Tuesday 31 May 2011

What is white balancing?

White balancing is where you ensure that the white in your photos really is "white" and not cream or blueish white or any other shade of white. Digital cameras may have an auto-white balancing (AWB) function but with all the different lighting conditions with their different shades of white, it's usually not as good as the human eye, so the photographer sometimes has to intervene and take action to ensure that the white of the photos is indeed white.

Sometimes the camera can be confused if a shot is mostly one shade of colour, say green, it may mistakenly think that the scene is being lit by a green light and will auto-white balance accordingly, so the photographer has to step in and make sure this doesn't happen.

How can a photographer intervene to do white balancing?

1.) Take RAW shots

Taking photos in RAW format enables you to manipulate the white balancing after the shot is taken. After taking the photo, the camera usually shows you a screen with a colour slider, where you can adjust it manually to white balance the shot. Depending on your camera, an alternate way to white-balance is to click on the part of the photo which you see to be pure white, and it will adjust the rest of colours of the photo accordingly.

2.) Ensure you have a sample of white in your photo

To allow you to white balance a shot, it's helpful to have white in the shot. This isn't essential and some photos don't have white reference points in them, but if there isn't a white reference point, white balancing is more tricky and your camera is more likely to struggle with auto-white balancing.

3.) Carry with you a white card to show you what white is

If your shot has no white in it,  you can have a reference card or object with you to help you white-balance by eye. You can buy photographer card kits for a range of colours, including different ranges of greys, to help you white balance by eye.

Friday 27 May 2011

What is Shutter Speed?

Shutter speed is the amount of time the camera's shutter stays open, allowing light in, before taking a shot. It is usually measured in fractions of a second so is seen as a fraction like 1/125, or 1/2000. The larger the denominator, the faster the shutter speed (because the fraction makes up a smaller part of a second).

The standards figures for shutter speeds are: 1/1000 s, 1/500 s, 1/250 s, 1/125 s, 1/60 s, 1/30 s, 1/15 s, 1/8 s, 1/4 s, 1/2 s, 1 s, and a few settings for super-long exposure.   Each increment (apart from the super-long exposure) roughly doubles or halves the amount of light entering a shot. The fastest shutter speed available is 1/16,000 which is found on high quality DSLRs.

A fast shutter speed (eg 1/16000-1/1000) means that there is little time to let light in, so the picture will appear darker. This setting is suitable if you're in high light conditions or have other settings on the camera set to allow light in.

A slow shutter speed (eg 1/125 - 1/2) gives more time for light to get into the camera, so the shot will appear lighter and brighter.

Because of it's relationship with light, shutter speed is also known as "exposure time". A fast shutter speed is a short exposure time and a slow shutter speed is a long exposure time.

Effect of shutter speed on exposure vs the effect of aperture size on exposure

If you compare how much brighter a shot is made by a low shutter speed or by a large aperture, you find that doubling the aperture has a more dramatic effect on light than shutter speed:
  • halving the shutter speed doubles the exposure (ie it increases the exposure by a unit of 1 EV, where EV stands for exposure value ), 
  • halving the f-number (ie. doubling the aperture) increases the exposure by a factor of 4 (or by 2 EV units).  
Shutter speed and aperture have such a closely linked relationship that you could effectively get the same exposure of the shot at wildly different settings, by  considering this relationship. For example, all the following settings will have roughly the same exposure:
  • shutter speed of 1/250 s and f/8 
  • shutter speed 1/500 s and f/5.6, 
  • shutter speed 1/125 s and f/11.  
Advantages of fast shutter speeds
  • It allows more light into a shot which can be useful if you need to boost exposure without changing aperture or ISO.
  • It allows you to capture things in motion without a motion blur. The fast shutter speed snaps a super-brief moment in time, so it can capture a movement that occurs in a fraction of a second. The less time there is to allow light to enter the shot from the next part of the movement, the less blur there will be. This can be useful in capturing wildlife mid-flight or mid-run, catching subjects in races and sporting events, and generally capturing anything in motion. For example, if you want to capture someone mid-jump with both feet in the air, fast shutter speed is ideal.
Advantages of slow shutter speeds
  • Creating artistic motion blurs: This can be fun if you're using flashlights or photographing moving cars at night. It can create almost abstract shots.  It can also create magical looking effects like when you shoot running water with slow shutter speeds, the resulting motion blur gives the illusion of flowing fog sometimes. The amount of blur depends on the speed at which the object is moving, as well as on the distance the object is from you and the amount of zoom you're using (or focal length). Zoom accentuates motion blur.
Disadvantages of slow shutter speeds
  • It's very easy to get a blurry shot even if you don't intend to. Any movement of the camera can result in a blur. It's really advisable to use a stabilizer like a tripod to steady the camera and prevent camera shake in anything slower than 1/60. 

