Thank you for being a valued part of the CNET community. As of December 1, 2020, the forums are in read-only format. In early 2021, CNET Forums will no longer be available. We are grateful for the participation and advice you have provided to one another over the years.

Thanks,

CNET Support

General discussion

Please Explain Pixels

Nov 1, 2004 10:16PM PST

As a former point and shoot person I felt a little overwhelmed at my first introduction to my digital camera (Canon A85). However I feel I now have a good grasp or its capabilities.

EXCEPT PIXELS!

If I take a picture of a scene at 680x480 and then take the same scene at 2272x1704 what differences can I expect?

Under what circumstances would I use a "lower" setting as opposed to a "higher" setting?

I have read a few comments on this subject and most were conflicting and all way over my head. This leads me to my last question.

Is there a source of information on this subject presented in such a way a dummy like me can understand it?

DC

Discussion is locked

- Collapse -
Re: Please Explain Pixels
Nov 1, 2004 11:48PM PST

You can use Google to search for the definition of pixel but it may not help much.

Just take photos of the same object under the same conditions at the different settings. Then examine them on your computer screen using Windows Picture and Fax Viewer. Click on the magnifying glass icon with the + and enlarge the same portion of each photo at least several times.

The difference in the setting should be obvious.

- Collapse -
Re: Please Explain Pixels
Nov 2, 2004 12:23AM PST

Understanding digital camera pixels is over most peoples heads, including mine. The cameras sensor array is difficult because there are so many types.

Here are two links if you really want to get an education:

http://www.dpreview.com/learn/?/key=effective%20pixels

http://www.dpreview.com/learn/?/key=sensors

.............

Lucky for us, you don't have to understand all of that to use the camera.

Pixels....Why?

Let's say you have a piece of paper that is 8 inches wide and 6 inches high. You are going to create a picture using dots. You will have 840 dots across and 480 dots verically (total of 403,200 dots). That works out to 80 dots per inch.

Now do the same thing but use more dots (2272 x 1704).
You end up with 284 dots per inch.

More dots per inch means you will have a sharper picture with more detail.

...............................

The best megapixel size for a photo depends upon what you intend to do with the photo.

Send it to a friend via email, use 640x480.
Why....The friend is going to see it on his monitor which displays at about 80 dots per inch. If you send him a photo that is 2272x1704, it will be so large that he will only see a piece of the photo on his monitor. Plus, it takes more time to send/receive a large photo file.

Now if you are going to print a photo, use a larger pixel count (2272x1704), because most printers print their best quality at 300 dots per inch. Which means you can produce the absolute best photo at 7.5733 X 5.68 inches. You can also print that same photo file at 10.666 X 8 inches and the quality will be lessened but not by much.

Why....?

Most modern printers use a layering method of printing. They make multiple passes across one area giving them an effective print density of 1200 (or more) dots per inch.

....


You can use software to change the size of a photo. That gets you into the world of interpolation.
The results can be very good, but not as good as having the camera produce the photo at the size (pixels) that you want for your final usage.

...

- Collapse -
By Jove! I Think I've Got It!
Nov 2, 2004 9:35PM PST

Thanks for helping me understand.

DC

- Collapse -
Re: Please Explain Pixels
Nov 3, 2004 8:02AM PST

The higher the pixel count the more realistic your picture will look... as in more life like. A time when you would want a lower count is if you wanted a more digital looking picture. The reason why there are different options on the market is because usually the higher the count, the higher the quality and the higher the price. Check out kevinkringle.com if you are shopping of something specific but, normally you don't need the highest pixel count to get a good quality picture.

- Collapse -
Re: Please Explain Pixels
Nov 3, 2004 9:45AM PST

I don't see what the web site you reference has to do with the question.