I thought I'd go ahead and calculate out how much of our photo is lost when we print at different sizes. I put it all into an Excel spreadsheet and here are the results:
2.5 X 3.5 Print (Wallet)
Sensor 2.5 X 3.5
5D 2912 4368 2912 X 4076 Loss(W): 292 ( 6.68%)
G3 1704 2272 1622 X 2272 Loss(H): 82 ( 4.81%)
1Ds III 3744 5616 3744 X 5241 Loss(W): 375 ( 6.67%)
40D 2592 3888 2592 X 3628 Loss(W): 260 ( 6.68%)
A560 2304 3072 2194 X 3072 Loss(H): 110 ( 4.77%)
Ratios: 3000 4000 2857 X 4000 Loss(H): 143 ( 4.76%)
2000 3000 2000 X 2800 Loss(W): 200 ( 6.66%)
Other: 480 640 457 X 640 Loss(H): 23 ( 4.79%)
1200 1600 1142 X 1600 Loss(H): 58 ( 4.83%)
1536 2048 1462 X 2048 Loss(H): 74 ( 4.81%)
1944 2592 1851 X 2592 Loss(H): 93 ( 4.78%)
***************
4 X 6 Print
Sensor 4 X 6
5D 2912 4368 2912 X 4368
G3 1704 2272 1514 X 2272 Loss(H): 190 (11.15%)
1Ds III 3744 5616 3744 X 5616
40D 2592 3888 2592 X 3888
A560 2304 3072 2048 X 3072 Loss(H): 256 (11.11%)
Ratios: 3000 4000 2666 X 4000 Loss(H): 334 (11.13%)
2000 3000 2000 X 3000
Other: 480 640 426 X 640 Loss(H): 54 (11.25%)
1200 1600 1066 X 1600 Loss(H): 134 (11.16%)
1536 2048 1365 X 2048 Loss(H): 171 (11.13%)
1944 2592 1728 X 2592 Loss(H): 216 (11.11%)
***************
5 X 7 Print
Sensor 5 X 7
5D 2912 4368 2912 X 4076 Loss(W): 292 ( 6.68%)
G3 1704 2272 1622 X 2272 Loss(H): 82 ( 4.81%)
1Ds III 3744 5616 3744 X 5241 Loss(W): 375 ( 6.67%)
40D 2592 3888 2592 X 3628 Loss(W): 260 ( 6.68%)
A560 2304 3072 2194 X 3072 Loss(H): 110 ( 4.77%)
Ratios: 3000 4000 2857 X 4000 Loss(H): 143 ( 4.76%)
2000 3000 2000 X 2800 Loss(W): 200 ( 6.66%)
Other: 480 640 457 X 640 Loss(H): 23 ( 4.79%)
1200 1600 1142 X 1600 Loss(H): 58 ( 4.83%)
1536 2048 1462 X 2048 Loss(H): 74 ( 4.81%)
1944 2592 1851 X 2592 Loss(H): 93 ( 4.78%)
***************
8 X 10 Print
Sensor 8 X 10
5D 2912 4368 2912 X 3640 Loss(W): 728 (16.66%)
G3 1704 2272 1704 X 2130 Loss(W): 142 ( 6.25%)
1Ds III 3744 5616 3744 X 4680 Loss(W): 936 (16.66%)
40D 2592 3888 2592 X 3240 Loss(W): 648 (16.66%)
A560 2304 3072 2304 X 2880 Loss(W): 192 ( 6.25%)
Ratios: 3000 4000 3000 X 3750 Loss(W): 250 ( 6.25%)
2000 3000 2000 X 2500 Loss(W): 500 (16.66%)
Other: 480 640 480 X 600 Loss(W): 40 ( 6.25%)
1200 1600 1200 X 1500 Loss(W): 100 ( 6.25%)
1536 2048 1536 X 1920 Loss(W): 128 ( 6.25%)
1944 2592 1944 X 2430 Loss(W): 162 ( 6.25%)
***************
11 X 14 Print
Sensor 11 X 14
5D 2912 4368 2912 X 3706 Loss(W): 662 (15.15%)
G3 1704 2272 1704 X 2168 Loss(W): 104 ( 4.57%)
1Ds III 3744 5616 3744 X 4765 Loss(W): 851 (15.15%)
40D 2592 3888 2592 X 3298 Loss(W): 590 (15.17%)
A560 2304 3072 2304 X 2932 Loss(W): 140 ( 4.55%)
Ratios: 3000 4000 3000 X 3818 Loss(W): 182 ( 4.55%)
2000 3000 2000 X 2545 Loss(W): 455 (15.16%)
Other: 480 640 480 X 610 Loss(W): 30 ( 4.68%)
1200 1600 1200 X 1527 Loss(W): 73 ( 4.56%)
1536 2048 1536 X 1954 Loss(W): 94 ( 4.58%)
1944 2592 1944 X 2474 Loss(W): 118 ( 4.55%)
My calculations use a best fit approach. Some prints lose their pixels in height; some in width. This is indicated by the "Loss(H)" and "Loss(W)" respectively. I also show a percentage loss next to these numbers to account for different source image sizes.
I do NOT take DPI into account in these tables. I just wanted to show how much of your source image is lost in the printing process.
If you have any other print sizes or sensor sizes you'd like to see, let me know. However, if your sensor size is 2:3 or 3:4 format, Look at the "Ratio" section of my tables. You'll get the percentage losses from there. Likewise, if you have a print size that scales to those I've listed, you already have your answer.
I did NOT do any widescreen calculations. The A560 does do widescreen captures, but I'm not familiar with widescreen prints. Ask nice and maybe I'll run the numbers for you.
