Like most digital cameras, my phone offers a “digital zoom” function whereby I can take close-up pictures of an object. But of course this function cannot do anything about the hardware constraints of the camera, such as resolution - unlike an actual optical zoom lens. So my guess is that using the digital zoom when taking a picture is just the same thing as taking a normal photo and then cropping and enlarging a section of it. In other words, the digital zoom doesn’t give me, in terms of pixelation and otherwise, any benefit that I couldn’t have by means of photoshopping an un-zoomed image ex post. I/ that so? If yes, then I needn’t worry during my sightseeing about the zoom.
That is my understanding, yes. There may be some arcane details of how the camera internally compresses digitally-zoomed images, but you can (should?) just export the raw image format.
Actual zoom lenses are pretty cool; I had a lot of fun with a 35–200mm lens
Just a wag but, I’d bet the cropping and enlarging is done better by a photo editing program than by the phone.
There could be situations where the onboard hardware/software does something different about the exposure based on the dynamic range of the cropped vs full frame. I’m not absolutely sure saving as raw would give you the same options afterward, if the camera has already actually exposed the sensor differently based on the crop/zoom.
Yes, it offers convenience.
Personally, I don’t think it does. Knowing that the digital zoom is equivalent to ex post photoshopping gives me peace of mind; I don’t need to worry, as I’m taking the picture, whether I’ve chosen the right zoom factor or whether I should close in or move further out. I just take the picture and worry about that later, when I’m at my desktop and have plenty of time.
The main thing I could see it doing is changing autofocus, exposure, etc, based on what’s actually visible. But I don’t know if any cameras do this.
I will say that it would be nice if the actual RAW file would still include all the data so you could reframe later on a computer.
I am under the impression that if the camera sees something interesting (like a face) at a point other than the center of the photo, the camera will focus on that other point. If so, then there may be an advantage to zooming in, so that the camera knows to ignore points outside of what you want.
Similarly, suppose you have zoomed out to include a large area in your frame. If there are significant bright or dark spots in the periphery, wouldn’t the camera miscalculate the proper exposure? Wouldn’t you be better off zooming in so that it calculates the exposure based on what will actually be in the picture?
If you’re shooting with a lossy image format like JPEG, then at the very least using the camera’s digital zoom should only compress the image after it’s been cropped/zoomed, which could help the quality versus if you tried to crop and zoom in on the full size compressed image. Depending on the camera’s internal processing abilities (which nowadays are being augmented with neural processing and other artificial intelligence in some cases), it may be able to better upscale the shot since it knows more about the properties of the sensor, lens, and the best sharpening algorithms to use. That’s no guarantee, but at least there’s been some advances in this technology.
I may be wrong, but generally AFAIK a digital zoom picture is actually the crop. If you have a 12Mp camera, for example, the 2x digital zoom is a 6Mp picture, not 12Mp blow up from 6Mp data. JPEG compression is typically dividing the pic into 8x8 pixel chunks and using an algorithm to encode each square. (Hence the parquet floor effect in overly compressed or too much enlarged pictures) So I don’t see that a zoomed picture with the same level of compression would be any different detail than the cropped pic.
This to me would be the biggest reason - if you get extraneous bright elements out of the pic, or the reverse, zoom in on a bright scene surrounded by dark (say, a singer under lights in a dark auditorium), the camera may better evaluate the necessary exposure without including the surrounding differently lit parts. My earlier cameras had a real problem focusing when bright lights were in the picture because it selected them to autofocus and could not discern a sharp edge. .
There are cameras (not just Google Pixels) that use tricks to give real increased detail on digital zooms.
Super-resolution is a real technique, but why wouldn’t it be applied all the time? Not only to do a “digital zoom”.
The article that Darren_Garrison linked to says:
- For now, the Pixel 3 does not use super resolution for standard 1x shots. Super Res only kicks in at 1.2x and above, currently for performance reasons.