This interactive Java tutorial explores the various features available in the Nikon DXM 1200 ACT-1 software Live settings panel. Among the options included in this tutorial are exposure time, focus, the focus mark, sensitivity, and the color levels function. Tutorial controls are identical to those found in the native software.

	Interactive Java Tutorial
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The Nikon DXM 1200 digital camera system software (ACT-1) has a live image control function (termed the Live settings panel, which is utilized to control the focus rating, white balance, exposure time, and camera sensitivity prior to capturing digital images. The Focus Rating is a relative value of the image sharpness represented in a normalized numerical form. Current focus conditions can be viewed in the Focus Rating frame located in the Live control panel, just beneath the image window. A green progress bar provides an indication of the current focus relative to the "best" focus position, which is represented by a red line positioned in the bar window. To the left of the progress bar is another window that presents a numerical value of the current focus conditions.

Focus is measured at the position where the Focus Mark appears on the live image window. The user can relocate the focus position by moving the set of crosshairs to another position within the window. This is accomplished by clicking on the crosshairs (Focus Mark) and dragging it to a new location with the mouse. The Focus Mark feature can be deactivated by using the mouse cursor to place a check mark in the square radio box positioned in the Live control panel. Clicking the check mark to the on position (check mark present) activates the Focus Mark, whereas removing the check mark turns off the function.

The Live control settings panel also contains a Docking function selection. Turning the docking function on by clicking the radio box (placing a check mark) fixes the position of the Focus Mark in the center of the Exposure frame (Figure 1). When the Focus Mark is docked, translating the exposure frame with the mouse simultaneously moves both the frame corners and the set of crosshairs positioned in the center. To deactivate the Docking function, uncheck the square radio box. This allows independent movement of the Focus Mark and the Exposure frame. Note that when the Focus Mark is turned off, the focus rating does not appear in the control panel settings window and the green progress indicator bar is also absent. Instead, these symbols are replaced by the term N/A in the settings panel window.

The image can be evaluated for proper brightness based on the red, green, and blue (RGB) signal amplitude levels by examining these values with the Color Level monitor. To activate the monitor, click the mouse on the Color Level monitor button that appears just beneath the Live image window, on the right-hand side of the ACT-1 software panel. When this button is activated, a line graph appears on the live image that plots each of the three RGB signal levels. The horizontal line of pixels at which the color level is monitored is located by a white bar (Pixel Line) that traverses the live image window. This bar can be translocated anywhere within the window by dragging with the mouse.

The Color Level monitor interprets individual pixel information for a selected horizontal row of pixels into a set of RGB values that are displayed on the screen in the form of a graph. For example, a pixel that has a RGB value of 30 (red), 238 (green), and 207 (blue) will appear teal when viewed alone. When displayed as a graph in the Color Level monitor, this pixel will be broken down into three individual RGB values that will each be represented as discrete points on the graph. The information gathered in this format can be utilized to determine the relative brightness level of a digital image. If the graph displays a flat waveform on the top, then the camera sensitivity is saturated and the gain (or microscope illumination) should be reduced to improve the image. Alternatively, when the graph shows a flat waveform positioned at the bottom of the live image window, sensitivity is at a minimum (or zero) and either the camera gain or microscope illumination should be increased. Image gradation is determined by the waveform spread, with larger spreads leading to improved performance and a wider spectrum of color gradations.

The ACT-1 exposure control panel is presented in the applet window. The slider is used to adjust the exposure time in discrete increments by dragging with the cursor. As the exposure time is adjusted by translating the slider, the Exposure Time window changes to indicate the reciprocal of the selected time. For example, the number "15" appearing as a simulated LED readout in the control panel window indicates an exposure time of 1/15 second. If the exposure were 1/12000 second (the fastest exposure), the numerals 12000 would appear in the control panel window.

For longer exposures (exceeding one minute), the slider should be dragged to the rightmost position and a specific time entered into the text box. When the slider reaches the right-hand position, the text box becomes active and the time (in minutes) is displayed in the Exposure Time window. The user can specify an exposure time either by typing a time value in the text box or by clicking on the up/down arrow buttons. The buttons increase or decrease exposure time in discrete increments, but any time value between 2 and 170 seconds (integers only) can be specified by typing that value into the text box.

Camera sensitivity (gain) can be adjusted through a set of radio buttons located in the Photo control panel. There are three options in the sensitivity window, Normal, High, and Max, which can be utilized to control the exposure time. Increasing the sensitivity by checking the High or Max radio buttons will shorten exposure time at the expense of increased noise. Avoid exceeding long exposure times (several tens of seconds), which can cause the image to be degraded by excess camera noise. Instead, adjust the microscope illumination intensity so that shorter exposure times can be comfortably utilized.