this post was submitted on 11 Feb 2026
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Won't work and if it does work, the resulting image has little to nothing to do with the original.
Source: I opened a badly taken .raw file a few thousand times and I know what focal length means, come at me.
Do you have a good way to remember which way fast and slow f. stops go? I always have to trail and error when adjusting camera settings to go the right direction or especially listening to someone talk about aperture.
Wider open you let in more light, and want faster shutter speed, more closed you get less light and want a longer shutter speed.
And f stops work backwards. Think of it as percent of sensor covered. The bigger the number the more covered it is and the smaller the hole/aperture.
So Wide open = low coverage = small f stop -> lots of light -> "fast" shutter speed. And then the other way around. I think you finally worded it in a way it can stick in my brain! I like thinking about the f value as how much you're covering the lens.
I like trying to simplify stuff to basic language and I am happy it was helpful
To add more specifics here for you, note that the f-stop is usually shown as a fraction, like f/2.8, f/4.0, etc.
So first of all, since the number is on the bottom of the fraction, there's where you get smaller numbers = more light.
It's also shown as a fraction because it's a ratio, between your lens's focal length (not focal distance to the subject) and the diameter of the aperture.
So if I'm taking a telephoto shot with my 70-200 @ 200 with the aperture wide open at f/2.8, that means the aperture should appear as 200/2.8 = 71.4mm. And that seems right to me! If you're the subject looking into the lens the opening looks huge.
What does focal length means?
It's the distance from the lens to the focal point, as in where the picture focuses on the sensor behind the lens. If you have a very long focal length like a telescope, you can see things further away but the range you can see is very small. With a short focal length you can't see as far but you can see a much wider view. Check out this chart:
If you get very close to something with a short focal length or far away from it with a long focal length you can get essentially the same picture of a main subject (although what you can see in the background will be different), but even then a short lens will sort of taper your subject closer to a single point and a long lens will widen it. You can see this effect easily on faces: see this gif or this gif or this picture for an example.
Wow, what an amazing reply, thank you very much. Those images help a lot.