Optoacoustic microscopy (OAM) is a hybrid imaging method that can achieve high spatial resolution at superficial depths through use of focused illumination; it can be adapted for imaging with ultrasonic resolution at much greater depths where the excitation light is diffuse. These two distinct modes of operation can be further combined to create a highly scalable technique that can image at multiple penetration scales by gradually exchanging microscopic optical resolution in superficial tissue layers with ultrasonic resolution at diffuse (macroscopic) depths. However, OAM commonly employs scanning acquisition geometries that impede the effective use of synthetic aperture focusing techniques due to varying illumination patterns and non-uniformity of the excitation light field. Here we present a universal framework for scanning optoacoustic microscopy that uses a weighted synthetic aperture focusing technique (W-SAFT) to create a uniform imaging sensitivity across microscopic, mesoscopic, and macroscopic penetration regimes. Robust performance of the new multi-scale reconstruction methodology is showcased with simulations and synthetic phantoms, and validated with experimental data acquired from a highly scattering juvenile zebrafish specimen. It is shown that consideration of the light fluence is vital for maintaining the optically dictated lateral resolution at ballistic depths while optimizing the resolution of out-of-focus ultrasonic data; additionally, the dynamic-range compression facilitates the visualization across the entire imaged volume. The newly introduced W-SAFT reconstruction framework is universally applicable to a wide palette of scanning-based optoacoustic imaging techniques employing non-uniform and/or varying illumination, such as acoustic resolution and hybrid focus microscopy, raster-scan optoacoustic mesoscopy, as well as tomographic approaches using scanning of focused array transducers.