C40/RetroCam Observing Procedures
Contents
1. Initialize System
1.1 Swap CCD to RetroCam (if
needed)
- If RetroCam is not in place for observing, go to the dome and
follow these
instructions to swap
between CCD and RetroCam. Two people are
required.
- Check that switch on TCS Switch Box (behind blue
rack) is set to IR Camera.
1.2 Instrument Control Computer (csp5)
(Windows XP)
- User name: cspuser
- Password:
- Double click on the RetroCam icon.
- A window called Database Initialization pops up:
- Check Camera, Telescope, Guider, and
FilterWheel ar all ONLNE.
- TemperatureControl should be OFF.
- Type in observer's name in Observer.
- Then click OK
- A window called RetroCam-Control pops up.
- Go to the Modules tab and open the TeleGUI,
Display and Guider modules.
Once you open TeleGUI the UT time updates.
- In Telescope Control window go to the File tab and
open SkyMap, Airmass, and ObjectList.

- In RetroCam-Control window go to the Option tab and
select DataPath.
- In the window that pops up write the directory in csp4 where the data
will be directed. Use the CSP naming convention.

For example, for the night starting on Sep 06 2005, type:
"\\200.28.147.133\data\20050906_07".
- In Guider Control window click on the Park button
to move guider camera out of the detector's field.
Check that guider position starts at 0,0. If not, try File --> Init. If
this also fails, go up and reset
Blister Box.
1.3 Data Reduction Computer (csp4) (Linux)
- User name: cspuser
- Password:
- Open a terminal (you can use the icon in the task bar).
- Create a directory for the night and make it writable by
csp5. For the example above:
> cd /data
> mkdir 20050906_07
> chmod 777 20050906_07
- Open an IRAF window by clicking on the "drawer" icon in
the task bar.
Or in the terminal, type:
> cd
> xgterm -sb -e cl &
- In the IRAF terminal, go to the data directory, e.g.:
cl> cd /data/20050906_07
- See the use of observing scripts in Section 5 below.
- Open DS9 from the Linux terminal:
> ds9 &
1.2 Check UT time
- Check the current UT time (e.g, the USNO web page).
- If the Universal Time at the TCC-Guider PC differs from
this more than a few seconds, do the following:
- In TCC-Guider PC type 'UT hh mm ss' and press RETURN at exactly
that time.
- If the DATA PC (located in light blue rack) gets rebooted,
you will have to reset the UT time there too:
- User name: root
- Password: check label on monitor
- Type 'date -z0'
- Type 'date -d0'
- Type 'date yyyymmddhhmm.ss'
- Type 'date' (to confirm entry)
- Type 'exit'
- It is very important that you check
the UT and ST are right (within some seconds) in the
Retrocam-Control window in csp5.
- If this is not the case, restart the RetroCam control program in
csp5 as described in Section 1.2.
- Once you re-open the TeleGUI module the UT should update
and be close to the time in the TCC-Guider PC.
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2. Activate Telescope
- Turn console ON (rotate key).
- Turn Power ON.
- Check that platform is clear and in TCC-Guider PC, type 'COVER' (telescope will slew South).
- Go to the platform, raise platform, and remove the telescope cover.
- Lower platform.
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3. Calibrations and Telescope Setup
3.1 Dome Flats
- Turn OFF platform lights from console.
- On console, raise the windscreen (PANTALLA).
- In TCC-Guider PC, type 'DOMEFLAT' to slew telescope to white
screen.
- In Retrocam-Control window set:
- Exptime = 5
- Readmode = Double
- ObjType = dflat
- Loops = 15
- Object = Domeflat (no space)
- Turn ON quartz light from grey box over light blue rack and
adjust voltage to the values given below (updated on Sep. 15 2006),
according to the filter:
This way you should get about 12,000 ADU on average.
- Go to the dome and check both the telescope and the quartz light
points to the white screen, and that no shadows are cast on the screen.
- In Retrocam-Control window select a filter and click the
Go button to start a loop of flats.
- When done, turn OFF quartz light.
- Click Go again to get "lamp-off" flats.
- Change filter and lamp level, and repeat the two previous steps.
- When the sequence of dome flats is complete, check that the quartz
lamp is OFF.
- On console, lower the windscreen (PANTALLA).
