The　effects　of　scattering　noise　on　input　images　for　holographic　storage　in　photorefractive　lithium　niobate　crystals　have　been　investigated　in　detail　by　means　of　measurements　of　loss　of　signal-to-noise　ratio　(LSNR).　A　variety　of　lithium　niobate　crystal　samples　with　different　dopants,　different　doping　concentrations　different　annealing　after　growth,　and　used　for　different　recording　geometries　are　studied.　More　attention　has　been　paid　to　the　characteristics　of　scattering　noise　resulting　from　object　beams.　The　experimental　results　show　that　the　effect　of　scattering　noise　in　oxidized　crystals　is　less　significant　than　that　in　reduced　or　as-grown　crystals.　Comparing　with　transmission　and　90°C　recording　geometries,　reflection　geometry　is　less　subject　to　the　effect　of　scattering　noise.