digital zoom

Bolerus · 2 Jan 2007 at 11:25

I know that the unspoken rule is only use optical zoom, digital zoom is nothing more than a crop.

but what is the advantages of cropping using software rather than letting the camera crop with digi zoom.

I have never personally used the digi zoom, was just wondering whether its is worth playing with in the "more experienced" opinion

SDK^ · 2 Jan 2007 at 11:39

Digital zoom is a complete waste of time - There is no advantage of cropping in camera over doing in your image editor.

Bolerus · 2 Jan 2007 at 11:54

why

Don't get me wrong, im not arguing for digital zoom, but rather asking why it's useless.

surely if it is that useless camera's with optical zoom simply wouldnt have it on, so the manufacturers must rate it for some reason.

Is the "never use digital zoom" (and I also have that opinio, but as part of trying to learn this art I am trying to question everything I have ever "known" in an attempt to inmprove) just snobery or is there a real reason not use digital zoom, if al lit does is crop the image.

For example, I have noticed that sometimes, cropping in software creates strange resolution sizes (for example might get 800 x 490 instead of 800 x 600) would camera digi zoom, keep the resolution in a "standard" size format

Scam · 2 Jan 2007 at 12:12

Bolerus said:
For example, I have noticed that sometimes, cropping in software creates strange resolution sizes (for example might get 800 x 490 instead of 800 x 600) would camera digi zoom, keep the resolution in a "standard" size format

Possibly. I think it's more just so that the companies can add it to the 'impressive specs' of the camera though! I think it's just there so that people who dont use PS can have the image they want, processed by the camera, ready to show their friends.

^^Gord^^ · 2 Jan 2007 at 12:27

I would expect you are more likely to get "camera shake" using the digital zoom as you are magnifying the movements of the camera where as cropping on a PC wouldn't.

Johnny|lucidcomposure · 2 Jan 2007 at 12:33

It is there because every comsumer doesnt have a photo editing package or do they have any skill to use it.

It is also listed as a feature and as crap as a feature it is. It catches the eye of punters who have little idea.

whitecrook · 2 Jan 2007 at 13:01

^^Gord^^ said:
I would expect you are more likely to get "camera shake" using the digital zoom as you are magnifying the movements of the camera where as cropping on a PC wouldn't.

No, that's the no-point of digital zoom. You aren't actually zooming in, you are cropping so the level of shake is exactly the same as the level of shake as whatever the optical zoom is set at. (most cameras will max the optical zoom before using digital)

The advantage of cropping after the picture is taken (say in PS) rather than in the camera using digital zoom is you have more control over it. If you crop in camera you have lost the info for good. Cropping outside the camera allows you to precisely position the frame etc.

As for odd sizes when cropping in software, errr lol? Just crop to the same size as the camera would if it bothers you. PS has fixed aspect ratio settings, and determined size settings for selection so you can accurately cropp to any size/ratio you want.

Alex53 · 2 Jan 2007 at 13:29

While fully agreeing that digital zoom is indeed useless for anyone who can crop later in his PC if he wants to...

Then there are DLSR owners trying to justify that their 1.6x cropped sensor DSLR works better for them than a full frame DSLR (e.g. Canon 5D) because it gives their lenses more reach. And you get this even from supposedly experienced people. At the end of the day a DLSR with a 'cropped' sensor is like a permanently digitally zoomed in full frame camera at 1.6x zoom.

mrgubby · 2 Jan 2007 at 13:30

Digital Zoom costs nothing to put in a camera & lets manufacturers/shops fool the unwashed with "x 300 zoom" stories.

Raymond Lin · 2 Jan 2007 at 13:58

Alex53 said:
At the end of the day a DLSR with a 'cropped' sensor is like a permanently digitally zoomed in full frame camera at 1.6x zoom.

Technically it isn't zoomed at all, just like it says, cropped. The outer bit cut off, there's no zoom of any kind. A bit like looking through a loo roll tube really, cuts off the surrounding field of vision.

Bolerus · 2 Jan 2007 at 14:03

just playing devils advocate a bit, whilst at the same time trying to gleen as much information as possible.

whitecrook said:
The advantage of cropping after the picture is taken (say in PS) rather than in the camera using digital zoom is you have more control over it. If you crop in camera you have lost the info for good. Cropping outside the camera allows you to precisely position the frame etc.

In that case, why not get a camera with a monster resolution but no zoom/magnification and do everything in the software

(i seem to remember reading about a 12mega pixel point and click)

wouldnt that then give you even more control, as zooming in also looses what is outside of the field of view, whether it be optical zoom or digital zoom

Raymond Lin · 2 Jan 2007 at 14:07

Bolerus said:
just playing devils advocate a bit, whilst at the same time trying to gleen as much information as possible.

In that case, why not get a camera with a monster resolution but no zoom/magnification and do everything in the software

(i seem to remember reading about a 12mega pixel point and click)

wouldnt that then give you even more control, as zooming in also looses what is outside of the field of view, whether it be optical zoom or digital zoom

Except optical zoom will give better results in terms of image quality, DoF, focus and the rest of it.