3.2 Opening Dome and Preparing Telescope
Control System (TCSS)
Before sunset you must do the following:
- Turn ON fans in adjacent room (turn ON switch and set reostat
near maximum value).
- Move telescope to HA 2:30 East to secure that nothing falls
on mirror while opening dome shutter.
- Push OBTURADOR on console to open shutter.
- Push PANTALLA on console to lower windscreen.
- Push ASENCION RECTA on console to turn ON tracking.
- In TCC-Guider PC, type 'DOME AUTO' to activate dome rotation.
- In TCC-Guider PC, type 'TP' to activate telescope pointing
model.
Note: this is not needed if already done; check
on the TCS screen if the TP flag is on.
- In TCC-Guider PC, input the values of ROFF and DOFF provided by
the observer that used RetroCam the previous time.
3.3 Sky Flats
- Go to the zenith by typing 'ZENITH' in TCC-Guider
PC or choose an empty field from the list sticked to the
console.
Beware that some of these fields are dark clouds in
the Milky Way which contain plenty of stars in the NIR.
- In Telescope Control window set dy = 10 (10 arcsec
steps).
- In RetroCam-Control window set:
- Exptime = 5
- Readmode = Double
- ObjType = tflat
- Filter = Hc
- Loops = 2
- Object = Skyflat (no space)
- Start a test exposure with Go. Repeat until you have gone down
below 20,000 ADU. Make sure that average counts are indeed
going dwon between subsequent integrations. If not, the chip is
saturating.
- Change Exptime = 5.
- Reset counter in Filename to first unused number you had before the
tests.
- Push Go to start the first flat.
- Push the N or S buttons in Telescope Control
window between exposures.
- Alternatively, you can do the offsets by running a dither macro:
In RetroCam-Control window press Dither and select
- Dither-Pattern = rot-5
- Dither-Step = 10
- Guiderp = none
You can change the exposure time while the telescope offsets between integrations.
- Take at least five (5) images.
- Change Filter to Yc and repeat the procedure above.
- Take at least 5 images with 8,000 to 20,000 ADU, and offsetting
the telescope between them.
- Finally, go to Filter = Jo and move the telescope 2 or 3
hours West.
- Try to get 5 images in Jo with high counts and few stars.
3.4 Telescope Zero-Point (CSET)
- Choose a bright star near the zenith from "The Astronomical Almanac."
- In TCC-Guider PC, set the current coordinate epoch, for example
typing 'MP 2007.5'.
- In TCC-Guider PC type in 'RA hh mm ss.s' and
'DEC dd mm ss.s',roff=0.0; doff=0.0
and then 'SLEW'.
- In RetroCam-Control window set:
- Exptime = 3
- Readmode = Double
- ObjType = test
- Filter = Yc
- Loops = 1
- Object = Test
- Take an image with Go.
- In the Display window click on the center of the bright
star.
- In the same window click on Center Telescope.
- In Telescope Control window click on the 0,0
button.
The telescope will now center the bright star.
- In TCC-Guider PC type 'CSET'., and change equinox from MP
2007.5 to 2000
- In Guider Control window move guider to center of the chip
by clicking on the MoveTo button in the second row, the one
labeled Center.
- Check that the star appears in the field of view of the guider.
- Focus the guider camera using the switch in the light blue rack.
- Move the guider camera back to park position by clicking on
Park in the Guider Control window.
- Reset the Filename counter in the RetroCam-Control
window to its original value before the pointing process.
3.5 Telescope Focus
- The focus value is set with the Focus buttons on the
console.
- Always end this process by increasing the focus
value.
- You can follow these approximate rules:
New J filter
Focus Y = 21.20 * ( T - 15 deg) aprox.
Focus J = Focus Y , 0.20 units more, e.g.= 22.40
Focus H = Focus Y
where T is an average of the T_Cell and T_inside
temperatures in Celsius as read from the weather station monitor.
- If these values are no satisfactory, choose a 10 mag star and
take a series of exposures with:
- Exptime = 10
- Filter = Yc
- Loops = 1
- ObjType = test
- Object = Test,
and modifying the focus value by 0.05 units between them.
- Display the images in csp4 and run imexamine and its
commands 'r' and 'e' to see the size and shape of point-like sources.
- You can trust Focus (J) = Focus (Y) and roughly the offset for H.
- Remember to reset the Filename counter in the
RetroCam-Control window once you are done with the focus tests.
