Question about focus (Nikkor 50 mm)

So, I went from a kit lens 18-105 mm to a 50 mm 1.4 and I have a little problem with the focus. With the other lens there was no problem because the maximum aperture was 3.5 so it wasn't hard to make things focused. But with the 50 mm I am struggling to make the focus right, like I think it's focused but later when I see it in my laptop is not. What's the best way to dominate the focus?

 

Large apertures have very small depth of filed. The points of focus you see on your viewfinder might not be exactly as you think you see them at time you push the button. Practice, but also just because it f.4 does not mean you need to shoot f1.4. If you have time to use live view and focus that way,it also can be benefitial

 

Is a portion of what you were trying to get in focus. Or is the whole picture oof (out of focus)?

 

The 18-55mm kit zoom has a maximum f/stop of f/5.6 at 50 or 55mm...so...stop the 50mm prime lens down, to f/5.6, or to f/6.3, or to f/7.1, or to f/8....problem solved!!!

 

Understanding Depth of Field in Photography

 

Like Darrel said, until you get the hang of it, shoot at F4, etc....

 

First; are you not allowing the camera to achieve focus? Manually focusing is the hard way.

Second; the depth of field (DOF) (or could be said; depth of focus) at maximum aperture can be very thin, depending on the distance to your subject. For example: If you are trying to use your lens at maximum aperture (f/1.4) and your subject is about 10 feet (3 meters?) distant; then the calculation would be something like this:



.68 feet is about the depth of someone's face, not counting the ears. If you are hand-holding your camera, shooting at f/1.4, any little movement can throw off the focus.

1. Let the camera focus.
2. Use a smaller aperture.

 

And note that f/5 is a smaller aperture - and a smaller number because it's a fraction - than f/4 is.
One fifth of a 10" pizza is a smaller slice than 1/4 of a 10" pizza.