In a couple of places, I've seen folks mention "increasing resolution" in the context of digital after-shot processing. This isn't truly possible. The best resolution you can manage is with the object of interest as large as possible in the frame, and with the quality or resolution settings as high as possible. These settings determine how good your picture can be. Any kind of "zooming in" or resolution increase, in post-processing, is nothing more than inventing new pixels to go inbetween real ones. This is called interpolation. The "invented" pixels can give the impression of better quality in some circumstances, but are not true or accurate. You might say they are "fuzzy guesses".

There is something called digital image "sharpening" which is an editing technique that emphasizes the edges, or contrast balance. Again, if the quality is bad to start with, this won't help "create" better detail in a picture; it will just help bring out what is there.

In a related sense, "digital zoom" is just an automatic cropping routine. No new pixel data is created. Existing pixels might be doubled, even interpolated, but it is really just the same picture with the edges cut off, and blown up. In general, a digital photography program can do a better job of this, with greater control. There isn't any good reason to use digital zoom while taking shots. Crop it later for best results. Use the "optical" specifications to compare cameras, and even scanners.

Video cameras almost always have fewer pixels to work with. Stills with these will never have the resolution of decent still digital cameras, because they are usually limited to less than 500 X a smaller number of pixels. That is much less than a megapixel.

If you are looking for the very best in resolution, and don't need color, a monochrome CCD with a given megapixel rating will give you much sharper pictures. (complicated) A 35mm camera with good film might be said to have an approximate resolution of 5 megapixels, but with the slower shutter speeds required, may give worse results than a 3 MP digital. Depends on the light, height and a bunch of other issues.



As far as I can tell, the limit to resolution effectiveness is the degree of vibration. I'd be interested in your experiences with reducing vibration with building techniques, but in another thread. (not talking about image stabilization here...)

(disclaimer: simplified for beginners!)

I had a hard time trying to explain this point of Zoom to family and friends. They like to see the large numbers on the zoom but don't realize that you are loosing quality with the Digital Zoom. Great point!!!!! If you have a Digital Camera and are buyign a Digital Video camera DON'T spend the extra money thinking that it will be worth it! I spent the extra and I have used it....NEVER because the Pix look bad! Much worse than my 3.2 MP camera.
Thanks for the topic.

Here's the same image, one at 6x optical zoom, the other a 6x digital zoom..
The digital zoom is from the 1x image.

Yes - Digital Aerial Photo Guy is 100% correct in what he has to say about interpolating and such. However, if you don't make some changes somewhere, you will be in a world of hurt when it comes time to make a printout. Imagine trying to make an 8" x 10" print if you left your dpi at 72 or else 150 . As I had said eariler to someone on line, I take the 72 dpi and change it to 300. I take the largest of the cameras numbers and make it 10("), the remaining number will almost always fall in at 7.5" The size of the file, depending on the cameras megapixels will be much smaller than the previously size referred to. That 10" x 7.5" @ 300 dpi file wil be 19.3 MB.

Now then, what is acceptable in viewing to the naked eye. When something goes "out of focus" the "circles of confusion" are sized at about .026mm when referring to a 35mm neg. It will be larger as the neg format size increases as well.

Interpolating too much will just make things look muddy.

In essence, this is only one mans opinion, but this is what I have been doing since day one of my first digital camera. Not ONE customer has complained about my prints of them being "not acceptable" And that is what we are all stiving to do hear within the digital world. Make a print that is acceptable to all those that look at it.

much, much more indepth details could go on forever - to no point.

marwen