In addition to the very comprehensive article by Sean Kelly Here, I thought that I might try my hand at instilling a few ideas into any budding photographers out there, and probably learn a few things myself from the responses. I should point out that I have never had any photography schooling at all- so if any part of this article is incorrect then please feel free to email and I will amend. I think like most people, I started out by borrowing my dad's camera (a Nikon FM2); unfortunately I had no idea what I was getting myself in to. The on-line manual only served to further confuse me so I came back from my first trip to the Alps armed with photos that seemed to prove that I had spent my time in a constant white out rather than the perfect blue skies that had prevailed above Zermatt at the time.
One by one I started to work out how to make film speed, aperture, and shutter speed all work together so I could try and get the maximum out of every shot I took. I hope that in this article I will be able to explain how each one work in layman's terms and try and make some sense of them all for those trying to get their heads around it.
Note: This article will be of use to those who can manually change the above variables, most digital compact cameras wont let you.
It was ages until I even heard about this! The film speed is denoted by an ISO number which range from 25 to...well something ridiculously high now. The lower the number the 'slower' the film- what this means is that the film or sensor will take longer to capture the light it needs to produce a correctly exposed image. The downside to this is that you will have to hold your camera still for longer, but the benefit is that you will reduce noise (digital) / film grain (film). (NB film speeds are often quoted on the ASA scale) The film grain is observed when shooting with a 'fast' film- as you might have guessed the image is more 'grainy'. This might sound a bit odd but think of shooting with a slow film as resulting in a very smooth image whilst shooting with a faster film will result in a less smooth (grainy) image. The difference can be very large when observing your slide or negative up close.
Noise, on the other hand, is the tiny coloured specs you can often observe in darker areas of a (digital) photo. Whilst noise is most noticeable in darker areas, it is also noticeable in lighter areas when the film speed is too high. Due to the advances in the digital area it really depends on what make and model you have when it comes to deciding an optimum ISO speed (have a play around). Personally I have always shot on ISO 100 on both positive film and digital. I try and keep the film speed, or ISO, as low as possible- though there are some who prefer the effect that a faster film speed has.
“It's worth mentioning how slower film has finer grain and can be better for enlargements, and how that's why a lot of people used slide film before digital, because it's slower still and has amazing colour saturation" - Clare Danek
So it comes down to a choice of how grainy, or 'noisy, your image looks like VS how long you (or more importantly your subject matter) can stay still for. (NB I am ignoring aperture here and taking it as a given fixed)
Simply enough, this is the duration which the shutter on your camera lifts up to reveal the sensor or film behind it, exposing it to the necessary light to create the photo, before closing again. Shutter speed is a handy tool when you wish to blur a climber or a scene- obviously if you leave it open for longer then anything which moves in the scene will blur. In the same way, if you keep it open for a very short amount of time then you can freeze frame an action (like freeze frame a dyno).
Shutter Speeds are denoted in parts of a second and range from 1/8000th of a second all the way to an unlimited exposure length ('bulb' setting).
The aperture is the iris of the lens world. It controls how much light enters through the lens, past the open shutter, to the sensor or film at the back of the camera. The size of the aperture (the hole through which light passes through) is denoted by 'F stops'. To make matters more confusing, a high F stop (generally between 22-32) actually means that the aperture is smaller; allowing less light in. conversely a small F stop of say 2.8 means that the aperture is larger, allowing more light in.
Putting them all together
Obviously all three variables are very closely interlinked (I say obviously but its not easy to understand!). If we start at the front (lens) end of the camera then as the light enters the lens, the size of the aperture will dictate how much light passes through into the body of the camera. The shutter then plays its part and this dictates how much time that amount of light is allowed to shine through onto the sensor or film at the back. If we take the ISO or film speed as a given then we can further concentrate on how the aperture and shutter speed interlink. For an image to come out looking 'normal' you have to make sure that it is correctly 'exposed'. An under-exposed image will result in the image being too dark, whilst and over-exposed image will end of in the image being too light. Think of the term exposure in the sense of 'exposing the sensor/film to the light source'. Therefore if you under-expose the image you are not allowing the sensor/film to be exposed long enough to the incoming light to form the image.