What happens if you change the zoom whilst a picture is being exposed with a slow shutter speed? 

This is a photographic trick called "zoom burst" where you set the camera to a long exposure/ slow shutter speed, and whilst the shutter is open, you zoom in on the object you want to capture. The result is a sharp object in the centre (as long as it is still and not moving during the long exposure), and a radial blur in the surroundings from the motion of the zoom.

    Red Eye in Photos

    What causes red eye in photos?

    I've written a post about this on my www.saywhydoi.com website which you can check out here: http://www.saywhydoi.com/what-causes-red-eye-in-photos/

    What is resolution?

    What is resolution on a camera?

    Resolution in digital photography  relates to how detailed and high quality your picture is. The detail is determined by the number of pixels in your photo.

    Every digital image is composed of little pixels. Each pixel in a photo is smaller than a computer screen pixel. Computers usually display about 72 pixels per inch, whereas on paper you may print off a shot with 300 pixels per inch. The more pixels there are per a photo, the higher the quality of the image. For this reason, resolution is often measured in megapixels (millions of pixels per image). The resolution is determined by the quality of the camera's technology.

    A camera that captures images that are 1920 pixels high and 1080 pixels wide is said to have 1920x1080 resolution, or around 2 million megapixels. Incidentally video quality is also measured in this pixel-related resolution, and 1080 pixel width (1080p) is the common image width for high quality blu-rays and some HD discs.   Most DVDs are 720x480 pixels (720p) and normal  analog TV broadcast is around 500x480 (480p). Youtube videos allow you to set your resolution from 240p to 480p.

    Still cameras generally have higher resolution than 2 megapixels with the best ones having up to 8 or more megapixels.

    The higher the resolution, the  higher the quality of your shots, so you can zoom in on a shot and still retain detail, and you can blow a photo up to a large size and it'll still look good.  So really, the higher the resolution, the better.

    Can you change your camera's resolution for individual shots? 
    Yes. On my camera there are settings for:
    • Large (L) which is high resolution at 3264x2448 pixels (ie 8 megapixels)
    • Large to medium (L/M); Medium (M); and Medium-to-small (M/S) settings which vary in resolution
    • Small (S) which is the lowest resolution at 640x480 pixels (ie 3 megapixels)

    Thursday 26 May 2011

    Lens flares: What is a lens flare?

    A lens flare is a light artifact in shots which is a result of light entering the lens. The appearance of the lens flare depends on your lens diaphragm but usually it's a circular-type shape at its centre, with streaks emanating out of it.Usually lens flares are undesired artifacts which dilute the contrast of the shot, but sometimes they can be used to enhance a photo.

    How do lens flares form?
    To understand how lens flares form, first you need to understand that there are two main types of light:
    1.) Image light: These are light rays which bounce off the objects within the image you are trying to capture.
    2.) Non-image light (aka "stray light"): These are light rays which are entering the camera from places outside your intended shot.

    When non-image forming light enters your camera lens, it can create a lens flare through the internal reflection of stray light in the lens.

    The most common non-image forming light is from the sun being in your shot i.e. pointing your camera onto a scene that has the sun within your viewfinder, or just outside it. Aside from the sun, lens flares may be the result of other very bright objects shining light into the shot or just outside it, including light bulbs, the moon, and reflective surfaces.

    Not all lenses are equally prone to lens flares. The higher the magnification of the lens, the more internal reflections of stray lights occur so zoom lenses are more prone to the lens flare effect.  Wide-angle lenses are far less prone to lens flare.

