How do you know which laser wattage is right for you? We wrote this guide to help you decide.
If you're mainly engraving photos onto ready-made coasters or other blanks, we'd start by comparing 10W and 20W diode machines. If you also cut your own blanks, a 40W model deserves a look. More power can help with cutting, but for a detailed portrait, you'll want to see the laser's spot size and an actual engraving before spending more.
This guide draws on manufacturer specifications and LightBurn documentation. We haven't tested these machines side by side; the recommendations are our reading of those sources.
First, check what the wattage means
We're comparing blue-diode lasers here. When we say 10W, 20W, or 40W, we mean optical output: the power in the laser beam. A listing may also show how much electricity the machine uses or the rating of its power adapter. Look for optical output in the specs so you're comparing the same thing.
The type of laser matters, too. A 20W fiber laser, a 20W blue diode, and a 40W CO₂ machine use different sources and wavelengths, which affects the materials they can work with. Check that the laser suits your material before comparing wattages.
For photos, look at the spot size
Dithering turns a photo's shades into a pattern of dots. Your laser has to reproduce those dots as marks on the material. Small details, such as whiskers or the edge of an eyelid, depend partly on how small those marks can be. That's why the focused laser spot is worth checking. Read both dimensions: the spot can be rectangular.
Take the xTool S1 as an example. Here are xTool's published figures for three heads in the same machine family:
| Laser head | Specified spot size | Maximum working speed |
|---|---|---|
| 10W | 0.06 × 0.04 mm | 400 mm/s |
| 20W | 0.08 × 0.06 mm | 600 mm/s |
| 40W | 0.08 × 0.10 mm | 600 mm/s |
Note: These figures describe the S1 heads. They don't tell us the size of the marks on your material or how long a photo will take, and they aren't a rule for every laser at these wattages.
See a sample on your material
In that table, the 10W head has the smallest specified spot. It's a good reason to consider it for photos, but you'd still want to see a sample on the wood or slate you plan to use.
Focus changes the spot at the surface. Speed and power affect the mark, and the material adds its own texture. Compare the finished photos at the size you'll make them. If you can only see a difference under magnification, it may not be worth paying for on a coaster.
You'll also see claims about positioning accuracy. That's how precisely the machine places the head, which is a separate question from how wide a mark it makes. Ask for the focused spot dimensions and a close-up of a real photo engraving.
Turning down a 40W head
You can lower the power setting on a 40W machine. That helps you control the mark, but you can't assume it gives you the same spot as a dedicated 10W head. In the S1 table, those heads have different spot dimensions. Check whether changing modes also changes the beam size on the machine you're considering.
Some heads offer that option. Creality's Falcon2 40W has an adjustable beam, with Normal and Precise modes described in its operating guide. If a machine has an engraving mode like this, ask to see a photo made with it. Check the exact model's manual, since similarly named machines can have different features.
Choose around what you'll make most
Think about your usual projects. If you buy blank coasters and engrave photos onto them, cutting power may not earn its keep. If you cut the blanks yourself, the time saved on that step matters too. Here's where we'd start looking:
| Your work | Start with | Check before buying |
|---|---|---|
| Photo gifts on ready-made blanks | 10W or 20W | Detail, light and dark tones, and time to engrave your usual photo size. |
| Photos plus some cutting | 20W | Clean cuts and the number of passes needed for your material and thickness. |
| Frequent cutting as well as photos | 40W | Time saved cutting, plus a photo sample from the engraving mode you'll use. |
Note: xTool recommends the S1 40W for more demanding cutting and the 20W for work focused on engraving. We've used that distinction to suggest starting points here. Ask for a sample on your material before choosing.
Find out how long a photo actually takes
A 40W laser won't necessarily engrave a photo twice as fast as a 20W laser. The S1's 20W and 40W heads even have the same advertised maximum working speed. That still doesn't tell you how long either takes to finish a portrait.
More power can let you run a faster pass when the material needs it, but the machine's movement and the quality of the result also limit the speed. Ask for a timed comparison using the same photo size and material, with each head adjusted to give a similar result. That's more useful than a maximum-speed claim or a video of the machine cutting plywood.
Higher DPI can make a photo muddier
It's tempting to turn up the DPI to get more detail. But DPI changes the spacing between the image's dots; it doesn't make the laser spot smaller. When the marks overlap too much, the gaps that create lighter tones disappear. LightBurn describes this as a cause of dark, muddy images.
