TOMLOV DM9 Max 10.1″ HD IPS HDMI Digital Microscope 1500X 20MP Coin Microscopio Magnifier Soldering Microscopes For Repairing (WHL #100)
Aah. Looks like #100 is finally here.
So why not spend a hundred bucks and buy something nice? Something that I’ve been thinking about for quite some time now, but with the professional options up in the thousands of Euros, and the cheapo versions (for a tenner, or two) making my skin crawl?
Well, here’s my new digital microscope, a Tomlov brand DM9 Max. Apparently pretty new, only released in the last month or so. Couldn’t even find it on Amazon, eBay or (whoa) a regular shop in Germany, so I ordered directly from Tomlov via AliExpress. 124,55€, shipped within a week. Nicely packaged, I have to say.
What is it? Basically a souped-up tablet with and oddly placed webcam. I specifically avoided all the nasty USB cameras over the years that were praised as microscopes, because they do require a connected computer to operate, some even specialized software that requires Windows (or worse, some legacy Windows). I also avoided regular microscopes because I likely need to take pictures from the stuff that is inspected, and that’ll be fiddly without a fixed camera in place. Instead, we’re now in the era of cheap tablets and somewhat high-res displays are a commodity now (I’ll come to that in a second). CPUs also have gotten so fast that it’s no longer a gruelling slow 5fps slide show with horrendous lag, but the video output is pretty much instant.
Here’s how the thing looks on their marketing photos:
Starting with the first lie: In here, it says “FHD display”. That doesn’t appear anywhere else, especially not on their AliExpress product page (where they never answer the open “what’s the display resolution” question…), but I was under the impression it would be a FHD 1920×1080 screen, which is why I bought this one and not one of the more expensive units.
It’s not. It’s a 1024x600px “HD” one. Well, whatever qualifies as “high definition” these days…crappy 1366×768 15″ laptop displays also were called HD for quite a while.
Display size however is true, 22.2cm of usable screen width (no additional black border inside the display glass) is basically a diagonal of 10.1″. Which brings us to the next banner spec, which is magnification. “5x to 1500x”, it says.
Well, the question always is: How do they measure that number? And while for a classic magnifying glass, that is pretty obvious, it does get more tricky with real microscopes, and especially difficult with digital ones. Tomlov being a Chinese brand, they clearly went the Chinese scammy way of doing this:
That marketing image is bullshit, no surprises here.
Here’s the display view of an INCRA ruler, a very nice precision tool that costs around 1€ per centimeter. This is on minimum zoom level on somewhat medium height. Kind of where I would put the optics in a general use scenario, as it does get a bit wobbly when moved up high.
And that is on max “18x” zoom level
With the screen width being 222mm, fitting 20mm (and a hair) onto the display is a 11x zoom. Fully zoomed, that field goes down to 12mm, which is 18.5x. Even area-wise that is not a 3x difference, but wherever their “18x” comes from…
Funnily enough, their photo output does not correspond exactly to the screen output, so some mystery cropping is going on:
Well, anyway. For min and max zoom levels, the microscope needs to be moved up and down. Here’s the top level shot with the unit moved to ridiculous heights as shown on the very first marketing photo. It’s 31.5ish mm on a 222mm screen, so 7x is minimum zoom – not 5x as promised.
I didn’t really optimize anything here, but it’s clear lighting is an issue at that distance. The photo is taken, according to the EXIF data, at 1/32s with f/1.8 and ISO580. Good thing photos can be triggered via a remote, as touching the device for the hardware button would clearly mess up the photo.
Maximum zoom is like this: Bottom position (can go down a little more, but fails to focus) at default zoom:
That is basically 10mm or spot-on 6mm of the ruler, equal to 222/10mm = 22x and 222mm/6mm = 37x magnification. That is best-case, maximum the thing can do.
Where’s my 1500x?
