Ins-ani: this is not called fore ground blurr. This the depth of field and its positive to have your subject in sharp focus and rest blurred whether its background or foreground.
1st one has a shallow dof because its taken at focal length of 105 mm(157.5mm wrt 35mm) while the second one at 85mm(127.5mm wrt 35mm).
I reget my misinformed comment.
But here's my point, which of the following two options gives a better view?
1) blurring the background (or the object we don't wish to focus)
2) A little desaturation of the background?
I tried both of them in a sample image taken from net, and i found the second option gives better response.
I am no expert, but here's an explanation i can think of.. eyes are more sensitive to color when it comes to finer details and more sensitive to intensity if it comes to monochrome.
whereas, if any object in focus is blurred, eye detects it instantly hence it may not be able to focus completely on the object meant to be center of image.
I found some reduction in exposure and saturation gives good results.
Here's what i tried:
This is the original image
image1)
*solutions00.files.wordpress.com/2009/09/lotus-flower-wallpaper.jpg
and this is the image i tried
image2)
*lh4.ggpht.com/_FszDxDFtyog/TAtBo4hhU-I/AAAAAAAAAyo/3Smz61Xv-tA/s640/lotus-flower-wallpaper1.jpg
and this is the third try (image3): decrease in background exposure and saturation
*lh6.ggpht.com/_FszDxDFtyog/TAtC9E0yM-I/AAAAAAAAAy4/kciNped4pVU/s640/lotus-flower-wallpaper.jpg
And this one is the original image with blur:
(image4)
*lh6.ggpht.com/_FszDxDFtyog/TAtFiRuRdmI/AAAAAAAAAzI/VCnVBfl16eM/s640/lotus-flower-wallpaper.jpg