    How do you avoid lens flare?
    If you use a lens hood it can reduce the amount of non-image light entering your shot. 
    Another option is to ensure the light source if behind your camera rather than in the direction in which you are shooting a photo.

    What is a telephoto? and what is a telephoto lens?

    What is a telephoto? 
    A telephoto is one taken with a telephoto lens.

    What is a telephoto lens?

    It is not a complete coincidence  that telephoto and telescope sound a bit alike. Both serve in magnifying things. In fact, with a big enough telephoto lens, you can kind of use it like a telescope and have a play with astrophotography.

    A telephoto lens is an expensive, long lens you can buy to fit over an SLR or DSLR and it's purpose is to achieve great magnification of things that are really far away. It has an optimal effect where it flattens a scene so that the picture appears as though it's nearby when in fact you may be miles away. You can also get super-telephoto lenses which have even greater magnification. This makes them useful for wildlife photography, photographing things like planes or nature shots of landscapes in the distance, and it's also useful for stalkers.. :D

    Some signature marks of a telephoto include beautiful bokeh, and also the fact that it's notoriously prone to get blurry shots unless you keep the camera perfectly still. Even pressing the shutter to take the photo can vibrate the camera so that the whole picture comes out blurry.

    Wednesday 25 May 2011

    Photography Blogs & Websites

    Just bookmarking some cool photography websites & blogs as I find them:

    Websites to learn from
    Inspiring Websites

      What is ISO in photography?

      ISO stands for the International Organisation for Standardization. What does this mean?  It's a standardization that was introduced to film rolls before the days of digital cameras, and refers to how sensitive the film was to light. So ISO is all about exposure to light and how bright or dark your photo will be.

      Low light sensitivity film (low ISO) had to be exposed for a long time in order to get a photo with a reasonable amount of light registering, whilst high sensitivity film (high ISO) only needed to be exposed for a short duration.

      It's pretty much the same thing with digital ISO, which you can control for every shot. Changing the ISO settings changes the camera's light sensor's sensitivity to light. The higher the ISO the more sensitive the sensor is to light and the brighter your photo will be.

      ISO usually ranges from 100 to about 3200.

      Benefits of low ISO
      When should you use low ISO? What are the benefits of low ISO?
      • It's handy for outdoor shots and shots where there is already sufficient light present. Using flash and/or other special lighting devices allows you to use a low ISO whilst maintaining enough light in your photos.   If you have low ISO and insufficient light, increasing aperture and exposure time also helps (i.e. set your camera to a slow shutter speed). You can also use a tripod to help you use slower shutter speeds to maintain a lower ISO.
      • Low ISO gives better quality shots: The lower the ISO the better quality the image will be, so as a general rule of thumb, you should aim to use the lowest ISO possible. This enables you to blow up the picture to larger sizes and still maintain better quality. When you use high ISO, the picture is at risk of appearing grainy or speckled because ISO introduces "digital noise" to the photo. It generally creates an effect that isn't as clean and sharp as you'd perhaps like and take note that this graininess is often not perceivable when looking at your shots through the LCD screen after shooting, but it will be noticeable when you upload your pictures and scrutinize them on your computer. Good cameras should exhibit less digital noise, but even the best cameras probably have some at high ISOs.
      Benefits of high ISO
      When should you use high ISO? What are the benefits of high ISO?
      • It's useful in indoor situations where there isn't as much light, or in generally darker situations where you need to boost light but aren't allowed to use a flash or lighting devices.
      • If you want to create a grainy, speckled effect in your photos, you can use high ISO to achieve this. Some photos look better with grain, although there are post-editing programs that allow you to create this effect on photos too. 
      • It's useful for when you need high shutter speeds and you need as much light sensitivity as possible without allowing for it with shutter speed exposure. High shutter speeds may be important if you're holding the camera on a very wobbly surface (e.g. from a moving vehicle), or if you're trying to photograph a still shot of a moving object.
      • If you know you need a low quality, small image and grain doesn't matter, increasing ISO can be a quick-fix for getting the lighting right.

