I dont mean when for example 35mm on a crop sensor “equals” a 50mm on a full frame camera. My question is a bit weird, here we go.
So i have a 18-55mm lens (on a crop camera) and people say that 50-55mm is the focal length of the human eye. Here, my experiment comes into the play:
My camera has a 1.5x crop factor so 35mm looks like 50 mm on a full frame because of narrower field of view right? So when people say field of view of a 50mm on a full frame is the same as your eye, my first thought is 50mm on a full frame = 35mm on my camera. Then what i do is i take my camera put it on 35mm and then look at the vizor. What i expect is no zoom at all but the objects look smaller in the vizor (so fov is higher). When i put my camera at 55mm, the objects size match up with exactly what i see. But from what i learned 35mms should be like a 50mm on a full frame therefore it should match my eye.
So here comes my question:
Are the numbers of focal lengths on my lens already multiplier by 1.5x ? So do i have to subdivide the numbers to get the full frame equivalent ?
Sorry for spelling mistakes.
FYI, good luck with this question - there have been thousands of threads across countless forums arguing aggressively as to what the concept of equivalent focal length and aperture actually means, because a lot of it has to do with how pedantic you want to get and how detailed you want to get in the comparison. And lord help you if people start talking about the amount of light a lens gathers based on aperture, sensor size, pixel resolution, and so on. That’s an argument that never ends because it gets even deeper into pedantry.
Honestly it’s an interesting discussion and it’s worth reading about, but be aware that there will be a lot of people defending their opinions very strongly, whether or not they’re actually correct. Believe me, it gets spicy, especially with the people who are technically correct but in was that don’t actually matter.
The best way to look at it is simply that lower is wider, higher is narrower. A smaller aperture number means more light and faster shutter speed options, and narrower depth of field.
Multiplying the focal length by the crop factor does help as a shorthand to help you compare with other lenses but it’s basically a simple cheat sheet rather than anything meaningful.
The real best way to do it, for any camera, is to use the kit lens or some cheap equivalent, and actually take pictures with it and get used to what you actually see. Try it and see how you like it, and use that knowledge to guide your purchase decisions. People on the internet will tell you what they think you should think, but ultimately what matters is how it looks and feels to you and how it matches your eye and the physical spaces you have to shoot in.