Framing devices are used by professionals to help them.Read More
Analogous colours are adjacent to each other in the colour wheel. This months challenge is to photograph with them.Read More
How to get the colour of your photographs right with white balance settings in camera, tools to capture the correct colour temperature at image capture, and some a couple of tutorials on how to change the colour temperature in Lightroom.Read More
Len examines what makes photograph fine art photography...Read More
Does your choice of camera matter? For me loving my camera is so so important. It comes with time, so you love the moment you see them, others take time to fall in love with. For some advice on how to fall in love with your camera read on.Read More
Who is the boss of your camera? Do you control it or do you let the electronics of the camera control you? Auto or Manual. P for program or professional? Learning to control your camera is a key ingredient to mastering your photography.Read More
ISO was originally our film speed. Our first wet plates were very very slow. Ten minute exposures were not uncommon. It is one reason that early photographs had a certain look. For example soft water in waterfalls, or the very still stances in portraits. Portrait photographers had to have a special clamp so that the models could push their heads into the clamp so they could hold still for that time. Hence the lack of smiles. We used to call ISO, ASA. These are both acronyms, ISO is the International Organisation for standards while ASA was the American version. For all intents and purposes they are the same. This is trivia unless you remember learning photography in the film days.
Digital sensors have their own quirks, just like film did. So here is a list of things you should know about ISO and how it effects your images. I have included some exercises to help you figure out how it works with you and your camera.
A small ISO number means that the sensor isn't very sensitive to light (50 or 100). A high ISO number means that your sensor is more sensitive to light (3200 or 6400). As the sensor becomes more sensitive it loses its ability to work as effectively, therefore it isn't going to give you as a large exposure latitude as less sensitive setting. It will also be noisier.
- What ISO gives the cleanest photographs?
- What ISO gives you the most colours?
- What ISO gives you the biggest exposure range (sometimes called latitude)
- What happens with the noise as you increase your ISO?
- What ISO is your acceptable upper limit for large prints, small prints and web-sized images?
- Why is the acceptable upper ISO limit different between photographers and camera models?
- How well does your software handle noise reduction?
- What happens to your photographs as you increase the noise reduction?
- Do you need to set your noise reduction in camera while shooting RAW?
- Why does your acceptable upper ISO limit change depending on your subjects? Why is it different for landscapes and portraits?
The best way to figure out your acceptable limit is to experiment. I would start to see what other users are getting from your camera and use that as a starting point. Take some photographs and then look at them at 100% and see how much noise there is. Now apply the noise reduction. I just edge it up slowly and look to see if it is eating into the clarity and sharpness of the photograph.
Adding a little grain is a good way to hide excessive noise reduction.
Now resize your work. Print out a section for a large print, and a small print. Look at the print carefully and decide what your acceptable ISO level is.
Me, I use a mirrorless micro four thirds camera. And I find I can use mine at 3200 ISO and get reasonable A3 prints. For A2 prints I prefer to keep my ISO down to under 800. For portraits I can push this up too 6400 ISO and get a very beautiful A3 print.
Types of sensor noise (for the technical minded readers)
Understanding apertures is important... just as important as understanding shutter speeds. The web and books are full of information about apertures so I have no intention of repeating what all ready has been done before. So here you will find a couple of links and a list of things you should know or go and find out about. Then some exercises that you should do.
What I recommend you should know about apertures:
- what is depth of field?
- what aperture gives you a shallow depth of field
- what aperture gives you a deep depth of field
- when using a small aperture (large f number) what is happening to the amount of light coming into your lens
- when using a large aperture (small f number) what is happening to the amount of light coming into your lens
- how does depth of field relate to your different focal length lenses? which lens has the greatest depth of field & which one has the least?
- what aperture gives you the sharpest photographs for each of your lenses (if you have zooms this changes with the amount of zoom)
- what does bokeh mean?
- which of your lenses has the most beautiful bokeh?
- in the newspaper press film photographer days the saying to the photographer was "f8 and be there", why do you think they said this?
- what is the "sunny 16 rule" - what does that tell you?
- what is diffraction? can you see it on any of your photographs? what f stop does it start?
- what is the hyperfocal distance? how do you use hyperfocal distance in your photography? how do you calculate hyperfocal distances?
- for advanced photographers: what is the circle of confusion?
Depth of field calculators - lots and lots of good ones
- photograph an object to create subject isolation with a blurry background
- photograph a scene to maximise depth of field so that everything in the photograph is in focus
- align three similar objects on a table in a line so that the objects are at different distances from the camera. Photograph lots and lots of photographs with your camera on a tripod in a fixed position. Try focusing on each of the objects and changing the f stops. Try using different focal length lenses
- use hyperfocal distance to calculate what areas are going to be in focus in a photograph and then take a photograph where all of the objects are in focus
- find some approximate rules for hyperfocal focusing - why might these lead you astray when using them
- photograph a still life with all of the objects in the still life are on the same plane that is perpendicular to the path of the light into the camera. use your sharpest lens and your sharpest aperture