      Photography forums

      I'm just bookmarking some photography forums that I want to check out. If I have any comments on them as I go I'll come back here and add commentary.

      Tuesday 24 May 2011

      What is a hot shoe?

      A hot shoe is the place on the camera where you can attach an extra flash. It's also known a flash socket.

      Why is it called a hot shoe?

      It's called a hot shoe because the heat refers to the fact that it's electrical, and if you look at the hot shoe you can see the electrical contact points. It's called a shoe because you slide the flash into the hot shoe much like you'd slide your foot into a shoe.

      Related Products 

      What is focal length?

      The focal length is the distance between the lens and the camera's sensor (or film if you're using a non-digital camera).

      At first glance this seems confusing because books and blogs talk about varying the focal length and my first thought was: "Isn't the distance between the lens and the camera's sensor a constant, unvariable thing?" Well, turns out the distance between the lens and the sensor is indeed something that can be modified.

      How can you change the focal length? 

      1.) Zooming in and out change the focal length

      One very clear example of modifying the distance between the lens and the sensor is when you use the zoom. As the camera zooms in, it projects the lens outwards, effectively increasing the distance between the lens and the sensor, and thus increasing the focal length.

      Usually if you look at your camera on the bit around the lens, it should give a number in milimeters. On my Canono PowerShot Pro1 for example it says 7.2-50.8mm on it for example. This number gives your camera's focal length. i.e. On my camera, the distance between the sensor and the lens at maximal zoom is a little over 5cm, and 7.2mm when no zoom is on. This is revealing of my camera's zooming capabilities: 7.2 x zoom capabilities = 50.8 ; so my zoom capabilities are about a x7 zoom.

      2.) Changing the lens on your SLR or DSLR to one with a different focal length

      One of the benefits of SLRs and DSLRs is that unlike point and shoot cameras, you can change the lenses. If you want, you can fit a lens with a different focal length on it to automatically get a different focal length.

      What is the significance of a short or long focal length? 

      In simplest terms, increasing the focal length increases the magnification.

      In more complicated terms, this is how it works: The shorter the focal length, the less room there is for the light rays to travel before hitting the sensor, therefore they have to bend at a steeper angle in order to hit the sensor than at a longer focal length and this means that the image that it captures is over a larger area (ie you can get a large chunk of a landscape in shot).

      With a longer focal length, the light rays can bend more gently to reach the same spot on the sensor, which means that the area over which the picture is coming in from is narrower, and you can get far less of the surroundings into your shot. ie out of a whole landscape you might just be able to capture a little bit of it.

      The more you zoom in and when it starts to use digital zoom, there comes a point when you exceed the camera's capabilities and any zoom beyond this point starts to appear less sharp. For this reason you really should avoid using the digital zoom if you want super-crisp and sharp photos.

      Related Products 

      What is exposure? Camera exposure explained

      Exposure refers to how much light enters the camera when you shoot a picture.

      If there is optimal exposure, the amount of light that enters is just right (which is subjective according to the effect you want to achieve).

      If there is over-exposure (too much exposure), your image will have too much light in it and is likely to appear very bright and white. This is sometimes said to be "washed out". With extreme over-exposure the whole thing can appear just white. Sometimes you want a picture to be more white than it actually is for effect, or to lose details on purpose.

      If there is under-exposure your image will have too little light in it and will likely appear very dark. With extreme under-exposure the shot can be virtually completely black. Sometimes a photographer desires darkness to get a certain look.

      Factors that effect exposure

      Exposure depends on two main factors:

      1.) Aperture - The larger the aperture, the more light can enter the camera and the more exposed the picture will be. Large aperture gives high exposure and small aperture gives lower exposure.

      2.) Shutter Speed - This refers to how long you leave the shutter open to capture the light before you take a shot. If there is a really fast shutter speed there is little time for light to enter and the picture appears less exposed. At longer (slow) shutter speeds there is more time for light to enter and the image has greater exposure.

