Digital Zoom

[kenlc3]

Here's a question that is boggling my mind. A digital zoom only crops the photo at the loss of pixels. So my question is:
When a 7 mp camera is zoomed in 4x, does the 3072x2304 image drop down to 768x576 pixels? That would be 4 times smaller.

Just trying to get my brain wrapped around this stuff!
:rolleyes:

[Norm in Fujino]

Here's a question that is boggling my mind. A digital zoom only crops the photo at the loss of pixels. So my question is:
When a 7 mp camera is zoomed in 4x, does the 3072x2304 image drop down to 768x576 pixels? That would be 4 times smaller.
:rolleyes:

Basically, yes, except then in order to produce the same physical size on the monitor, it enlarges each pixel to occupy the same physical space. That enlarges the image, making it appeared "magnified" (zoomed), but since the pixels have been enlarged, it's a much coarser image than the original. See This Site (http://www.tenfootpolesoftware.com/fun/digitalcameraguide/digitalversusopticalzoom.htm) for more info.l

[kenlc3]

So that blows my theory of, if you get a higher mp camera that when you zoom it simply becomes a smaller mp camera. I was hoping to get one of the high mp camera's with a 3x optical and 4x digital zoom and making a 7mp into maybe a 3mp.

I wish someone would test these cameras visually and show what effect the digital zoom had on the photo.

For example. I work in Adobe Photoshop for a large printing firm and we will enlarge 150% no questions asked without worrying about the quality. But if you go over the 150% we inspect the quality carfully. If I understand you correctly these camera companies are enlarging 400% no questions asked and expecting customers to have good quality photos. What a crock! :eek:

[Norm in Fujino]

If I understand you correctly these camera companies are enlarging 400% no questions asked and expecting customers to have good quality photos. What a crock! :eek:

That's basically it. I ignore any camera claims about digital zoom since I know I will never use it. As you noted, you can get the same effect by cropping a larger image and then enlarging the remaining center part, pixellation and all.

[hallbilly]

from my experience with the kodak easy share dx4330 ( i think is the name of it?) digital zoom is no different than zooming into your picture using your computer... so to me it is useless. now the 700x digital zoom on cam corders... that is something different... i don't believe it pixelates as bad... maby it does and i just cant tell from the overall poor quality of video? oh well... my .02

[Shooter]

People are all against digital zooms, sometimes to the point of hysteria, but really. Take a few pictures without the digital zoom in case you want to crop later then take a couple with the zoom. Remember we all bought digital cameras to facilitate lots of pictures in the first palce. If the cropping works out you then you saved a bunch of work, and if the megapixels are reasonable for your camera (4+) then small to medium prints will look fine with or without digital zoom.

[kenlc3]

I see your point but my orig question was because I was investigating cameras to help my friend decide on a camera. To go out and purchase a camera for $300 to $500 to only experiment is insane. I am looking for someone (maybe this website) who has done that for me. I can't afford that. :cool:

[emalvick]

I see your point but my orig question was because I was investigating cameras to help my friend decide on a camera. To go out and purchase a camera for $300 to $500 to only experiment is insane. I am looking for someone (maybe this website) who has done that for me. I can't afford that. :cool:

Well, if you are looking into spending that kind of money, your best bet is to not look at digital zoom at all and go for the optical zoom and decent megapixels.

As you mentioned previously, you know how to crop and enlarge photos using photoshop. I think that is a much better way to go as you can in essence digitally zoom on your own if all you are looking for is a crop (i.e. 7 to 3 MP) or you can enlarge the photo if you want the extra pixels. At least you have a bit more control over the enlargement process outside the camera.

In my experiences, I have a camera that has a 12X optical zoom and then can add 4X digital on top of it (48 total). I don't use the digital zoom for photos I want to keep for printing, but I use it to get an idea of how the cropped image would look and then back out for my "print" photo that I will crop later on... I hope that makes sense.

Erik

[stevage]

I used to think there was no point at all in digital zoom. But I have discovered one scenario where digital zoom was handy: using the camera as a telescope. Once I could just see a distant object with the naked eye but couldn't tell what it was. I took a photo of it at maximum digital zoom, then on the camera's LCD screen, zoomed in again to maximum, and was able to work out what the object was. Obviously had I had a laptop with me, I wouldn't have bothered with the digital zoom.

Not a useful scenario, but still. :)

Steve