Few basic terms used in photography

In the journey through the path of photography and cameras, you will come to face few terms that will turn out to be a big barrier if you do not know about them. So, here I am to introduce you to these few terms.

1. Focal length

Have you ever wondered what the number mentioned in 'mm' on your lens actually means? Well that is the focal length range of your camera lens. But what exactly is focal length and how is it calculated?

Focal length is the distance between the camera sensor and the point where light rays converge inside the lens, and this distance is measured in millimeters (mm). So when you are clicking photos at 50mm, the distance between the sensor and the point of convergence inside the lens is 50 millimeters. Similarly, if you move from 18mm to 55mm in your 18-55mm kit lens, the distance between the two changes to 55mm.

2. Depth of field

Depth of field is the area that appears acceptably sharp, ahead and behind the point where you set the focus of the camera.

Depth of field can be classified as:

1) Shallow depth of field = less area appears sharp ahead and behind the subject = more blur effect

2) Deep depth of field = more area appears sharp ahead and behind the subject = less blur effect

So if you want to click a photo which has less area in sharp focus ahead and behind the subject (more blur effect), it is shallow depth of field (left image).

And when you click a photo which has more area in sharp focus ahead and behind the subject (less blur effect), it is deep depth of field (right image).

3.Crop factor

You must have heard people say that if you use a crop-sensor camera, you can increase the focal length by 1.5 or 1.6 times because of the crop factor. But what exactly is this crop factor? Let me answer 

Largely there are two types of digital cameras being used, full-frame camera and crop-sensor camera. The sensor used in the full-frame camera is considered as the standard and thus when you use any lens on it the focal length remains the same as mentioned.

Because the sensor size of the crop-sensor camera is smaller as compared to that in a full-frame sensor camera, the effective focal length on a crop-sensor camera gets multiplied by 1.5x (in Nikon cameras) and 1.6x (in Canon cameras). This 1.5x or 1.6x multiplication in effective focal length is known as the crop factor.

So when you use a 50mm lens on a full-frame camera, the effective focal length would remain 50mm. Whereas, you would get an effective focal length of 75mm (50mm x 1.5) on Nikon and 80mm (50mm x 1.6) on Canon crop-sensor cameras because of the 1.5x and 1.6x crop factor. 

4. Reciprocal rule

One of the biggest concerns a digital camera user has is not getting sharp photos even after investing so much money in the gear. In the majority of situations this might be because of wrong choice of shutter speed. This is where the reciprocal rule might help you, which makes sure that you use correct shutter speed.

The reciprocal rule states that the shutter speed of your digital camera should be at least the reciprocal of the focal length you are clicking photos at. This means that your shutter speed should be equal to or faster than '1/focal length'.

As you can see in the comparison shared above, the photo clicked at 50mm at 1/50 sec is sharp whereas the one shot at 1/13 sec appears shaky because of slower shutter speed.

So for example if you are using the 100-400mm lens, so practically your shutter speed at 100mm should be 1/100 sec or faster. Similarly if you shoot at 400mm, you must keep your shutter speed at 1/400 sec or faster. If you use a slower shutter speed than the reciprocal of the focal length, there are higher chances of camera shake ruining your photo.

5. Exposure stops

Exposure 'stop' is a term used to denote the increase or decrease of exposure by double or half. And you must also know that the exposure depends on three factors: aperture value, shutter speed, and ISO value. So when someone says increase the exposure by one 'stop', it means that you have to double the exposure. And, when someone says reduce the exposure by one 'stop', it means you have to reduce the exposure by half.

Now in order to increase/decrease the exposure you can adjust three settings:

1) Shutter speed: if you take the shutter speed from 1/100 sec to 1/200 sec, you reduce the exposure by half. But you can double the exposure by using 1/50 sec.

2) Aperture: if you take the aperture value from f/4 to f/5.6, you reduce the exposure by half. But you can double the exposure by using f/2.8.

3) ISO: if you take the ISO value from ISO 400 to ISO 200, you reduce the exposure by half. But you can double the exposure by using ISO 800.

I hope this article helped you learn about 5 interesting photography terms that can help you improve your photography skills.

6. Shutter Speed

Shutter Speed is simply nothing but the time period in which the image will be captured.
In the above image, 1/125 means that the shutter will take 125 parts of a second to record the details in the image. So a faster shutter speed(less the value, faster the shutter speed; 1/125 is less than 1/50), sharper will be the image of a moving body (a fast moving train). Similarly, to capture light trails or take low light photos, a slower shutter speed is recommended.
[Note: Whenever you use a shutter speed more than 1 sec, take use of a tripod, tor avoid shaky blurs in the image.]

SO HERE ARE THE FEW BASIC TERMS YOU NEED TO KNOW FOR LEARNING PHOTOGRAPHY.

content and photo credit: Kunal Malhotra, the photography blogger.

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