FLATS for the CORONADO PST

Example of why flat is needed !

I use an extremely powerful led torche, a semi-transparent PVC plate and some tubing so that illumination covers all of the PST lens ... See bottom for another idea ...

No change in focus has been done, same as in captures !

Exanple of real flat done in RegiStax (16bit PNG) result from a SER files of 7 frames that is 120s total exposure (see data way below)

How to make / use the flat :

In Registax load the flat SER file (AVI Ok only if you worked in 8 bit for acquisitions) and create flat field

When done save it

Then load SER (AVI) file to align then load Flatfield

Proceed as usual ...

Below a real flat PNG used.

FireCapture v2.4 beta Settings
------------------------------------
Camera=ZWO ASI120MM-S
Duration=132.880s
Frames captured=7
File type=SER
Binning=no
ROI=1280x960
Shutter=20.0s
Gain=30
SoftwareGain=10 (off)
Gamma=50
Brightness=16
Limit=120 Seconds
Sensor temperature=13.2 °C

After this successful attempt and for a much much cheaper realisation based on the same principal here is another new idea that could work (not tested yet !).

The rather concentrated Sun light is shined onto a piece of a large translucent ceramic knife which now acts as an heat-resistant dazzling light source.
Some tubing which length has to be determined by experience permits a nice homogeneous light covering of the PST lens ... It- would fit either inside or outside of the PST.

The use of glued PVC tubing could be enough to accomplish this setup.
If not enough flux, ceramic could be replaced by a sheet of 4-6 mm semi-transparent glass.

Be sure to take all the necessary precautions to avoid any kind of burns to you or others !