Manual Exposure and buckets of water

I had a student with me the other day who was really keen to get to grips with the 'M' (Manual) exposure mode on his Nikon D60. She felt - with some justification - that having the ability to set the camera's exposure herself would enable her to get better photographs. Well, I explained that this would not necessarily follow as there are many other elements that go into creating a good picture. But I did tell her that an understanding of, and familiarity with, the manual settings on any camera would certainly mean that she would have more control and, eventually, she would be able to interpret a scene in her own way. This can often lead to better pictures.

The problem was that as she had kept the camera on a program mode for most of her photography in the past, she had little understanding of shutter speeds and aperture settings and the way they must work in harmony.

I tried very hard to explain in the simplest possible way that, for instance, an exposure of 1/125sec at f11 lets into the camera exactly the same amount of light as an exposure of 1/25osec at f8. This was part of the age-old problem that f numbers do not work logically for normal people. The fact that big apertures mean small numbers and small apertures mean big numbers is enough to confuse anyone.

And then I remembered a really old chestnut of an explanation...

With much theatrical acting, I placed an imaginary and very full bucket of water on the table in front of us. This, I said represented the correct amount of light to expose our picture correctly. The water was not sloshing out (over-exposed) nor was the bucket half full (under-exposed), it was full to the brim. Just right.

There were two ways of filling that bucket with a hose pipe (more acting) - I might use a big wide hose pipe (wide aperture) and fill the bucket very quickly (fast shutter speed). Or I could use a very small diameter hose pipe (small aperture) and trickle the water in very slowly (slow shutter speed).

Either way, I got the same amount of water in the bucket (or the same amount of light in the camera).

It worked like a charm - the penny dropped and from that moment my student understood a concept that had been totally confusing her. I do like simple.

I've posted a fair bit about using manual exposure in the past, so you could try these pages if you want to learn more...

http://philipdunn.blogspot.com/2008/01/how-to-use-manual-mode-part-2.html

http://philipdunn.blogspot.com/2008/01/how-to-use-manual-mode-part-1.html

Photography tuition by the sea

My students Tony and Dave with RNLI Lifeboat man 'Tattie'

It’s been a busy week here in Bonnie Galloway. Quite apart from having several hundred photographs to sort and catalogue, I have had students with me for the last two days as well.

On Thursday pals Dave and Tony came for a shared day’s tuition. Dave has been to me before on one of my weekend workshops. This time he and Tony wanted to take things several steps further by doing a mini ‘assignment’ that would present a challenge. They felt they wanted to be ‘pushed’ a little, and could I arrange something.

I spoke to the local RNLI lifeboat secretary and got permission to take Dave and Tony along to the lifeboat station down the river here in Kirkcudbright Bay. One of the lifeboat crew members was able to join us for the morning and he proved to be not only great fun, but a willing and interesting photography subject.

The plan was to treat the morning as an assignment for an imaginary magazine editor who wanted a photo essay on the station and the lifeboat man. After they had got over their initial nervousness, both Dave and Tony did a fantastic job. They managed to find a couple of really good ‘key’ pictures and then set about gathering a whole range of really worthwhile peripheral, or detail, pictures. These included everything from the crews’ lifejackets hung in a row on the wall, to the winch that pulled the boat from the water into the boat shed, the inscribed plaques listing the number of rescues and rescued people, and shots of the boat’s powerful engines. By the end of the morning, they both managed to put together a really comprehensive photo essay, and everyone had a great time doing it. We went through the pictures together and did critique comments and advice during the afternoon

Today I have had Phil with me. He came up from Yorkshire for the day. Although he had taken up photography only 10 months ago, the moment I saw some of his work, it was obvious that he has a really good eye for a picture. He was less confident about composition and the workings of his camera, though. But we could soon help with that.

We spent the morning indoors as the rain lashed the windows and I went through each aspect of the camera controls with Phil. After lunch the sun broke through and we set off to my favourite little beach and cove. The light was truly spectacular, and the place presented a perfect situation to work on composition.

Phil was in seventh heaven shooting away happily. Whenever he had a query I would explain a few shortcuts and tricks. By the end of the afternoon, he was fully converted to the idea of the Manual ‘M’ settings on his little Canon 400D and wondering why he every bothered with the auto settings. I think we might be seeing more of Phil in the future

So another busy week comes to an end – have fun with your camera over the weekend.

Above: My student for today - Phil, at work on the coast near my home here in Galloway.

Below: One of the photographs I took during the afternoon - the light has been spectacular.

Aperture Value

Carl posted a comment yesterday about Ken Terry's beautiful wildlife pictures.

Ken said that he used ISO 1000 and an aperture of f5.0 in AV mode as the light was changing so quickly. Sometimes the shutter speed was 1/500 and sometimes 1/4000.

Carl commented:
...really enjoyed this. But trying to work out what AV is, in relation to rapidly changing light?

'AV' - Aperture Value - is an automatic exposure mode in which you set the aperture you want and the camera decides on the correct shutter speed to match it. This can be very useful in rapidly changing light conditions like those Ken experienced when he was photographing the red kites and the red squirrels. In these conditions it can be difficult, if not impossible, to constantly adjust the exposure manually. In other words, you just cannot keep up with the fast changing light levels by correcting the exposure yourself in the Manual ('M') mode. When shooting a fast-moving subject like a bird in flight, operating the camera quickly is vitally important, so setting the exposure mode to an automatic setting can be a boon and one less thing to bother about.

So in Ken's case, he set f5.0 in 'AV' mode. When the sun went behind cloud and the light level dropped, the camera chose a shutter speed 1/500sec. When the sun came out and light level went up, the camera chose a shutter speed of 1/4000sec.

