Two Lens Options<\/h3>\n\n- High Efficiency Lens (Lens_HF)<\/a>. \u00a0This is the standard lens shipped on our kits. \u00a0It works very well, especially on the 2.8W laser for doing most engraving and cutting projects. \u00a0It will output a more rectangle beam profile with minimal loss of power.<\/li>\n
- High Resolution Lens (Lens_HR)<\/a>. \u00a0This is our newer lens offering. \u00a0It will “round” the beam profile by slightly reducing the long axis and slightly increasing the short axis of the laser beam profile. \u00a0In cases where you need a more round profile, this lens is a great option. \u00a0It works especially well on the 3.8W laser because the spot size is larger.<\/li>\n<\/ol>\n
In the case of the the lasers at 2.8W or below, the long axis of the laser is not as pronounced compared to the short axis. \u00a0This means that the benefits of the High Resolution Lens might not be needed in most cases. \u00a0However, in the case of the 4.2W (3.8W) or 7W laser we see the long axis is considerably larger than the short axis causing the more “rectangle” profile of the beam which can be visible in engravings.<\/p>\n
Here is a comparison of the two beam profiles using a 4.2W(3.8W)or 7W laser as an example:<\/p>\n
![\"Lens](\"https:\/\/jtechphotonics.com\/wp-content\/uploads\/2017\/05\/Lens-Comparison-2.jpg\")
<\/a><\/p>\nNotice how the lens transforms the laser beam profile in both axis to make a more symmetrical more “round” beam profile.<\/p>\n
Typical Spot Sizes<\/h3>\n
Here is a list of the different lasers with both lenses for typical spot sizes when engraving in wood.<\/p>\n
Standard High Efficiency Lens:<\/p>\n
\n- 1W 405nm: \u00a00.004\u2033 (0.1mm)<\/li>\n
- 2W 445nm: 0.006\u2033 (0.15mm)<\/li>\n
- 2.8W 445nm: 0.007\u2033 (0.18mm)<\/li>\n
- 3.8W 445nm: 0.011\u2033 (0.28mm)<\/li>\n
- 4.2W 445nm: 0.011\u2033\u00a0(0.28mm)<\/li>\n
- 7W 445nm: 0.011\u2033 (0.28mm)<\/li>\n<\/ul>\n
High Resolution Lens Option:<\/p>\n
\n- 1W 405nm: \u00a00.004\u2033 (0.1mm)<\/li>\n
- 2W 445nm: 0.0055\u2033 (0.14mm)<\/li>\n
- 2.8W 445nm: 0.0065\u2033 (0.165mm)<\/li>\n
- 3.8W 445nm: 0.0075\u2033 (0.19mm)<\/li>\n
- 4.2W 445nm: 0.0075\u2033 (0.19mm)<\/li>\n
- 7W 445nm: 0.0075\u2033 (0.19mm)<\/li>\n<\/ul>\n
Beam Profiles Burnt in Paper<\/h3>\n
We did a series of tests in paper to see the difference when the laser interacts with material by processing it. \u00a0This can give you a good idea on how the laser will actually burn. \u00a0We did a quick shot with the laser and then took the results under the microscope. \u00a0Note, the timing of the burn was not exact, so the profile might not be the correct size (it might be larger because the paper burned more). \u00a0This test is supposed to give just an idea of what your beam might look like.<\/p>\n
2.8W Laser\u00a0Burn Test Lens Comparison<\/h4>\n
With the 2.8W laser, the beam profile is so small that both lenses will make an almost round burn profile. \u00a0Note the only different is the hole in the paper. \u00a0One is a rectangle and the other is more of a circle.<\/p>\n
![\"2_8W](\"https:\/\/jtechphotonics.com\/wp-content\/uploads\/2017\/05\/2_8W-Lens-Comparison-Burn-Test-J-Tech-Photonics-1024x768.jpg\")
<\/a><\/p>\n3.8W Laser\u00a0Burn Test Lens Comparison<\/h4>\n
With the 3.8W (4.2W) laser you can now see that the High Resolution Lens has a distinct benefit. \u00a0The burn pattern is much more round and the the hole created is a lot more round as well.<\/p>\n
![\"3_8W](\"https:\/\/jtechphotonics.com\/wp-content\/uploads\/2017\/05\/3_8W-Lens-Comparison-Burn-Test-J-Tech-Photonics.jpg\")
<\/a><\/p>\nEngraving Fonts in Birch<\/h3>\n
