Cooling Basler camera

To examine the effect of heating up a Basler acA640-100gm on image dark current noise during imaging, I conducted an experiment where I took multiple longer (~2 min) films (conditions: dark room, cap on, constant ambient temperature) with different frame exposure lengths and observed mean image pixel value at the beginning and end of the test. Frame exposure lengths and film durations are approximately equal to the ones used in planetary imaging with this camera and not suitable for DSO imaging.

Image exposure length With cooler – mean pixel value Without cooler – mean pixel value
At the beginning of the test 10 ms 17.8 17.5
50 ms 18.1 18.3
500 ms 26.7 26.0
1000 ms = 1 s 44.7 40.1
In the end of the test, after ~2 min when the casing temperature was constant 10 ms 18.1 18.5
50 ms 18.7 19.4
500 ms 32.5 42.4
1000 ms = 1 s 60.6 96.1
Basler camera with attached DIY aluminium cooler (without any fan), salvaged from an older CPU.

The following graphs show, the change of camera casing temperature over time in comparison to the constant ambient temperature. From the plots it is observable that majority of heat up occurs in the first 30 sec of imaging and remains almost constant after that.

Working temperature plot with attached cooler.

Working temperature plot without attached cooler.

Sun filaments on 30 March 2014

Some of the filaments visible on the surface of the Sun on this day.

Object: Sun filaments
Date: 30 March 2014 10:44 UT
Equipment: Basler acA640-100gm, Lunt 60 mm + 2xBarlow
Capture and processing : FireCapture, AutoStakkert2
Object: Sun filaments
Date: 30 March 2014 10:31 UT
Equipment: Basler acA640-100gm, Lunt 60 mm + 2xBarlow
Capture and processing : FireCapture, AutoStakkert2

More images in gallery.

Sunspot AR1944

A few days ago, on New Year’s Day, a sunspot appeared over the western edge of the Sun. AR1944 is huge and actually consist of more than 50 individual sunspots, the largest of them is far larger than the Earth itself. It was possible to observe it using only unaided eye and proper solar filter (e.g. eclipse glasses).

It has been classified as having a beta-gamma-delta magnetic field and these fields are prone to instability that can produce X-class solar flares. During the rotation around the visible limb of the Sun it was quiet and produced only one major X1 flare.

Object: Sunspot AR1944 and AR1946 in the upper right corner
Date: 12 January 2014 12:40 UT
Equipment: Basler acA640-100gm, GSO 200/1200
Capture and processing : FireCapture, RegiStax6

During imaging the seeing was very poor and was even more obvious while imaging at higher focal ratios.

Object: Sunspot AR1944
Date: 12 January 2014 12:55 UT
Equipment: Basler acA640-100gm, GSO 200/1200 + 2xBarlow
Capture and processing : FireCapture, AutoStakkert2, RegiStax6

This giant spot is about to rotate off the face of the Sun, this was probably my first and last shot of it. But this is not the only obvious sunspot currently visible on the Sun. I managed to capture a few other.

Object: Sunspot AR1949(left) and AR1953(right)
Date: 12 January 2014 12:45 UT
Equipment: Basler acA640-100gm, GSO 200/1200
Capture and processing : FireCapture, AutoStakkert2, RegiStax6

Object: Sunspot AR1949
Date: 12 January 2014 12:55 UT
Equipment: Basler acA640-100gm, GSO 200/1200 + 2xBarlow
Capture and processing : FireCapture, AutoStakkert2, RegiStax6