website:
http://www.astrohk.cz/ccdview/

Aim: quickly view recorded data; tools for reasonable checking of frames

tkirkman@linphys1 4% ccdview /media/disk/date/*
                            in general this   ^  is a file name
                            in this case, all files in this directory are loaded

a frame (file.ST7) is displayed: PGPLOT Window 1
a new Konsole appears...it displays info about the frame (the "header")

put cursor into picture (it becomes white cross)
hit right (normal) mouse button...next frame
hit left mouse button...previous frame
and hit z on the keyboard...
Konsole reports: 
CCDVIEW: Zoom is on.
In the task bar a new process is displayed: XPGPLOT (there are three...click 
on them until the tic-tac-tow window (window 2) appears...move the window to 
the side

(with cursor in window 1) hit the space bar on the keyboard...
Konsole reports: 
CCDVIEW: Photometry, astrometry mode.

move cursor in window 1 (see the white crosslines) click on a star
notice that window 2 now displays a zoomed picture of that 
star; the star may overfill the tic-tac-tow pattern.

with the crosshair in window 1, repeatedly hit the t key until the star is 
contained in the central square.
"t" toggles to increase the ROI (region of interest)
"T" toggles to decrease the ROI

hit q on keyboard (exit photometry mode)
hit P
hit f
Konsole:
CCDVIEW: Viewer mode (another q to exit).
CCDVIEW: Profile is on.
CCDVIEW: Vertical flip is on.

The Vertical flip matches the usual way the sky is presented (N up; W right)
Profile shows count values along horizontal and vertical slices through the ROI
This Profile display is PGPLOT window (Window 5), click on
its icon, and move the resulting window to a nice spot.

(with cursor in window 1) reenter the photometry mode by hitting the space  bar,

click on a nice blank spot...see random noise in Profile and  Zoom
to use the selected nothing as background level hit b

now again find a dimmer of the two stars...
(use t key to expand box if needed, look at profiles in Window 5)

read the magnitude (second to the last number in row)

do the same for a brighter star:
mag should be *smaller* which is brighter

with cursor in window 1, keyboard: ? produces some help, also see the web 
site.

Summary:
z=zoom
P=profile
f=vertical flip
space=photometry (b=background, t=toggle box)
in Viewer mode: mouse R/L next/previous frame
h=histogram
q=quit
g=make .gif

note ccdview.in to set defaults