The aperture and shutter speed allow you to control the amount of light that is necessary to expose the film/sensor. Since you are going to need 'x' amount of light to expose the sensor for a correctly exposed image you can play around with the two variables. To steal an analogy from John Hegecoe it's rather like filling a glass from a water tap. If the glass represents how much light is needed to correctly expose the image and the water represents the light then you can see how the aperture represents the opening hole in the tap, and the shutter speed represents how long you leave the tap open for. The bigger you make the hole in the tap (the more you 'open' it) the less time you have to leave it open for before the glass is full. And conversely if you open the tap so that only a small dribble of water comes through, you will have to leave the tap open for a lot longer to fill the glass.
Why do you want to change the variables?
Lets start with the easiest which is shutter speed. In the mountains you are likely to take shots of climbers of skiers in fast action scenes. Sometimes you might prefer to have the subject blurred or freeze framed. Personally I don't like having the whole subject blurred but there are times when a blurred hand or foot can add a lot to the image.
There is no rule book for shutter speed and it takes time to get to know which speed will allow you different effects. For starters the closer you are to a subject the faster the shutter speed will have to be to freeze the same action that a slower shutter speed could have done from further away. The best thing to do is to have a play around. However as a very rough guideline something in the region of 1/250 will give you a blur whilst 1/600 will freeze frame for you - this is from a distance of a couple of metres away. It is worth remembering that there are some actions that are very fast and others that aren't - eg an ice axe travels very fast compared to someone reaching for a handhold. Skiers for example require a very fast shutter speed as they travel very fast and it's not just them but the powder clouds as well.
When shooting skiers from a few metres away or zoomed in (so that they occupy a large area of the viewfinder) I find that I have to shoot above 1/1000 or else the skier will come out blurred. You also have to think about where the person/object is coming from. If he is skiing (for example) directly above you towards you then he will actually be moving less (as far as the camera is concerned) compared to if you are shooting him from the side- even though the skier will be travelling at the same speed.
Finally, you have to remember that holding the camera without the use of a tripod causes camera shake from your body. Getting into a more stable position and learning how to calm yourself and control your breathing between shots helps a lot as does the new IS on many lenses. The amount of camera shake transferred to the image will depend on how zoomed in you are on your lens. If you are shooting with a wide angle field of view then you will not have to worry too much about camera shake compared to if you are shooting with a high powered zoom where every heart beat affects the stability of your image.
This is an important thing to get your head around as there are few things more annoying than getting home to find that you missed a lot of fantastic shots because you were 'shaking' too much - and this isn't you, there a lot of variables in the mountains; whether it be wind or just sitting in an awkward position.
The aperture is your next step it taking better photos. To be honest the aperture is the last thing I got my head around and I think it is probably the most important thing when it comes to brushing up your photos so that they start to look clear and crisp in the exact way that you would like them to. Before I continue I would like to quickly point out the difference between the sharpness of an image and the correct focusing of an image- they aren't the same. The focusing part is inevitably the easiest part on modern cameras as it is all automatic. As long as you tell it where to focus it will do an excellent job of it and your image, or at least your subject, will be focused. However that does not necessarily mean that your image will be sharp. The aperture value is the one that dictates how sharp or soft an image is. If you have ever wondered how to get super crisp images then read on...
I would like to dispel a myth that all landscape photos should be taken with the maximum aperture value (anything above F22). I might get flamed for this by professionals but you wont necessarily get the crispest image just by whacking up the F stop. Every lens is different and it's a fact worth remembering. For my preferred lens (a 24-105mm) I find that the optimum F stop is around F11. When I shoot at F11 everything that I have focused on will be at its sharpest possible. If you look at the examples below you can see that there is a huge difference between the F stops when it comes to sharpness.
The main visual effect of the aperture size, apart from sharpness, is that it changes the depth of field of an image. OK, in laymen's terms it extends or reduces the focused area around the subject you have focused on. Imagine you have focused in on your subject which is say 5m away. By shooting at F22 you effectively extend the area around the subject which will remain in focus so that if someone was standing a couple of metres behind, they would be in focus too. By shooting at F2.8 you will effectively reduce the focused area so that the person behind will now no longer be in focus. This is obviously a major tool at a photographer's disposal but nevertheless a rather complicated one to master.