      Adjusting the shutter speed affects what's known as "exposure time", and this tool can be used not only to manipulate how bright or  dark a shot is, but it can also be used to capture movement in unusual ways. When the shutter is open for a long time to record a shot, if the shot is moving in this time, it captures the motion blurs brilliantly. Conversely, if you have a short shutter speed, it creates a sharp shot of the thing in motion - like a sharp snapshot of a moment in time with no motion blurs.

      3.) ISO - This is an artificial manipulation of how sensitive your camera is to light for a particular shot.

      What does SLR stand for?

      SLR stands for Single-Lens Reflex. Or if you have a DSLR camera, it's a Digital Single-Lens Reflex camera.

      What does this mean?

      It's all to do with the fact that the viewfinder and the lens can't possibly see the same picture  at the same time in normal cameras; but an SLR or DSLR has a special mirror system in place which reflects the exact image that the lens sees to the viewfinder. Because the same shot has to be seen at two places at once, there is usually a brief delay between switching views, and when the viewfinder appears black when the picture is being taken, this is because the mirror system is flipped to allow the light to pass to the camera sensor at that time rather than to your eye in the viewfinder. The best cameras have really fast-acting mirror systems with short viewfinder blackout periods.

      Most point-and-shoot cameras (P&S cameras) have an LCD screen which you can look at instead of look through a viewfinder. The picture on this LCD screen is poor quality which means it is not well-representative of the shot you're taking. SLRs and DSLRs give a far more accurate, high quality representation of your shot.

      Advantages of a DSLR over a normal camera 

      1.) SLRs and DSLRs have larger sensors

      DSLRs have larger sensors (microchips), and as described in an earlier post (what is 35mm?), the larger the microchips the better the quality of the photos.

      The large sensor is advantageous for several reasons:
      • It is more sensitive to light and picks up more light at low light frequencies than a usual camera. So for example, you can shoot indoors in low light conditions and get a higher quality picture with an SLR than with a normal camera. 
      • It has a more manipulatable depth of field
      2.) SLRs and DSLRs have more buttons to play with

      In general, if you're investing in an SLR or DSLR, you're probably eager to step away from the automatic settings and play with controlling the settings manually yourself. This gives you a lot more control over your shots to get the effect your want.

      3.) SLRs and DSLRs have the option to change the lens

      Point and shoot cameras have only one lens, but SLRs and DSLRs can have many different potential lenses. You can buy add-on interchangeable lenses for an SLR or DSLR which gives you more  freedom to manipulate and control the look of your shots. For example a wide angle lens or a long-focus lens can be fun to play with.


      What are some DSLR brands?
      • Canon 
      • Nikon 
      • Panasonic 
      • Pentax 
      • Sony 
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      What is Depth of Field?

      In photography, what is the definition of depth of field? (Note, depth of field is also referred to as DOF in some places)

      The depth we're referring to is in terms of near vs far objects, and the field refers to the range between these objects. The field can be composed of two main parts: the "camera-to-object distance", and the "object to end-of-focal-length" distance, which is distance between the subject and the distance behind it, traveling the opposite direct from the camera.

      Depth of field is measured in meters and it is the distance between the nearest and farthest points in a shot which are sharp and in-focus.



      Depth of field is usually used when talking about the sharpness and focus of a shot.  When you get a photo that shows  both nearby and far away things being both sharp, we say the image has a deep or large depth of field (aka deep focus), whilst images that show sharpness at just one distance, but everything else is blurry, have a shallow or small depth of field (shallow focus). The shallow depth of field effect can be very handy where you want to emphasize one aspect of the photo and not others, or when you want to introduce a general softness to your photos.

      Both the camera and the human eye can only focus on one distance at a time, and the other distances appear blurrier, although sometimes this blur is very subtle, and other times it is more obvious, depending on the conditions. With the human eye the change in sharpness (and depth of field) is so subtle that we usually don't even notice it because it's "acceptably sharp". We only start noticing the blur either if you take a picture and examine it under high magnification, or once it is extremely blurry to the point that it passes a certain threshold. This blur-perception threshold is called the "circle of confusion". The second that something appears blurry, it is said to be "outside the depth of field", and the blurry out-of-focus areas of the shot are called "bokeh".

