MDF is probably your biggest issue. I can see from the images that it tried to burn in grey scale. Basically with MDF you get untouched or black as coal, with little in between. If you still aren’t happy with the results on other wood I got the lens off ebay. It’s cheap but coming from China it took 25 days to get stateside for me so you may wait a while. This is the one I got and the credit for this gem goes to @picengravertoo