3.6 Darks
Darks may be taken in the afternoon if the temperature is not much
higher than the expected one for the night.
Else, they should be taken
in the morning, or during the night in case no object can be observed.
Darks should be taken every night with each exposure
time used that night.
Therefore, you may need to add darks in the morning, once you know
which exposure times you have used.
Note that this includes all the exposure times
used for twilight flats.
- In TCC-Guider PC type in 'ZENITH' to point the telescope to the
zenith.
- In the RetroCam-Control window select:
- Readmode = Double
- ObjType = dark
- Filter = dk
- Loops = 15
- Object = Dark
- Set one of the required exposure times in ExpTime.
- Click Go to start taking the darks.
- Repeat with every required ExpTime.
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4. Observing
4.1 Supernovae
- Check the current list of targets and exposure times for RetroCam.
- Check the target RA order and priorities. Also look at the
finding charts and the airmass plot, if available.
- In the Object List window go to File and Load.
- Select the file csp.objects and click Open.
- The current list of SNe being followed is displayed.
- You can use the buttons to Add, Edit, or
Remove an object.
- Remember to save your changes or else
you'll lose them when you close the application.
- The Preview button shows the situation of the selected
target in the Airmass and the Skymap windows without
having to point the telescope to the object.
- The SendTo button has no effect here.
- In the TCC-Guider PC type 'MP 2000.0'.
- Select an SN and, in the TCC-Guider PC, type its 'RA hh mm
ss.s' and 'DEC dd mm ss.s'. Then type 'SLEW'.
- When the slew is complete, press the
Get button in the Telescope Control window in order to
have the right coordinates RA and DEC written in the image headers.
- To check the pointing, in the RetroCam-Control window set:
- Filter = Yc or Jo
- Exptime = 10
- Loop = 1
- ObjType = astro
- Object = SNYYYYaa (no spaces; YYYYaa is the IAUC or temporary
SN ID).
- Take a test image by clicking on Go.
- Check that the field is the one shown in the finding chart.
- Remember that the coordinates in NIR not
necessarily match those given in the yellow table.
- If you need to correct the pointing, use the dx and
dy offsets and the directions panel in the Telescope
Control window.
- The upper-left (NE) quadrant should be avoided because it
contains several dead spots.
- Also check that the SN and some of the field stars will end up having
decent counts and not saturating with the exposure time to be used.
- Reset the Filename counter to the value previous to the
test, and set Exptime, Loops, and Macro as
indicated in the target list of the night.
- To define the Macro, press Dither and select the
options of Dither-Step, Dither-Pattern, and
Guider. Make sure you select Guider =
auto.
- Set Readmode = Quadruple for filters Yc and Jo, and
Readmode = Double for filter Hc.
- Choose a suitable guide star and start guiding.
See instructions Section 4.3.
- Start a dither sequence by pressing Execute in the
RetroCam-Control window.
- Keep an eye on the guider screen and check that the guide star is
not lost (this may happen a couple of times in the night.) There is no alarm when this happens.
- When the sequence is done, you may need to offset the
telescope as indicated in the Beam Switch column of the target list. See
instructions on how to recover the same guide star in Section 4.3.
- Repeat this procedure with every requested filter.
- Keep in mind that each filter may require a
different dither macro.
- Also remember to apply the
focus offset when you change from/to Hc.
- Make use of the quick-processing scripts described in
Section 5 below to check the quality of the data
and perform quick photometry.
4.2 Standard Stars
- If the night is photometric, observe at least 3 or 4 Persson
Standard stars.
- In the Object List window go to File and Load.
- Select the file persson.objects and click Open.
- The list of Persson standards is displayed.
- Pick a star from this list
with J magnitude between 10.8 and 12.0.
- Make sure the standard stars you observe in one night cover a
wide airmass range between 1 and 2.5.
- In TCC-Guider PC type in the 'RA hh mm ss.s' and
'DEC dd mm ss.s' and then 'SLEW'.
- When the slew is complete, press the
Get button in the Telescope Control window in order to
have the right coordinates RA and DEC written in the image headers.
- In the RetroCam-Control window select:
- Exptime between 5 and 10
- Readmode = Double
- ObjType = standard
- Loops = 1
- Object = SJ#### (no space, #### is the number of the standard)
- Take a test exposure with Go and check the field and
exposure time.
