Photography basics-2

When I bought my first DSLR - Sony A200, I was using it in the auto mode for a long time. I was also making fun of my friend who always keeps his camera in the manual mode and struggles in changing the settings to match the scene. My question was simple, if the camera can find out what is the best setting for a given scene, why bother fiddling with that and waste your time learning what those settings are for? Very soon I realized that I was wrong, but I still don't keep my camera in full manual mode always. There are a lot of places where you just can't go with the default camera settings. For example you want to take the photo of a waterfall showing how the water is flowing. Or you want to take a portrait picture with blurred background sometimes and focussed background some other times. Without knowing the settings, you can't tell your camera how to capture these specific scenarios. So, it becomes essential to know how to use the camera controls rather than leaving the full control to camera and it deciding how the photos should look like.

Every camera has hundreds of settings, I haven't looked at most of them. So I will only try to cover some of the basic concepts that helps in understanding few of them.

1. Sensor - sensitive plate that absorbs the light and transforms it to pixels, equivalent of film in the older camera

2. Exposure - Amount of light allowed to fall on the sensor for a good photo

3. Depth of field - Distance between nearest and the farthest object that is acceptably sharp in the view
4. Aperture - size of the hole in the lens that controls the amount of light entering the sensor
5. Shutter speed - How fast the shutter (placed in-front of the sensor) opens and closes exposing the sensor to light
6. ISO - sensitivity of the sensor

In simple words, the process of taking a photo is to make the light rays of the subject fall on the sensor. The right amount of light that needs to be collected by the sensor is called as exposure. If the subject is exposed too long, the picture looks washed out, also called as over exposed photo. If the subject is exposed too short, the photo looks very dark, called under-exposed photo. If you are able to determine the right amount of light for the subject, the task of taking the right photo is almost done. All cameras generally have a built-in light meter, which determines the right amount of exposure for a given subject. Once the right exposure is determined, that is converted to actual settings by changing the aperture, shutter speed and the ISO. Light meter generally gets the exposure right for all the cases except for very bright and very dark scenes. I am not sure how or on what basis the camera auto mode balances between these three settings to get the right exposure. The balance of these three parameters is very important as they also affect some other parameters affecting the final result. So these three are commonly called as photographic triangle.

Aperture is the hole in the lens that controls the amount of light entering the sensor. A lens marked as 18-250mm f/3.5-6.3 has a focal length range of 18mm to 250mm and aperture size of 3.5 at 18mm and 6.3 at 250mm. Aperture is actually expressed as f/aperture. That means, lower the aperture number, higher is the lens opening and more light entering the sensor. Higher the aperture number means lower the hole size and light entering the sensor is also minimal. The number 3.5-6.3 on the lens represents the maximum aperture size for that focal length and can go as low as f/22 or lower based on the lens. Apart from the light, aperture also controls what is called as depth of field, which determines how blur the background(or non focussed) objects will be compared to the subject. While taking the portraits or some specific object, you might want to give the full attention of the viewer to the subject by making all other elements in the view blurred. This can be done by choosing a higher aperture (lower aperture number). Similarly, if you want your photo with a nice background in a famous location, you need large depth of field to keep the foreground, background and your subject focussed in the photo. This needs a small aperture (ie large aperture number in the camera). The depth of field can also be controlled by the focal length. In general, higher focal lengths give shallow depth of field.

Shutter speed determines how long the shutter will be open thereby exposing the sensor to the subject. The longer the shutter is open, more light that enters the sensor exposing the subject longer. If you want to freeze the motion of a subject, you need to keep a smaller shutter speed like 1/2000 or smaller. Bird photography, wild life and sports generally need very small shutter speed. If you need to capture the motion, you need to keep higher shutter speed, like flowing water or waterfall.

ISO is probably more easier to decide, which changes the sensitivity of the sensor to collect the light. Higher the ISO speed,  faster the camera collects light but it also adds more noise to the photograph than the lower speeds. So, it is always better to keep the camera in lower ISO speed when there is enough light and increase it only in tight lighting conditions like indoor or night photography.

So, putting a camera in manual mode is all about deciding the right aperture, shutter speed and ISO for a given scene. Understanding these three helps to determine the best settings for a given scenario. However, you may not have to keep your camera in manual mode always changing all three settings. Instead it would be often easier to keep it in Aperture(A) priority mode and set the aperture, which automatically determines the shutter speed for the right exposure. In general most of the lenses have a sweet spot, generally at around f/8, which is suitable for most of the scenes. You might have to change that when you need to control the depth of field. Similarly, when your aim is to capture the motion or freeze the same, you could keep the camera in shutter priority mode which selects the right aperture. When you are not satisfied with both, you can turn your camera to manual mode.

Photography basics- 1

So far I have been resisting to write this as I don't consider myself to be having enough knowledge to write even a basic article on photography. But then thought there is nothing wrong in putting what I know which might be useful for few people. It will also serve as a note for myself in case I need to refresh it in the future and someone more knowledgeable might correct my mistakes. So, this is more about summarizing what I know about photography from different sources that I have referred.

I consider good photography as having 3 distinct elements.

1. photography equipments

2. photographic mind

3. understanding of post processing tools

The first one is a religious  topic. I can probably find an answer to the 'best language between Java and C++', but I am sure I can't find an answer to 'the best photographic equipment'. There are a lots of camera brands like Canon, Nikon, Sony, Pentax, Leica, Olympus etc. All of them have their own mark in the photography industry. Majority of the camera market is dominated by Canon and Nikon. But the rest of them also have very good cameras and able to play in this market so far with their unique offerings. So instead of talking about the brands, I will try to concentrate on other basic things.

