Last week I converted several hundred slides to tiff. Some of the slides were from my grandfathers and were glass too thick for the holders so I put them on the bottom slide and after adjusting the position it worked fine. So far I haven't had any problems other than not being able to figure out how to use the USB cable to transfer photos directly to my computer. Using an SD card works, just a few more steps in the process. I have no problems with the device.