Do you think is still possible to earn extra income by selling stock photos ?

The potential is there, but you need to upload few hundred photos or thousand to see the results.

The same applies with writing a hubpages.

Uploaded about 30 pictures to BigStockPhoto and manage to get some sales.

About 50 - 60 % of my photos that I have uploaded were rejected because of poor quality .

Read my experience below.

http://hubpages.com/hub/How-to-make-residual-incom

Good Luck .

I need to get a better camera !

It is definitely possible to earn extra income by selling stock photos.I am doing it myself.The new trend is called microstock photography.This is internet based stock photo agencies that pay the photographer a small commission on the use of their images.It is definitely a growing trend with the top agencies having thousands of photographers and millions of images on file.This is commercial stock photography,no pretty sunsets and landscapes or snapshots of the family picnic.Although the commissions seem quite low,anywhere from 25 cents to a few dollars,you still must know your stuff,ie.lighting,exposure and composition.The best way to learn more is to visit some of the sites and read their guidelines and photo needs.Search their best sellers and most popular images.Some of these microstock agencies include shutterstock,istock,fotolia,dreamstime and bigstock photo.They all differ in what they accept and commissions paid.

Regarding... I took photography as a hobby and it would be great if I can earn some extra income to supplement my hobby.

You might find this hub a interesting read on...

"How to Make Lots of Money with your Digital Camera"

http://hubpages.com/hub/How-to-Make-Lots-of-Money-

Don't forget in micro stock you need to submit a large number of images as well, to help offset the small payout.

telliott, thank you so much for the info. It really give a good insight on this field. Appreciate your info allot

Yes. Microstock photography!!! It takes a while to make it worthwhile and to pay substantial commissions. But if you approach it from a "hobby" standpoint, and something that you "already" enjoy doing....you can make it worth your while.