When taking photos i tend to use the presets such as “sunset” etc. but would like to be able to understand how the camera is working/what settings work for different situations etc.
For example – last night very bright moon illuminating vapour trails over roof tops – cool looking in my minds eye – how do i go about taking that sort of picture – essentially letting the camera capture what i see??

I understand that at night the aperture needs to be wider to take in more light, the shutter speed slower, but what about iso?
wider – how wide? slower – how slow?

mine field!!

I would suggest you buy a decent book.

I found this one very good and goes much further than “basic” IMO.

Basic Photography

but what about iso?

ISO isn’t really a thing on digital cameras (it is just computer gizmotronics aping an effect).

ISO relates to the ‘speed’ rating of traditional film – the quicker the film, the grainer it is so it is great for low light conditions or sporting events as the shutter remains open for less time in order to record the detail which then (naturally) minimises blurring.

But I agree with the above – there is lots to take in so read, read, read and experiment….

Yeah, this isn’t a one-liner answer. Aperture, speed and ISO work together; for a given photo that’s correctly exposed, if you increase one you’ll need to decrease another. You really need to read up on this, get it firmly straight in your head. Everything else is gravy.

I don’t know what camera you’ve got but you don’t have to jump straight from full auto to full manual. You probably have “aperture priority” and “shutter priority” settings – this gives you direct control over one or the other whilst leaving everything else as ‘best guess’ to try and take a properly exposed photo. I’m not suggesting this is the best way to take photos necessarily, but it’s a good way of trying different settings in isolation and seeing what difference it makes to the outcome.

I understand that at night the aperture needs to be wider to take in more light

The aperture also affects depth of field. A wide aperture (low F-stop) gives you a sharp object and blurry background, a narrow aperture (high F-stop) gives more focus through the picture. You might shoot a portrait at F/2.8 say, or a landscape at F/11. For both of those shots, shutter speed is (for the benefits of this example) irrelevant so you could shoot in aperture priority and experiment with what you want in / out of focus.

Shooting, say, a fountain can give you practice with shutter priority. A fast shutter will freeze the action, showing individual water droplets hanging in the air; a long exposure will give you ethereal-looking misty trails. Which should you shoot? That’s up to you.

ISO isn’t really a thing on digital cameras (it is just computer gizmotronics aping an effect).

If it helps you to visualise it, you can think of it as the sensitivity of the sensor. Higher ISO film needs less light to expose a shot; it’s broadly the same principle with digital photography, if you’ve less light coming in for whatever reason (shorter exposure, narrower aperture, it’s dark, etc) then you need a more sensitive sensor to catch the same data, and vice versa.

One thing to bear in mind, it’s all a case of halves/doubles so the maths is easy – for example, 1/500 second at f/1.4 would (in basic terms) take the same picture (as in expose the sensor) as 1/250 at f/2 (although the depth of field would be shorter).

A book is a good starting point.

But you just need to fiddle with the settings and see what happens.

It also helps if you understand what your camera is trying to achieve in the first place when in any auto or semi-auto mode.

The camera is trying to achieve a certain ‘brightness’ in the image. At a basic level, it doesn’t know whether that is a good brightness or not.
More modern cameras with ‘intelligent’ auto will try to recognise the scene you are taking from a database of scenarios and adjust the settings to get a ‘more pleasing’ result.

Using your moon shot as an example. The camera doesn’t know you are trying to take a picture of the moon – it just knows that most of the scene is very dark, but there’s a bloody bright bit to one side. It has to decide what exposure level to set, but it doesn’t know if the moon should have detail rather than being a bright white disc, or whether the vapour trails are the most important thing etc.
This is where adjusting the settings yourself come in.

Aperture or shutter priority will still try to achieve a ‘normal’ exposure because you are only fixing one variable and the camera will try to compensate with the other variable until it runs out of adjustment on that one variable. You can use exposure compensation to make the image ‘brighter’ or ‘darker’ than the baseline target.

I’d definitely recommend setting the ISO to a fixed value while experimenting – autoISO changing the sensitivity of the sensor will just confuse things.

Your sunset setting will probably also be adjusting the colour balance to make the reds & yellows really pop out & also setting the focus point to infinity, so the auto-focus doesn’t hunt around trying to find something to lock onto….

