Figure 7. XTEND Workflow: Microscope DOF and in-focus z-range estimation are used to calculate number of focal series projections and z-step.

For 3 focal series projections, images are acquired at z-positions −L, 0 and +L. Image projections are normalized using flatfield images. Focal series projections −L and +L are aligned to reference 0-shift at each tilt angle and combined by averaging. Averaged projections stack is deconvolved by synthetic ATF-XTEND considering z-range and the SNR from projections and flatfields. Once deconvolved, the XTEND projections are then aligned to the common tilt axis and reconstructed using standard algorithms.