We have modeled propagation of source signal and noise for a future camera of TAIGA-IACT Cherenkov gamma-ray telescope, which will be based on silicon photomultipliers sensitive in the 240 -- 600 nm range. It has been shown that employment of such detectors instead of traditional vacuum photomultipliers will allow one to decrease the energy threshold by a factor of about 2.5: from ~ 1.5 TeV down to ~ 0.6 TeV. We have also shown that application of a standard ultraviolet filter ZWB3 will decrease the source signal by a factor of 3, while the noise signal from the night sky will be decreased by a factor of 6. In this way the duty cycle of the telescope can be extended (the telescope will be able to operate during moonlit nights and during twilight) and the energy threshold further decreased down to ~ 0.3 TeV. A narrow 260 -- 300 nm filter can be employed to improve gamma-hadron separation of primary cosmic particles in the ~ 25 -- 50 TeV band.

Full-particle modeling of gamma-ray and proton induced extensive air showers (EASs) in the Earth's atmosphere as well as Monte Carlo modeling of photon transport in a small size Cherenkov telescope and signal registration with its camera based on the OnSemi MicroFJ SiPM detectors have been performed. Calculations have been carried out for primaries within the 0.3 - 30 TeV range and a telescope with a 10 m(2) mirror similar to the unit employed at the TAIGA observatory. It has been shown that even with strict selection criteria aimed at high quality EAS images, the threshold detection energy of the SiPM-based camera would not exceed 0.8 TeV - about twice as low as the current threshold of the TAIGA-IACT camera based on vacuum photomultipliers.