Fallow deer hind. Example of large aperture/fast shutter speed.  Large aperture gives a very small Depth of Focus ensuring that the subject stands out from the foreground and background, and that there is plenty of light entering the camera to allow a fast shutter speed.  The fast shutter speed ensures that there is no camera shake with the large lens used in this shot, and that if the animal moves it will not blur the image.
1/1000th sec @ f5.6, 400mm lens, Kodachrome 200.  Photo by Rob Suisted.

Photos of my very first unfortunate victims, goats, a few deer and the occasional pig, can still be found tacked into my first photo album; they’re far from impressive, but the bounty they presented was tasty.  Photo-wise the awesome piece of optical averageness that I used to lug around to produce those images had probably previously  existed as a yoghurt pottle in Taiwan - lens included.  It was a ‘Point and Shoot’ model, small and lightweight, both in physical appearances and the quality of photos it took. 

My occasional hunting mate of the time referred to it as the ‘Point and Pull’, describing the manner in which photos were randomly framed up and fired off.  Actually, he referred to my rifle of the time in the same way, an old No.4 MkI .303 whose sights where of dubious parentage - though he shot no better. With an eagerness to increase the standard of my photos I next set forth into the wilderness armed with an orphaned Asahi Pentax S1, complete with screw on lenses and independent lightmeter. 

The key was that I had made it into the realm of the SLR (Single Lens Reflex) - the camera had changeable lenses, you looked through the lens, and it made the required wholesome ‘clunk’ sound when triggered. It soon became apparent though that having more sophisticated equipment was not a straight recipe for success - quite the opposite actually.  With it came a multitude of choices and resulting compromises not readily apparent with my old ‘Point and Pull’ model - stops, f-stops, shutter speeds, depth of field, ASA, exposure compensation etc.  In order to take images that even remotely reached the quality of my earlier shonky images I had to learn heaps quickly.  Oh I wished for an article like this.

Unfortunately most people these days tend to start photography with a relatively modern camera that can do everything without much thinking from your behalf - turn it on and shoot - dummy proofed and satisfactory in most situations except when it comes to developing your skills.  You are highly limited unless we can get back into the driver’s seat and understand exactly what it is that the camera is doing for us, i.e. we need to understand the basics.  Fortunately this is very simple, it’s designed to be simple, and conveniently it is exactly what you’re going to get from me today.  I’m asked a lot of questions by people wanting to come to better grips with their cameras.  It’s enjoyable being able to help, but it regularly amazes me how far some people have got into photography without understanding the basics, and boy does this cause headaches. 

You might well switch off at this point - ‘I know what I’m doing...’ I hear you say, ‘...I don’t need a cabbage course in camera use!’  Fair enough but I’ll tell you that I often sit down and again focus on the basics.  If you aren’t familiar with the foundations or principles of camera use, you can’t develop your skills.  Hang on and I’ll try to make it quick. Just try forgetting everything you presently know about photography for a moment and ponder the following.  When we cut through the buttons, bells and whistles on the average camera it comes down to this:
The camera body is no more than a box that holds film and lets in a burst of light for a certain amount of time, say 1/60th of a second and the lens is no more than an object that focuses the light onto the film, and lets through a measurable amount of light, say f8.  Pretty simple really!  It is the variation of time light is let in for, and the variation of the amount of light let through the lens, and the effect these adjustments have on the image that are the key points we need to understand

Shutter speeds
Now, every time we alter a shutter speed on the camera, say from 1/60th sec down to 1/30th sec we are exactly doubling the time light reaches the film.  This is increasing the amount of light hitting the film by ‘one stop’.  If we changed from 1/60th sec up to  1/125th sec we are exactly halving the amount of light, i.e. we reduce the light by ‘one stop’; easy.  Why do we need a selection of shutter speeds? Of course we must have a way of varying the light level that enters the camera, but the primary reason is movement control.  If we’re photographing a fast moving object, we want a fast shutter speed to photograph it so it won’t be blurred (like in sports photography).  If we want the effect say of running water, we want a very slow shutter speed, such as 1/2 sec (with tripod of course).

Tararua Forest side creek.  Example of small aperture/long shutter speed.  Small aperture gives lots of Depth of Focus ensuring that the whole image is in focus from front to back.  Long shutter speed gives a blur to the water movement.  Tripod and cable release necessary.
1 sec @ f16, 24mm lens, Ektachrome 50.  Photo by Rob Suisted

Apertures
On your lens, you should have an aperture ring marked with a series of numbers - 4, 5.6, 8, 11, 16, 22 etc.  These have nothing to do with your local lotto shop but they are important nevertheless.  There is no real need for you to know what these numbers stand for other than to know that the smaller number (f-stop), say f4, will let more light through the lens.  Conveniently, every time you move this ring, the light allowed through the lens will either double, or half (like the shutter speeds) - it will go up or down a ‘stop’ in light.  So, if your lens is on f5.6 and you turn the ring to f8, the number has gone up one which halves the amount of light the lens lets through.  If you turned it the other way to f4 you are letting double the amount of light through, therefore you have ‘opened the lens up a stop’....easy.

Depth of Field
OK I hear you ask, why would you ever use a lens at say f8 when you could use if at f4 and let in 4 times (2x double the light) the amount of light?  The reason is Depth of Field; call it Depth of Focus for simplicity.  As you turn the aperture ring you alter the amount of light, and the Depth of Focus.  What is Depth of Focus?  Well, have a look at the next landscape photo you see, it has heaps - it will be in focus all the way from the farthest mountain to the closest blade of grass.  If you look next at a portrait photo, or a sporting photo, you’ll notice that it has sod all depth of focus - only the main subject is in focus, the background is blurry. 

