 may not cause significant noise but, eventually increasing the ISO causes noise.
However, some cameras are better at producing noise free high ISO images.

Dave
 
Tringa said:
ISO is, as Shakil has said, relates to the sensitivity to light.

This may not be exactly correct but I think it is pretty much right.

Light hitting the sensor creates a small electrical output.
This is amplified and is sent to card.
If the amplifier is turned up then the data sent to the card is increased and produces a brighter image.
Turning up the amplifier in a camera is achieved by increasing the ISO and it allows you to get a photo in darker conditions - there is a small amount of light hitting the sensor but this is amplified to give a brighter image.
However, turning up the amplifier in a camera is a bit like doing the same in a hifi. At first the sound gets louder but still sounds good, but eventually the greater amplification causes distortion.
In a camera this distortion is called noise. Going from a base ISO of 200 to 400, 800 or 1600 may not cause significant noise but, eventually increasing the ISO causes noise.
However, some cameras are better at producing noise free high ISO images.

Dave
Click to expand...

Distortion is not the same as noise.

Setting the ISO sets the amplification level used on the signal processor.

The data coming off the sensor has noise in it (caused by heat causing random electron motion etc. etc.) and the wanted signal (the light levels). The amplifier then amplifies the signal and the noise and adds some of its own noise. The higher the amplification, the more noise it adds in general.

For a given viewing system and environment, providing the level difference between the signal and the noise is large enough, you won't really notice any noise. Increase the gain (because you're now shooting in lower light levels), the ratio between signal and noise decreases and the noise becomes more and more visible.

Distortion is different. Say your camera can record light levels between 0 and 100. You've got a person on a cloudy day - the face is at 35 and the clouds at 45 - 60. To get the face looking nice, you amplify it by a factor of 2 (change ISO from 200 to 400). The face is now nicely lit at 70 but the sky which should range from 90 - 120 has clipped all the brightness values over 100. So you've lost all the detail in the sky. This is a signal distortion, but it isn't noise.
 
Chris989 said:
Aperture: (f-stop number) The aperture is the size of the lens hole, the smaller the number the wider the lens hole is.
Shutter Speed: How long the shutter is open for. The higher the number the faster the shutter.

WB: I know what it does but don't know how to explain. (Also don't know how it works, please explain)
Click to expand...

The aperture and shutter numbers are both fractions.

For apertures people say f8 when they mean f/8. So f/11 is actually a smaller fraction of f than f/4, say.

White Balance - the eye adjusts to light sources, the camera doesn't. So you need to adjust the camera to map the colours correctly.
 
Good point st599 I ment the number not the fraction and thanks for the wb explanation. Thank you to the others who explained ISO in detail!
 
Tringa said:
Turning up the amplifier in a camera is achieved by increasing the ISO and it allows you to get a photo in darker conditions - there is a small amount of light hitting the sensor but this is amplified to give a brighter image.
However, turning up the amplifier in a camera is a bit like doing the same in a hifi. At first the sound gets louder but still sounds good, but eventually the greater amplification causes distortion.
In a camera this distortion is called noise
Click to expand...

Not quite. A better analogy would be an amplifier in a cassette tape recorder (if you remember those!). If the recording is made at a decent volume (lots of light) the amplifier doesn't have to be turned up much to get a good sound.

However, if you have a very low level recording (low light) you need to turn up the amplifier to hear it. Whilst it can bring the level up to a suitable level, it also amplifies the background noise or hiss on the tape.

There will come a point where the amplified noise is greater than the recording just as there is a point at which there is too much noise to see the image properly.


Steve.
 
White balance:
White light contains a spectrum of colours (different wavelengths). Different 'white' light sources have more or less amounts of different colours usually 'bluer' or 'redder'. Some call these 'warm' and 'cold' because at higher temperatures a light source will give off more blue and less red light. The WB settings on the camera will adjust what it thinks of as true white depending on the light source e.g strip lights are 'bluer' than tungsten bulbs. This can be adjusted manually if you shoot RAW files.
Hope this helps.

J
 
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