Updates - the Nifty Fifty.

I'm working on a post explaining the last part of the exposure triangle (ISO) but I've hit a wall with it, in that I understand what it does and when to use it, but am struggling to explain it in an understandable way. So bear with me on that. :)

In other news, I received a new lens the other week - a 50mm f/1.8 portrait lens, otherwise known as the "Nifty Fifty". It has a fixed focal length, meaning no zooming in or out, but I really haven't found that to be much of an issue, and at 50mm it's roughly close to the focal length of the human eye, meaning that what you see through the viewfinder should be more or less the same magnification as what you see normally. This lens has a ton of practical applications and really hasn't been off my camera since I got it.

First off, the wide maximum aperture allows for some seriously shallow depth of field. While I'm already sensing my skill improving past the "bokeh-whore" stage, I do love bokeh, and opening that aperture right up allows me to capture some really great shots.



What I have learnt though, is that opening the aperture up to its widest at f/1.8 is inadvisable if you are doing close-ups and your subject might move even the slightest amount, e.g. a flower in a breeze. The DOF is so, so shallow that movement of the subject will throw it outside of that narrow focus area:



What's happened in the above shot (f/2.2) is that the breeze blew slightly and I ended up with the little leaves cupping the bud being totally focused, and the bud itself slightly out.

As I've used the lens more and learned about its strengths and weaknesses, it really has proved itself as a marvellous bit of glass. When I have used it for its intended purpose (portraits) the results have really been stunning.



Just look at that little sweetheart. Doesn't his face just make you "aww"? Look at the little water droplets in his beard! Is that water or drool?!

This shot was taken the first day I had the lens, and I went mad with the wide aperture (that shot is f/1.8). The result is that, even at 6pm on a pre-Spring evening, there is enough light coming into the camera for the shutter speed to speed up and capture him crisply before he moved. Unfortunately though, the focus is roughly at the bridge of his nose, and due to the insanely shallow DOF, his eyes are ever so slightly out. If I had stopped the aperture down to about f/2.5 his whole face would have been tack sharp, and in fact reviews I have read say this particular lens performs at its best when stopped down to f/2.5 - f/2.8. Either way I am very happy with that shot.

The other most impressive use of the lens so far was when I went to see my friend's band play the other night; I took my camera to experiment with the sort of candid photography a gig atmosphere provides and when Dan spotted it he asked if I would try and get some shots of the band. I played the whole thing down a little (I'd never shot in such dark conditions before, am a total amateur, didn't want them to anticipate any really good shots) but I was really, really happy with the results.



I opened the aperture up all the way (f/1.8) but because I wasn't right on top of the guys, the shallow DOF was less pronounced. This meant I was letting in the maximum amount of light possible. I also had to bump up the ISO (light sensitivity -- will explain this more when I get rounf to finishing the jargon post!) to 1600 which is very, very high and resulted in a lot of digital noise (or graininess) on the shots. However in doing so I was able to speed up the shutter speed to about 1/25 sec, and avoid the guys just being artsy blurs as they performed. Grain is always preferable to blur -- it can be fixed, to an extent, in some processing software, and also for the black-and-white shots it added a really gritty, "live" feel which I think added to the shots.

Speaking of black-and-white... my researching on the best way to turn a picture from colour into B&W has generally led me to believe that a) don't use your camera's B&W function as you then have much less control over the highlights in post-processing; and b) use the Channel Mixer instead of just desaturating as it means you have control over the highlights, luminosity and tones. I will cover B&W post-processing in more depth in the future, but the gig shoot has helped me to learn a lot more about how to do this successfully. Most of the B&W shots in that gig set were done because the real light was so red or unflattering; the Channel Mixer enabled me to turn the light into something more natural-looking.

Overall I am beyond happy with the 50mm lens. The band were so chuffed with the shots that they have asked me to do some staged promos. Also another friend whose girlfriend is very heavily pregnant has asked me if I would do some artsy bump shots before she drops -- the prospect of this is a little daunting but I'm going to do it; if it goes wrong at least it's just my friends and not someone who is paying me!

Erk...

Jargon: The Exposure Triangle Part I - Aperture (and Bokeh)

There are a million blogs and a million articles on the web that will explain these terms in more eloquent or technical ways than I can, but I will give it my best shot.

When taking any photograph, the first consideration has to be the exposure. The exposure is exactly that: how well the camera's sensor was exposed to the light at the moment the shot was taken. There are three main things to consider when aiming for the right exposure: Aperture, Shutter Speed, and ISO; known collectively as The Exposure Triangle.

Aperture

Aperture was, for me, the more confusing term when I first started out. The aperture setting controls the size of the lens opening to allow more or less light into the camera. If you consider your camera lens to be like the human eye, the aperture would be the size of the pupil. Bigger = more light, smaller = less light.

As well as controlling the amount of light let in, the aperture also controls something called Depth of Field; that is, the area or amount of the shot that is in focus. A narrow depth of field means that only a small area of the shot is sharply in focus:



See how just a small part of the fence is sharp, but the foreground and background are all out of focus? That's what a wide aperture will do to a shot, especially one where your focus is very close.

A smaller aperture limits the amount of light coming into the camera, but also ensure more of the shot is in focus:



Here you can see the sundial in the foreground is just as in-focus as the trees and sky in the background.

Ok so here's where it gets confusing, and why it is this way, I couldn't tell you. To select a larger aperture on your camera, you have to choose a smaller number, and to select a smaller aperture, you choose a higher number.

Narrow depth of field = smaller number = wider aperture.
Wide depth of field = larger number = narrower aperture.

In order for your shot to be correctly exposed, if you limit your aperture you must then slow your shutter speed to allow enough light in to the camera. I'll go over shutter speed in more detail in a later post.

If you select your camera's Auto mode, you will have no control over any of the settings; however all DSLR cameras and even some Point and Shoot models have an Aperture Priority mode. This will allow you to select the aperture size you want, and the camera will then work out the optimum shutter speed to correctly expose the shot. I currently shoot almost exclusively in Aperture Priority mode.

Bokeh

Ahh, bokeh. I've come to realise from my reading that bokeh is a notion that is more pleasing to amateurs, and the more experienced photographers out there don't really consider it that much.

The word "bokeh" (pronounced "bock-eh", not "bow-kay") is a Japanese word and it refers to the part of a photograph that is out of focus. A lot of people, myself included, will compose a shot not just to capture a subject, but also to capture some attractive bokeh in the background. I find it pleasing to the eye; in the professional world I don't know how much weight it carries. To achieve bokeh, one must open up their aperture really wide when photographing a foreground subject; the subject will be in focus, the background out of focus, and this blurry background is the bokeh.



See how the cute little flower is sharp and then there's loads of out-of-focus jazz in the background? That background jazz is bokeh. The best bokeh, in my opinion, is created with a really narrow depth-of-field (the capability for which, my current lens just doesn't have) and contrasting colours or lights in the background. Bokeh itself can be an artistic device, or can be used to highlight the subject of the shot even more.



My next Jargon post will be about shutter speed.

Happy snapping.
xxx