10 LS-785 High Throughput Lens Spectrograph User Manual
Focus Adjustment
When purchased with a Princeton Instruments CCD detector, the LS-785 is normally focused and aligned at the
factory and shipped as an integrated system ready to operate. In this instance no further adjustments are required.
We do recommend focus adjustments in the following instances:
1. The grating has been adjusted to a new wavelength position.
2. A CCD is purchased separately from the LS-785 and is being installed at the customer’s facility.
3. The CCD has been removed from the LS-785 and is being re-installed.
4. The user wishes to check or optimize focus.
For focus adjustments, locate the lens focus micrometer on the back of the
instrument labeled “FOCUS ADJUSTMENT”.
Procedure:
1. Rotate the locking nut counter-clockwise to unlock the micrometer
spindle.
2. Rotate the focusing micrometer until best focus (image quality or
spectral resolution) is obtained at the CCD detector.
CAUTION: Do not apply excessive force to the knob.
3. Lock the micrometer in place by rotating the locking nut clockwise.
Wavelength Adjustment
For wavelength adjustments, the LS-785 includes a micrometer which
is located on the rear of the housing labeled “WAVELENGTH
ADJUSTMENT” (see Figure 2-5). Please note that we refer to
Wavelength Adjustment as moving (rotating) the grating to a new
center wavelength position on the CCD detector. To help with
wavelength adjustments, a table showing micrometer settings for
different center wavelengths is provided with the LS-785. To move to a
new center wavelength, the user simply rotates the micrometer
clockwise or counter-clockwise until the desired micrometer setting is
reached. If desired, the micrometer can be locked into position by
rotating the locking nut 1/8 turn clockwise.
Figure 2-4. Focus Adjustment
Micrometer
Figure 2-5. Wavelength Adjustment
Micrometer
