1. Focus confirmation
It’s not always easy to tell just by looking through the viewfinder, if your subjects are in focus. However, you can actually use the camera’s auto-focus system to help you when using manual focus!
Nikon cameras have a separate sensor for the auto-focus system. This is still active no matter what lens you put on your camera. However, if it’s not an auto-focus lens or if both your camera and lens lacks an auto-focus motor (which would be the case with say a D3200 and any AF-D lens) there is no way for the camera to automatically adjust the focus, but it would still be able to tell you if your subject is in focus though.
So, how can you utilize this? Well, first you’ll need to be aware that this requires a lens with an aperture of 5.6 or faster. In the lower left corner of your viewfinder you’ll see a green dot appear when your subject is in focus. Depending on your model some cameras also have two little arrows guiding you further or nearer.
– Turn the focus ring on the lens until the green dot is lit. This means your subject is in focus. Some models feature two arrows telling you if you should focus closer of further away.
– If the green dot is flashing it mean your subject is moving in and out of focus.
– If both arrows are lit, pointing towards each other it mean the camera can not find the accurate focus.
On some newer lower end Nikons (D3xxx and D5xxx series) when in manual mode you have the option to activate what Nikon calls a rangefinder that takes the place of the exposure meter in the viewfinder. This is usually activated in the a4 menu.
However, since this separate sensor requires light to be reflected off the mirror, it will not operate once the mirror is lifted. Hence this will not work in Live View. Unfortunately. If you are using Live View your best chance of focusing correctly is to use the display zoom-function and zoom in to easier see the accurate focus.
2. Non-CPU lens data
Newer lenses got loads electronics inside them. This is why your camera automatically recognizes which lens is mounted and saves information such as focal length and aperture in the image’s meta data. Older lenses however, are stripped of electronics and are often called non-CPU lenses. If you mount an older lens on your camera the camera will not be able to figure out the current F-number.
Before you continue to read all this, you should know that unfortunately not all Nikon cameras support adding non-CPU lens data. Most newer mid- and high-range cameras from the D7000 and up will support it, but lower end Nikons may not. You will still be able to use manual lenses on cameras that do not support adding non-CPU lens data, but you will have to shoot in manual mode and light metering in the camera will not work.
Since the camera lacks information such as focal length and aperture about the lens, auto functions, such as certain flash functions and light metering, may be crippled. But there are ways of getting around it! You can manually tell the camera what lens you are using. Your Nikon can store information about 9 different non-CPU lenses.
At the bottom of the wrench menu you’ll find the Non-CPU lenses data menu. By adding focal length and maximum aperture, the camera will automatically display the current aperture in the display. If you use a lens that supports aperture indexing (Ai/Ais lenses) the camera will register when you change the aperture and change the aperture in the display to the next whole step. This means the camera can work out the light metering and flash functions and information about aperture and focal length will also be saved in the image’s EXIF data.
This is a great solution for fixed focal lenses. Unfortunately, you can not add shortest and longest focal length for zoom lenses. You can however save a lens under several lens numbers say one for 70mm and one for 200mm on a 70-200mm zoom lens.
If you use a lot of different non-CPU lenses make sure to add this menu to your custom My Menu for quick access as you have to change the lens number manually if you change lenses.