Canon zoom question

Will someone explain the difference between optical zoom and digital zoom to
this newbie? Thanks.
Will

Will wrote:
Will someone explain the difference between optical zoom and digital zoom to
this newbie?

Optical zoom involves the moving of lens elements to produce a longer or
shorter focal length of a lens. Digital zoom is a marketing buzzword that means
digital cropping of only the center of a frame. Basically, digital zoom is
worthless, and it could be done easier and better in an image editing program
anyway.

---Bob Gross---

Robertwgross wrote:

Will wrote:

Will someone explain the difference between optical zoom and digital zoom to
this newbie?


Optical zoom involves the moving of lens elements to produce a longer or
shorter focal length of a lens. Digital zoom is a marketing buzzword that means
digital cropping of only the center of a frame. Basically, digital zoom is
worthless, and it could be done easier and better in an image editing program
anyway.


Yep. Although my Dad likes digital zoom because he doesn't do any image
editing. He just prints what he shoots. He's not that concerned with
quality.

Greg
--
Destroy your safe and happy lives
Before it is too late
The battles we fought were long and hard
Just not to be consumed by rock'n'roll

I really appreciate your reply. Is there a way to disable the digital zoom
or do I have to actually engage it somehow when I wish to use it. Frankly,
I don't know if it's being used each time I click or not. I'm too new at
these cameras right now. I have a Canon Powershot 200.

"Robertwgross" wrote in message
...
Will wrote:
Will someone explain the difference between optical zoom and digital zoom
to
this newbie?

Optical zoom involves the moving of lens elements to produce a longer or
shorter focal length of a lens. Digital zoom is a marketing buzzword that
means
digital cropping of only the center of a frame. Basically, digital zoom is
worthless, and it could be done easier and better in an image editing
program
anyway.

---Bob Gross---

In article . net,
"bb" writes:

Will someone explain the difference between optical zoom
and digital zoom to this newbie? Thanks.

Optical zoom is implemented through a variable focal length
lens system. When you increase the zoom lens' focal length
its magnification increases. The advantage of optical zoom
is that image quality (prime pixels) is maintained throughout
the zoom range. The disadvantage of optical zoom is heavier
complex expensive optics.

Digital zoom is accomplished by empty magnification. A subarea
of your dSLR's sensor chip is digitally blown up to full sensor
size by adding interpolated (averaged) pixels among the subarea's
prime pixels. The advantage of digital zoom is (relatively)
low cost -- the digital zoom functionality can be incorporated
into the dSLR electronics at little additional expense. The
disadvantage of digital zoom is loss of image quality at high
magnifications.

Some camcorders have both optical zoom and digital zoom.
I assume some dSLRs also have both optical zoom and digital
zoom capabilities. If your system has optical zoom capabilities,
use the optical zoom first -- you always can postprocess digitally
for additional magnification.

'Hope that helps.

Richard Ballard MSEE CNA4 KD0AZ
--
Consultant specializing in computer networks, imaging & security
Listed as rjballard in "Friends & Favorites" at www.amazon.com
Last book review: "Guerrilla Television" by Michael Shamberg

Thanks, Richard. Now let's see if I have this...when I use the zoom feature
on my Canon Powershot 200 (to get closer to the image), I'm using optical
zoom. Does this feature lessen the quality of the photo? Should I just
move closer to the subject rather than using the zoom? Also, when am I
using the digital zoom, if at all? I am unaware at this point when it comes
into play, if it's automatic. Thanks for your patient explanations.

"Richard Ballard" wrote in message
...

Optical zoom is implemented through a variable focal length
lens system. When you increase the zoom lens' focal length
its magnification increases. The advantage of optical zoom
is that image quality (prime pixels) is maintained throughout
the zoom range. The disadvantage of optical zoom is heavier
complex expensive optics.