Now that we have seen the beam profiles in burn paper, lets actually engrave on wood. \u00a0Using the Inkscape Plugin<\/a>, we created a font file using the Arial font. \u00a0The output g code file will engrave both the inside and the outside of the letter. \u00a0So, if you want to get even better resolution at the small font sizes (under 5 point) it might be better to just to one line for the letter. \u00a0Other programs like Vectric <\/a>will allow for this type of engraving. \u00a0We just opted for using the\u00a0Inkscape Plugin<\/a> for this test.<\/p>\n2.8W Laser Font Comparison<\/h4>\n
Since the 2.8W laser already has a very fine beam profile, you can see the High Resolution Lens does not have a considerable benefit when engraving. \u00a0You can tell there is power loss with the High Resolution Lens because it does not burn completely running at the same feedrate.<\/p>\n
![\"2_8W](\"https:\/\/jtechphotonics.com\/wp-content\/uploads\/2017\/05\/2_8W-J-Tech-Laser-Font-Testing-2-1024x656.jpg\")
<\/a><\/p>\n3.8W Laser Font Comparison<\/h4>\n
On the 3.8W laser the benefit of the High Resolution lens is noticeable. \u00a0The lines are a bit smaller, so the fonts are more crisp, especially when they get below 10 point.<\/p>\n
![\"3_8W](\"https:\/\/jtechphotonics.com\/wp-content\/uploads\/2017\/05\/3_8W-J-Tech-Laser-Font-Testing-1024x632.jpg\")
<\/a><\/p>\n3.8W Cutting Example<\/h3>\n
When cutting different materials that are a bit less dense, the High Resolution Lens might be a benefit for the 3.8W laser. \u00a0Depending on which way you have the beam profile aligned with the 3.8W laser and the High Efficiency Lens, you can have difficulty cutting thin lines and even lines in every direction. \u00a0This is seen in the next example test when cutting a popular foam product, 1\/2″ Fomular<\/a>. \u00a0These lasers can cut through this like butter, but sometimes it is difficult to get the speed, power, and also the orientation for the 3.8W laser with the High Efficiency Lens.<\/p>\nIn this case, we positioned the 3.8W laser with the High Efficiency Lens with the long axis perpendicular to the cut axis (the worst case) and tried to cut at 2500mm\/min. \u00a0Here are the results:<\/p>\n
![\"Foam](\"https:\/\/jtechphotonics.com\/wp-content\/uploads\/2017\/05\/Foam-cutting-lens-comparison-J-Tech-Photonics-Laser-1024x576.jpg\")
<\/a><\/p>\nNow, just because the High Resolution Lens performed better cutting Foamular, it does not suggest it will perform better in every material. \u00a0That being said, the smaller kerf and higher power density can override the loss of power in a lot of cases making this lens a better option.<\/p>\n
Can I use Both Lenses with my J Tech laser?<\/h3>\n
Yes, both lenses are interchangeable with all of the lasers. \u00a0Both lenses will have a focus range between 1″ and 3″ from the work surface.\u00a0 \u00a0We set them from the factory at 1.5″ from the base of the heatsink.\u00a0 If you have the shrouded version, then it is 1\/8″ from the base of the shroud.\u00a0 When changing them, just don’t tension spring behind the lens too much when changing them out!<\/p>\n
Here are my Final Thoughts<\/h2>\n
You just finished reading all of this and you are saying to yourself, “great, now what should I do?” \u00a0Well, I think it depends on which laser you have, so I’ll break it down:<\/p>\n
If you have the 2.8W laser or lower power<\/strong><\/em><\/p>\nYou are going to be good with the High Efficiency Lens for almost all cases. \u00a0We have not seen a strong benefit for cutting or engraving to suggest that it is necessary to have the High Resolution lens. \u00a0Now, if you are going to do microscopic engravings and you just can’t handle the beam being slightly rectangular when you look at it under the microscope, then you should get the High Resolution Lens as well.<\/p>\n
