Other Is the iPhone Zoom feature just based on iOS Cropping the image?

[kat.hayes]

Whether it is the iPhone 16, 17 or upcoming 18 Pro Max, are the zoom features just based on iOS cropping the image? Are there any true optical lens advantages with these phones zooming in on an image vs. you taking an image without zoom and just going into the Photos app and cropping an image down that way to create the look of a zoomed image?

Thanks

 

[windmark]

You have multiple lenses with different levels of zoom 0.5, 1, 2, 4 (depending on which iPhone you have). The lenses themselves don’t have any hardware that zooms (like you’re thinking about on a normal camera).

Any zooming that happens in between, e.g. 2.5 zoom, is just a cropped photo using the 2 zoom lens. Note that they do some tricks to keep the photo at the same file resolution, but it technically has a lower optical resolution.

 

[maerz001]

The pros have optical zoom lenses as described above but the normal line is „digital zooming“ by cropping

 

[FreakinEurekan]

No “true lens” advantage. However, pre-cropping the image can reveal aspects of the photo you might not see at full-width, e.g. a shadow you could move something/someone to eliminate or a facial expression.

That said, I tend to just use the pre-set buttons 0.5x, 1x, 2x, 5x on my 15 Pro.

 

[kat.hayes]

You have multiple lenses with different levels of zoom 0.5, 1, 2, 4 (depending on which iPhone you have). The lenses themselves don’t have any hardware that zooms (like you’re thinking about on a normal camera).

Any zooming that happens in between, e.g. 2.5 zoom, is just a cropped photo using the 2 zoom lens. Note that they do some tricks to keep the photo at the same file resolution, but it technically has a lower optical resolution.

Can you please elaborate on what you mean by "Note that they do some tricks to keep the photo at the same file resolution, but it technically has a lower optical resolution."

1. what do you mean by keeping the photo at the same resolution? Do you mean that since it is cropped the resolution should be changing but they are keeping it the same somehow?

2. What do you mean by that it technically has a lower optical resolution? What is an optical resolution?

Thanks

 

[windmark]

If you take a photo and crop it with the photo app, you will see that the actual megapixel count decreases since you removed pixels.

If you do the same but instead zoom from e.g. 2 to 2.5 and view the image resolution, it’s the same. Since a couple of years, the sensors have gotten so high resolution that Apple normally downsamples from e.g. 48MP down to the actual 24MP you see if you view the photo. That means there actually is head room to do an image crop without losing any of the 24MP you see as final result.

Petapixel covers it briefly here when they reviewed the iPhone 15 PM.

I was very skeptical about the 28mm and 35mm “lenses” that are incorporated into the main camera. Make no mistake, these are digital crops. However, unlike the 48mm FOV which is relegated to only 12-megapixels, the new 28mm and 35mm FOVs combine a 48mm detail shot into the image capture and compilation process. This gives you a 24-megapixel image which is very similar to the 24mm main camera’s standard output.

Because of this, despite the main camera cropping in to give these different lens options, I found the images to have excellent detail and were very usable in real-world situations.

My comment about optical resolution is thus not really noticeable anymore and it used to be more significant when the sensors only were 12MP.

The iPhone 15 Pro and Pro Max Review for Photographers

We may have seen some of the hardware before, but the magic is in the processing.

petapixel.com