Lens Options for Thunder Lasers – Better Photos, Deeper Cuts

Hi there, I’m Ron, and welcome back to Farbulous Creations! I’ve had my Thunder Nova 35 laser for a bit over a year now, and I’ve made tons of cool things with the stock 2 inch lens that came with it, but I’ve been increasingly curious about the capabilities of the other two lenses Thunder sells for their Nova line of lasers. I also get a decent number of questions on the video I released a year ago explaining why I decided on a Thunder Laser in the first place where people are interested whether I decided to add additional lenses or a camera to my setup.

So I reached out to Thunder to see if they’d be interested in sending me the other two lenses if I did a video explaining the different uses for each lens. I figured it would be a good win-win-win arrangement – y’all get a chance to see the various lenses in action and Thunder has a video they can point people to when they have questions about the lenses. Me getting a few free lenses that I can use on other projects
is a nice bonus too, of course.

So here’s what I had in mind. Each of the three lenses has certain applications that it particularly excels at, and ones that it’s not so suited for. I’m going to run each lens through a series of cuts, etches and other tests to see how they perform at each type of task. Armed with this information, hopefully you’ll be able to determine if you need one or both of these lenses for the type of work you do with your Thunder Laser. Let’s jump on in!

Before we begin, let’s go over each of the lenses and what I know about them already. This is the standard two inch lens. This is the lens that comes with every Thunder Nova machine when you purchase it. It can cut and it can etch, and it does a pretty darn good job at both.

Then this is the four inch lens. It’s got a narrower cone of focus, making it excel at cutting through thicker items. But that comes with a larger dot size, so it probably isn’t the lens you want to use when etching photographs.

And then this is the HR lens (or high resolution lens) and in many ways, it’s the opposite of the four inch lens in that it’s got a wider cone of focus and a smaller dot size, making it really excel at getting fine detail in photographs.

So with the specifications of each of these lenses in mind, let’s quickly go over what I hope to learn from my testing.

Since this lens is specifically meant for photographs, I want to see how much better at photographs it etches than the standard two inch lens that comes with the laser. The four inch lens is not recommended for photos, but I’m curious what photos look like with it if you used it for etching. So I’m going to run the same photo with all three lenses and see what it looks like.

One of the other tests I want to run is: I want to see what the maximum amount of thickness it can cut. With the two inch lens. I’ve been able to cut half inch plywood pretty easily – it needs pretty high power settings and low speed, but it can do it and the edges are burnt, but it’s not like flaking off. The four inch lens, I’ve heard you can cut decently thick hardwood with it! So let’s get to it.
So I fully realize this is sort of a strange way to start the segment, but after fiddling around with some early etchings and it not coming up quite how I knew they should, I suspected I might be doing something wrong. But here, let’s let “day of Ron” explain.

So I was having a bit of trouble getting the type of image I was expecting to get on my first handful of tests with the HR lens, and so I decided to do a series of… well first I did some research… regarding image etching and stuff. Because while I’ve done image editing in the past, I will be the first to admit that I’m not an expert on it.

I found some research by a guy named Russ. I can’t remember his full name, so I’ll put his name down below. But he did a ton of tests between dot size and speed and power and recommended this graphic. It probably doesn’t even show up on camera because it’s so fine, but you basically have to examine it close up with a magnifying glass or almost take like a macro photo of it and zooming way in to determine which speed and which power is best for image etching, because if you go too fast, from what I understand, if you go too fast, the laser can’t ramp up in time to fire the dot, and it may miss some dots. And so you may have areas that should have dots from the image that are just blank. And if you have the power too high, you’re going to have dots overlapping each other and then you’re going to get like 3D depth in the image when you really shouldn’t be. The complete surface of the photos should be uniform and just have dots in place where the photo is. I did this test… after I did these tests, I decided to do a test etch of our dog Winnie on here, and where there was a lot of dots, the laser burned all the way through, so the power I found is too high for paper because while this is card stock paper., it’s not the thickest card stock, but it

burned all way through. But the areas that are lighter and not all the way black look really, really nice and like, there’s a decent amount of detail there. And so I’m going to try these same settings on the wood now that I have them kind of dialed in. I believe they should translate to the wood since I’m not like trying to get a deep engraving. I’m just trying to get the laser to fire the dots where there are dots without missing any and going too fast.