Find a subject and have a play.

ISO isn’t really a thing on digital cameras (it is just computer gizmotronics aping an effect).

Not really “aping” – that suggests it is an artificial construct on digital cameras. But really it’s the same thing but for a different medium.

On film, ISO is basically a measure of how sensitive the film is to light. More sensitive films (higher ISO) require less light to capture an image (so less time, or smaller aperture, or both) but the images can also end up a bit “grainy”.

On digital, ISO is a measure how sensitive the sensor is to light. Higher gains on the sensor (higher ISO) require less light to capture an image (so less time, or smaller aperture, or both) but the images can also end up a bit “noisy”.

Apart from either buying a book or watching one of the many You Tube tutorial videos on photography basics, the best way to go from where you are now is to start shooint in Aperture Priority mode (probably labelled as something like A or Av on your camera). This will let you determine the aperture, which like you say is how big the hole is that lets the light through) with the camera chosing a combination of both the ISO and the shutter speed.

On digital, ISO is a measure how sensitive the sensor is to light.

ISO on a digital camera is effectively applied gain, i.e. the camera’s internal circuitry boosting the signal from the base level ISO. With more signal boot comes more noise, which in some cameras can look nice, like film grain but in most just makes the image look washed out.

Some digital cameras let you set an upper limit for ISO and also let you set a minimum limit for shutter speed.

One neat rule that helps is to not shoot with a shutter speed slower than 1/focal length. This is slightly complicated by the fact that on a sensor smaller (or even larger) than a full frame 35mm, you should really use 1/equivalent angle of view, which I am sure is going to confuse you!

Your aperture does influence your depth of field but if you’re shooting (for) the moon, it won’t make any difference what aperture you use, your depth of field will be infinite. This is because the further something away is, the larger the DoF will be for the same aperture. That’s not to say that stuff in the very near foreground won’t be out of focus (it will be) but if all that is in view is the horizon, then everything will be in focus.

[video]https://www.youtube.com/watch?v=Nzn6yKTVcfs[/video]

A book is a good starting point

This one nailed it for me…..

As said, you first need to understand the ‘triangle’ of aperture/shutter-speed/iso

Here’s a good basic overview with visuals

This one nailed it for me…..

That book is the bible of photography, and is an absolute must-buy… as a second book, after you understand the mechanics of what you’re doing.

That book is the bible of photography, and is an absolute must-by… as a second book, after you understand the mechanics of what you’re doing.

Was the other way round for me. I had read loads of other stuff and it was just techno-babble…. I couldn’t properly grasp the “how” until I read that and understood the “Why”…..but I might be wired up funny.

Fair comment.

Do a night course a your local adult education centre? Normally quite reasonably priced

The best explanation I’ve seen is to imagine the light entering the lens as a cylinder. You can either have a short wide cylinder like a coin or a long thin one like a pencil but both will admit the same amount of light. How much light the film or sensor needs depends on the ISO, which is the level of sensitivity.

What i “understand”

Aperture – F-stops
Low F number = wide aperture = more light
Low F number = less in focus other than focal point
High F = good for landscapes
Low = shallow depth of field
High = less light and deeper focus

Shutter speed
1/300th for moving objects
No motion as long as 1/30th
Lower speed = more light = susceptible to camera movement
Higher speed = less light in
Slow shutters peed for:
Motion blur – light trails/water 1/30th – narrow aperture – shutter priority
Over exposed arty pix
Low light to keep noise to a minimum – ISO needs to be low also

ISO – set to auto
Sensitivity to light
High ISO – noise

Combining
Depth of field – aperture priority
Accurate light representation – ISO priority
Then shutter speed

Shutter speed
1/300th for moving objects
No motion as long as 1/30th

You may want to look at this again. Also you might want to compensate for camera shake if hand-held or even windy on a tripod.

From what I understand you are for sake of argument only limited by your gear and your imagination. I often use exposures as long as 30sec at night or sometimes bulb-mode for night-sky.

Same with capturing motion, I sometimes go as high as my shutter-speed and aperture allow for a given situation. ie 1/1000th sec. Obviously if there is a very strong light source you may yet find it overexposed and so require a filter.

johndoh – Member 
ISO isn’t really a thing on digital cameras (it is just computer gizmotronics aping an effect).

