Found some pretty nice 2x4s last month at Home Depot for a clamp rack project. They were stamped HEM FIR, from Stimpson and the Eugene F. Burrill Lumber Co., and I think they're probably white fir from the Pacific Northwest of the U.S. Can't say I ever recall seeing waxed ends on 2x4s, but the ones I bought all did, and none of the ends were split, a nice touch. Dimensional variation from 1.500x3.500 was remarkably, and on random samples, only ± 0.01 in thickness and ± 0.025 in width.
This also serves as a little review of the Jiusion F210 WiFi USB Digital Microscope I bought a couple of weeks ago to aid in wood specie identifications. The hardware has a decent feel to it, and while the software has much room for improvement, the device's image sensor (1/4) isn't too bad for an entry level device, or at least that's my take on it so far. You can arrive at your own conclusions from the full-sized side-by-side images attached below. Note that depending on which Android app was used; the size of the resulting image saved to the phone varied: DW WiFi (1280x720); Max-see (1920x1080). One cautionary note, both apps write JPEG files, but are incorrectly appended with the extension *.png, so you will need to rename them *.jpg. I've written to Jiusion informing them about this bug FWIW.
The sample was prepared a couple of weeks ago using a freshly sharpened cutting iron and a hand plane; either a No. 4 Stanley or a No. 14B Millers Falls, before sawing off the end of the 2x4. The photos were taken today using my cell phone, a couple different Android apps already mentioned, and the device's own WiFi. The (English) documentation that comes with the device is poorly written, but there are sufficient graphics that help get the key points across to the new user. Just note that when you're using a wireless connection, you first need to turn on the Jiusion device. This then becomes a new WiFi access point that will be recognized by your phone to which your phone will need to connect, noting that it's 1) not connected to the internet, and 2) the range of the connection is limited. From my tests, using the Galaxy A71, I was able to stay connected and take pictures while being up to about a 100' from the device. Also, there is limit to the life of its 900mAh lithium battery. Depending on use of the integral 8 adjustable LED lights, or some other light source(s), or some combination of both, working time is listed as being about 1 to 1.5 hours. If you're using a light source other than the adjustable 8 LEDs that encircle the recessed lens seen in the photo below, the plastic (ABS) loupe-like shroud can introduce color and light modeling aberrations on the subject when the shroud is in contact with the subject. You can see this modeling I'm referring to in the [Hem or Fir - Highest magnification.jpg] examples.
Magnification is a direct function of the distance to the object and while the advertising boasts "50 to 1000x", it remains a complete mystery to me how Jiusion is able to make this claim. In the example [Hem-or-Fir---Low,-Medium,-High-Magnifications.jpg], and based upon the steel rule seen in each photo, there is a little 1mm square that I've drawn on each photo for scale. When comparing the lowest (mechanical) magnification to the highest magnification (and without using the internal software multiplier) there is about an increase of 5.5 times, which seems to me as a beginner, quite satisfactory for doing wood specie identification. The travel distance on the provided and nicely made stand, is about 4.5"; however, the device can focus to much greater distances. It can also output video (.mp4)
I tried using this device with different phones whose aspect ratios were quite different; the Galaxy A71 and the Moto E4 Plus. When viewing images from the F210 with the phone in portrait orientation, proportions of objects clearly appeared a little squished and when the phone is in landscape orientation, they look ridiculously squished. There doesn't appear to be any means within the Android apps DW WiFi, or MaxSee, to correct their displayed distortions; however, the actual captured image files are reasonably free of distortion when viewed in other applications.
Most of my using the Jiusion F210 was via its built-in WiFi; however, I did try some experiments using the provided USB cable, my Windows 10 machine and the two separate apps, S-EYE, and xploview. Everything worked and you can see and capture images, but like the Android apps, these programs for Windows are very basic and lack documentation.
The soft shell carrying case and sturdy metal stand really make this device a great value at just under $50.
One last thing, don't forget to take the lens cap off when you're taking pictures! It's also made from clear plastic, so it might not be immediately obvious the first time you use it.