The speed I’m working at on my Nova 35-80 is 250 millimeters per second and the power I’m doing is 19% power. So I’m going to set up my main action camera and we’re going to give this another go now that I have a little better idea of what my settings should have been in the first place.

All right. Let’s take a look! At first glance, this is much better than my previous tests. You can see a lot of detail in her fur in the chest here and stuff, it looks really nice. I’m gonna sand it just a little bit. And I’m also going to blow it out again. And that looks really, really good to me. It’s still maybe a bit dark, so

I should potentially edit the gamma or brightness. It’s just a little darkness here by her other eye and ear that doesn’t need to be there.

And I had mentioned that it should, for the most part, feel uniform, and it does like throughout here. But I am feeling some 3D-ness to her nose and a little bit of it like right here. So I’m gonna adjust the image, just a hair and do this one again.

Yeah, without even sanding it, it looks a lot better already. But let’s treat it the same…let’s give it a light brushing, light sanding. And this is really fine sandpaper, 600 grit sandpaper. So it’s not it’s not going to be too aggressive on the surface. So that looks… phenomenal. That is a really good representation of this image. Here’s the first one, and yeah, that’s just too dark. This just shows the entire image a lot better.

My previous tests with the two inch lens were with a different image; I find this image has better detail to really do testing with so I’m going to rerun the same image on the two inch lens to give it a better chance to stand up to the high quality of this, because yeah, this just looks really nice now.

All right. This is the photo that just came out of the laser etched with the two inch lens at 508 DPI.

This objectively looks good. If you had nothing to compare it to. Like, you can see detail in her her eyes and ears, like variations in the lightness of her chest hair and ear hair. This is the same photo etched with the same settings on the HR lens that Thunder set me. As I am doing these tests, I’m realizing that the benefit of the HR lens is not necessarily the ability to get higher resolution photographs because this is etched at 508 DPI as well. And the same etch settings. It’s just that because the dot size is smaller, you’re able to pinpoint the detail of the dark areas where they’re meant to be instead of getting more spread out. Like, there’s laser dots in this field, but they’re like they’re more fine and and pinpointed, whereas here the dot size is larger. And so it’s it’s they’re almost like bleeding into each other. It’s making a much softer image. It’s not a bad image, but when you can compare it to this. I think this looks better, this has a lot more contrast if all you had was this, that’s fine, but if you’re doing a lot of photographs, I think it could be worth it to get the HR lens.

The other thing I’ll point out is… this is a really easy photo to work with. There’s a lot of contrast, there’s a lot of variation in lighting. And so it’s going to look good regardless. But harder to work with photographs, having the HR lens, you’re going to be able to pull out the detail in the various shapes and faces a lot easier than with this lens.

I could adjust the gamma on this photo to maybe get it looking a little closer to this. But if anything, you’re going to lose detail because you’re not firing the laser as often. So, yeah, for my money, for my money, this is a better photograph. This is not bad, I will say that… like, this is just better. Like if I was doing a photograph etch for a customer, this would be acceptable in my opinion. But if I could give them this instead, I would prefer to.

So I just got done laser etching this one, and I thought it’d be nice to compare the same photo etched with the same power settings, but different lenses. Right away, the thing I’m noticing the most between the four inch lens and the two inch lens is that virtually all the detail in the midtones, like the chest and like the coloring of her fur, is just absent in the one with the four inch lens. It really does seem like it was just able to get the high contrast areas, the darkest, high contrast areas of the photo. The fact that this is colored in on the two inch lens result tells me that the laser fired on the four inch lens through those areas. But like, I don’t know quite why it didn’t show up. It’s as if the overlapping, lightly colored dots was not enough to leave a mark?

But as soon as we switch to the two inch lens you can see like there’s nice detail in the midtones. And like I said earlier, this is an acceptable result in my opinion. I would feel fine giving it to a customer, but the benefit of the HR lens really seems to be getting more power into each and every dot, without that dot overlapping neighboring dots. Because I think that’s why this is darker.

