as long as u dont hit it with a nail or something then wont break la... if u hit dgn sharp object confirm break what since its glass....

Some nikon fans kena trolled earlier   

Anyways to the rest, some updates on my left AF issue here. Nikon managed to fix the issue within 4 working days.

https://www.facebook.com/photo.php?fbid=490...er¬if_t=like

Today I tried out my 50mm f1.8D in PC fair. I found out that when I move my focus point to the red circled points (outermost), the image area that i focusing on tends to out of focus. (very obvious when using "Single Point" in AF-area mode)

This problems seems unsolved and not very sharp when I used 3D-tracking (11 points) also. Orange circled area also blur a bit?
When I use the middle focusing point only can get very sharp image.

My friend told me that that's the problem of 50mm f1.8D. Only the middle focus point is the sharpest. Is that true? If that so then i cant take full body portrait or half body already(focusing on face which using the red circle) 

I was using Nikon D90,SB-900, 50mm at F2.2 or 2.5
Is it the weakness of 50mm f1.8D? or something wrong with my lens? or the camera operating mode?

Sifu-sifu please enlighten me on this please....

same to mine, not sure is my lens or my D90 problem
when i shoot car's hood (front view), on the left side the head lamp clear, but on the right side the head lamp blur... 

try to shoot using live view..

to test if ur lens is sharp, use middle focus point, lock ur AF on subject, then frame the subject to edge of the frame..if image is nt sharp, then perhaps is the 50mm fault..

nono..hw to say leh..u use middle focus point, then press halfway until it focuses, then shft ur camera to left/right until the person is at the edge of ur frame, then fully click ur shutter. oh ya btw use single AF point, AF-S

I thought d90 only got 1 cross type af point which is in the middle?, so the outer focus point wont be as accurate as middle , hence ur outer focus point pic will look blur

I you standing exactly in the middle with the car facing you in the middle middle, if the car is parking sideways, even if you're shooting in the middle, the left and right headlamp will be in different focus plane. It will be more obvious when using large aperture and shooting up close because the DOF will be very shallow.

However, there is another problem whereby one side of the lens exhibit problem with the focusing, you can test this by shooting straight to a flat suface of picture; if you focus in the middle point, by right the entire picture should be in focus.
Pre-Focus is half-press shutter, it will focus and lock, you can do this with digital camera and some phone camera which comes with dedicated shutter key.

With small sensor camera, pre-focus to lock focus then shift your position of you subject, it may still look sharp or in focus because of the LARGE Depth Of Field. Google Depth Of Field (DOF) to see some examples.
For small sensor, if you pre-focus something very near, the you shift your position and try to shoot something far away, you will see it's blur. With big sensor like DSLR (and using large aperture), even small distance you will notice blur.
One more thing is, with digital camera or smartphone, the display is small, you may not notice the picture is not in focus, it may look acceptable viewing the picture small, when you transfer to a PC with huge monitor and set to high resolution, you may see the problem, especially if you view it in 100% zoom.

There's a lot of thing you haven't explore, do read up the manual of the type of focusing, there's also AF-C for AF-Continuous and AF-S for AF-Single, 3D Tracking, Auto, etc. It's all in the manual and some also come with pictures.
You can find tutorials online also if you need more clear understandings.

Google cross type AF point, you will understand better. Basically a cross type will detect vertical and horizontal where else a non-cross type only detects either vertical or horizontal. Cross type is known to be more accurate and consistent when compared to non-cross type.