Optical and Digital Zoom - Difference

[Nana2Callie]

Can someone explain the difference to me and when and when not to use the digital zoom? Thanks, my Sony has 20x optical and 40x digital.

 

[photo_chick]

Optical zoom is when you use the optics of the lens to zoom in. It magnifies the image as it's projected onto the sensor of the camera and it doesn't degrade the image quality. Digital zoom just crops in on the image, much like you would with editing software and can quickly degrade an image.

 

[coloneldebugger]

When to use optical zoom? Whenever you want a closer shot of something.

When to use digital zoom? Pretty much never.

 

[rebeccaariel]

If you want to retain image quality, don't use digital zoom.

 

[havoc315]

I generally agree, to avoid using digital zoom.

But to the extent you would use it in the same way as cropping in post-processing, if your picture is sharp enough, light is good enough, and you have enough resolution, a bit of digital zoom is okay.

You go back 6-10 years, cameras needed more megapixels just to get a decent 8X10.
These days.. with cameras of 8 mp, 10mp, 12mp, being fairly cheap -- You have plenty of resolution for a 8X10. In this sense, a 18-20mp camera is no better than a 8mp camera.
But where that 20mp camera still comes in handy -- the extra resolution gives you more cropping flexibility. You can crop half the picture, and still get a good 8X10.

Typically, I would still advise to use optical zoom. And if you have the pixel flexibility to crop, do it in post-processing.
But if you really just want instant results, don't want to bother with post-processing, then go ahead and use digital zoom judiciously.

For example, the iPhone only has digital zoom. Pictures I take on the iphone aren't meant to be blown up into 8X10s for framing. If I'm taking a picture with the iPhone, it's usually just because I have a moment I want to instantly capture and share on facebook with friends and family. In that instance, I use digital zoom.

On my regular compact camera, the Rx100, I basically keep the digital zoom turned off.

 

[maccagerl]

I would stick to optical zoom for better quality photos. There is no need to use digital zoom, all that does is basically crop your photo in the camera.
You are much better off only using the optical zoom to take the photo, then cropping your photo later in your photo editing program, that way you can decide how closely you can crop without losing quality.

 

[Nana2Callie]

Thanks for explaining that.

 

[npmommie]

yes thank you I never really knew the difference either.

 

[hakepb]

While Sony's "Clear Image zoom" is a step above most camera's plain digital zoom (it seems like Sony is extrapolating RAW data vs post processing with only a .jpg) ...it's only something I use as a quick "telescope" to look at something really distant on my camera's screen.
For instance, this is the new Grand Floridian DVC taken from the TTC dock at the 40x Clear Image zoom

While its recognizable when the picture is reduced down to the 1024x768 resolution of Photobucket, its no where as clear as an optical-only zoom picture:

 

[havoc315]

While Sony's "Clear Image zoom" is a step above most camera's plain digital zoom (it seems like Sony is extrapolating RAW data vs post processing with only a .jpg) ...it's only something I use as a quick "telescope" to look at something really distant on my camera's screen.
For instance, this is the new Grand Floridian DVC taken from the TTC dock at the 40x Clear Image zoom

I actually do keep the clear image zoom turned on. But almost never use it. I usually shoot in RAW, which automatically disables the clear zoom. (or technically, clear zoom isn't available in RAW). But if I am shooting jpg... the LCD screen does show me when I'm switching from optical to clear zoom. But it gives me the option, if I really feel the need to get a little more reach.
Reality is, I only shoot jpg if I'm being lazy and want quick usable images, with zero post processing. In which case, a little clear zoom isn't going to kill me.
But generally, where Im willing to do some post-processing touch-up, I'll just shoot in RAW and crop the picture myself.