It’s like, because in the midtones there’s the same number of dots here as there is here. But because they’re overlapping in this photo or in this, you know, in the two inch lens, the overall image is darker than in here where there is only dark, where they’re really, really, really, really like neighboring dots. And so I think the thing with the four inch lens is that the power… it’s almost like defocusing. It almost feels like the power is so defocused in the midtones that it’s not able to leave a mark unless it’s densely, densely packed. So that’s very interesting to me.

I don’t think I would…the reason I did a four inch lens version of this photo, even though I know it’s not meant for etching, was I was curious if there was any use case where, like, it might look cool to do it this way. But if you want a photo to look like this, you can just remove the midtones in post-processing with Photoshop or Lightburn. And I don’t see why you would use the four inch lens for this. So with that said, I think I’ve done all the testing I want to do with the photo engraving capabilities of these lenses. So now let’s move on to some cut tests.

I’m really, really curious to see how deeply into the materials the four inch lens can penetrate, as that’s kind of the selling point of it. And with its larger dot size, it means there’s a lot more bandwidth for the power to get into the material. So I have a number of pieces of wood, various wood species, various types. I’ve got two different thicknesses of maple, two different thicknesses of walnut. I’ve got some birch plywood. I’ve got some poplar. I’ve got some cedar. And I’ve got some two-by pine. So my plan of attack here is to run a straight line, vector line through each material at high power settings and low speed to give it the best chance of cutting through. And I’m going to use roughly the same settings on every type of wood just because I don’t want to, you know, figure out the lowest possible settings for each type of wood. Like, I’m really just curious, can it cut through on the highest power settings and the lowest speed that I typically use? Which is… I typically don’t go over 90% power…there’s various reasons for that that can get me down a whole rabbit hole just on that. But I typically don’t go higher than 90% power, and I typically don’t go slower than 5-10 millimeters per second. So we’ll see. I’ll post the exact settings I use on screen as we’re doing it. But if the vector line cannot cut all the way through a material, I will give it a second chance with a second pass to see if it can go through and note that, but I’ll do that as a second cut because for all the samples where the laser isn’t able to cut all the way through on either the first or second pass, I will measure that with my calipers to get like a really fine reading on it.

So with all that, all the way, let’s get going.

Before we get going, I wanted a quick show, this sample piece that I did many moons ago at my local maker space. That was, I believe, in an 80 watt tube. I don’t know what type of lens it was, but I wanted to try to cut through this roughly half inch thick piece of hardwood. I believe it’s maple and walnut that I just glued together this board out of scrap that I found in the scrap pile at the maker space. That laser cut quarter inch ply no problem, so I was curious if I could cut this roughly half inch hardwood. And… it did not, but I kept going, increasing the power, doing multiple passes until finally it cut through. But it had to use so much power, and this edge was exposed to the high intensity heat of the laser for so long that it really ended up getting almost… like it got charred to the point where material was flaking off. And it kind of looks cool. It almost looks kind of scalloped, like something that might be done by hand with chisels. So it is kind of a cool look. But you know, if you’re trying to cut something on the laser to be part of a glue-up, like an inlay, you definitely don’t want this type of look on the edge. So I’m looking for a clean edge, first and foremost, on all of these cuts, I don’t want a scalloped edge on any of them. So with that, let’s get going.

Now I ended up doing a test cut on each sample of wood with both the two inch lens and the four inch lens. In editing this video, I realized that showing each test in real time and showing all of my colorful commentary would take far too long in this already lengthy video. So I’ll do my best to summarize my findings as we timelapse over a lot of it and occasionally break for some of my real time findings. And don’t worry, I’ll have a table at the end of the segment breaking it all down. So don’t worry if you can’t follow along completely as we spin through these.

Look at that. Ha! That is very exciting. Let me focus in. Check that out. That was one pass. And it’s a very nice, clean edge. I could very easily see myself doing some inlay type work with boards this thick and, you know, various species of wood. The black edge could even give it like a tiny little, you know, appearance of contrast between the varying species of wood between a glue line. This is my favorite result so far. Yeah, this could be a game changer for some of the projects I do.

