optical zoom vs digital zoom

Are you unsure about the differences between Optical Zoom and Digital Zoom?
Which is better: 8X Optical with 3X Digital, or 8X Digital with 3X Optical?

Let me go off on a tangent and fill you in on some technical aspects on resolution and how we see.
The amount of pixels in a picture is the resolution. Simply put, it is how many triangles of information are crammed into a given area. Yes, pixels are actually triangles :)
A 10 megapixel camera has more information that an 8 megapixel camera. Now, the difference of 2 megapixels is not that much. It's simply a selling feature. (don't even start me on the instant gratification thing :)

However, the human eye sees at least 324 megapixels! So a 10 megapixel image is only 3% of the capability of the human eye. To understand more of this see my post.

When we see something, our vision fills in the blanks, fills in the bits of missing information. When we look at a digital image we think it's good, because our eyes are playing tricks on us by filling in the bits of missing information. But put a 4x6" print under 8X magnification and you can see the pixels.

Ok, now onto a real example. In 2006 I was photographing an eagle at the far end of a pier. I was shooting at 1200mm. The image of the eagle filled the viewfinder. When I was done, I looked over at some people who were photographing the same eagle with digital cameras. All they were getting was a black smudge. When they magnified it, it was just a larger black smudge.

I was using optical magnification to obtain a better image, ergo more information. The digital cameras were trying to use digital magnification to get an image. Digital magnification cannot compare to optical magnification.
The more information you can obtain optically is better than trying to digitally magnify information which isn't there.

My first blog

I want to share my thoughts on digital vs film.
These days everyone and his dog has a digital camera, and they think they can take good pictures. Well, everyone has a car, but that doesn't necessarily mean they are a good friggin' driver! Right?
Well, owners of digital cameras would say: "well, if I don't like the picture I can always delete it."
My response to that is: "well, I don't take bad pictures." That usually shuts them up.
To take good pictures, one needs to know some basic techniques; as well as their equipment. I can take good pictures with a piece of crap throw away camera; I just know what it can't do!

I love the quote by Frank Capra, the photographer who photographed the storming of Normandy Beach: "if it wasn't good enough, you weren't close enough." There he was, the first on the beach, dodging bullets and stuff, running around and taking pictures of soldiers up close. He had to, because zoom lenses didn't exist.

1) if you have a particular subject of interest, then get in close.
I don't know how many times other people have shown me their photos. "Isn't that a great picture of me?" Well, all I see is a grass field with a black dot. (A little exaggerated, but you get my point.) I used to critique them. I don't any more. If the person thinks it's good, well, I let them believe their fantasy.

2) cd's don't last forever, because they degrade over time. They may last 100 years. However, a photo printed on archival paper will last a helluva longer than a cd.

3) here's a little bit of technical stuff: film is analog, a sine wave, which is how we see; digital is a square wave. So if you were to superimpose the resultant waves, you would see that some information is missing.
This is the analogy I use: convert a phrase from English to another language, say French, you're not going to get the same phrase. Now convert it back to English. Do you get the same phrase? No. Something gets lost in translation.
So with digital that is what you have. The information is lost in translation, not once, but twice. Analog, the original view -> converted to Digital, another language, information is lost -> converted back to Analog, more information is lost.
Or to put it another way, in these days of digital music (i.e. mp3's and such) why is vinyl still around? Can you guess? Because, as any audiophile will tell you, it's real sound. There's a certain depth to the music that digital cannot reproduce.
Ever heard this before? :
"hey, I've got some great shots on cd." "well, can I see them?" "wait, let me put it in the computer." Hmmm..... see the problem?
Instead, this is how I do it:
"hey, I've got some great shots!" "can I see them?" "sure." as I hand them prints. See? no fancy equipment required. The photos have been taken they way are, and viewed the way they should be. Analog equipment: the camera; analog format: prints; being viewed by analog equipment: the eye. Notice there's no digital middleman screwing things up?

4) the ccd sensors on digital cameras are small. As consumer level digital cameras go the highest level of resolution is around 14 megapixels. Well, let me tell you, the human eye can see much, much more than that!
The human eye sees at least 324 megapixels
(reference: http://clarkvision.com/imagedetail/eye-resolution.html)
One of my cameras is a medium format camera. To translate that to the equivalent of digital would be in the neighbourhood of 40 megapixels!! So as you can see, most digital cameras would be just toys for me. "Well, digital cameras are getting up there in megapixels." yeah right.... sorry, ain't going to happen. Why? Simply due to the laws of physics. You can only cram so much information on it. However, the Megapixel camera has made a valiant effort. http://www.gigapxl.org/
However, you may want to check this article to understand more of how the human eye sees: http://www.swift.ac.uk/vision.pdf
This is the conclusion of the article:

"A model of the perception limits of the human visual system was given, resulting in a maximum estimate of approximately 15 million variable-resolution pixels per eye. Assuming 60 Hz stereo display with a depth complexity of 6, it was estimated a rendering rate of approximately ten billion triangles per second is sufficient to saturate the human visual system."

Yes folks, that's 10,000,000,000 pixels!

5) you can only enlarge digital prints to a certain size before they start to pixelate; usually 11x14 (read the fine print in the digital camera ads). Well, I can shoot some 50 or 25ISO film and make a friggin' poster out of it and it'll be tack sharp through and through. If you see a digital camera advertisement that says "poster size" they're friggin' lying. Unless they consider 11x14 a poster!

6) digital cameras fail in certain lighting situation. It's how they operate; how they translate light and shadows. I've done shots, where the lighting was tricky (i.e. hard light, heavy shadows) and digital would've failed in capturing the image.

So there you have it, for now, my two-bits on digital vs film.