      When the focus is on a nearby object, the background often gets "blur spots". The reasons why spot-shaped blurs occur is because they are the same shape of the aperture of the lens. 

      The appearance of the out-of-focus zones and just how blurry or sharp they are depends on a few things:


      1.) Aperture size affects the depth of field and the bokeh 

      If the blur spots are shaped like the aperture, this reveals that there is a relationship between aperture and depth of field. (Note: Some books refer to the aperture as the "diaphragm opening of the lens").

      The general rule is:

      • The smaller the aperture (large f-number), the deeper the depth of field.  This is because if there is a small hole for the light to travel through, effectively, there are few pathways for the light, so when the light reaches the camera sensor, it travels along more or less the same path to focus on the sensor at more or less the same spot where things appear in focus. This makes light traveling from all sorts of depths and distances roughly focus equally, giving a deep depth of field.
      • The bigger the aperture (small f-number), the shallower the depth of field.  The large aperture allows light to travel in through the lens on more than one pathway, and it enables it to land at more than one possible spot on the camera's sensor. Different light rays land at slightly different spots on the sensor. The further apart the light rays land on the sensor, (ie.e the more divergent they are), the more out of focus certain aspects of the picture will be.
        So if you take a macro photo of a flower using a big aperture (e.g. f-number 2.8), the area where you aren't focusing on (the distant background in this case) will be more blurry than if you take the shot with a small aperture (e.g. f-number 5.0).
      Aperture is probably the number 1 factor used to control depth of field.

      Some cameras have automatic settings for close-ups or distant shots which automatically adjust the aperture. Landscape settings usually are set for a deep focus whilst close-up shots and "portrait modes" are usually set to shallow focus.

      2.) The distance of the background and your subject affects depth of field and bokeh

      If there is a short distance between the subject of your photo and the background, it is likely that the background will be sharp because it is more or less within the same focal distance as your subject. If however there is a large distance between the subject and the background, the background is more likely to be outside the depth of field, and therefore out-of-focus

      If you're focusing on something nearby, like in a macro shot, the depth of field is likely to be more shallow. A larger focal distance e.g. taking a photo of a cow in a field in the mid-ground of a shot, is likely to make the out-of-focus areas less blurry. In other words, the greater the distance between the camera and the object, the greater the depth of field is likely to be.  

      3.) Focal distance affects depth of field and bokeh

      When we talk of focal distance (aka focal length) we're talking about the distance between the lens and its sensor, or in other words, we're talking about the zoom or magnification..

      Using magnification or zoom affects the focal length by increasing it the more you zoom. Increasing magnification usually lengthens the lens and this makes the background more likely to be blurry (creating a shallower depth of field). A shorter lens will have a larger depth of field whilst a longer lens will have a shallower depth of field.




      4.) Type of camera affects depth of field and bokeh 

      SLR cameras seem to generally have shallower depth of fields than your average point-and-shoot digital camera.

      Monday 23 May 2011

      What is compression?

      Or more specifically, what is image compression in a camera?

      Basically compression describes the way in which your image is stored on the memory card (CF card) in a more compact way that takes up less memory space, because the original uncompressed photo would take up a LOT of memory. You can have two main compression styles of storing your photos:

      (1.) Lossless Compression with RAW photos
      Lossless compression means that  you don't lose any information in the storage of the photo. The image that you save will contain exactly the same information as the original uncompressed image that was snapped, only it takes up about a quarter of the memory space as your uncompressed image. You can set your camera to take lossless images by setting it to take RAW photos, which are usually in RBG TIFF or just TIFF format. The problem with RAW images though is that, understandably, they take up more memory space on your memory card than lossy compressed pictures. For example, a RAW image may be around 6-4 MB in size whereas a lossy compressed picture can be 3.0 - 0.2 MB in size.

      (2.) Lossy Compression with usual photos
      Lossy compression, as the name suggests, is accompanied by some information loss, so that the picture you end up with is not exactly the same quality as the original uncompressed image. The difference is seen when you blow up the picture and inspect it under high magnification, although for most functional purposes of photos, you probably wouldn't usually need to ever magnify the picture to this extent so the information loss won't really be noticeable under normal circumstances. The format of lossy compressed photos is usually JPEG.

