files that shrink in size.
Posted on 2003-02-25
although not a photoshop user i thought this was the best place to get my q's answered. i have a konica kd 100 camera. now its 1.3 mp but the file sizes are a bit of a mystery to me. when i was buying a camera i looked at a 2.1mp polaroid pdc 2070 but as it was damaged and argos couldn't get more in at the time i took this as a replacement. now as for memory both have 8 meg nand flash onboard. the konica i have uses exif and dpof for files (saved as jpegs but could someone explain the diff between exif and dpof - is dpof 4 printing?), the polaroid states jpeg (hi quality is jpeg 90 norm qual is jpeg 70 but manual didn't say wether exif or dpof just that it compressed to jpeg after download to pc depending on application used. now the first odd thing is this. the polaroid stored 8 images at 1600x 1200 thats set to high as theres two quality settings per resolution. quality setting which is 2.1 mpixels. the konica i have stores only 7 in high qual at its top resolution of 1280 x 1024 1.3 mega pixels. i checked kodaks web site and saw its 2.1 mpixel cameras saved 8 at 2.1 mpixels on high setting same as polariod for 8 megs memory. the file size of a best hi res image before re-saving is betwwen 900k ans 1 2 megs. now that would seem to be similar to the file size for a 2.1 mp shot on the polaroid or kodak.
the other puzzle is that when downloaded and then opened in u lead photo impact without any editing or enhancing the filesize shrinks to 300 k or less. if i interpolate it to 1600 x 1280 pixels in u lead then the size shrinks to about 400 k yet image quality does not deteriorate as much as i expected (photos look awful blown up from my 0.3 mgapixel jam cam).
Why is this? my only explanation is that the konica has a 2.1mp lens but saves the info as a 1280x1024 sized file intstead of 1600 x 1200 (saves konica money by buying 2.1 mp lenses en bulk?) and only when u lead saves the file again does it revert to what it should be for its dimensions. that would explain why the images don't deteriorate much when enlarged. or is there another reason such as jpeg compression ratio?
any explanation would be apreciated