What do toothache, a crazy schedule and less than perfect health result in? Well, very little use of an excellent camera. And a criminal neglect of a blog. So now, we have resolved the issue of why there have been no updates on this blog for a while - profound apologies for the same, really - let's get on to tackling some terms that almost everyone toting a DSLR uses. Beginning with one that has always, always, scared the Bejeesus out of me:
Aperture.
It sounds pretty intimidating, truth be told. At least to me - I mean, it sort of amalgamates "apparatus" and "torture."
What it actually is, is, well, a HOLE.
Yep, the almighty "aperture" is nothing but a small opening in the lens which regulates how much light gets through to the sensor, and....
Hang on. Jargon alert again.
Sensor!
What the blazes is a sensor? Everyone keeps yakking about them too, sounding very knowledgeable when they do so - heck, even camera phone manufacturers go on and on about them.
Well, truth be told, a sensor is nothing but the digital substitute for camera film! Yes, that is all, really. Just as in the past, images were formed on camera film, they are now formed on the sensor. Yep, as simple as that. No, do not get too obsessive about it right now.
Which brings us back to the aperture. Yes, it is a hole inside the lens that determines how much light hits the sensor to form the image. It is a bit like a tap in the lens that determines the flow of light - make the aperture big and more light gets in, make it smaller and very little does.
And yes, you guessed it, the amount of light that hits the sensor for a period of time is referred to as "exposure. " Simple.
How long you keep the aperture open is determined by shutter speed. And just how wide the aperture is kept open is shown by what is known as f-stops. Really, that's all there is to it.
As a rule, you need fast shutter speeds in bright environments - where not too much light is needed - and slower ones in low light ones. Shutter speeds are generally expressed in terms of percentage of a second - 1/60 is 1/60th of a second, 1/250 is 1/250th of a second. The rule of thumb - if it is dark, just stick to the smaller number in the denominator, and the larger one if it is light enough.
Last stop for the day are f-stops, also referred to as f-numbers by some pundits (the ones with huuuuge cameras). These basically measure how wide the aperture opening is. They are expressed in fractions again (what IS it with photographers and fractions?) - f/2.8, f/4, f/5.6, f/8 and so on. The smaller the number, the larger the aperture opening. The larger the number, the smaller the opening. So the larger the number, the lesser the light that gets in.
Grand summary: Aperture is a hole in the camera lens that lets light on to the sensor, the area where an image is formed. Just how wide the aperture is open is determined by f-stops and just how long it remains open, letting light in, is determined by shutter speed. In the case of both f-stops and shutter speed, less in the denominator is more - the smaller the f-stop number downstairs, the larger the aperture opening, and the smaller the denominator in shutter speed, the longer the aperture remains open to let light in.
Makes sense? Am still working out the less is more equations in my head. Will be tackling them again and again in the entries that follow. But egad, enough for now. Hope this helps. Hope also to be more regular on the blog henceforth!!
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