>>3766073Do you have a list of the lenses she has so we can help you with proper recommendations? That way you won't give her a redundant gift.
1:4 and f/4 are indeed the same, sometimes it's written f=1:4 or f=1/4. The higher the denominator, the darker the lens will be. It's probably a bad idea for night-time photography.
On a zoom lens, what you adjust is the focal length, when you have a lens that says yy-zz mm, it's a zoom lens. xx is the minimum length and yy the maximum. You're right about it being akin to having different brushes, but most vintage zooms are far from excellent and tend to be darker. If she's shooting at night it wouldn't be the best idea. Prime lenses don't have that versatility but they tend to be brighter and have better optics in general. Zooms are a compromise, you trade in quality for versatility. If it's an awesome zoom, you won't be trading a lot of quality. Distortion is common among cheap zoom lenses.
There's basically 3 classes of lenses:
wide/short, normal, telephoto/long. Technically telephoto is a misnomer but usually long lenses are telephotos. It has to do with the design inside it (telephoto means the lens itself is shorter than its focal length, for example a 400mm lens that physically is shorter than 400mm is a telephoto.
Telephotos give you what most outsiders call "a lot of zoom", that is, magnification. It has nothing to do with zoom, actually. You use them to shoot from far away either to get a big image of a small subject or to "compress the perspective".
Zoom is actually the ratio between max focal length and min focal length. The lower the zoom ratio, the higher the optical quality usually is. To give you an example, if you have a 100-200mm lens you do 200/100 and get the zoom factor: 2x. Some zooms are extremely versatile at the price of quality, they're called superzooms and it's when you have ratios of about 10x and above, see 18-200mm.
