Table 2: Kernel parameters for both the V and R bands.
V band R band

Kernel size $27 \times 27$ pixels $27 \times 27$ pixels

Number of Gaussians 3 3

Respective sigmas of the Gaussians 1.2, 2.8, 5.2 pixels 1.1, 2.8, 5.4 pixels

Degree of the 2D apodization polynomials 4, 4, 4 6, 3, 2

Degree of the 2D polynomial enabling space-variation of kernel model's coefficients 1 1

Degree of the 2D polynomial describing the space variations of the sky background 1 1

Number of stamps selected in the images for the kernel fit $3 \times 3$ $3 \times 3$

Stamp size $45 \times 45$ pixels $45 \times 45$ pixels

**Table 2:** Kernel parameters for both the V and R bands.
	V band	R band
Kernel size	$27 \times 27$ pixels	$27 \times 27$ pixels
Number of Gaussians	3	3
Respective sigmas of the Gaussians	1.2, 2.8, 5.2 pixels	1.1, 2.8, 5.4 pixels
Degree of the 2D apodization polynomials	4, 4, 4	6, 3, 2
Degree of the 2D polynomial enabling space-variation of kernel model's coefficients	1	1
Degree of the 2D polynomial describing the space variations of the sky background	1	1
Number of stamps selected in the images for the kernel fit	$3 \times 3$	$3 \times 3$
Stamp size	$45 \times 45$ pixels	$45 \times 45$ pixels

Source LaTeX | All tables | In the text

	1 Introduction
	2 Observations
	3 Differential photometry by optimal image subtraction
	4 Magnitude zero-points: Towards absolute photometry
	5 Realistic error bars from simulation of CCD frames
	6 Photometric results
	7 Discussion
	References