Wednesday, June 6, 2018

A Clear Look at Focus Lenses for Laser Cutters

Focus Lens 1-1

Although your Muse or Pro-Series laser cutter came with a focus lens that is perfect for most projects, there are a variety of lenses available for your cutting and 3D engraving needs. Each lens specializes in a different cutting thickness or level of engraving detail. So let’s take a look at what each lens is made for and how they work.

Lens Size Comparisons

Each lens is listed by “inches” which is not an indication of the lenses’ physical size, but rather the focus distance from the material. For example, the 2.5” lens focuses 2.5 inches from the material. This means, all the lenses are actually the same size and fit into the same slot on your laser cutter. The difference is in the concave of the lens, itself. Creating a different spot sized on the material. This creates different results and capabilities of the lens. Full Spectrum Laser has four different lenses available for the Hobby and Pro Series machines: 1.5”, 2”, 2.5” and 5”.

1.5” Focus Lens

If you are requiring extra fine engraving such as fonts below 6pts, we recommend the 1.5” lens. This is a short focus lens has a smaller minimum spot size but spreads out more quickly after reaching the focus making them better for fine detail but not good for thick cutting. Best used for fine detail engraving and thin lines.

Uses: Fine Engraving for fonts as small as 6pt.

Spot size: 0.003”Tiny Fonts2” Focus Lens

Included with Muse, the 2” lens has a good combination of fine engraving and thin cutting. The short focus lens has a small minimum spot size but spreads out more quickly after reaching the focus, making them better for fine detail but not great for thick cutting.

Uses: All around lens for engraving and cutting up to .25” material.

Spot size: 0.004”

Completed Full Spectrum Raster Engraving Muse


2.5” Focus Lens

Full Spectrum Laser’s Pro-Series comes standard with a 2.5” lens which is good for cutting up to .5” of material and engraving detail to around 8pt fonts with a 90w tube.

Uses: All around lens for engraving and cutting up to .50” material (with a 90+ watt laser tube).

Spot size: 0.005”

Ukelele Neck Ebook 1-1

5” Focus Lens

A long focus lens keeps the focus longer allowing for straighter edges but does not focus down to as small a minimum spot. This optic is appropriate for cutting thick foam. The 5” lens has a large spot size, when focused, which prevents it from being ideal for cutting wood and acrylic. it is also a good lens for engraving into deep bowls, where you need more working space.

Uses: Long lens for engraving from a distance for irregular objects or for cutting thick, non dense foam.

Spot Size: 0.01”

Bowl engraved with 5 inch lens

If you enjoyed this blog, be sure explore our other Laser 101 related offerings such as our ebooks, video tutorials and our weekly live shows, all free to Full Spectrum Laser owners and operators.