- You may need to move the star off the quadrant divisions. If so,
in Telescope Control set dx and dy to something
like 50 and move diagonally in the chip.
- Avoid the upper-left (NE) quadrant. It
cointains spots of dead pixels.
- If the star is too bright, you may need to defocus slightly the
telescope so that it doesn't saturate.
- In the RetroCam-Control window select the macro by
clicking on the Dither button. Then select:
- Dither-Step = 15''
- Dither-Pattern = rot-5
- Guider = none
- No guiding is required.
- Launch a dither sequence by clicking on the Execute
button.
- Change filter and repeat the previous step until you have done Yc,
Jo and Hc.
- Remember to apply the focus offset
when changing to/from Hc.
4.3 Using the Guider
- Once you have gone to the SN field, you need to choose a guide
star.
- Go to the SkyMap window and select a star of mag between
10 and 12 in the guider field (a blue rectangle above the square chip
field.)
- Avoid the bottom region of the guider
field because this may cause vignetting on the chip.
- Double click on the star with the right-hand mouse button. This
will write offsets in the Guider Control window.
- Click on Move to move the guider to the selected star.
- You should in principle see the star in the Guider
screen. However, this is usually not the case. Move the guider
NW several times by
clicking on the corresponding button in the Guider Control
window.
- Once the star appears, place it in the upper part of the guider
screen.
- Check the guider camera focus and adjust it if necessary using
the switch on the light blue rack.
- In TCC-Guider PC press the Guider button to activate the
guider camera monitor.
- Move the guider box using the arrow keys and put it on the guide
star. You can select two "speed" modes for these movements by pressing
the Delete and
Insert keys.
- Check the count level mx in the guider camera monitor is
below 250 (saturation).
- With the star inside the box, press F3 in the TCC-Guider
PC to start guiding. Now you are ready for launching a dither macro.
- When the telescope is offset to a new position during the dither
sequence the guiding won't
be stopped. There will be a delay of 4 seconds before the start of the
next integration while the guider camera will try to follow the
telescope and bring the guide star back in the guider box
automatically. This is successful in more than 95% of the cases, and
you won't have to touch anything.
- If the guider fails to find the star instead, you can do the following:
- pause the integration by clicking on Pause in the
Telescope Control window until the star enters the box on its own.
- place the star in the box either by moving the camera using the
Keypad
in the Guider Control window in csp5, or by
moving the box using the arrows in the TCC-Guider PC keyboard.
- If the object is close to the pole (DEC < -80 deg), you will
have to pause almost after every integration.
- When you have to do a Beam Switch on an object, you can
recover the same guide star you have been using by moving the guider
according to the telescope movement. This way you won't need to stop
guiding.
- If, for instance, you did a telescope offset of dy = 180
arcsec to the N, in the Guider Control window enter
Xoff = 0
and Yoff = -180, and click on
Move right after you move the telescope. This will move the
guider roughly back to the guide star. You will need to move slightly
the guider box to place the star inside it.
- Before you move the telescope to a new object you will have to
stop guiding by pressing F1 in the TCC-Guider PC.
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5. Quick-Processing IRAF Scripts
- A series of IRAF scripts are available in csp4 to help the observations.
- The scripts are loaded automatically when you start IRAF. The
task definitions are given in the 'loginuser.cl' file in ~/iraf/.
- The script files themselves sit in ~/iraf/retro_quick/.
- The following tasks are available:
- dis:
Displays an image without having to type in the whole name.
Usage: cl> dis num loo
where 'num' is the frame number, and loo is the loop number.
- disi:
The same as above but it starts imexamine.
Usage: cl> disi num loo
- dp:
Displays the difference between two "_001" frames.
Usage: cl> dp num1 num2
where 'num1' and 'num2' are the frame numbers of the images to be
subtracted.
- pdiffi:
Displays the difference between any loop of two frames and starts
imexamine.
Usage: cl> pdiffi num1 num2
by default, it subtracts loops "_001" of both frames.
You can edit the optional parameters 'l1' and 'l2' to use other
loops.
- avgo:
Displays the difference of two frames after averaging all the
loops in each one.
Usage: cl> avgo num1
num2
You can modify the optional parameter 'scl' to change the scaling
factor to be applied before subtraction --- scl = "mode" is the
default.
- sky_stats:
Shows the median and mean sky level for a range of frames. Useful
to check flats.