So how does it work?  Simple, it’s directly related to those tiny f-stop numbers - the smaller the number, say f4, the less Depth of Focus the photo will have.  Therefore a higher f-stop, say f22, would be used for landscape photos so that everything will be in focus.  So if you, like the less light your lens lets through (say f22) the more depth of focus you get. Right, here we’re starting to get to the crux of it all.  The film in your camera is rated at a particular ASA, say 100 ASA - it requires a certain amount of light to take a properly exposed image.  When you are taking that image there will be a certain amount of light available, i.e. if it’s sunny there will be a lot; if it’s overcast there could be 16 times less light about.  Your decision is how you use this light to make an image. 

Very basically you are to decide whether to let in a lot of light (a large aperture, say f4) for a short time (say 1/1000 sec), or let in a small amount of light (say f22) for a longer time (say 1/30 sec) - As you’ll see these two settings will take the same exposure.  This is the key choice that you must decide.  There is no right or wrong way, but how you decide will have a definite effect on the result.  Think about what you intend to photograph.  Say it is a landscape - easy to choose because you want the most depth of focus possible so the most will be in focus, so set your aperture ring at say f22 (a small aperture).  Take a light reading with the camera meter (exposure metering tips will follow in a future column).  If it was a sunny day it would probably tell you that 1/60th sec shutter speed  will be needed, if you used 100 ASA film.  If, however, we were taking a photo of a fast moving object (like a hunting mate washing dags off in a freezing river) we would want to use a fast shutter speed to take the shot instead, so select a large aperture (say f4).  The shutter speed we would use would be 1/1000th sec.  More than enough to freeze the motion (or the thrashing).  However, because we’re using f4, the depth of focus will be very shallow so we must take extra care to focus correctly on the main subject. So here we see a direct relationship between shutter speeds and aperture settings.  If we go one stop faster in shutter speed, it equals one stop larger aperture. 

If we take the two examples above we can see that we’ve changed from f22 to the much larger f4 setting.  This involved 5 steps - from f22, 16, 11, 8, 5.6, to f4, every time doubling the amount of light going through the lens - because of this we can now go up 5 stops in shutter speed to take the  same exposure,  from 1/60th sec, 1/125, 1/250, 1/500, to 1/1000th sec.  So a photo taken at f22 and 1/60th sec has exactly the same exposure as on taken at f4 and 1/1000th sec, the only difference is that the first will have lots of depth of focus but any movement will be blurred, while the second will have sod all depth of focus but all moving objects will be ‘pin sharp’.  It is important to understand that no one set combination of shutter speeds and apertures is correct as both can be altered to get the same exposure of the film - it’s your decision.

Mount Cook Lily.  Use of a medium aperture to give a smaller depth of focus to draw attention to the flowers but to leave the background partially visible.  The medium aperture also gave a reasonable shutter speed that helped to freeze the movement of the flowers in the breeze. 1/60th sec @ f8, Fujichrome Velvia 50.  Photo by Rob Suisted

If I’ve baffled you, here’s a useful analogy I heard a few years ago.  Think of your camera as a box with a sponge in it.  The sponge is the film and it requires a certain amount of water to wet it (expose the photo).  Now the ‘light meter’ on our box  tells you how much water you’re going to need to do the job.  The aperture is the size of the funnel you use and the shutter speed is the time you pour water onto the sponge for to ‘expose’ it (Don’t take this literally!).  Again we would decide whether to pour water onto the sponge through a large funnel for a short time, or through a small funnel for a longer time, to get the same ‘exposure’ of the sponge.  This is decided by the subject you are taking and the effect of motion & depth of focus you desire.  You may also decide to compromise and use a mid shutter speed and mid aperture.

Camera shake
If you are hand holding your camera when taking a photo it is important to know that you should never use a shutter speed that is lower than the reciprocal of the lens focal length you are using.  That means if you’re using a 50mm lens, put a 1 over it i.e. =1/50th sec and never use a shutter speed slower than that.  You’d use a 1/60th sec or faster.  If using a 200mm lens, you should not use a shutter speed slower than 1/200th sec (i.e. 1/250th sec) on your camera - simple rule.  If you break the rule it is highly likely that your photos will suffer from camera shake and lock blurry - the biggest no-no in the business.  Use a tripod or other rest if you intend to break the rule.

Film speed
The most common film speed in use today is 100 ASA.  It has only moderate grain and is a useful speed for most people in bright daylight.  Today the technology in print film has increased significantly since 100 ASA was promoted as the best choice - the same can probably be said now for 400 ASA print film.  What is the difference between 100 and 400 ASA?  Well, as expected the numbers are very simple - as the number double the film sensitivity doubles, so 200 ASA needs only half the light to expose it as 100 ASA does.  400 ASA needs only half the light that 200 ASA needs etc.  So 400 ASA film requires 2 stops less light (4 x less light) to take the same photo.  If you were using 100 ASA film and your camera lightmeter read f5.6 at 1/60th sec, using 400 ASA film you could take it at f5.6 at 1/250th sec, or f11 at 1/60th sec.  I recommend that if you are presently using 100 ASA print film, that you change to using 400 ASA.  The benefit of 2 stops is fantastic and the difference in grain is unlikely to be noticeable unless you start blowing photos up larger than this page and how often do we do that?

Conclusion
Well, if you’ve made it this far I congratulate you, either you’re genuinely interested in getting a better grip on that expensive gadget that sits in the bottom of your pack, or you’re awaiting some prophetic words on L&P sauce, either way I hope you sit down with the affected piece of camera equipment and have a good play with it right now.  It would be great to see a reduction in the number of people that lack the confidence to take their cameras off fully automatic and have a bash with some of their own initiative - you’ll be amazed at the satisfaction it delivers - it could be the start of a new income?