Manual exposure
Many find manual exposure a bit intimidating and stay with the automated mode or one of the semi automated modes like aperture priority or shutter priority. Good news is that manual exposure is not complicated at all and that you have a lot of room for making exposure mistakes and still be able to fix it in post, provided you shoot RAW, which I highly recommend. And you will understand your camera a lot better when you know how to operate in manual exposure mode.
You camera has a built in metering system, that constantly measures the available light. This system continues to work also when you set the camera in manual mode. Select the manual mode on by pushing the “mode” button top right on the Nikon D4 while turning the rear command dial to scroll through the PASM options.
Once in manual mode, you will notice a little exposure indicator appearing, both in the viewfinder and in the top/rear LCD. This indicator will tell if the camera finds that the aperture, shutter speed and ISO settings will give a correctly exposed picture when you hit the shutter.
It is a good thing to keep an eye on the exposure indicator to make sure you get the exposure you are after. Sometimes you want deliberately to over- or underexpose your picture, and the exposure indicator is a good tool to make sure you get what you want.
Aperture and shutter speed
You control the aperture and the shutter speed by turning the front and rear command dials respectively.
As you do so, you will notice that the exposure indicator changes in accordance with the selected settings for the two.
If the camera flashes “FEE” in the top LCD when you mount the lens, it is probably because you have not locked the aperture on the lens to the highest f-stop number possible – the camera needs this setting to be so, in order for it to control the position of the aperture blades when shooting with AF, AF-D or AF-S lenses.
If your lens is an older model (say AI or AIS) where you have an aperture ring on the lens, it is not always possible to change the aperture with the front command dial – instead you will have to set the aperture on the lens. The top LCD will not show the aperture but just a “F–” to indicate it cannot “see” the chosen aperture. The metering indicator works fine still though.
ISO
On a digital camera, ISO is actually not part of the exposure. The sensor has the sensitivity it had when it left the factory and it cannot be changed.
By setting the ISO to other values than the base ISO 100, you apply a gain to the values read by the sensor. It is camera internal post processing that happens from the sensor has read the light and until the image sits on the memory card. Just like in the old days when you turned up the radio, you both amplified the signal and the noise – the original signal remains the same. ISO works the same way, so the price for turning up the ISO is more noise and grain.
The NikonD4 has a dedicated ISO button at the bottom left on the camera body. Press this one to change the ISO value selected.
Pushing the ISO button and at the same time turning the front and rear command dial, changes the ISO values. The front command dial switches between ISO and auto-ISO and the rear command dial shifts between ISO values, say from 200 to 400, and from 400 to 800, and so on.
When you have auto-ISO switched on, the camera will be in a – if not semi automatic – then quarter automatic mode. In other words, the camera will try to make the picture correctly exposed ALONE changing the ISO. So if you have a dark scene where the aperture is closed down and the shutter speed is fast, the camera will have to go to very high ISO values to compensate.
You can use auto-ISO to make sure you come home with images that show at least something, but be aware that grain and noise may be the price you pay for switching auto-ISO on. For starters, I would recommend that you have auto-ISO off, and keep an eye on the exposure indicator or the histogram to make sure the exposure is roughly right. Later, when you have some experience, auto-ISO can make you work faster.
Metering modes
The Nikon D4 has 3 metering modes. You can access these by pushing the metering mode button top left on the camera – the button the closest to the viewfinder – and at the same time turning the rear command dial.
The metering mode does NOT change the amount of available light, rather it changes how the camera meters the light that passes through the lens. I shoot almost entirely in the “matrix metering” mode as it is the most advanced one, that tries to take in the entire scene and find a good compromise.
Second option is centre weighted metering. This one is good if you shoot portraits where you don’t really care of the corners are exposed correct – the important is that the person in the frame is exposed correct. The manual also mentions this as a good mode if you shoot with filters.
The third option is spot metering (the logo is a small dot), where the focus point is where the metering is done entirely. This is a good option of you know that a particular point in the image needs to be correct exposed, but you do not care too much about the rest of the frame.
All of these modes may seem confusing, so my advice is to use matrix metering. If you shoot RAW, then there are plenty of options for adjusting the exposure in post and hence I find that these other options are more for backward compatibility with older DSLRs than anything else.
Related reading
Why the Nikon D4 and not the D4S?