Fine Tune Optimal Exposure – How Does it Work?

Have you ever thought your camera's metering system of choice was under or overexposing your images? If you are shooting almost any Nikon from the D90 up, you have the ability to fine tune the exposure, adding or subtracting up to one stop of exposure in 1/6 stop increments.

This allows you to push your camera's exposure in one direction or the other on a semi-permanent basis. I say semi permanent because you can set it back to factory specs any time you want. Fine tuning optimal exposure is like leaving the exposure compensation settings on all the time, except that you don't have to think about it with the fine-tuning system. You just test it (find best exposure), set it, and forget it.

As I briefly mentioned before, the Fine tune optimal exposure setting allows you to fine tune the Matrix metering, Center-weighted area metering, and Spot metering systems by +1/-1 EV in 1/6 EV steps. Nikon has taken the stance that most major camera systems should allow the user to fine tune them. The exposure system is no exception.

You can force each of the three metering systems to add or subtract exposure from what it normally would use to expose your subject. This stays in effect until you set it back to zero. It is indeed fine tuning, since the maximum 1 EV step up or down is divided into six parts (1/6 EV). If you think your camera mildly underexposes highlights and you want it to add 1/2 step of exposure, you simply add 3/6 EV to the metering system. (Remember basic fractions: 1/2 equals 3/6.)

As mentioned, Fine tune optimal exposure works like the normal compensation system, but it allows only one EV of compensation. As shown in figure 1, screen 3, an ominous-looking warning appears when you use Fine tune optimal exposure. It lets you know that your camera will not display a compensation icon, as it does with the +/- Exposure compensation button, when you use the metering fine-tuning system. This simply means that while you have fine tuning dialed in for your light meter, the camera will not remind you that it is fine tuned by showing you a compensation icon. If it did turn on the compensation icon (+/- on the Control panel and in the Viewfinder), it couldn’t use that same icon when you use normal compensation.

You use the Custom Setting Menu > b Metering/exposure > Fine tune optimal exposure setting to adjust the exposure.  Here is the actual Custom Setting number on several common Nikons. This feature is only available on advanced, semi-pro and pro cameras:

• Custom Setting b4 – Nikon D90
• Custom Setting b5 – Nikon D7000
• Custom Setting b6 – Nikon D300, D300S, D700, D3, D3S, D3X
• Custom Setting b7 – Nikon D200, D2X, D2XS

Here are the screens used to set the exposure fine tuning in a Nikon D7000 (screens may vary slightly in other Nikons but not drastically):

Figure 1 – Choosing Fine tune optimal exposure settings

Use the following steps to choose b5 Fine tune optimal exposure settings:

1. Select b Metering/exposure from the Custom Setting Menu and scroll to the right (figure 1, image 1).
2. Select b5 Fine tune optimal exposure and scroll to the right (figure 1, image 2).
3. Select Yes from the warning screen and scroll to the right (figure 1, image 3).
4. Select the metering system you want to adjust. In figure 1, image 4, I selected Matrix metering. Scroll to the right.
5. Scroll up or down in 1/6 EV steps until you reach the fine-tuning value you would like to use (figure 1, image 5, red arrow).
6. In figure 1, image 6, I selected +3/6 (1/2 step EV). Press the OK button to lock in the fine-tuning value for the metering system you selected in step 4.

That’s all there is to it! Remember that you have Fine tune optimal exposure turned on because the camera will not remind you. Watch your histogram to make sure you’re not regularly underexposing or overexposing images when you have the fine-tuning adjustment in place. If needed, adjust the fine tuning up or down, or turn it off. You must fine tune each metering system separately.

Note for D7000 users: Fine tune optimal exposure applies only to the user setting (U1, U2, or non-user setting) you are currently working with. If you are working with U1, then U2 and non-user settings are not changed. Be sure to save the user setting in the Setup Menu if you change one of them.

My Recommendation: Fine tune optimal exposure is a rather controversial setting. On my older Nikon D300, I found that I took better pictures when I ran the Matrix meter 3/6 (1/2 EV step) over the normal setting. The D300’s Matrix metering seemed a bit conservative to me and it worked a little too hard to keep from blowing out the highlights in my images. It seemed to underexpose them by about 1/3 EV step most of the time. I could see this underexposure because on most of my Matrix meter exposed images, the histogram didn’t quite make it to the right edge (lighter values) of the histogram window, which I prefer. I like to expose for the highlights, yet my older D300 seemed to slightly underexpose.

I do not need to change the default on my D7000. If anything, it tends to expose a little on the bright side. If I were to make an exposure adjustment on this camera, I would try –1/6 as a test. However, I doubt that I will make this adjustment on the D7000.

Remember that adjusting an exposure is always an experiment. If you choose to fine tune any of the three metering systems, you should thorougly test it before you do an important shoot. The way I fine tune my camera is based on my own photographic style, and my results can’t guarantee that you would get the same results. It certainly won’t hurt to play with these settings—as long as you remember to set them back to 0 when you’re done—if they don’t perform the way you expect.

Keep on capturing time...
Darrell Young

See my Nikon books at: 

http://www.photographywriter.com/NikonBooks.asp