Sony A350 has a
14.0MP APS-C (23.6 x 15.8 mm ) sized CCD sensor . On the other hand, Fujifilm X100S has a
16.0MP APS-C (23.6 x 15.8 mm ) sized CMOS X-TRANS II sensor and features EXR II processor.
One other difference between these two cameras that is worth mentioning is that Fujifilm X100S's sensor doesn't have an anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the A350 and X100S sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A350 and Fujifilm X100S Cameras
Sony A350 and Fujifilm X100S have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Sony A350 has 13% larger pixel area compared to Fujifilm X100S, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Sony A350
or the
Fujifilm X100S ,
including hyperfocal distance.
