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Being new to digital photography, I am having some trouble understand the
relationship of camera pixels to the PPI of video screens, printers and
internet publications.

On a recent photo outing, I took several photos of different subject matter
without changing the camera settings only to discover that the file size varied
all over the place. I didn’t understand this.

Could some please suggest the name of a good technicial book that covers this
subject matter in detail.


Thank you very much for your time and courtesy.

Gene

"GENEVIG" <> wrote in message
news:...
> Being new to digital photography, I am having some trouble understand the
> relationship of camera pixels to the PPI of video screens, printers and
> internet publications.
>
> On a recent photo outing, I took several photos of different subject
matter
> without changing the camera settings only to discover that the file size
varied
> all over the place. I didn't understand this.
>
> Could some please suggest the name of a good technicial book that covers
this
> subject matter in detail.
>
>
> Thank you very much for your time and courtesy.
>
> Gene

Your camera compressed the pixels on the imager and made it into a jpeg
(.jpg) file. The size of the file is large if the image is complex and very
small if simple, like a white or black wall. Although lossy, with some
detail lost, it needs to do the compression to get three to five times more
images onto your flash card.

GENEVIG wrote:

> Being new to digital photography, I am having some trouble understand the
> relationship of camera pixels to the PPI of video screens, printers and
> internet publications.
>
>
> On a recent photo outing, I took several photos of different subject matter
> without changing the camera settings only to discover that the file size varied
> all over the place. I didn?t understand this.

If you were saving as JPEG, that will happen. It's normal.

JPEG images are compressed.

The amount of compression that can be applied to an image depends on how complex
the image is. An image of a solid white wall will be always be much smaller than
an image with lots of detail such as a tree with fine branches and leaves.

> Could some please suggest the name of a good technicial book that covers this
> subject matter in detail.

Here's a pretty good web page..

http://www.larry-bolch.com/dpi-revealed/