Crazy Question on Print Sizes

[Bessar2]

OK, so I just uploaded a file from my new D80 to Costco's site to have a test print made. The specs on the file are:
Dimensions: 3872 X 2592
It is a jpeg with a size of 4.31 MB

I guess my first question is (with little to no knowledge of digital) why is the file so small? Is this merely a function of jpeg compression? I shot it at the highest levels of jpeg (fine+large). I didn't alter the original image in any way after transfer to my harddrive.

Now my second question, as this may be more about Costco than anything else. There site indicates the following:

Print size Minimum image resolution required
4x6 690x460 pixels
5x7 805x575 pixels
5x6 Photo cards 640x480 pixels
8x8 enlargements 920x920 pixels
8x10 1150x920 pixels
8x12 1380x920 pixels
11x14 enlargements 1610x1265 pixels
12x12 enlargements 1380x1380 pixels
12x18 enlargements 2070x1380 pixels
16x20 posters 2300x1840 pixels
20x30 posters 3450x2300 pixels
11x14 collage posters 1260x990 pixels
12x18 collage posters 1620x1080 pixels
16x20 collage posters 1800x1440 pixels
20x30 collage posters 2700x1800 pixels
Wallet prints 374x259 pixels

The site has a little triangle (their indicator of non-vaibility for print size) next to

11x14
12x18
16x20
20x30

Now, wouldn't the numbers I indicated for my test image conform to all of these in terms of minimal pixels?

Thanks for any thoughts and insights

 

[genece]

First let me say your file size is fine.......the size of a JPEG on a D80 is almost always under 5mbs.

And that will print a photo at least to 20 X 30 ....I have a few on my walls that size........

I am not sure why they would say non viability at 20 X 30 or 12 X 18 as they are the correct format........But if I were sending a photo to be printed I would crop to the correct ratio......20 X 30 is fine, its 3:2 ratio.....but a 12 X 16 print would need to be cropped or stretched or something as its a 4:3 ratio......something that fits a P&S but not a DSLR unless its cropped to fit.
I hope I made some sense.
4 X 6 is fine
5 X 7 needs work....ect.
--
Gene from Western Pa

http://imageevent.com/grc6
http://grc225.zenfolio.com/
FZ10....20 and 30 and FZ18

D50 ....D80 - 18 to 200VR- 50mm 1.8 - 80 to 400 OS



Just trying to learn and it's slow going!

 

[paulbanddi]

your file size is fine.

The reson you are getting that indicator that the file is not the correct resolution is the way you uploaded it to Costco's server.

The defalt for costco is a reduced files size to save space on their server. it is that way because most people don't want enlargments. When you are in the screen where you select the photos to upload, you will see two radio buttons on the bottom. One says Fast upload (up to 5X faster) This one means low res. the other one is the one you want it says large print upload (for poster prints and large gifts) click the large upload radio button and you will be fine.

Paul

 

[Bessar2]

Thanks you guys, now I feel like I know more than I did when this all started.

Now, I've got to figure out this whole cropping thing. . .ah, how I miss silver sometimes.