At 254 DPI, the spacing is 0.10 mm. At 508 DPI, it's 0.05 mm. These are examples of the calculation, not settings we're recommending. You can't find the best DPI for your material just by dividing 25.4 by the advertised spot size.
Use a material test to find a line interval that works, then prepare your photo at the matching size and resolution. If you're unhappy with an existing machine's photos, check its focus and interval before buying another head.
Send the seller one of your own photos
Choose a photo you'd actually engrave. A pet portrait with pale fur and darker patches gives you details to compare at both ends of the tonal range. Tell the seller the finished size and material you have in mind, and ask for close-ups as well as a view of the whole piece.
For a fair comparison, ask them to keep the source photo and crop the same, then adjust each head for the material. Using the same power percentage on all three heads won't give each one its best chance. If they prepare the image differently for each run, ask to see those files too.
- Look at the eyes and fine edges. Can you still make out texture in the light and dark areas?
- Ask them to record the head and mode, focus method, speed with units, power, interval, dither, passes, and total time.
- Step back to normal viewing distance. Decide whether the difference is worth the extra cost or engraving time.
Check what comes with the machine
When you buy a complete engraver, the laser is included. A listing for a laser module or upgrade kit may only contain the head and a few supporting parts. Read the bundle contents so you know what you're getting and what you'll need to add, such as exhaust equipment, a work bed, or software.
If you're upgrading, check compatibility with your frame, controller, mount, and power supply. For example, xTool's instructions for upgrading a D1 from 5W to 10W require the replacement power adapter supplied with the kit. Buying from the same brand doesn't guarantee a module will work with your machine.
Give your current machine a fair test
If you already own an engraver, take a close look at the bitmap you're sending it. Are the highlights missing? Have the shadows become solid black, or is the face too small in the crop? Fix those in the image and try another sample before spending money on hardware.
In EngravePrep, you can crop and adjust the photo, set its physical size and DPI, then export a dithered PNG. Keep that size when you import it into your laser software. In LightBurn, use Pass-Through for the finished two-color image so it preserves the dots you've prepared. You'll still need to choose and test the machine settings on your material.
Glossary
Terms in this guide
A closer look at the terms used above, with examples.
- DPIDots per inch, a density measure used to describe raster scan spacing and the pixel grid at a physical output size.
- Line intervalThe physical distance between neighboring raster scan lines, commonly expressed in millimeters.
- DitherA method of simulating continuous tone with patterns of a smaller set of values, commonly black and white dots.
- Material testA controlled set of small engravings used to compare machine settings on the actual material.
- Tonal rangeThe span and distribution of values from the lightest meaningful detail to the darkest.
- BitmapAn image made from a rectangular grid of pixels. PNG, JPEG, and WebP files are common bitmap formats.
- Pass-ThroughLightBurn's mode for engraving an externally prepared image as-is instead of applying another image-processing mode.
Common questions
Is a 10W laser enough for photo engraving?
It can be, if the machine suits your material and the result looks good at the size you want. Ask for a sample and find out how long it took. If you'll also be cutting blanks, consider how much cutting power you need alongside photo quality.
Should I replace my 40W head with a 10W head?
Check your file, focus, and line interval first. If you're still unhappy, compare a sample from the exact 10W head on your material. A lower wattage alone doesn't promise a better photo, and you'll need to confirm that the replacement works with your machine.
Sources and further reading
We used the manufacturer and software documentation below. Check the manual for your exact machine before choosing settings or buying an upgrade.
- S1 specifications: 10W, 20W, and 40WxTool. Checked October 22, 2026.
- S1 20W and 40W laser module comparisonxTool Support. Checked October 22, 2026.
- Laser TypesLightBurn User Guide. Checked October 22, 2026.
- Laser engraver optical powerCreality Falcon. Checked October 22, 2026.
- Falcon2 engraving and cutting guide: beam modesCreality Falcon. Checked October 22, 2026.
- Speed vs. PowerLightBurn User Guide. Checked October 22, 2026.
- Interval TestLightBurn User Guide. Checked October 22, 2026.
- 5 Steps to Perfect Image EngravingLightBurn User Guide. Checked October 22, 2026.
- Image Mode and Pass-ThroughLightBurn User Guide. Checked October 22, 2026.
- Install the 10W laser module on D1xTool Support. Checked October 22, 2026.
- S1 User Guide: package contents and setupxTool Support. Checked October 22, 2026.