If you plan to purchase a camera for Christmas, here is the one thing you need to consider

Will you be taking pictures in very low light situations without a flash?

   

Buying a camera is like buying any tool that you plan to use to make your life easier or to achieve a certain purpose.   Although most cameras purchased at retail stores are designed to meet most of the needs of the average family, there are exceptions to the rule. 

If you plan to take over 40% of your photographs in low light situations such as a church, auditorium, high school gym or football field without a flash, you need to make sure that the camera that you purchase has an ISO of 12,800.

If you plan to use selective focus, you need to make sure that the lens you purchase is an f2.8 or f4.0 lens.  Selective focus is the process of focusing on a subject and throwing the background out of focus.  Sports photographers and nature photographers use this composition technique to highlight one athlete or one flower.    Most cameras come with an 18-55mm f/3.5-5.6 lens, which makes selective focus challenging.   Furthermore, the aperture is 3.5 at 18mm and 5.6 at 55mm.

In other words, if you are taking a photo inside a gym at 18mm and the exposure is correct, when you zoom the lens to 55mm to get closer to the subject, the photo will be darker.   The reason for the change is the loss of one and a half stops of light.  The lens opening at f3.5 allows more light than at f5.6. 

So to counter the loss of light, you will need to regain the light by increasing the ISO or lowering the shutter speed.   If you lower the shutter speed, and the subject is moving, your photo will be blurry.  That is why you have to have the option of a high ISO.

However, if you purchase a lens such as 70 to 200mm f2.8, the amount of light will remain the same because the aperture is the same at 70mm as it is at 200mm and the ISO 12,800 may not be required.  In addition, the images will also be sharper because the lens quality is superior, and the selective focus will be easier.  However, the price of the lens will be significantly higher.