Hacker News Reader

Comment by vwoolf | Hacker News Reader

I have a Sigma 30mm 1.4 in Fuji X-Mount (https://www.sigmaphoto.com/30mm-f1-4-dc-dn-c), which is ~45mm full-frame equivalent (FFE), and it's one of the most cost-effective lenses in existence, given its quality relative to its price.

The downside around the "perfect framing" is that focal length will change perspective: https://en.wikipedia.org/wiki/Perspective_distortion_(photog... (take a head a shoulders portrait of yourself with a 20mm and then 85mm lens to see). Almost all professional photographers who need to get the shot have moved to zooms for good reason.

View on HN

> Almost all professional photographers who need to get the shot have moved to zooms for good reason.

Nitpick: I imagine you mean telephotos, not zooms.

What ? Why ?

https://en.m.wikipedia.org/wiki/Telephoto_lens

A 30mm zoom would give the same perspective as a 30mm prime. I think the parent post was talking about telephoto vs wide-angle perspective distortion, not zoom vs prime.

Lots of pros moved to zooms, 2x-7x f2.8 are pretty common for example

A telephoto lens isn't the opposite of a wide angle lens, it's a type of design for lenses with long focal lengths, not all long lenses are of telephoto design

Focal length doesn't do anything to perspective. Perspective is dependent on the location (distance) relative to subject.

Different focal lengths will make you want to change your position, to get the entire subject in frame, or, conversely, to get more details. Then you will change your perspective.

>Focal length doesn't do anything to perspective. Perspective is dependent on the location (distance) relative to subject.

That's a pedantic way to put it, in the sense that someone says "it's not the fall that hurts you, it's hitting the ground". Sure, but not very usefull. It's the same if you add the extra parameter of "changing the position" into the matter of focal lens vs perspective.

Another way to see it is that if you stand in the same place and point to the same thing, a larger focal length will do compress the perspective more.

> if you stand in the same place and point to the same thing, a larger focal length

What will happen then?

> will do compress the perspective more.

Beep! Wrong! That's why I'm pedantic about the topic. Try it yourself with a zoom lens. The right answer is:

"will capture a smaller angle of the same scene."

No perspective change. Ignoring details coming from resolution, you might as well crop the picture.

Reply on news.ycombinator.com