QUOTE(justified @ Mar 28 2014, 06:37 PM)
Dear all,
I wanna learn photography (like aperture, shutter speed or ISO). My main interest is dslr. however, my concern is that it is too bulky..i dont think i will wanna carry a 0.5kg item around me in the city..then i come acorss mirror less camera like sony nex 5. is there any difference in terms of image quality? Can i use lenses for dslr on a mirorless camera (thats if i have the mount specific for my mirorless camera) ? In long term, i would like to take macro picture like bugs/flowers... will a mirorless give me a great picture?
basically, what are the main difference between these 2 type? why would ppl choose a bulky dslr over the mirror less camera ?
Before understanding what is a mirrorless camera, you must understand what does the mirror in a DSLR do.
Basically the mirror does nothing but reflect the image from the lens to an optical viewfinder so you can see exactly what the lens see.
Because of this mirror and the pentaprism needed, the body of DSLR is bigger in size. Take a look at this diagram -

Now another byproduct of the mirror system is that a faster auto focusing system called phase detection.
So the two main advantages of a DSLR is that you get an optical viewfinder and faster auto focus system. The third advantage is that the DSLR system has been around for ages and their lens and equipment are more matured and maybe even cheaper.
Okay now lets see what mirrorless cameras are. Like the name suggest, there is no mirror. That means no optical viewfinder. How we see the image is thru the LCD screen or in higher end mirrorless cameras, there is an electronic viewfinder. The advantage is, because there is no mirror, the camera body can be made smaller. Thats it.
Now how about auto focus system for the mirrorless cameras? Without going thru too much details, currently some of the contrast focusing system is pretty fast and decent. And recently came something called hybrid focusing which mixed contrast detection and phase detection like those seen in the Sony Nex system (take a look at the new Sony A6000)
The lenses and accessories for mirrorless cameras can cost a bit more than those from DSLR and not all mirrorless camera makers have a good range of lenses so compare first.
Another thing to put into your deciding equation is the sensor. DSLR has basically two sensor sizes - Full Frame and APS-C
Mirrorless has quite a huge range from M4/3, 1in, APS-C and even Full Frame. The bigger the better.
These are the three basic differences. As for a great picture, that really depends on you