No question, everything being perfect a 1.5” will give the best results!
Everything being perfect, a 1.5” lens can easily achieve 500dpi:
Perfectly flat part
Perfectly level bed
Perfect beam alignment
Perfect distance set to the exact smallest focal point.
If 200dpi is the end goal because you know the piece can’t sit flat or isn’t flat, a 1.5” fl may not be the best choice.
It is important to know a 2” lens can easily achieve 400dpi, and a 4” can easily achieve 300dpi - Again, everything being perfect.
Because of the slower beam convergence, the 100dpi spot size is longer on a 4”fl than a 2” fl.
Engraving a curved flask you will get better results with a 4”fl -vs- a 2”fl because of the longer focal point.
Please check out our beam alignment tool and consider using the highest quality optics manufactured at American Photonics.
By Natalia Pereira
