I bought a Nikon AF-S DX 35mm f/1.8 G for my D5000. I used it for the first time on Christmas Eve and Christmas Day. All the photos I took with it looked fine on the LCD on the back of the camera. But once I downloaded them to my computer I noticed some problems. Only one part of the close up photos where in focus.
Examples; I took a picture of my granddaughter in front of the tree. She was out of focus, but the tree was in perfect focus.
I took a picture of my daughter holding up a box that a present was in. The box was in focus, But her face was not. She was holding the box in front of her.
I'm wondering if the lens is not focusing correctly, or if an adjustment needs to be made to the AF system of the camera. All the pictures that I took from a distance came out great, with no flash! What do you think about the lens being bad right out of the box? I bought it from B&H photo. I've bought other things for them and have had no problem. This shallow depth of field thing has me wondering?
Your lens is working perfectly. With a lens with that much depth of field you either need to raise the f-stop to reduce the depth OR ensure you have focused on exactly what you want in focus.
At 1.8 you could take a close up of someones face, focus on the nose and the ears would be blurry (while the nose would be in perfect focus).
Taking photos at that low of an fstop can be tricky and is almost impossible to tell on the small lcd screens ont he back of the camera.
Your aperture was too large. Increase the ISO so it can be smaller.
[URL Truncated] (Canon 24-70 mm f 2.8)
This was taken with Canon 135 mm f 2 at f 2). The depth of field was paper thin. [URL Truncated] If her eyes weren't in focus, it's ruined.
That will do it. Just make sure that the focus points on your D5000 are where you want to focus. If you need to, set the focus point to Single Point AF, and pick the point with the selector on the back of the camera. Or narrow the aperture to around f2.8.
Remember that the further away you are, the greater your depth of field will be.
Good luck!
Your lens is working just fine. This is all user error. If you have the camera in auto mode, and in low light, the camera will open the aperture all the way. This is going to leave you with a razor thin area that's in focus, and will make focus hit and miss all night long.
Pull away, and your depth of field will increase slightly.
This is a perfect example of having something and not understanding how it works. Get out of auto mode, and into aperture priority so that you can control your depth of field. You should stop down a bit to between f2 and maybe f/3.2 this will keep you from having to crank the ISO and give you a better chance at sharper images.
I also suggest hitting the web for tutorials on depth of field, aperture and general dSLR info.
It isn't the lens, its the user. Unfortunately you've apparently never studied Depth of Field (DOF) so you aren't aware of the trade-off involved with using a fast lens like your 35mm f1.8. This site will teach you about DOF: [URL Truncated] I took a quick look and found this information:
1) 35mm @ f1.8 focused on subject at 5'-0'', DOF is from 4'-5'' to 5'-3''. This means that anything from 0'-7'' in front of your subject to 0'-3'' behind it will be in focus.
2) 35mm @ f1.8 focused on subject at 10'-0'', DOF is from 9'-2'' to 11'-0''. This means that anything from 0'-10'' in front of your subject to 1'-0'' behind it will be in focus.
Even at f5.6, under the same conditions as shown in the first example, you don't gain any DOF in front of your subject. Its still 0'-7''. It does increase to 0'-10'' behind your subject though. Use f5.6 under the same conditions as shown in the second example and your DOF is from 2'-2'' in front of your subject to 3'-11'' behind it.
The DOF calculations shown are based on your D5000.
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