Taking a 12mb pixel picture and crop it to the 25% of what not will just look bad, and a lot of the time i can tell it was part of a larger image.

Bolerus · 2 Jan 2007 at 14:12

so back to the original question, sort of.

lets say for example, user 1 has a perfect eye for what he want in the picture.

And decides to use the digital zoom to crop.

would the image then be at a reduced quality, or would the camera compensate, or rather more to the point, would it be of a lesser quality than a software package cropped image?

I suppose that question is a bit of a piece of string one.

depends upon the camera and depends upon the software used?

I started this thread not because I wanted to use digital zoom, but more so I get a better insight from people who know what they are talking about, and that is working well

Mohain · 2 Jan 2007 at 14:15

Bolerus said:
just playing devils advocate a bit, whilst at the same time trying to gleen as much information as possible.

In that case, why not get a camera with a monster resolution but no zoom/magnification and do everything in the software

(i seem to remember reading about a 12mega pixel point and click)

wouldnt that then give you even more control, as zooming in also looses what is outside of the field of view, whether it be optical zoom or digital zoom

Cramming 12mp into a sensor the same physical size as a 8mp sensor will give you a bigger image but it will also add noise. So really it's a pointless exercise. If they made the 12mp sensor size proportionally larger then yes, it would make sense, but they dont so it's not worth the extra mp if your sensor size doesn't increase in pro.

clockworks · 2 Jan 2007 at 15:22

Bolerus said:
so back to the original question, sort of.

lets say for example, user 1 has a perfect eye for what he want in the picture.

And decides to use the digital zoom to crop.

would the image then be at a reduced quality, or would the camera compensate, or rather more to the point, would it be of a lesser quality than a software package cropped image?

I suppose that question is a bit of a piece of string one.

depends upon the camera and depends upon the software used?

I started this thread not because I wanted to use digital zoom, but more so I get a better insight from people who know what they are talking about, and that is working well

Digital zoom is effectively the same as cropping - you use a smaller part of the sensor, then the camera "upscales" the image before writing it to the memory card at the normal resolution.

The difference in quality (if any) between digital zoom and software cropping depends on the quality of the software. The camera has to interpolate the image, guessing at what to fill in the extra pixels with. A 2x digital zoom means that only half the pixels on the sensor are used, so the other half of the pixels in the final image are guesstimates.

When a full-frame is cropped on a PC, all of the pixels in that image are "real". If the image is resized back to to a full-sized image, the software again has to "fill-in the blanks". I'm guessing that a decent photo-editing package would do a better job than the camera's firmware.

If this image is then printed, it's probably re-sized downwards again. Half of the pixels the photo-printing software is working with aren't real, so quality is lost again. I'm guessing that you'll get a better print with a cropped photo that hasn't been resized (as long as the original aspect ratio has been preserved) before printing, as all the pixels are real ones?

SDK^ · 2 Jan 2007 at 15:22

okay
The problem with digital zoom is that after the camera crops the image the cropped section is then interpolated to the selected resolution on the camera L, M, S etc. Most people have their cameras set to maximum resolution so using digital zoom means the loss in detail is massive.

Also, an image editor like Photoshop is far more advanced than the internal camera software that converts your image, so if you really need to crop and interpolate the image then it's better to do it on your computer.

:: EDIT ::
Posted at the time as the message above

Bolerus · 2 Jan 2007 at 15:42

ok thanks for those excellend descriptions.

much better than "digital zoom sucks"

mrgubby · 2 Jan 2007 at 15:42

clockworks said:
Digital zoom is effectively the same as cropping - you use a smaller part of the sensor, then the camera "upscales" the image before writing it to the memory card at the normal resolution.

Nope , "cropping" does not use a smaller part of the sensor , the "cropping" is because the sensor is not the same size as full frame film. You get a x 1.6 factor because you are using the (field of view of the lens) divided by (the ratio of sensor to film size)

(I like Raymonds loo roll analogy , may have to steal it

)

Bolerus · 2 Jan 2007 at 15:44

Acceptable version of Photoshop?

Sort of following on from the digital zoom question

I am mostly using paint.net at the moment, which has been fine so far, and gimp.

I don't have £600 spare for photoshop CS but I was wondering, how far back int he photoshop versions, would it be acceptable to go and still get the decent results, or would it be a case of if I was to drop back a verson or two, for the sake of price, I may as well stick with paint.net or gimp2 ?

mrgubby · 2 Jan 2007 at 15:50

Bolerus said:
Sort of following on from the digital zoom question

I am mostly using paint.net at the moment, which has been fine so far, and gimp.

I don't have £600 spare for photoshop CS but I was wondering, how far back int he photoshop versions, would it be acceptable to go and still get the decent results, or would it be a case of if I was to drop back a verson or two, for the sake of price, I may as well stick with paint.net or gimp2 ?

I Use Adobe Elements 4.0 , does everything I want & I didn't have to sell a kidney (or my soul

) to buy it.