All right. The maple is done. It got nearly all the way through, and then I just broke it off there accidentally. As you can see, a few fibers are left to break manually. So this one was very, very close, but not quite through. Since it did make it so close, though I will try the de-focus technique and see if it makes it through on a third try.

If you’re not familiar with the out-of-focus technique that I mentioned, it’s basically where you focus the lens on the center of the board slightly, rather than the top surface, which allows more energy to penetrate deep inside the board. That did appear to cut through on its own. The edge profile is not quite as clean as it is on the thinner samples. I think there’s a little bit of flakiness maybe starting to happen here, but it still did cut all the way through. So cool on only two passes.

Look at that. That is pretty cool. On a single pass, and that doesn’t smell as pleasant as walnut does. But yeah, on a single cut, single pass, 90 power, 5 speed. It was able to cut through 19 full millimeters of poplar and it’s overall a pretty clean cut that cut through on one pass. I’m impressed.

Alrighty, onto the two inch lens and the same samples. I’m not going to stop and talk as much as I did for the four inch samples, primarily so we can get to the end and compare all the results all at once a lot faster. But I will say that the two inch lens did perform better than I thought it would. But as you’ll see, certain samples that would have got a second chance at cutting through, I had to stop mid-way through because it got a little flaming. Yeah, not going to have a fire inside my laser cutter. Don’t need that. That happened primarily on the thicker samples like the birch plywood. I’m pretty sure that’s something to do with all the glue in there; would not surprise me at all. But it also happened on the thicker sample of maple on its second pass, too. So that was interesting. With the cut tests of each sample complete with each lens, let’s dive into the results.

Let’s look at the four inch lens results first. Each row represents a different sample of wood with a unique thickness. The first pass column represents how thick into the board the lens penetrated on the first pass and if it was necessary, the second pass column shows how much further it got on a second pass. The results column with the emojis represents a quick glance to see how each sample performed on its first and second pass. But it’s not the end of the story. I’ll speak more on this shortly. But as you can see, the four inch lens was able to cut a decent number of samples in just one pass and was able to get through a few more when allowed a second pass.

Now, the two inch lens definitely performed better in some of these tests than I thought it would. I had no idea it was capable of cutting half inch walnut, so I haven’t ever really tried. But while the two inch lens was able to do half an inch on many of the samples, the edge wasn’t quite as clean as it was on the four inch lens.

Okay, so I mentioned the results column with the emojis isn’t the end of the story. Just because it might not have been able to cut through the random thickness of boards I had on hand doesn’t mean it wasn’t still an impressive result.

The true metric we should be looking at is the maximum thickness it could penetrate on a single pass, as that tells us what we can expect to get through if we had a board of that exact thickness. The four inch lens for the materials I tested was able to penetrate anywhere from 13 to 30.5 millimeters, or 0.51 to 1.2 inches. Meanwhile, the two inch lens was only able to do 9 to 20.25 millimeters, or 0.35 to 0.8 inches. Another thing worth noting is if the two inch lens didn’t get through my samples on the first pass, a second pass was far less likely to help, often providing only an additional millimeter or so of depth, while also overly burning the edge.

The four inch lens, by comparison, often got much further on its second pass, meaning if you’re willing to do a second pass, the four inch lens adds even more cutting depth capabilities to your setup. With my fancy tables and data out the way, let’s jump into the final overview.

Now I know this was a long, slightly in the weeds video but hopefully you found it useful. I’ll be honest, when I first got my Thunder Laser, I didn’t really see the point of these auxiliary lenses. But now that I’ve had a chance to use them firsthand, I definitely see the appeal. If you do a lot of photo engravings, the HR lens will definitely make your photos pop and appear less soft, and if you want to cut thicker stock on your laser, the four inch lens will give you that option and overall give you cleaner cuts on those thicker materials.

I put links to Ross Saddler’s video and a few related articles down to the video description, as well as links to the two lenses on Thunder’s website. If you’re interested in checking them out.

So with all that said, what do you think? Did you like this video? Was it useful? Are there other tests or demonstrations you’d like to see me do with these lenses in future videos? If so, leave a comment down below and give this video a like so that I know that this is the type of content that the laser community on YouTube wants to see. Thank you so much for watching, and I’ll see you in the next one. Cheers!