for the intro

[mtewes]

terminology: add skyflat / domeflat

add filters, broad bands

review text of pre-reduction: there are instrumental effects we want to remove, for example: dark current unevel illumination bias level ... and there are callibration frames: images aquired with camera in different conditions called dark, bias...

The key to understand pre-reduction steps is to not confuse the "frame" and the "effect": The dark frame is called dark frame because it is taken to caracterize the dark level, but of course it also of course also contains the bias! The flat frame is taken to , but it also has dark current and bias level!

[mtewes]

where to take sky flats

[mtewes]

Tip: Displaying images

usefullness of a figure showing an image varies greatly with the mapping. A dark frame that appears completely black does not tell anything. Select the cuts appropriately (no need min max, it's ok to clip values),

[mtewes]

pre-red corrections are small: while there is a standard procedure to follow, always be aware if the effect you're trying to correct for is significant at all. correctign for a badly done flat field might well be much worse that not correcting at all.

Improve defs: what is a light curve

what is the background how to subtract it

[mtewes]

Update telescope schema, add lens group, filter wheel, camera with sensor.