Some time ago I posted a photograph of Freddie Mercury. Click the link below. I used 'AV' exposure mode for this because the stage lights in the studio where the photograph was taken were constantly going on and off, with light levels going up and down. It would have been impossible to keep up with the exposure manually in 'M' mode, so I set something like f2.8 in 'AV' mode and let the camera sort out the shutter speed.

Just one tip here... Aperture Value (AV) used to me known as Aperture Priority (AP), far more sensible and descriptive. Until some fool decided to change it.
http://philipdunn.blogspot.com/search?q=mercury

How to use Manual Mode - part 2

There is nothing mysterious about the Manual (M) mode on your camera. I said last time that ‘M’ also stands for ‘magic’, well it’s true – the magic comes from you being in control and not the camera.

For those who have not used their camera on ‘M’ before, let’s take away some of the confusion and myth by saying that you do not need to juggle BOTH the shutter speed settings AND the aperture settings straight away and at the same time. You simply start with one or the other, set it – then look at the exposure scale (see pictures in last post) and move the other setting until the pointer is in the centre of the scale.

So how do you know whether to set the aperture or the shutter speed first?

Well, there are many subtleties, but basically it is very simple - let’s say you know that your subject is moving quickly so you need to set a fast shutter speed. Do it – set maybe 1/250sec. You can do that even before the camera comes up to your eye. Now, look through the viewfinder at your subject and change the aperture setting until the pointer on the exposure scale is in the centre.

If you know you need a small aperture in order to get the maximum depth of field for a landscape shot, for instance, set the aperture first – say f16. Then look at the exposure scale through the viewfinder and change the shutter speed (slow it down or speed it up) until the pointer is in the centre of the exposure scale.

Of course, as a rough guide, the smaller the aperture (higher the f number) the slower the shutter speed will have to be. The faster the shutter speed, the wider (lower f number) the aperture must be.

All this needs practice – but so does anything worth doing. Eventually you will get to the stage where you can take pride in the fact that your camera craft has become intuitive. You will make mistakes – don’t worry. We all do.

Never let setting the exposure get in the way of capturing the moment. You will be surprised how quickly you will be able to set your exposures manually. Do bear in mind that once your exposure has been set roughly for the light in a particular situation, chances are that only minor adjustment, if any, will be necessary for each different picture. If you think you are going to miss a picture – revert to Auto Exposure mode. It’s the picture that matters, not the way it’s exposed.

For photograph of the cows on the beach, I set a small aperture first – f16. That was because I needed all the depth of field I could get. The shutter speed was then set to match that aperture. The photograph is not just about cows, it is about cows out of context in an unusual setting. That setting had to be sharp and clear – hence lots of depth of field.

How to use Manual Mode - part 1

'M' MEANS MAGIC

Most digital Single Lens Reflex (SLR) cameras give you a choice of automatic or manual shooting modes…
P - Programme
TV - Time Value, sometimes known as Shutter Priority (S)
AV - Aperture Value, sometimes know as Aperture Priority (AP) or even just ‘A’
M - Manual

I rarely use anything but the ‘M’ mode, so here are the basics – or at least, the way I use it. If I had a dollar for every photographer who has asked me to explain in simple terms how to use ‘M’, I’d be a rich man.

In all modes except 'M' , the camera goes all, or some way, to deciding what it thinks is the ‘best’ exposure. I refrain from saying the ‘correct’ exposure, because like all automatic processes, it doesn’t always do what you want it to in the real world.

That’s why I almost always use the ‘M’ setting. I like to decide on the exposure I want.

The first thing to remember is that when your camera is on the ‘M’ setting it does not mean that you are left entirely to your own devices to arrive at a correct exposure either by guess work or by using a separate, hand-held exposure meter – you certainly do not need one of those. Your camera has a very efficient and perfectly useable exposure meter already built into it.

If you have always used your camera on automatic settings, you might not have noticed that when you switch to the ‘M’ exposure mode, a scale appears somewhere at the side or bottom of the viewfinder. On some cameras this scale appears on the LCD as well. All cameras vary, but most scales will have a plus sign ‘+’ at one end and minus ‘-‘ at the other. Beneath or beside this scale might be a moving pointer, or the graduations themselves may light up. Whichever it is, when the pointer is in the centre of the scale, you have a correct exposure. The graduations are often in 1/2 or 1/3 values, or f stops, so if you have the pointer on either the plus or minus sides of the centre, you will be over or under exposing by the indicated amount. Easy.

In ‘M’ mode, the exposure is adjusted by altering either the aperture and/or the shutter speed settings. As you do this, the pointer on the scale moves. To keep things easy, set your metering to ‘Centre Weighted’ mode. ‘Averaging’ mode is too… well, average, and ‘Spot’ mode is too precise and sensitive until you get used to things. I use ‘Centre Weighted’ almost all the time. In ‘Centre Weighted’ mode, most cameras will take an average light reading of the whole scene, but will take much more notice of the central area, and this can be very useful.

Once you master the basic of the Manual mode, you will quickly realise that you can have total contril ver your exposure. Yes, you will make some mistakes, but that is all part of the learning process. You will find that the rewards from ‘doing it yourself’ and being in control will really enhance your enjoyment from your photography. ‘M’ doesn’t just stand for Manual – it stands for MAGIC!

1
You will see something similar to this in your viewfinder when you are in ‘M’ (Manual) exposure mode. The exposure scale has ‘+’ at one end and ‘-‘ at the other. Here, 1/30sec at f5.6 has given a reading on the ‘minus’ side of the scale – the picture will be under exposed.

2
By slowing down the shutter speed to 1/8sec, the reading is now in the centre of the scale at ‘0’. This is the correct exposure for this subject.

Next, in Part 2, I’ll explain more about the Manual mode and how to use it.