Plate Scale and Field of View
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Plate Scale
F. Marchis (UC-Berkeley) and J. Berthier (IMCCE) have kindly provided
a plate solution for the new 4096 x 4096 CCD (installed January, 2006).
N.B., This solution was derived from an observation of NGC752 made
with pixels binned 2 x 2, as is the typical practice for PFCam observing.
Seeing was approximately 1.5 arcseconds.
Plate scale is 0.370 arcseconds per binned pixel, +/- 1 milli-arcsecond
With North up and East left, and the CCD binned 2 x 2, the plate
constants are:
| Orientation | 0.2614 degrees |
| X Scale | 0.3695 arcsec/pixel |
| Y Scale | 0.3707 arcsec/pixel |
These constants may be added as WCS keywords to your PFCam FITS
headers. Bear in mind, however, that the plate solution given here
does not take all possible terms into account, or may change as a result
of such factors as changes in the telescope's or instrument's optical
alignment in the course of regular maintenance. However, it is good enough
for many purposes and convenient when using FITS viewers such as DS9.
Field of View
The field of view for the entire array is about 12.6 arc-minutes,
but some partial vignetting occurs near the edges when used with
the standard 3" x 3" filters. The filter wheel can accommodate filters up
to 4" x 4" to obtain the full, unvignetted field, but must be
provided by the observer, along with its own filter holder. Contact
a support astronmer for details of custom filters.
(See Filters and Count Rates for
specifics of PFCam filters.)
Any of Lick's large collection of 2" x 2"
narrow-band filters can also be used with PFCam, but they reduce the
useful field of view to about 6 arc-minutes.
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Support Astronomers (sa@ucolick.org)
Last modified: Tue Mar 8 18:50:35 PST 2011