      Note that once you convert something to a JPEG file and lossy compression takes place, it is irreversible and you cannot restore the raw quality from this file.

      With lossy compression, you can control the image quality to be 100% quality and all the way down to 20% quality if you want (although the latter probably isn't advisable!).

      How do you control the compression on your camera? 

      Most cameras allow you to control the compression.

      On my camera you can control how fine the lossy compression is (i.e. whether the JPEG is 100% quality or lower) by entering the camera Function menu and selecting compression. My camera gives you options for superfine compression, which gives the best quality shots (marked by S on my camera screen), high-to-normal (marked by a quarter circle image on my camera screen), or normal quality shots (marked by a step-like pattern on my camera screen). I tend to set mine to superfine for normal shots or if I know I'm going to do an artistic shot, I may want to set the image to RAW lossless compression and compress it further later (with a program like Lightroom or Raw Therapy) if needs be. I guess professional photographers would work more with RAW images. On my camera if you want to take a RAW shot you shoot the image and before it saves you can disrupt the save by twiddling the zoom lens as it saves, click the function button and set it to RAW.

      What is a CF card?

      CF card, also sometimes called a memory card, stands for Compact Flash Card and it is basically the camera's storage spot for your digital photos.

      Most cameras save the photos onto the camera's internal memory first, and then transfer the photos onto the CF card.

      CF cards come in different sizes depending on your camera and depending on how much memory storage it can hold. The more storage space (usually given in gigabytes, GBs) the more expensive these cards are. Some common brands of CF cards are SanDisk, Kingston, Lexar, Fujifilm and Transcend.

      You can also get CF card readers to transfer your photos directly from the CF card to your computer. It should be pretty easy to remove the CF card from your camera to do this. I have one that's similar to this one: High Speed CF Compact Flash USB Card Reader It plugs into the computer's USB port and I find very handy.

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      What is aperture?

      What is aperture in photography?

      Aperture definition:

      The aperture is the the hole in the lens through which the light enters the camera.

      Although the lens has a constant diameter, the hole through which the light enters can be varied by the opening or closing of a "shutter" which, like the iris of the eye, makes the hole smaller or larger. In the metaphor where the shutter is the iris, the aperture is the pupil.

      Opening the aperture allows more light in, and the more light there is we say you increase the "exposure", and the picture looks brighter or whiter. Opening the aperture also decreases the depth of field (i.e. it decreases the focus range so that only the things at one focal point are sharp and things in other focal points are blurry. For example if the focus is on the foreground, the foreground will be sharp but things in the background appear blurry).

      Closing the aperture allows less light in, so this decreases the exposure and makes the picture look darker. Closing the aperture also increases the depth of field (i.e. it increases the focal range so that whether things are close or far away they appear sharp).

      How do you change the aperture?

      To change the aperture size you need to change the F-number (where F stands for focal length).

      What is "focal length"? It is the distance (measured in millimeters) from the center of the camera lens to the focal point of the image (ie, the "image sensor surface").

      The F-numbers can range from 1 to 16, although my camera only rangers between F2.4 and F8.0 which I guess means that the maximum distance my camera lens can go from the image sensor surface is 8mm? I need to check this! More sophisticated cameras can have a greater focal length capability.

      You can also buy special lenses that have shorter focal lengths of longer focal lengths.
      - Short focal length lenses = wide angle lenses
      - Long focal length lenses = telephoto lenses

      I mentioned above that when you set the camera to have a large aperature there is decreased depth of field. Another way of saying this is that there is an inverse relationship between F-numbers (focal length or depth of field) and aperture size.

      To decrease the size of the aperture (i.e. to allow less light in),  you want the F number to be  large. The larger the F number the smaller the aperture. So the larger the F number the darker your picture will appear.

      Similarly to increase the size of the aperture (i.e. to allow more light in), you want the F-number to be small. The smaller the F number the larger the aperture and the brighter and more exposed your picture will be.

      How do  you change the F-number? 

      I suspect you may need to check your camera user manual for how your specific camera works. On my camera (Canon PowerShot Pro 1) you have to set it to manual setting (M) and fiddle around with a dial to change the F-number. 

