Why are my exported files so small with lightroom 3?

Question

I have been editing 10 mb raw files and they are no bigger than 2 mb jpegs afterwards.why is that?
i have been using presets while editing and i reset all settings at some point as my crop tool wasn't working properly.the resolution slider in the export window is at 100%, 240 pixels per inch, and everything else seems to be the way it was before.What am i doing wrong? I used to get much bigger exported files, cca 7-8 mb.

Answer 1

emi ion wrote:
I have just imported  raw file from my camera, taken at a full resolution of 21 MP. The raw file has about 23mb and the exported jpeg without the resize to fit box ticked 7 MB. I uploaded the photo on the website and it's still not good enough for a 20''x30'' print. I am not sure if other websites accept other formats than jpeg, as this one doesn't. Not that i want to use them but it was the easiest way for me to check.
I am not sure if my client will want a canvas print, i am only assuming they might as they did in the past and i want to know what to do if that happens. I read that genuine fractals 6 pro is good, enlarges about 4 times the original size.
The ppi image resolution required for "handheld" print viewing is higher than that for pictures to be hung a wall and viewed at a distance of  three feet or more.
The ppi image resolution required for a large canvas print is even lower, with good results obtainable a 100 ppi. Canvas prints have a textured surface that reduces the print resolution and doesn't require as high ppi image file. Print houses use RIP engines that process the image file for both paper profile and printer native resolution. These RIP engines use very sophisticated "upscaling" algorithms, which are as good or better than a photo editing software application such as LR and Genuine Fractals. Because of this it is advisable not to upscale image files to meet a specific printer resolution such as 300 dpi.
Your 21 mp image files (5184 x 3456) at 100 ppi equates to a 50" x 33" canvas print with edge wrap. Many print houses only accept sRGB profiled JPEG files, but exporting from LR with 100 Quality you create a virtually lossless JPEG image file. You should have no difficulty producing a high-quality canvas print from a well processed 21 mp raw image file up to 50" x 33" in size.
For enlargements on regular photo paper 150 ppi minimum is required for good results. For your 21 mp image files this equates to 35" x 23," so there should be no problem printing 20" x 30" enlargements for framed wall mount viewing.
What website gave you the "still not good enough" message for the 20" x 30" print and what is the actual resolution (???? x ????) of the JPEG file you uploaded? Reimport that JPEG file into LR to see the resolution if necessary.