Home Forums Classifieds Blogs Today's Posts Search Social Groups


Glock Talk
Welcome To The Glock Talk Forums.
Thread Tools Display Modes
Old 07-06-2004, 15:46   #1
sharpshooter's Avatar
Join Date: Dec 1999
Location: NV
Posts: 5,087
Digital Camera question about compression

I have a Canon PowerShot S30 3.2MP camera, it does a terrific job. I know about resolution. What about compression? I can set the images to L, M, or S compression. With L I get 77 images, with S I get 275 images on the card.

I can't tell the difference in image quality, they're identical as far as I can tell. And the file sizes are the same. So what's the advantage of using the L or S compression settings?
sharpshooter is offline   Reply With Quote
Old 07-06-2004, 15:50   #2
Be Prepared
Garr's Avatar
Join Date: Jun 2004
Location: Washington State
Posts: 298
It's all about the number of pixels. I am guessing that you are talking about a 64mb card. The larger the file, the less the compression. On my Fuji FinePix 3800 (see new model S3000), a 3mp "fine" image is about 1.2mb on the card, whereas a 3mp "normal" is only about 700kb. The larger the initial file, the larger you can print the image. My 3mp fine images make excellent 8"x10"s and occasionally larger. Try printing 5"x7" or lager versions of each file (take the same picture in each mode) and compare to find out what you really need.
"Bruno will dive one thousand feet into a block of cement! On my head yet!"

Garr is offline   Reply With Quote
Old 07-06-2004, 16:46   #3
Senior Member
chevrofreak's Avatar
Join Date: Dec 2001
Location: Billings, Montana
Posts: 9,364

Your camera might be changing the resolution, as well as increasing the compression.

Many cameras have modes such as Fine, and Standard. Standard having more compression, which means a smaller file and a slightly lowered picture quality.
smoke free since 4:58AM July 29th 2002!
View My Ebay Auctions <-- currently 0 auction(s) running
Threat Solutions UCR The best IWB holster money can buy!
chevrofreak is offline   Reply With Quote
Old 07-06-2004, 23:51   #4
sharpshooter's Avatar
Join Date: Dec 1999
Location: NV
Posts: 5,087
I haven't tried printing the different compressed images yet, but when I zoom on Paint Shop Pro they all look identical, compressed or not. I don't understand how the printed image would look different than the one on the screen... ?
sharpshooter is offline   Reply With Quote
Old 07-07-2004, 08:33   #5
Senior Member
Toyman's Avatar
Join Date: May 2003
Location: West Michigan
Posts: 3,788
There is actually a quality difference between the compression levels, but it's not always easily seen with standard photos. If the photo had areas of all one color, such as a large white board, or blue sky, the compression would be more visible. The compression works by taking some of the pixels, and making them span several nearby pixels that are almost the same color. (Simple explanation)

Your computer monitor has a resolution of 72 dpi (dots per inch) whereas a printer can range from 300 to 2400 dpi. When you print the picture, the "spanned" pixels are spanned again several times more, make larger areas of a single color, therefore making printed images a lower quality do to large "blocky" areas of a single color (or almost single color).

See the area in the attached picture:

Tech Talk

See Also:
Mike - A forum post should be like a skirt. Long enough to cover the subject material, but short enough to keep things interesting.
"It's not about the odds, it's about the stakes." - quake

Last edited by Toyman; 07-07-2004 at 08:35..
Toyman is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -6. The time now is 13:13.

GT Wiki
GT Blogs
Social Groups

Users Currently Online: 1,256
358 Members
898 Guests

Most users ever online: 2,244
Nov 11, 2013 at 11:42