If you have the 3.8W laser or higher power<\/strong><\/em><\/p>\nThere is a bigger case for the High Resolution Lens for this laser. \u00a0Because the beam profile is exaggerated in the long axis, having a slightly more round beam makes more sense. \u00a0In cases where you are doing picture engraving you can get a better resolution image at the expense of some speed. \u00a0In some cutting applications it might work better because you have a more round spot which will lead to a smaller cut line and better cut properties. \u00a0If you are doing logo engraving, then the larger beam with the High Efficiency Lens will be better because you can do the “fills” a lot faster and reduce your engraving time significantly.<\/p>\n
![\"High](\"https:\/\/jtechphotonics.com\/wp-content\/uploads\/2017\/05\/High-Resolution-Lens-Highlight-2-sm-800-150x150.jpg\")
<\/a><\/p>\nPurchase the High Resolution Lens (Lens_HR)<\/a><\/p>\n![\"Lens](\"https:\/\/jtechphotonics.com\/wp-content\/uploads\/2017\/05\/Lens-Highlight2-150x150.jpg\")
<\/a><\/p>\n
In the case of the the lasers at 2.8W or below, the long axis of the laser is not as pronounced compared to the short axis. \u00a0This means that the benefits of the High Resolution Lens might not be needed in most cases. \u00a0However, in the case of the 4.2W (3.8W) or 7W laser we see the long axis is considerably larger than the short axis causing the more “rectangle” profile of the beam which can be visible in engravings.<\/p>\n
Here is a comparison of the two beam profiles using a 4.2W(3.8W)or 7W laser as an example:<\/p>\n
Notice how the lens transforms the laser beam profile in both axis to make a more symmetrical more “round” beam profile.<\/p>\n Here is a list of the different lasers with both lenses for typical spot sizes when engraving in wood.<\/p>\n Standard High Efficiency Lens:<\/p>\n High Resolution Lens Option:<\/p>\n We did a series of tests in paper to see the difference when the laser interacts with material by processing it. \u00a0This can give you a good idea on how the laser will actually burn. \u00a0We did a quick shot with the laser and then took the results under the microscope. \u00a0Note, the timing of the burn was not exact, so the profile might not be the correct size (it might be larger because the paper burned more). \u00a0This test is supposed to give just an idea of what your beam might look like.<\/p>\n With the 2.8W laser, the beam profile is so small that both lenses will make an almost round burn profile. \u00a0Note the only different is the hole in the paper. \u00a0One is a rectangle and the other is more of a circle.<\/p>\n With the 3.8W (4.2W) laser you can now see that the High Resolution Lens has a distinct benefit. \u00a0The burn pattern is much more round and the the hole created is a lot more round as well.<\/p>\n Now that we have seen the beam profiles in burn paper, lets actually engrave on wood. \u00a0Using the Inkscape Plugin<\/a>, we created a font file using the Arial font. \u00a0The output g code file will engrave both the inside and the outside of the letter. \u00a0So, if you want to get even better resolution at the small font sizes (under 5 point) it might be better to just to one line for the letter. \u00a0Other programs like Vectric <\/a>will allow for this type of engraving. \u00a0We just opted for using the\u00a0Inkscape Plugin<\/a> for this test.<\/p>\n Since the 2.8W laser already has a very fine beam profile, you can see the High Resolution Lens does not have a considerable benefit when engraving. \u00a0You can tell there is power loss with the High Resolution Lens because it does not burn completely running at the same feedrate.