As mentioned previously the aperture values are measured in F stops where a small number means that that the aperture or 'iris' is open wide, whilst a larger number means that the aperture is smaller. To cut to the chase, a smaller size aperture (a large F stop like F22) will result in a greater depth of field whilst a larger sized aperture (a smaller F stop like F2.8) will result in a smaller depth of field. Whilst this is all well in theory, in practice it didn't actually mean too much to me. As a quick recap so far I have explained that the aperture size allows you to extend or reduce the focused area (so that at F2.8 you may only have a 1 metre area focused whilst at F22 you may have miles of focused area)
If we take a second to combine what I have said in the last 2 paragraphs it would make sense in landscape photography to have a high F stop so that the depth of field is extended over the whole panorama (so that the whole image is focused). However as I have already demonstrated, shooting at F22 will soften the image so that although it may be all in focus, it may not necessarily be all that sharp. As always with photography things are starting to get complicated! However once you get your head around it, it isn't too hard to master.
You have to start thinking in terms of focal planes. Luckily a lens works very similar to your eye so you can see this for yourself. If you are focusing on an object that is very close to you (say 15 cm from your eye) then you can see that the background is blurred. If you focus on an object that is say 10m away from you, you will notice that even though the background may be hundreds of metres away it will remain relatively in focus. You can also pick up your camera and see this by focusing in on close and far away objects and see what difference it has on the background. It is important to note that the longer the focal length (the more 'zoomed in' you are) the bigger the difference is going to be on the focal planes.
Once you can fully start to see these focal planes you can start to incorporate aperture control. If say your subject is close enough to you so that your backdrop is out of focus then you can increase the F stop to try and bring out the background and therefore extend the depth of field. By shooting at F22, for example, you can allow for the foreground and the background to both be in focus which would otherwise not be if you were using a larger aperture (like F8). It may help to visualise what your actions are to fully understand what is going on. The first step that you are going to do is focus in on your foreground which, for example, is a person standing a few metres in front of you. However your mountain backdrop is going to be out of focus- something you will be able to see through the viewfinder. What you really want is for the foreground and the background to both be in focus. By increasing the F stop you are therefore increasing the focused distance / depth of field all the way from the foreground to the background therefore allowing both foreground and background to be focused even though you initially focused only on the foreground. Of course the converse is possible and if you wish to isolate just the subject but are not able to blur the background by using a longer focal length then you can focus in on your subject and shoot at a a lower F stop such as F2.8.
Make sure that you fully understand what is going on as well as look at the example images before you continue reading.
I mentioned before it really does depend on the focal length you are shooting at and its important to get a feel for your lens. If I am shooting at 24mm and my subject is some 10m away then I don't find that it matters whether the mountain backdrop is right behind him or a mile away as for that focal length all the respective parts of my shot are practically all in the same focal plane. On the other hand if I now zoom into my subject I will very quickly notice that whilst my subject might be in focus, my backdrop is no longer in focus due to the fact that at this new focal length (say 100mm) the lens no longer sees the subject and the background in the same focal plane. As I said it really is a case of getting used to your lens.
A quick and easy way I find of checking whether the subject and background are in the same focal plane is to simply focus the camera on the subject, then move to focus on the background- if there is no change in the focusing ring (you will be able to hear it move) then they are in the same plane. If however the focusing ring shifts you should think about using the aperture control to compensate for this. The easiest way of course is just by looking through the viewfinder and seeing whether the background is blurred or not but it may not be perfectly obvious to the naked eye.
So far I have explained and shown how you can extend the focused area using the aperture. Obviously this is a very useful and powerful tool and from the images provided you can see that it makes all the difference in some cases between a great shot and a poor one. However you have to remember that high and low F stops result in soft images. There is a trade off between sharpness of an image, therefore, and making sure that everything is in focus. This is why I stated earlier that the 'standard' F22 used in landscape photography may not always give you the best result.
Personally I am real fan of getting an image as pin sharp as I possibly can. Therefore I tend to shoot my foreground so that it is not too close to me. In this situation I do not need to use a high F stop as the foreground and background are both focused on 'infinity' (OK not actually infinity) distance away. Therefore I can concentrate on shooting with my F stop at F11 thus producing the sharpest image possible. If there is a slight discrepancy between the foreground and background I don't just whack the aperture up to F22 but increase it just a little to something like F14-F16 so that I can preserve as much of the sharpness as possible. For example in the image below the foreground (the climber) is about 5m away from me, shooting at F11 provides me with fantastic sharpness compared to at F22 whilst the background peaks of the Verte and Drus show no real difference between F22 or F11:
It is worth noting that on SLR cameras there is a preview button that allows you to view the scene with aperture control through the viewfinder- meaning that you can effectively see the depth of field being enlarged or reduced in the viewfinder. However I very very rarely use that as I find that I cant really make it out very well- I prefer to bracket my apertures instead so that I take a few shots with different aperture values (if I'm not sure) and then choose the best one later on.
