Just a question about the 50mm1.8G nikon i recently purcchased

[tinman84]

is there a way that the piece i purchased is not focusing properly ??


i saw that its not focusing properly a couple of times

primes are suppposed to focus better right ? ?

so was just thinking if may be the piece i recieved wasnt working fine

 

[tirediron]

Of course it's possible, even Nikon, despite stringent QA on all their products lets the odd lemon slip through. Why do you think that it's not focusing correctly; can you post some example shots? Is there any chance that you are shooting wide open (f1.8) with a VERY shallow depth of field and simply missing the focus on the subject?

 

[Robin Usagani]

More than likely user error. When you open the aperture blade real wide, the DOF is real thin so you can miss focus real easily.

 

[Markw]

+1

Mark

 

[tinman84]

i always shot at F2.0 or 2.2

i thought the focus is off cause, its kinda motion blur, but i was shooting at shutter speed of around 1/600 and using a tripod to shoot

and this non focus things also if the pic is like seen normally then it appears all fine but if i look at it closely then its there


thanks for the replies

 

[Robin Usagani]

post the photo with exif on it.

 

[tinman84]

ok will do once i get home

 

[jake337]

What camera body are you using?
I thought most autofocus systems, even in pro bodies have trouble with lens aperture wider than F2.8.

What focus mode are you using?
Are you using single focus point or letting the camera decide the focus point? Are you using AF-C(countinous focusing), if you are, and you do this and recompose the camera will continue focusing as you recompose.

Under what lighting conditions is it mis-focusing?
Indoors or dim lit situations will give the AF system some trouble.

Are you autofocusing then recomposing?
At wider apertures this will shift your plane of focus, leaving the original focus point on subject off that plane.


Or it could be front or backfocusing.

 

[tinman84]

Body D3100

no i compose and then focus ..

umm may be the point they are night shots so may be autofocus isnt working properly

By Are you autofocusing then recomposing? do you mean i half press the shutter release and then change the composure or the subject ... then no ..


what exactly is front or back focusing ??

What camera body are you using?
I thought most autofocus systems, even in pro bodies have trouble with lens aperture wider than F2.8.

What focus mode are you using?
Are you using single focus point or letting the camera decide the focus point? Are you using AF-C(countinous focusing), if you are, and you do this and recompose the camera will continue focusing as you recompose.

Under what lighting conditions is it mis-focusing?
Indoors or dim lit situations will give the AF system some trouble.

Are you autofocusing then recomposing?
At wider apertures this will shift your plane of focus, leaving the original focus point on subject off that plane.


Or it could be front or backfocusing.

 

[cbarbero]

I am going to have to agree with mis-focusing. Do you have your camera on tracking metering by chance? That has been known to cause havoc. Even at 2.0/2.2 that still leaves very little room for error on focusing.

 

[2WheelPhoto]

Change camera focus from "C" to "S"

 

[jake337]

Body D3100

no i compose and then focus ..

umm may be the point they are night shots so may be autofocus isnt working properly

By Are you autofocusing then recomposing? do you mean i half press the shutter release and then change the composure or the subject ... then no ..


what exactly is front or back focusing ??

What camera body are you using?
I thought most autofocus systems, even in pro bodies have trouble with lens aperture wider than F2.8.

What focus mode are you using?
Are you using single focus point or letting the camera decide the focus point? Are you using AF-C(countinous focusing), if you are, and you do this and recompose the camera will continue focusing as you recompose.

Under what lighting conditions is it mis-focusing?
Indoors or dim lit situations will give the AF system some trouble.

Are you autofocusing then recomposing?
At wider apertures this will shift your plane of focus, leaving the original focus point on subject off that plane.


Or it could be front or backfocusing.

So when you compose and focus are you manually selecting the focus point or letting the camera pick?

front focusing is when you focus on a point and the lens focuses just in fornt of that point. Back focusing is the opposite, you focus on a point and the lens focuses just behind that point. On higher end bodies you can micro adjust your focus to compensate for this.

I'm gonna stress setting your focus to single point AF-S. I think you are using multipoint AF-S or AF-C. When you autofocus, how many of the points light up in your viewfinder? If more than one at a time, then your in multipoint.

Check out your d3100 owners manual on how to change these.