stupid beginner question

dukeboy1977 · Aug 13, 2011

I bought a Nikon 24-120mm AF-S lens and had a question. I understand it's supposed to be a 'softer lens' but does having a bigger sized lens mean you're going to have more in a photo than a smaller lens? EX - 72mm vs 52mm

I never researched this and figure I'll get faster answers here. Sorry to waste your time

Gaerek · Aug 13, 2011

All that matters with the field of view of the shot (sensor size is not a factor but we'll ignore it for this discussion) is the focal length. Typically a longer lens physically means a smaller field of view. Though, there are some lenses that actually are longer on the short end. Physical girth has nothing to do with the field of view. Does that answer your question?

Keep in mind that researching yourself is almost ALWAYS going to be faster.

flatflip · Aug 13, 2011

dukeboy1977 said:
EX - 72mm vs 52mm

I guess you're talking about the lens diameter and not the focal length, since your new lens has a 72mm filter size and your other lenses have a 52mm filter size. The way I understand it is, the short answer is "design". Each particular lens is designed with a parameter set. Maybe for popularity or IQ or ease-of-manufacture. Maybe designed to utilize left over or surplus parts. I often wonder what's going on in any field's R&D.

dukeboy1977 · Aug 13, 2011

If I understand right, the focal length is the ONLY variable which makes a difference, right? If this is so, and I'm sure I'm not the only one to ask this one, why have multiple sized lenses? Why not make them all one standard size no matter what the focal length is or can be? Now not only do I need 52mm filters, but I need 72mm ones also. It just don't make much sense to me...maybe I'm just stupid or something :lol:

Gaerek · Aug 13, 2011

Bigger opening means more light through the front element. It doesn't change the apparent field of view

BuS_RiDeR · Aug 13, 2011

I have no answer to your question.... But remember that in most circumstances, the only stupid question is a question that goes unasked.

Gaerek · Aug 13, 2011

dukeboy1977 said:
If I understand right, the focal length is the ONLY variable which makes a difference, right? If this is so, and I'm sure I'm not the only one to ask this one, why have multiple sized lenses? Why not make them all one standard size no matter what the focal length is or can be? Now not only do I need 52mm filters, but I need 72mm ones also. It just don't make much sense to me...maybe I'm just stupid or something

I couldn't find a comparison of the size of these different lenses in a photo, but go ahead and forward to about 1:00 in the below video to see Canon's 3 current 50mm lenses, the f/1.8, f/1.4, and f/1.2 side by side.

You're probably thinking, "Wow, why are they different sizes if they're the same focal length?" There is really one answer, though there are some other reasons as well. That is simply, the amount of light that can enter the camera. The 1.2 can let in an extra stop of light compared to the 1.8. That's twice as much light. Apertures smaller than 2.8 on zooms are rare (if they exsist at all?) and apertures smaller than 1.4 are pretty rare on primes as well. The faster the lens (ie. the smaller aperture number) the bigger then lens must physically be in diameter to let enough light in. I hope that explains it.