Weeelll, here’s where the dirty tricks of the Chinese come in. I currently cannot find it anymore on their website, but it goes like this: If you take the HDMI output, which by the way also is NOT FullHD, only the MicroSD video dump is, or take a photo and move the card over to a computer, then the image can be displayed on a larger screen.
I think they advertised it with a 28″ display, assuming it’s a 16:9 ratio, that would be 620mm of display width. Displaying 6mm over 620mm already is a cool 103x zoom. They do show this application in their marketing material, but that’s probably the biggest stretch I would accept for their magnification rating. 100x is what this thing can reasonably do – at 720p resolution, so not great quality.
Everything beyond that is pure number wankery that is typical for the Chinese. Sure, 1500x can be done in static mode – the image is 6096×3424 pixels, so one millimeter is roughly 1024px wide. For 1500x magnification without fake digital interpolation, those pixels need to spread out over 1.5 meters. Any 20 year old 1024×768 movie projector can do that, no problem…
Anyway, so back to realistic use cases. Here’s a 40x view from a 1.27mm pitch device (= 1.27mm from pin center to pin center) from the old Vision Engineering Lynx microscope at work. Very difficult to take a photo through the active optics, as that is a stereo/3D microscope. I’d say the viewport is half the width of the Tomlov display, but exact sizing is up for debate (again, active optics, no classic eyepieces but instead one can move around freely and still have a 3D view of the scene)
This is the same PCB on the Tomlov (low to medium height, max zoom), saved to file:
Twice the viewport size, and about twice the PCB area. I’d say that is perfectly fine for ordinary inspection tasks, and for a quick overview, standard zoom will also do:
All the fake numbers aside, I consider this a usable tool and certainly acceptable for the price. Resolution is okay on the screen and decent on static photos, lag is pretty low so soldering or other manipulation tasks can be executed well. And there’s a couple more features:
* MicroSD card is included – compared to the contenders in the recent MicroSD test (WHL #96), this one is actually pretty decent and on par with a Samsung Pro card of the same size – impressive.
*There’s a ring light on the top unit, as well as two swan lights on the base plate. Top and bottom brightness can be adjusted independently
*Both top and bottom unit are battery-powered. I haven’t had the need to recharge the bottom one yet (so 10h+ runtime, excellent), and the top unit including the entire microscope and display runs for exactly 2 hours between charges on full brightness on display and ring light. Marketing claim is “up to 3 hours” – maybe that’s possible with lowest settings, I don’t care, I consider 2 hours a pretty good number already. Battery capacity is about 5800mWh, so about 1500mAh assuming a single Lithium cell is used. Charging is done on 5V only (no PD fast charge), 0.9A max – full charge takes two hours as a result.
*The remote feels extremely cheap, light and tacky, but it can do zoom level adjustment (needs multiple button presses…why?) and take photo and start/stop videos without the need to touch the main unit
*Product descriptions says the USB-C port can also be used as an output, I can unfortunately not confirm that since USB-C charging takes precedence over video output. And as my monitor does offer USB-PD (at like 10W or so), which cannot be disabled, the thing only wants to charge. But the HDMI is working (1280×720 resolution, 60/61 fps!). It’s the unusual miniHDMI port, but a cable is included. If you’re using this feature, and switching cables on your monitor/TV is a bit of a hassle, a HDMI gender change for like 2 quid is a good investment. 720p pretty much works over anything, including railroad tracks and medieval chainmail.
*One more wankery feature: It has a microphone. So that, when capturing video, you can talk about what you’re doing. That could be interesting as a commentary track for editorial notes in post-processing, but I highly doubt anyone will directly upload such files to Youtube…
Here’s a couple more product photos, you know, unboxing and stuff:
Final verdict: Would buy again – but also would check if a FullHD display model is available for not much more money…
[…] addition: There’s one more test over on the Tomlov microscope page (WHL #100), featuring the unbranded MicroSD card that is included in that […]