Usage: cl> sky_stats num1
num2
where 'num1' and 'num2' give the range of frames to analyze.
- p_fid:
Mark a fiducial star used to align dithered images.
Usage: cl> p_fid r
num1 num2 aut/man
where 'num1' and 'num2' give the range of frames in a
sequence. Options 'aut' or 'man' allow to make the program select
a star, or the user to mark it. The task will write the star
position in the headers of frame num1.
- p_fx_asecs:
Correct the RA and DEC offsets between frames that are written in
the header keywords ASECS and DSECS.
Usage: cl> p_fx_asecs r
num1 num2
where 'num1' and 'num2' give the range of frames in a dither
sequence. The user will be prompted to mark the same star in all
frames (after averaging the loops). r_quick will usually fail if
this is not done in advance.
- p_mimdel:
Delete a range of frames of some kind.
Usage: cl> p_mimdel pre
num1 num2
where 'pre' is a frame prefix ('icr' for loop-combined, 'isx'
for sky-subtracted, etc.), and 'num1' and 'num2' give the range
of frames in a dither sequence. Since p_fx_asecs fixes the
headers of 'irr' frames only, you will need to delete the 'icr'
frames before running r_quick, in order to get the right
offsets.
- r_quick:
Produce a quick and dirty stack of a range of frames.
Usage: cl> r_quick num1
num2
It produces a sky by averaging the frames. It asks the user to
mark a few stars with 'a' in imexamine. It may fail if the
dither steps are too large (>30''), or if the guider star got lost.
- To make a fast combination of a dither sequence:
For example, a sequence of frames 10 to 18.
- p_fid r 10 18 aut
- p_fx_asecs r 10 18
- p_mimdel icr 10 18
- r_quick 10 18
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6. Copying Data to a CSP Machine
- At the end of the night, tranfer the data from csp4 to
csp3.
- Open a terminal window in csp4.
- Go to the directory with the data of the night, e.g.:
> cd /data/20050906_07
- Do a secure copy to csp3 giving your user name in that
computer, e.g:
> scp -r ../20050906_07 username@csp3:/data/ir
- You will be asked for your password in csp3.
- The link should be fast enough to copy more than 100 MB per minute.
- While the secure copy runs, you can proceed to the next item.
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7. Closing the Telescope
- Turn OFF power of guiding camera in lightblue rack.
- Move telescope to HA 2:30 East to secure that nothing falls
on mirror while closing dome shutter.
- Push OBTURADOR on console to close shutter.
- Push PANTALLA on console to raise windscreen.
- Push ASENCION RECTA on console to turn OFF tracking.
- In TCC-Guider PC, type 'DOME IDLE' to de-activate dome rotation.
- In TCC-Guider PC, type 'DOME PARK' to park dome to the south.
- In TCC-Guider PC, type 'COVER' (telescope will slew south).
- Go to the platform, raise platform, and put on the telescope cover.
- Lower platform.
- Turn OFF fans in adjacent room (turn OFF switch and set
reostat to zero).
- In TCC-Guider PC, type 'ZENITH' (telescope will slew to the zenith).
- Turn Power OFF on console.
- Turn console OFF (rotate key).
- Turn OFF monitors in control room.
- Fill out Night Reports and SN Logs (see below)
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8. Before You Go to Bed
8.1 Fill in Night Report and SN Logs
- Fill in the LCO Night
Report.
- Add a line requesting the staff to switch to the
CCD camera, if applicable.
- To make sure the request is heard, stick a note on the
telescope console directed to the daytime technicians so that they see
it in the morning.
- Fill in the CSP
Night Report. (User name and password required. If you are not a
CSP member, please be so kind to send an e-mail to Gastón
Folatelli, gfolatelli@lco.cl, instead.)
- In the "Night time report" field, inform about objects observed
and calibrations taken. Give details about weather conditions and
describe technical problems, if any.
- Fill in the CSP SN Log of the night. (User name and password
required.)
- This form allows you to input all the SNe of the night at
once in a comma-separated list.
- The SN names can be introduced in a variety of formats. The
program then completes the names in the standard form.
- In the Filters field you can input a generic 'YJH'.
- Click on Submit and an editable list will appear.
- Modify the fields according to what you observed in the night.
- In particular, check the Filters and Weather fields
because these may change from SN to SN.
- The rest of the fields will generally have the same information
for all the SNe.