      What is AF? and what is an AF sensor?

      AF stands for auto-focus and an AF sensor stands for an auto-focus sensor. This enables automatic focusing of the camera so you don't have to manually adjust the focus every time you shoot a photo. It's the thing which enables the photo to appear sharp when you half-press the shutter and it goes "beep beep!" (well that's what it does on my camera!). If you have a look on the front of your camera you're likely to see a little glass window that may have something that looks like a glass bead or two inside it. That's the AF sensor.

      Personally I think that's all I need to know about it because when you get into how the AF system works it starts to get complicated and technical, but if you're interested in that side of things, wikipedia has a good entry on it here.

      - - -
      Disclaimer: I'm new to photography and my understanding of it is still growing by the day. If you ever spot any mistakes in what I write, feel free to correct me in the comments below.

      What is 35mm? What does 35mm mean?

      If you've heard shop talk amongst photographers or read some photogrpahy books you may have come across the measurement "35mm" now and again. What is 35mm? What does 35mm refer to?

      In the days before digital cameras when cameras had that old style roll of film inside on which photos were printed, the film had a certain width and the standard width of film since the early 1900s, was 35mm.

      Movies and video were and still are printed on 35mm wide film too. The big screen IMAX films however are often on 70mm film.


      In digital cameras today there is no film. Instead you have a microchip which picks up the light and translates it into electrical information, which is then transfered onto the camera's memory card in order to take a photo. The size of the microchip differs between cameras. The larger the microchip the better quality your pictures can be. And the larger the microchip, generally the more expensive the camera will be.

      - - - 


      If you want to read more about 35mm film you can visit wikipedia's entry on it.

      Image by Jay Holben

      Beginning photography: Where to start with photography?

      For a beginner, the idea of mastering a complex contraption like a camera can be quite daunting with it's gazillion buttons, menus and settings. So where do you start with photography?

      Here's my plan:

      Step 1: The Camera User Guide 

      I for one thought that a good starting place will be to dig out the camera user guide and go from there.

      I have a digital Canon PowerShot Pro 1 and have been slowly trawling my way through its user manual recently. So far it's been very enlightening if not a bit overwhelming because there is so much to know! At the moment I'm stopping and googling every second term I read in order to understand what I'm reading, but I'm posting up my discoveries on here as I go so you can benefit from my reading too. What I'm realizing from this initial bit of reading is that it's a bit tricky getting to grips with all the camera buttons, settings and the general terminology and theory of photogrpahy but I think that's natural for it to be tricky at first, and as things become more familiar, reading such things should get easier too.


      Step 2: Check out Photography Books 

      After I finish the camera user guide I plan to go searching amazon for some good photography books. I usually go by the reviews and see what's a well-recommended book. I think investing in a photography bible to turn to should be useful. I'll post a future blog when I come across good books to recommend.

      Judging by my progress so far with reading the camera manual it seems there's  a lot of information online too so perhaps there is no immediate need for a photography book to start off.

      Step 3:  Check out Photography Blogs and Forums

      I'm already aware of the fantastic photography blog by Darren Rowse, the Digital Photography School, which I think will be a wonderful resource. As I discover other good resources I'll be sure to post them on here.

      Well, that's the plan so far. If any one has any extra tips, feel free to share them :)

      Getting into Photography

      My first memory of being aware of photography is having my father point a camera at me when I was little. My uncle used to joke that my brother and I were so well-trained that every time a camera was pointed in our direction, no matter what we were doing, or whether we were mid-talking or mid-tantrum, our faces would automatically switch on the charismatic smiles.

      Around the age of 4 or 5, I remember seeing one of my dad's photos which he captured with a magical looking speckled background of rainbow-coloured interwoven spots, and I remember thinking: "I want to know how to do that some day".

      20 years later, here I am, finally on the path to finding out how to do that (and hopefully a lot more!). At this stage I know pretty close to zero about photography, but every journey starts somewhere, and for me, this journey starts here.

      I'll be delighted to have your company as I explore the great unknown world of photography before me.

      It's gonna be interesting! :)