  Selective plane illumination microscopy (SPIM) is an optical sectioning
imaging approach based on orthogonal light pathways for excitation and
detection. The excitation pathway has an inverse relation between the optical
sectioning strength and the effective field of view (FOV). Multiple approaches
exist to extend the effective FOV, and here we focus on remote focusing to
axially scan the light sheet, synchronized with a CMOS camera's rolling
shutter. A typical axially scanned SPIM configuration for imaging large samples
utilizes a tunable optic for remote focusing, paired with air objectives
focused into higher refractive index media. To quantitatively explore the
effect of remote focus choices and sample space refractive index mismatch on
light sheet intensity distributions, we developed a computational model
integrating ray tracing and field propagation. We validate our model's
performance against experimental light sheet profiles for various SPIM
configurations. Our findings indicate that optimizing the position of the
sample chamber relative to the excitation optics can enhance image quality by
balancing aberrations induced by refractive index mismatch. We validate this
prediction using a homebuilt, large sample axially scanned SPIM configuration
and calibration samples.
