What is the significance of digital camera lens?

Question

Hi!

I would like to ask what is the signficance of the lens? I know it specifies how much light can pass through for the sensor, but apart from that, what should I know about it?

For example, I normally see this when looking at a camera specs:

Lens

Focal Length: F = 5.2 mm (Wide) – 15.6 mm (Tele)
[35 mm film equivalent]: [29 mm (Wide) – 87 mm (Tele)]
F number: f / 3.5 (Wide) – f / 6.4 (Tele)
Lens Component: 7 elements in 7 groups
Focusing Range Normal: 11.81 in. ~ infinite / 30 cm ~ infinite
(Wide), 39.37 in. ~ infinite / 100 cm ~ infinite (Tele)
Macro: 1.97 in. ~ infinite / 5 cm ~ infinite (Wide Only)

Which should I mostly take note of? Like for example, when looking at sensors, generally the larger one is the better. Is this also the same with lens?

Thank you!

Answer 1

The part that specifies the amount of light that passes through is the diaphragm which controls the aperture size. The lens is the light collecting device.



http://keerok-photography.blogspot.com/2011/05/lenses-so-many-of-them-there-is-no-best.html



Almost all lenses focus to infinity. They vary in their minimum focusing distances. Macro lenses have the nearest minimum focusing distances to allow taking pictures of small objects at 1:1 ratio.

Answer 2

A lens is what focuses the subject to the sensor.



Unlike sensor sizes, a long lens is not necessarily any better than a short one. The length of the lens determines how close up something is.



A long lens will bring in a distant bird for a close up shot. But you would not want to use that lens to take a photo of a mountain range or some other landscape where you would want to show the wide open vista.



A zoom lens will help in that regard as it can do both landscape and close up. But there is a limit to how well any single lens can work. The higher the power (the difference between landscape and close ups), the less quality the lens has.



For that reason, many photographers use interchangeable lens cameras so that they can get the best performing lens each specific purpose.

Answer 3

Hi Lance,



As one Lance to the other, I think this link will be

very use full to you :



http://www.elizabethhalford.com/2010/07/20/lens-lingo-what-do-all-those-letters-numbers-even-mean/



And more important, which lens is suitable for you :



http://www.dpchallenge.com/forum.php?action=read&FORUM_THREAD_ID=421792



Bigger is not automatically better in the world of lenses. The more zoom a lens

has the longer it gets.The amount of light has to travel a longer distance and

will be less at the sensor. So, with a tele-lens the picture quality will decrease

according to the amount of zoom you use.In that case bigger is not better.

If you're planning to travel to Africa and like to shoot (with a camera) some lions,

bigger is better.



Greetings, Lance.