I'd like that feature also. From what i've seen it can't be done currently. The only way to prevent overexposure/blown highlights is thru the use of the histogram. Maybe sigma can address this in a firmware update. I emailed sigma with a request that this be done in the next firmware update. If everyone with a merrill requested it perhaps they would do it.
Last edited by ivoire; June 18th, 2013 at 12:31 AM.
EP5, Panasonic 14mm, 45-175mm; Olympus 45mm; Sigma 30mm, Meyer Optik 100mm; Helios 44-2 58mm: E620, Oly 14-42mm, Sigma 10-20mm: Fuji F10 converted to IR, Samsung TL350, Sigma DP2 Merrill, Sony RX1