When performing flat-field correction, what is the primary reason for normalizing the master flat frame before applying it to science images?
Question 2
What is the key difference between bias correction and dark correction in astronomical data reduction?
Question 3
If the uncertainty in a raw science image pixel is $\sigma_{raw}$ and the uncertainty in the master bias frame pixel is $\sigma_{bias}$, what is the uncertainty in the bias-subtracted image pixel, $\sigma_{bias-sub}$?
Question 4
Which of the following scenarios would most likely lead to an inaccurate flat-field correction?
Question 5
In the context of error propagation, if a corrected science image $S_{corr}$ is derived from a raw science image $S_{raw}$, a master bias $B$, a master dark $D$, and a master flat $F$ using the formula $S_{corr} = \frac{S_{raw} - B - D}{F}$, which of the following statements about the uncertainty in $S_{corr}$ is true?
