On a smartphone, why is a telephoto camera better than a wide angle with more megapixels?


The new Samsung galaxy phone has a 200MP wide angle camera and a 10MP 10x optical zoom camera. Is it not better to take a picture with the 200MP camera then zoom in on it 10x then get a 20MP picture, than use the 10MP camera? I’m trying to wrap my head around this.

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3 Answers

Anonymous 0 Comments

A 10x zoom means the width of an object the 10x larger in the image, and the hight gets 10x larger too the result is the area is 10 * 10 = 100 times larger in the images. So 10x digital zoom will only use 1/100 of the pixels, with a 200MP image resulting in a 2MP picture if you do not do any interpolation.

So the 10MP sensor provides 5x the number of for the same object compared to digital zoom because you need to square the zoom factor for the pixel reduction

Anonymous 0 Comments

The 200 megapixel camera is effectively upscaling a much smaller image to have more pixels. If you’ve ever zoomed way in on a smartphone picture and noticed that it starts to look almost like one of those ai paintings this is why. It makes the overall image look very sharp but the finest details aren’t actually being captured perfectly

Anonymous 0 Comments

There’s already some good answers here that don’t quite get to the point.

So, digital zoom isn’t real. Any digital camera that doesn’t have a telephoto lens (or similar) can’t actually zoom. What it can do is enlarge and crop.

So say (for the argument) you have a camera with a 200MP sensor and no telephoto lens. You want to take a zoomed photo at 90% zoom, a real closeup. So you zoom in on your camera app. Your phone can’t actually zoom, because it doesn’t have a lens to zoom with, so it instead crops the view to the part you zoomed in on, fills the screen with it, and does some AI upsampling to try and make the view look better. You end up with a 20MP image that’s had some AI sampling done to try and make it look more detailed than it actually is.

Say you had a 50MP camera with a telephoto lens. You zoom the same picture to 90%. Because this is real zoom with a telephoto lens, no cropping needs to happen. You get a full 50MP image.