- Click on Submit to send the logs to the database.
8.2 Burn two DVDs
- To burn the data to DVD you have three alternatives:
1- Use growisofs in csp4 (Linux).
- Follow these instructions by David Murphy.
- Put only the irr_*.fits in a subdirectory. E.g.:
> mkdir todvd
> mv irr_*.fits todvd/
- Check the size is less than 4.3 Gb:
> du -h todvd
- In the unlikely case that the data are more than this value,
separate them in two directories and burn two DVDs.
- Burn:
> growisofs -Z /dev/cdrom -R -J -apple todvd
- Do not run heavy processes (e.g., image processing) while
burning. Other light processes like mozilla, editors, etc are not a problem.
- Burning takes about 15 min for a whole DVD (4.3 Gb), at
speed=4x.
- When done, the DVD is ejected and loaded again.
- Take the DVD from the drive by pushing the eject button.
2- Use RecordNow DX in csp5 (Windows).
- Close all other applications. (Yes, do you like Windows...?)
- Double click on the RecordNowDX icon on the desktop.
- Choose the option Make a Data Disc.
- In the following window click Next.
- Click Add Files and Folders.
- Click the drop down arrow in Look in.
- Select data on 'Linux Samba Server ...'.
- Select only the irr_*.fits files with drag and drop.
- Check the total size of the stuff to be burnt is less than 4.3 Gb.
- In the unlikely case that the data are more than this value,
leave some files to a second DVD.
- Click Next. You'll be warned not to run other
applications. Click ok.
- The DVD burning will start right away!
- Don't run other processes while burning.
- This program by default verifies the written data after
burning. This is a nice feature but it takes twice the time.
- When done, the DVD will be ejected.
3- Use K3b in csp4 (Linux):
- Open K3b either from a terminal:
> k3b &
or by clicking on the icon at the task bar.
- Select the option Create Data DVD Project.
- In the upper half of the window select the files to be burnt. Use
the left-hand mouse button in combination with the Shift and Ctrl keys.
- Select irr_*.fits files and drop them in the lower half of
the window.
- Check the total size of the stuff to be burnt is lees than 4.3 Gb.
- In the unlikely case that the data are more than this value,
leave some files to a second DVD.
- Click on Burn.
- Under the Writing tab, select:
- Speed = 2x
- On the fly
- Verify written data
- At the Volume Desc tab you may input a Volume name for the
DVD (e.g.: '20050906_07 - RAW'.)
- Under the Filesystem tab, select:
- Generate Rock Ridge extensions
- Generate Joliet extensions
- Click the Burn button to start recording.
- After the data are written and verifed the DVD will be ejected.
- Label both DVDs with:
C40'' + RetroCam
Raw data
Observer's name
Directory name (e.g. "20050914_15/")
Total size
Copy number (1 or 2)
DVD number, if there is more than one for the night.
- Put the DVDs in plastic cases and send one of them to
Gastón at El Pino along with the log sheets.
- Keep the other DVD in Nidia's office at the ASB.
- Plastic cases can be found in Nidia's office.
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9. Linearity Tests (Only for Cloudy Nights)
- Wait until it is dark outside and close the dome.
- Turn OFF the incandescent dome lights from the console.
- In TCC-Guider PC, type 'DOMEFLAT' to point the telescope to
the white screen.
- In RetroCam-Control window set:
- Filter = Yc
- Readmode = Double
- ObjType = dflat
- Loops = 1
- Object = Linearity
- Turn ON the quartz light from the grey box over light blue rack and
adjust voltage so that you get 2000 ADU in 10 s (550 V should be OK).
- Take the following series of exposures, changing
ExpTime each time to the values below, and pressing
Go.
ExpTime values: 10, 3, 10, 7, 10, 15, 10, 20, 10, 30, 10, 45,
10, 60, 10, 75, 10, 90, 10, 105, 10, 120, 10, 135, 10, 150, 10, 165,
10, 180, 10, 195, 10, 210, 10, 225, 10, 240, 10, 255, 10.
- You must reach about 48,000 ADU in 255 s.
- Turn the quartz light OFF and take Darks at each Exptime
above, using Loops = 1.
In RetroCam-Control window set:
- Filter = dk
- Readmode = Quadruple
- ObjType = dark
- Loops = 1
- Object = Dark
- Only ONE dark at 10s is needed.