How to optimize exposure and sharpness using custom settings to fine-tune your camera settings.

Contributed by Paul Janosi
[EDITORS  Note: Correct exposure has become nearly a religious issue with the advent of the "expose to the right" mantra for many raw shooters. But not everyone sees exposure the same way. Thanks to newsletter reader Paul Janosi for contributing this article with his thoughts on tuning exposure on your high-end D-SLR and even more importantly his meticulous technique for fine tuning your AF system for use with your long lenses and Teleconverters. I tried it with my 200-400f/4 and my TC-14E (both of which had just been serviced and aligned by Nikon) and found that indeed a correction to AF improved the sharpness of my images noticeably--David]  
High end digital cameras such as Nikon D300, D700, D3,  D3X and their Canon equivalents are packed with an incredible collection of user adjustable custom settings.
Setting your Exposure Preference
Ever since I first purchased my Nikon D300, I always felt that it was over exposing images.  I decided to Fine Tune the Optimal Exposure.  It is very simple to do. This is done by selecting b6 under the custom menu.  Exposure can be corrected separately for each meter--Matrix, Center-weighted or Spot meter. Exposure compensation can be applied in steps of 1/6 of an f-stop from +1 to -1 EV.  I reset my Matrix meter to -3/6 and have been very happy with the results.  Please note that exposure can be fine tuned for each Custom Settings bank and is not affected by the two button reset.  Also it is important to note that the once reset, there is no exposure compensation warning.  To determine how much exposure compensation has been dialed in you need to look at the Fine Tune Exposure menu.  If you are not happy with your exposure, I highly recommend fine tuning the optimal exposure.  
As a nature photographer I often find myself not being able to get as close to my subject as I would like.  To get a frame filling portrait of my subject I have to resort to using teleconverters. This has been a love hate relationship at best.  I love the magnification but hate the light loss and loss of image sharpness.
I use two lenses for nature photography.  The AF-S Nikkor 200-400 mm f/4 lens is my first choice for mammals and the AF-S II Nikkor 500 mm f/4  lens is my first choice for bird photography. I use both the Nikon AF-S Teleconverter TC-14E II (1.4X)  as well as the Nikon AF-S Teleconverter TC-17E II (1.7X). When I was shooting film, I had acceptable results with both teleconverters, however when I started taking digital images, I was not satisfied with the sharpness.
I tested my prime lenses using a Gitzo GT3530LSV 6X carbon fiber tripod and a Wimberley head.  I used my best long lens technique to minimize vibrations.  I had sharp images with both prime lenses, but when it came to the teleconverters, I could not get a sharp image if my life depended on it. I decided to try to calibrate the teleconverters by adjusting  the micro adjust setting with the lens wide open. I found the results overwhelming successful.
Fine-Tuning your Auto-Focus System
I came across a variety of testing procedures on the web for fine tuning a camera's AF and tried several.  I finally came to the conclusion that the simpler the setup, the more repeatable it is and the better it works. I followed the following simple steps:

1. Mount the camera on a good tripod.


2. Set up a reference target for the camera to focus on.  It should have sufficient contrast for the AF system to detect it. Make sure it is mounted flat and parallel to the camera's focal plane, and centered. (I tried several things, including a page from a magazine with fine detail and text; I also photographed a cereal box, and even shot signs in a parking lot)


3. Make certain that the target is well lit and it is evenly illuminated.


4. Ideally the camera-to-subject distance should be not less than 50 times the focal length of the lens. For a 500 mm lens, that would be at least 25 meters. Shoot at the maximum aperture of the lens via manual mode or aperture-priority. Set the lens for AF and the camera for One-Shot AF, and manually select the centre focusing point. Use low ISO setting like 200.


5. Adjust the exposure level to get an accurate exposure. If the lens has vibration reduction (VR or IS), turn it off.


6. Turn AF fine tune on (for the D300 see instruction manual page 327). Auto focus can be fine tuned for up to 12 lenses and lens plus Teleconverter combinations.


7. Take three consecutive images at each micro adjustment setting starting at 0, +5, +10, +15, +20 and -5, -10, -15 and -20, with no teleconverter, then repeat all settings with each of your teleconverters.  Ideally you want to reset the focus to infinity between shots and let the camera acquire focus each time prior to taking the image.


8. Upload the images to your computer and look at the images on your screen at 100% magnification.


9. Using Nikon View to select Metadata you'll see that under camera info it will display the settings for: Lens, Focal length, and Auto Focus Fine tune on (Setting). Under Exposure it will show: Exposure tuning (where ever you set it, in my case -3/6).


10. Now it becomes a method of elimination.  Simply remove the soft images. Once satisfied that I found the sharpest image, I set the camera to that setting. Both teleconverters required around +15 adjustment on both the 200-400 and 500 mm lens.

To confirm I picked the correct setting I photographed a plastic owl at those setting and looked at the eyes at 100%
When I was happy, I went out and photographed some real birds using the teleconverters. I was pleased with the 1.7X.  The sharpest it has ever been.  I had to fine tune the 1.4 a second time.  For the 2nd fine tuning I did another set of fine tune calibration between +15 and +20 one at a time. It seems to be fine now.
If you are unable to achieve sharp focus between -20 and +20, its time to have your equipment serviced.
Good luck. May all your images turn out well exposed and sharp.--Paul Janosihttp://pauljanosidigitalnaturephotography.com/
And a special thanks to Paul for contributing the article and his excellent technique. If you have an idea for an article that would be of value to our readers make sure and let us know through a quick post or PM to me in the forums--David Cardina