The way that you use aperture is of course very dependant on how you want your image to look. I have concentrated on trying to get everything in focus but there are times when you will want the exact opposite so that you can draw the viewer's eye to just one particular part of the image. In any case I hope that you can appreciate that by learning how to use the aperture properly you can fully control the image as well as start to manipulate it.
The beauty of digital cameras is that you can change the ISO instantly for each photo- in the past you were stuck with 36 photos at the same film speed setting. The ISO tends to be something that I don't fiddle much with. I have my camera set so that the ISO remains at ISO 100 and then concentrate on getting the image that I want through manipulation of the shutter speed and aperture. However there are times when the ISO will be quite a useful tool.
You can imagine that in a low lit situation such as sunset, shooting at F22 to get the maximum depth of field will mean that you will be shooting with a slower shutter speed (as we discussed before, F22 will allow less light in so we need to allow that light more time to expose the film/sensor to gain a correct exposure). The problem with this is that you are exposing yourself to two problems: the first is that you will start to notice camera shake from your own body, and the second is that your subject may be a moving one and therefore will appear blurred. The former problem can of course be overcome with the use of a tripod, but the latter is a little harder. On the one hand you don't want to lower the F stop or else you will lose your depth of field but on the other you also don't want a blurred subject. What to do?
Well you can simply increase the film speed. Recap: the slower (lower ISO number) the film speed the longer it takes to react to the incoming light to form a properly exposed image. If you therefore increase the ISO then your image will take less time to be captured even if the same amount of light is being allowed in. So to overcome this hypothetical problem, by increasing the ISO to say ISO400 you can still maintain your same depth of field but your shutter speed will be a lot faster meaning that you can freeze frame your subject. If you find yourself in the opposite scenario whereby you want to blur your subject or his/her movement then you can use the lowest ISO possible to try and slow the shutter speed down.
Hopefully you can now see how all three link together and how a good knowledge of them will open up new doors when it comes to photography. However don't think that just by reading this article you will be able to master them all over night- and don't get disheartened by it! It took me ages until it all finally clicked into place for me and I had to keep coming back to photography books to further understand what I was doing. The main issue was that there was so much to deal with that even though I had read it a hundred times before it still wasn't perfectly making sense and linking up as well as it should do. The best thing to do is just to get out there and take thousands of shots and play around with the settings- the great thing about digital nowadays is that you can see all your aperture, shutter speed, ISO details when you get home on your computer. Take time to get the same shot but with different settings and then remember to go home and actually sit down and look through the images and see which ones work best. It's really only by spending a lot of time behind my computer analysing images at 100% side by side that I really started to make huge advances. Then one day it will all suddenly fall into place and it will become second nature - you wont have to think about the settings you will just do it in a split second...and I promise you that when that day comes it will all have been worth it!
“It's also definitely worth emphasising that people can get amazing results from compacts and that you don't need an amazing camera to get great results”- Clare Danek
Many thanks to Al Evans & Clare Danek for proof reading and helping out on film speeds and aperture.
Jon Griffith - age: 24 - Chamonix
My first climbing days were back in Bristol where the Avon gorge
provided countless trad limestone routes that were great fun to get
into climbing. Having no climber friends I ended up 'teaching' myself
how to lead climb and thankfully I managed to get through the first
few months without falling which was great since most of my gear kept
falling out anyway. That summer I bivied across the high route of the
Pyrenees and come that winter I decided that I wanted to head out to
the Alps and see what that was like. No surprises then that I ended up
in Chamonix and was initiated into ice climbing down at the Crémerie.
From then on I took advantage of the huge university holidays and tried to spend a maximum amount of time out in the Alps. I spent my first few years out in Zermatt (thanks to my climbing partner at the time Brian Birtle who put me up countless times) getting more into the mixed and alpine element rather than just rock climbing Chamonix style stuff. I finished my 'time' out in Zermatt on a high point with the Lyskamm North Face and decided I was ready to move on and try Chamonix style rock routes. I finished university last summer and moved out to Chamonix where I am currently working in photography and film work.
It's hard to pick one specific type of climbing that I prefer over the
others but I think my heart still lies with big mixed alpine routes
that potentially involve a couple of nights bivying. I am still
getting used to the whole Chamonix 'get back in time for the last
lift' style- I still include bivying as a part of any decent
mountaineering experience. I am also still getting used to crack
climbing- it hurts.... a lot.