Never use the Auto (P) function on the camera
Three critical components to taking a photo –
1) ISO setting
3) Shutter speed
Always try to use A (aperture), TV (shutter speed) or M (Manual) settings on your camera.
For all three you first need to set your ISO.
Best way to think about ISO is in terms of the amount of ‘noise’ in a picture (or grainy pixels). A low ISO setting e.g. 100 will give you the lowest amount of noise and thus the highest quality image. A high ISO e.g. 4,000+ will give you more grain.
The high-end cameras will still provide excellent quality at very high ISOs, and sometimes, especially with a black and white, the grainy look can be what you wish for anyway.
Using a high ISO is good when you want to avoid using a flash but you are inside a building or if it is darker outside. You can retain a low ISO if you reduce the shutter speed but try to avoid a shutter speed lower than 60 as if the camera is hand held it will introduce camera shake (obviously if you use a tripod, go as low as you like with shutter speed)
Suggest, switching to M, and then create levels of darkness inside and try out the different ISO settings until you understand what your camera will achieve at the different levels, in different conditions.
Generally speaking for hand held photography –
Bright sunny day = 100 ISO
Cloudy day = 400 ISO
Inside = maybe 600/800
Evening or in dark churches etc. = could be 2000 plus
Once the ISO is set…
Switch the camera to A – this means aperture priority!
Therefore, if you choose an aperture setting (numbers from 1.5 – 22 usually, depending on lens used), the shutter speed will change automatically according to the light conditions and ensure that you have the correct exposure.
(meter reading – there is a line on your camera screen with 0 in the middle. You aim to get a middle reading. If the arrow goes above 0 it indicates that some of the picture is over exposed, or if under 0 it is under exposed)
There will be times where you will actively select an over or under exposure but I will comment on this later.
Aperture numbers – there are more technical explanations that what follows but the general rule is a low aperture number or WIDE aperture as it is correctly put e.g. 1.5 / 2.0 etc. will provide part of the picture in detail and the rest as a blur.
You can aid this process by introducing distance between the subject and the background. The more distance between, the more blurred the background will be at wide aperture settings.
Also, if you then get close to your subject e.g. a coke bottle, with a wide setting, you will only get part of the label in focus. If you steadily back away, more of the bottle will come into focus.
The flipside, is if you have a high number e.g. 18 / 22 (NARROW aperture), then all of the picture will be in focus and there will be no blur.
Lets say the subject is where the two lines cross. Your aperture number tells the camera how much either side (front and back) of the subject is to be in focus.
Therefore, if you are taking a landscape picture, you do not need to focus on the horizon. Focus on something in the middle and with a narrow aperture, the front and back of the middle will then be in focus.
Change the setting to TV (might be S on the camera too?)
This now gives the shutter speed the priority!
Select your shutter speed and then the camera will automatically change the aperture to ensure a correct exposure.
I use this function less often, but broadly speaking, if you are taking pics of kids running, or cars driving past and you want them in sharp focus then 1/700 or higher is effective. For static objects, then its about how well you hold your camera (and what you want your other settings to be) but I’d advise never going lower than 1/60 without a tripod.