Go Back   Steve's Digicams Forums >

LinkBack Thread Tools Search this Thread
Old Oct 20, 2004, 4:30 AM   #1
Senior Member
Join Date: Oct 2004
Posts: 141

I need to be educated.

I see in the EXIF data 'X resolution' and 'Y resolution'...

I've tested a few cameras, and, as far as I can see, two of the cameras I've tested (Olympus C-740, Minolta Z2) have 72 for both 'X' and 'Y' resolution at the highest, largest, finest settings, as well as at the lowest, smallest,most 'unfine'settings.The Canon S1 IS has 180 instead of 72 at the highest, largest, finest settings, as well as at the lowest, smallest, most 'unfine' settings.I have downloaded sample photos of the Nikon 5700, and they are at 300. I've downloaded photos from the Panasonic FZ-20, and some photos are 72, while others are 200.

And so I am confused.

Now, I assume this number (72, 180, 200, 300, etc.) has something to do with DPI (dots per inch).

I suppose my questions are... Can this 'X'/'Y' resolution number be set by the user, or is it fixed within the camera? If it is fixed within the camera, why do photos from the FZ-20 show two different numbers for two different photos? (72 and 200)

I know that 300 DPI is considered 'proper' for printing. So, if I have photos from a 4 MP camera taken at highest resolution (2272x1704), and want to print a 6x4 inch photo, I'm at around the 400 DPI range, right? What does the 'X resolution 72', 'Y resolution 72' mean, then?

I apologize for not explaining this as efficiently as it should be explained... but my deficient understanding of the circumstance prevents me from offering a better explanation of that which I wish to resolve.

Many thanks to anyone who can aid my understanding of the issue here.
EOS RT is offline   Reply With Quote
Sponsored Links
Old Oct 20, 2004, 6:16 AM   #2
Senior Member
NHL's Avatar
Join Date: Jun 2002
Location: 39.18776, -77.311353333333
Posts: 11,599


NHL is offline   Reply With Quote
Old Oct 20, 2004, 6:20 AM   #3
Senior Member
Mikefellh's Avatar
Join Date: May 2004
Location: Toronto, ON, Canada
Posts: 1,707

Until you get to printing, this number is really meaningless. 72dpi is a left over from the original Mac days, but an image will be taken and displayed the same way on a monitor whether it has a dpi of 10, 100, or 1000, becuase the image would still have the same number of pixels across and horizontally (say 1600x1200).

But when I go to print, that 1600x1200 prints different sizes depending on the dpi assigned to it, or if it's changed through the resizing option in photo editing software. For example, using that 1600x1200 dpi the way the camera took it at 72dpi:
At 72dpi it prints a 22.2x16.6"
At 180dpi it prints an 8.8x6.6"
At 300dpi it prints a 5.3x4"

That's the relationship. In my case with my 2mp camera that's what I get (which is enough for me for now). With changing it that way you aren't adding or subtracting information from the image itself, merely telling it how to print with the information already in the picture.
Mikefellh is offline   Reply With Quote
Old Oct 21, 2004, 3:38 AM   #4
Senior Member
Join Date: Oct 2004
Posts: 141

Thanks to both of you.

I believe I am beginning to comprehend the matter. Sure is more complicated than photography used to be.

I figure, with any luck, I should understandthis resolution stuffcompletely byApril or so.

Thanks again.
EOS RT is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -5. The time now is 9:11 AM.