Photography Step By Step

This system allows the camera to maintain focus on subjects that are moving. It is a very useful feature for sports or wildlife photography and it is normally found on digital DSLRs.

Autofocus Servo is normally triggered by switching focus to “AI Servo” on Canon, or “Continuous” on Nikon, followed by half pressing the shutter release. The camera will continue to focus on the subject as long as the shutter release will be half pressed or fully depressed (actually taking shots). The Autofocus Servo usually also puts the camera into “release priority” mode so that the camera will take the shot when the shutter release is depressed, regardless of the current AF status.

This is a lamp which is used to illuminate  the subject you are focusing on when shooting in low light conditions. The lamp is usually located beside or above the lens barrel. These lamps are not very powerful and they usually only work over a short range, up to about 4 meters. The light that they make is usually visible light, but there are lamps which uses infrared light instead. This is better for candid shots where you don’t want to startle the subject. Notable higher end external flash systems feature their own focus assist lamps with far greater range.

The picture above is a hologram AF found on some Sony cameras. This works by projecting a crossed laser pattern onto the subject. This bright laser pattern helps the camera’s contrast detect AF system to lock on to the subject. The system works well as long as the subject is large enough to be covered by several laser lines.

Sensors from your digital camera consists of millions of pixels with photodiodes which convert the energy from the light (actually from the incoming phototns) into an electrical charge. That electrical charge is then converted to a voltage which is amplified to a higher level so that it can be further processed by the ADC (Analog to Digital Converter). In accordance with the voltage value, the ADC classifies it into a number of discrete levels of brightness and assigns each level a binary label (a number in binary code, consisting of 0 and 1). The ADCs are classified by the number bits that this labels are formed of. So a one bit ADC will classify the voltage as either 0 (black) or 1 (white). A two bit ADC would categorize it into four (2^2) groups (black-00; white-11; and two levels in between-01 and 10). Most consumer digital cameras use 8 bit ADCs, allowing up to 256 (2^8) distinct values for the brightness of a single pixel.

The minimum resolution (bit rate) of an ADC is determined by the dynamic range (accuracy) of the sensor. For example if the dynamic range of the sensor is 1000:1 (or 60dB) the ADC must be at least 10 bits which is 2^10 = 1024 discrete levels. This will avoid loss of information. Theoretically a 10 bit ADC is the perfect fit for this dynamic range (1000:1), a 12 or 14 bit ADC will not generate additional tonal information other than noise. However, in practice it makes sense to overspecify the ADC to 12 bits to allow for some margin of error on the ADC.  It is also useful to have extra bits available to minimize posterization or banding when applying the tonal curve to the linear data.
Often, marketing material advertises the bit rate of the ADC to suggest the digital camera or scanner is able to output images with a high dynamic and tonal range. From the above it is easy to understand that this is only true if the sensor itself has sufficient dynamic range. The tonal range and dynamic range can never be larger than the dynamic range of the sensor.
Digital SLR cameras have sensors with a higher dynamic range and are usually equipped with 10 or 12 bit ADCs. Normally such cameras offer the option to save the 10 or 12 bits of data per pixel in RAW because JPEG only allows 8 bits of data per channel.

I will conclude this first beginner tutorial with some basic ideas that you need to have in mind when taking photos, so that you will be satisfied with the final result.

What goes through your mind in the moments as you raise your digital camera up to take a shot and before you press the shutter? If you’re like many digital photographers you’re not thinking about too much – you just want to capture the moment and then move on. However getting in the habit of asking some simple questions can help take your images to the next level. Here are some questions to get in the habit of asking while framing your shots.

What story am I telling? – This is an important question and one that should help you to make any number of decisions in terms of composition, framing, exposure etc. In essence what you’re asking is “why am I taking this shot? What is it’s purpose and what am I trying to convey?” Is it purely a way to keep a record of a moment, are you trying to capture the emotion of a moment, is it possibly a shot to give to someone, is it part of a larger series of shots or will it be the only shot to commemorate the moment etc.
What is the visual focal point of this shot? – What will viewers of this picture naturally have their eye drawn to in this scene? Once you’ve identified this focal point you can think about where to place it in the frame (consider the rule of thirds for example).
What competing focal points are there? – Once you’ve identified what you do want your viewers eyes to be drawn towards and have placed it in the frame – scan your eyes over the shot and see if there are any competing focal points and ask yourself whether they add to or take away from the image? Secondary focal points can add depth to shots but they can also be very distracting and so you might need to reposition yourself or adjust your focal length and/or depth of field to accommodate or remove them from your shots. Also keep in mind that if your shot has more than one focal point that it might be worth taking two shots, one of each focal point, in order to keep things simple.
What is in the background and foreground? – One of most common places for distractions in digital photography is the background of your shots. Run your eyes over the space behind your subject to see what else is in the image (do the same for the foreground). Consider whether you want the background in focus or nice and blurry.
Am I close enough? – Another common mistake in digital photography is taking shots where your subject is too small in the frame. Shots that fill the frame with your subject tend to be much more dynamic and show a lot more detail of your subject. To get this effect you have the option of moving yourself closer, moving your subject closer or using a longer focal length to give the effect of closeness.
What is the main source of light? – Always give consideration to how your subject is lit. Without light you’ll lose detail and clarity in your image and your camera will have to compensate by doing things like increasing ISO and lengthening shutter speeds (which could lead to noisy and blurred images). What is the main source of light, where is it coming from, is there enough light, do you need artificial light sources (flash etc), do you need to stabilize your camera on a tripod to stop camera shake due to low light etc.
Is my Framing Straight? – It’s amazing how many otherwise good photos are spoiled by framing that is slightly offline. Sloping horizons and slightly leaning people or buildings should always be in the back of your mind to check.
What other perspectives could I capture this subject from? – Put 10 digital camera owners in front of a scene and most of them will take exactly the same shot from the same position. Make your images stand out from the crowd by challenging yourself to not only take the standard shots that everyone else will get but to find creative and fresh angles and perspectives to shoot from.
How would holding the camera in the other format change this shot? – Many photographers get into the habit of always holding their camera the same way (horizontally/landscape or vertically/portrait). While it’s OK to have a preference one way or the other it’s also worth remembering that changing the format can drastically change the impact of the shot. Don’t forget you can also hold your camera at an angle for an effective result too.
How will the eye travel through this image? – This is related to asking about focal points but gets in touch with the fact that while you’re photographing a still image your viewers eyes don’t remain still as they look at an image. People tend to follow lines and are attracted to shapes and colors so considering all of these different visual elements and cues can help improve your shots considerably.

Of course you probably won’t remember all the questions and you’re unlikely to go through each of them with every shot you take – however next time you head out with your digital camera concentrate on asking yourself at least one or two of them as you take your shots. As you do you’ll find that they become more automatic and in time you’ll naturally take digital photography shots that take into account all of these elements.

Hello everyone! I’m on vacation right now and this is the reason why I haven’t post nothing new lately. So I just wanted to assure you that new lessons and many other interesting articles will come soon. Meantime I hope you all enjoy holidays and take as many beautiful pictures as you can! I wish you all a Happy New Year!