Earthshine blog

Earthshine blog

"Earthshine blog"

A blog about a system to determine terrestrial albedo by earthshine observations. Feasible thanks to sheer determination.

Shutter/FW failure - 2456693.2

Observing logPosted by Peter Thejll Feb 04, 2014 04:31PM
Testing the system on a lamp-illuminated flat field. With a script, sequences of images are taken with commands to change filters. Kinetic sequences.

There is obviously some problem with either the shutter or the setting of the FW, because while some images are well exposed at more or less recognizable exposure times (we use a different lamp from the hohlraum we had on MLO) some are simply almost all black at those same exposure times.

To test if it is the shutter that is failing to open, or the FW that does not set, we must eliminate one thing at the time - first let us run a script with exposure times of varying lengths, and simply listen for how long the shutter is open.

If it seems the shutter is always open as long as we ask it to be, we move on to the FW - perhaps we can open the telescope box and simply look at whether it turns (pant a white spot on the side!).

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