Digital zoom is accomplished by empty magnification. A subarea
of your dSLR's sensor chip is digitally blown up to full sensor
size by adding interpolated (averaged) pixels among the subarea's
prime pixels. The advantage of digital zoom is (relatively)
low cost -- the digital zoom functionality can be incorporated
into the dSLR electronics at little additional expense. The
disadvantage of digital zoom is loss of image quality at high
magnifications.

Some camcorders have both optical zoom and digital zoom.
I assume some dSLRs also have both optical zoom and digital
zoom capabilities. If your system has optical zoom capabilities,
use the optical zoom first -- you always can postprocess digitally
for additional magnification.

Thanks, Richard. Now let's see if I have this...when I use the zoom feature
on my Canon Powershot 200 (to get closer to the image), I'm using optical
zoom. Does this feature lessen the quality of the photo? Should I just
move closer to the subject rather than using the zoom? Also, when am I
using the digital zoom, if at all? I am unaware at this point when it comes
into play, if it's automatic. Thanks for your patient explanations.

"Richard Ballard" wrote in message
...

Optical zoom is implemented through a variable focal length
lens system. When you increase the zoom lens' focal length
its magnification increases. The advantage of optical zoom
is that image quality (prime pixels) is maintained throughout
the zoom range. The disadvantage of optical zoom is heavier
complex expensive optics.

Digital zoom is accomplished by empty magnification. A subarea
of your dSLR's sensor chip is digitally blown up to full sensor
size by adding interpolated (averaged) pixels among the subarea's
prime pixels. The advantage of digital zoom is (relatively)
low cost -- the digital zoom functionality can be incorporated
into the dSLR electronics at little additional expense. The
disadvantage of digital zoom is loss of image quality at high
magnifications.

Some camcorders have both optical zoom and digital zoom.
I assume some dSLRs also have both optical zoom and digital
zoom capabilities. If your system has optical zoom capabilities,
use the optical zoom first -- you always can postprocess digitally
for additional magnification.

"bb" wrote in message
news
I really appreciate your reply. Is there a way to disable the digital
zoom
or do I have to actually engage it somehow when I wish to use it.
Frankly,
I don't know if it's being used each time I click or not. I'm too new at
these cameras right now. I have a Canon Powershot 200.

Which 200 model? For instance, the A200 has a fixed lens with a 4X digital
zoom... Not much you could do about that!

dwight

S200 elph



Which 200 model? For instance, the A200 has a fixed lens with a 4X digital
zoom... Not much you could do about that!

dwight

In article . net,
"bb" writes:

Thanks, Richard. Now let's see if I have this...when I use the zoom
feature on my Canon Powershot 200 (to get closer to the image), I'm
using optical zoom. Does this feature lessen the quality of the photo?

I am not familiar with the Powershot 200. If it has an optical zoom,
image quality should be maintained throughout the zoom range --
Canon is a reputable OEM.

Should I just move closer to the subject rather than using the zoom?

That depends upon your desired depth of field -- depth of field reduces
both by moving closer and by increasing optical focal length (optical
magnification). I am not prepared to quantify the difference. (Digital
zoom degrades image quality, but does not reduce depth of field.)

Another factor is lighting. Sometimes you might want to move closer
to a subject to take advantage of natural shade.

In portraiture, a short (35mm film equivalent 75mm or 90mm) telephoto
lens produces pleasing effects by compressing range distances --
e.g., the short telephoto lens does not make peoples' noses look
excessively long.

This is a scene-dependent composition question that can not be
answered generally.

Also, when am I using the digital zoom, if at all? I am unaware at
this point when it comes into play, if it's automatic. Thanks for your
patient explanations.

I am not familiar with the Powershot 200 and whether it has digital
zoom. You need to consult your camera manual.

'Hope that helps.

Richard Ballard MSEE CNA4 KD0AZ
--
Consultant specializing in computer networks, imaging & security
Listed as rjballard in "Friends & Favorites" at www.amazon.com
Last book review: "Guerrilla Television" by Michael Shamberg