All cameras can be broadly classified under 4 types.

1. Point and shoot or compact camera

2. Entry level DSLR

3. Mid range DSLR and 

4. Pro DSLR

Main difference between a compact camera and DSLR is that you can change the lens in DSLR. DSLR stands for Digital Single Lens Reflex, which basically stands for the working principle of those cameras. The light coming through the lens falls on a mirror which sits just in-front of the sensor(equivalent of old film) and reflects that light upwards(90°), which will be shown via the optical view finder. While taking the photo, that mirror assembly goes upwards exposing the sensor to the light, thereby capturing the image.

DSLR operation (source:chucol)

There is another kind of camera called mirror-less interchangeable lens camera which looks very similar to DSLR, but in a smaller size. This doesn't work like DSLR's, Instead of moving the mirror element they adopt another element which redirects a part of the light to the electronic view finder. They are in between compact camera and DSLR which allows you to change the lens, but lighter in size compared to DSLR. Still, they can be  treated same as DSLR and falls in one of the  three categories. No company has yet announced a Pro mirror less interchangeable camera, but it may not be too long to see one. So here onwards when I say DSLR, its a broad category of cameras which allows you to change the lens.

Entry level and Mid range cameras are mainly differed by its price, features and image quality. Pro DSLR's are more costlier and often has a full frame sensor. Full frame sensor makes the camera equivalent to older film cameras. They give the same angle of view as in a film camera for any lens, whereas most of the other DSLRs uses APS-C sensor which is much smaller compared to the full frame. In general they have a crop factor of 1.6, which means a 10mm lens on a full frame camera is equivalent to 16mm on APS-C sensor camera. In other words, Pro cameras gives you a large angle of view covering a larger area for the same lens compared to other cameras. In compact cameras the sensor size is generally even smaller.

In DSLR world, the lens also has a major weight. Probably it is considered more important than the camera body as they last longer and changes in lens technology is lot less compared to camera body. There are different categories of lenses. 

1. Prime lenses

2. Zoom lenses

This category is made based on the lens focal length. In ordinary language, focal length of a camera decides the angle of view of the subject. Lower the focal length, you get a broader view and higher the focal length your view gets restricted, but the range/magnification(how far you can see) increases. Prime lenses have a fixed focal length where as zoom lenses have a range of focal length. If you are having a zoom lens, you can change the zoom level which changes the focal length internally to change your angle of view or to get a closer view of the subject. But if you have a prime lens, you have to move yourself to achieve the same. So, why buy the primes lenses? Because zoom lenses are harder to make and therefore expensive. Also the sharpness and image quality of a prime lens is always better compared to zoom lens.

The other classification is based on the usage

1. Wide angle lenses

2. Normal zoom lense

3. Telephoto lenses

4. Macro lenses

Wide angle lenses have a focal length range of around 8mm-21mm. Anything lesser than 21mm is considered as wide angle (for APS-C sensor) in general, which is around 35mm for the full frame camera. They are generally used for landscape photography. Another use is in real estate where you have to cover the entire room showing it as having a lot of space to fool the customers. Normal zoom range is between 35mm-105mm, which is generally used for street photography. Telephoto lenses are generally used for wild life photography, bird photography and sports. They generally have a longer range between 105mm-300mm or even higher. Sometimes they are also called as Macro as they provide decent subject magnification and can be used for photographing flowers. Macro lenses are generally prime lenses which provides 1:1 image magnification and allows close focussing of the subjects. They are used for flower, insect photography and also for portrait photography sometimes. 50mm Macro lens is good for flowers but you would need 100mm macro for insects and other moving subjects which needs to be focussed with some distance. Otherwise they might get distracted and move making it difficult to shoot.

Most of the kit lenses come with 18-55mm or little longer than that, which covers a short wide angle and normal zoom range. There are lenses with long zoom range like 18-250. But they are generally considered as inferior image quality compared to lenses having a short zoom range. But it mainly depends upon the lens and may not be true for all the lenses.

Apart from the camera and lens, it is also very important to have a tripod and a cleaning kit. And the addition of an external flash probably completes all the basic needs of an amateur photographer.

Having good equipment is just one part of the photography which you can buy by spending some money. But the more important thing is knowing what to shoot and how to shoot. This is more of an art than understanding the technology. There are a lot of established rules which might simplify the process of knowing how to shoot. But there is one rule above all these rules which says 'there are no rules in  photography'. That needs a pure artistic mind to see things differently than others and capture the same. People have taken photographs even 60 years back which are still considered the best. The technology at that time was no where compared to the current one, but not the photos taken at that time. That suggests, you really don't need a high end camera to take good photos. The photos taken by a DSLR need not be better compared to the one taken from a point and shoot camera. Good equipment definitely adds a lot of weight, but it is not the equipment alone that decides a photo.

Finally, it is very important to give a final touch to the photos you have captured before sharing it with others. In the film camera age, people are more careful before clicking a photo as the camera reel and the development used to cost a lot. Taking a photo with digital camera doesn't cost anything, but the people may not be interested in seeing each and every photo that you have clicked. So it is good to select only those distinct photos, make minor adjustments like cropping unwanted areas, changing the contrast, brightness where required. Adding a border might also make the photos look better. There are a lots of free tools to do these basic editing like picasa, picnic, f-spot etc. If you are looking for advanced editing, photoshop and GIMP are the best options. While photoshop is a paid software, GIMP is a free application available for both windows and Linux. The learning curve for GIMP is said to be high compared to Photoshop, but its free and allows almost everything that is possible using Photoshop.

In my next article I will try to cover what are the main things that you need to know in your camera instead of keeping the camera in auto mode, making your camera decide everything about the photo.