ISO relates to the ‘speed’ rating of traditional film – the quicker the film, the grainer it is so it is great for low light conditions or sporting events as the shutter remains open for less time in order to record the detail which then (naturally) minimises blurring.

Principle is the same as ISO ratings are used in a comparable way in terms of sensitivity of the sensor.

Grain in digital still applies and is a function of the lower quantity of photons hitting sensor receptors much the same as photons hitting film cells.

iamanobody – Member 
I understand that at night the aperture needs to be wider to take in more light, the shutter speed slower

The moon is tricky. When lit, it’s very bright compared to the surrounding scene. You actually want to decrease the light. A smaller aperture and/or faster shutter. Exposure sensors though on cameras tend to get confused. Sometimes using an ND filter can help to cut the light down.

Longer shutter speed will blur the moon as it and the earth are moving. That’s also a tricky one with stars. They need lots of light but a slow shutter will give you star trails, although they look pretty cool. Unless you hook up a tracking system to move the camera with the sky 😉

Even more difficult is exposing both for the moon and a surrounding scene. One is very bright, the rest is not. Though can be a job for HDR.

Couple of general photography stuff though to start with…

Control of light & exposure – On camera controls like aperture, shutter speed, exposure compensation and sensitivity, and then filters, flash, controlling light externally to the camera (shades, reflectors, etc).

Depth of field – aperture, focal length & focal distance.

With the controls of aperture and shutter, I’d start with priority settings, e.g. Aperture Priority and Shutter Priority. Manually controlling one and the other is auto set. I typically use them over pure manual. Mostly I use AP to control Depth of Field or light, and SP when shooting fast moving subjects to control the shutter speed or slow shots for dark or night sky.

On DoF…

Wider aperture will decrease DoF, smaller increases.
A longer focal length (longer lens / increasing optical zoom) will decrease DoF compared to a shorter.
Focal distance also decreases DoF the closer to the subject and increases the further away.

Three things to play with. The latter is a nice cheap way as you can just use your feet. Combine the three for maximum effect.

Another one for the “Understanding Exposure” book.

Look up Sunny 16, set your iso to 400, say, and shutter speed to its nearest equivalent (usually 500th) and go out shooting for the day.

When you start to run out of light, you’ll have to fiddle with iso or slow down the shutter. You’ll just about have it nailed then.

To get a properly exposed moon is tricky, you have to take into account it’s a sunlit-object, and the exposure has to take that into the equation when taking the photo, which is very difficult with any compact camera, especially if you’re trying to include other features in the sky, like contrails.
Fortunately, these sort of features aren’t what you might call fast-moving, so experimenting with a bunch of exposures with the camera on a tripod is pretty easy.

I was told to guess the exposure, based on 400asa film and 125th of a second shutter speed, so, just guess the f stop. Eg, it’s an f11 day today.

It’s surprising how good you get at it, from there it’s simple enough to ( for example) speed up the shutter speed and so decrease f stop number accordingly, as with film speed changes.

Also I found the Ansel Adams books very good. There’s 3 I think. The negative, the camera? Third is probably called the print but I’m guessing.

Second also for a further education course. Well worth it. I’d avoid camera clubs, full of camera snobs and bores imo.

I’ve been taking photos for a while and have stumbled into the situation where I’m being asked to take photos of events and friends etc and have a couple of portfolios online. If anyone would like to see them I can post the links.

The best thing you can do is be a master of the camera in your hand. That being so the best book to read is the camera manual. Whenever you come to a concept or term you don’t understand, google is your best friend. As has been said above, a photography course is a good idea. Self teaching is a great method of learning for many people, but I still think that there is something to be said for standing in front of someone and having them explain something to you. You can’t ask a textbook ‘what does this button do’?

Last thought…you never stop learning and developing. I’ve done half a dozen shoots with models, a few paid shoots and many days out at the pitchside or trail. I’ve never come away from a shoot having not learned something. On a couple of occasions this has meant hours fixing things in photoshop and on one occasion it meant going back to the client and saying ‘I’m sorry. I borked it. This is what I got and there’s no charge.’