<\/p>\n On the 3.8W laser the benefit of the High Resolution lens is noticeable. \u00a0The lines are a bit smaller, so the fonts are more crisp, especially when they get below 10 point.<\/p>\n When cutting different materials that are a bit less dense, the High Resolution Lens might be a benefit for the 3.8W laser. \u00a0Depending on which way you have the beam profile aligned with the 3.8W laser and the High Efficiency Lens, you can have difficulty cutting thin lines and even lines in every direction. \u00a0This is seen in the next example test when cutting a popular foam product, 1\/2″ Fomular<\/a>. \u00a0These lasers can cut through this like butter, but sometimes it is difficult to get the speed, power, and also the orientation for the 3.8W laser with the High Efficiency Lens.<\/p>\n In this case, we positioned the 3.8W laser with the High Efficiency Lens with the long axis perpendicular to the cut axis (the worst case) and tried to cut at 2500mm\/min. \u00a0Here are the results:<\/p>\n Now, just because the High Resolution Lens performed better cutting Foamular, it does not suggest it will perform better in every material. \u00a0That being said, the smaller kerf and higher power density can override the loss of power in a lot of cases making this lens a better option.<\/p>\n Yes, both lenses are interchangeable with all of the lasers. \u00a0Both lenses will have a focus range between 1″ and 3″ from the work surface.\u00a0 \u00a0We set them from the factory at 1.5″ from the base of the heatsink.\u00a0 If you have the shrouded version, then it is 1\/8″ from the base of the shroud.\u00a0 When changing them, just don’t tension spring behind the lens too much when changing them out!<\/p>\n You just finished reading all of this and you are saying to yourself, “great, now what should I do?” \u00a0Well, I think it depends on which laser you have, so I’ll break it down:<\/p>\n If you have the 2.8W laser or lower power<\/strong><\/em><\/p>\n You are going to be good with the High Efficiency Lens for almost all cases. \u00a0We have not seen a strong benefit for cutting or engraving to suggest that it is necessary to have the High Resolution lens. \u00a0Now, if you are going to do microscopic engravings and you just can’t handle the beam being slightly rectangular when you look at it under the microscope, then you should get the High Resolution Lens as well.<\/p>\n If you have the 3.8W laser or higher power<\/strong><\/em><\/p>\n There is a bigger case for the High Resolution Lens for this laser. \u00a0Because the beam profile is exaggerated in the long axis, having a slightly more round beam makes more sense. \u00a0In cases where you are doing picture engraving you can get a better resolution image at the expense of some speed. \u00a0In some cutting applications it might work better because you have a more round spot which will lead to a smaller cut line and better cut properties. \u00a0If you are doing logo engraving, then the larger beam with the High Efficiency Lens will be better because you can do the “fills” a lot faster and reduce your engraving time significantly.<\/p>\n Purchase the High Resolution Lens (Lens_HR)<\/a><\/p>\n<\/a><\/p>\nTypical Spot Sizes<\/h3>\n
\n
\n
Beam Profiles Burnt in Paper<\/h3>\n
2.8W Laser\u00a0Burn Test Lens Comparison<\/h4>\n
<\/a><\/p>\n3.8W Laser\u00a0Burn Test Lens Comparison<\/h4>\n
<\/a><\/p>\nEngraving Fonts in Birch<\/h3>\n
2.8W Laser Font Comparison<\/h4>\n
<\/a><\/p>\n3.8W Laser Font Comparison<\/h4>\n
<\/a><\/p>\n3.8W Cutting Example<\/h3>\n
<\/a><\/p>\nCan I use Both Lenses with my J Tech laser?<\/h3>\n
Here are my Final Thoughts<\/h2>\n
<\/a><\/p>\n<\/a><\/p>\n