A few months ago I learned of digital cameras with integrated thermal printer for instant photo printing. As toy cameras aimed at kids, they have colorful exterior and low price to match. I decided it would be fun to get one. Play with the novelty for a while, then take it apart to learn its electronic guts. Perhaps it can be modified to satisfy one of my friend Emily’s suggestions for my Sawppy rover: instead of a robot arm with scientific instruments, maybe I can build a robot arm with a selfie camera. And with this design, I can instantly print the photo to share!

There are multiple vendors selling different implementations of the same basic concept. I decided on this particular unit (*) for two reasons. First, because it was the cheapest offering of the day and second, it has a camera sensor that can swivel 180 degrees to switch between front-facing (normal use) and back-facing (selfies). The swivel implies a long flex cable, and that should make rover integration easier.

A lot of accessories came bundled inside the box. Starting with five rolls of thermal paper to feed lots of prints. A pack of color markers let us perform colorization by hand, and a USB type A to type C cable for charging its internal rechargeable battery. Even a neck strap was included!

The camera enclosure was surprisingly well built. I had expected a few simple piece of ill-fitting injection-molded plastic, but it turned out to be more sophisticated than that. The eyes are separately molded pieces of white plastic instead of the sticker I had expected from product listing pictures. The ears are likewise separate pieces, as they are molded in a soft material. No weird plastic flashing and all pieces fit together well. This is pretty amazing quality considering the price point. I’ve paid more for stuff from Harbor Freight that weren’t made as well as this camera. I will be sad to break open the case later, but not enough to dissuade me from my original plan.

I got this device for its instant-print photo capability, but it can also record videos and there’s even a “Hungry” game that’s a weak implementation of the immortal snake game. It reminded me that, as primitive as the screen may be by modern standards, it is generations ahead of the black-and-white LCD used in classic Nokia brick phones.

Photo image quality and print quality were about as expected, which is to say quite poor and appropriate for an inexpensive toy. Certainly Canon won’t lose any sleep over this thing. But it’s definitely good enough to tell what the picture is supposed to be, and its unashamed low fidelity has an unique charm of its own. Given the price point I really can’t complain.

After playing with it for a few hours, print contrast was noticeably faded compared with earlier prints. I first thought maybe the device was designed fully expecting kids to get bored and lose interest quickly, and thus designed with a short service life in mind. But that’s inconsistent with bundling five rolls of paper! It then occurred to me I should try recharging the battery, and that turned out to be the answer: a topped off battery restored the full (if not very wide) range of contrast. Print quality a direct function of battery voltage? Wow. This thing is so spectacularly simplistic it has become its own special kind of awesome. It’s fun, I like it!

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(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.

Starting with the recent Philips Sonicare teardown investigation, I’ve reintroduced the use of my Canon EOS M100 camera to take pictures for project documentation. Its excellent sensor paired with a macro lens for close-up photography work quite well to capture small surface-mount components and related circuitry detail. Late in the investigation, I added polarizers to the setup and was amazed at how much of a difference it makes under the right circumstances.

My current understanding is: if I use a light source that is polarized in a direction, then take a photograph with a filter polarized in an orthogonal direction, most direct reflections are eliminated. This means the resulting pictures will not be blown out by reflective glare, even though the subject can be very brightly lit Letting us make out details we could not otherwise see.

Here’s the Sonicare HX6530 circuit board again, taken without polarizers. All the solder pads are very shiny, as are some of the circuit board surfaces. I tell the camera to focus on the markings on the surface of the PIC16F726 microcontroller, but we can barely make it out.

And now a picture taken with polarization. All the shiny reflections are gone, letting us see far more detail that were previously obscured. PIC16F726’s markings are now clearly legible.

This is a great tool to add to the project documentation photography toolbox, but like all tools there are right and wrong times to use them. Even though I can see details with the polarizer in place, some of those details may be misleading. Example: actuator coil pads 1 and 2 show up as red in the polarized picture above. I don’t know why but it tells me to view colors in polarized pictures with skepticism.

But sometimes polarizers are just magic. There’s clear packing tape protecting this solder joint. Normally the tape would directly reflect light into the camera sensor, causing a bright glare on the surface making this solder joint impossible to photograph. But a polarizer can filter out that glare and let the camera focus on the solder joint almost as if the packing tape isn’t there. The downside of removing bright reflection is that it also removes a lot of visual cues for dimensions. Look at the red wire: all visual cues it is cylindrical are gone leaving it looking like a flat red thing.

Polarizer filters are sold for camera lenses for use in this and other scenarios. The Canon EF-M macro lens takes 43mm filters so I started with the cheapest option on Amazon (*) to see how well it worked. The outer ring is assembled from two parts: one part threads onto the lens and stays put, the other part holding the filter rotates freely letting me adjust the polarization angle. These initial tests look promising so I’ll use the cheap filter until I can articulate a reason to move upscale.

The camera lens polarizer is cheap to buy and easy to use, but getting these results also require a source of polarized light. I think the easy solution is to buy sheets of polarizer film (*) and put it over your existing light sources, but that’s not what I did. I wanted to put some old stuff to work.

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(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.

Recent changes to Chrome browser motivated me switch to Firefox, but that wasn’t the only recent Google decision that irked me. Google also decided to be a lot less generous with Google Drive. Google Pixel camera images received unlimited Google Drive backup storage, but that perk ended with the Pixel 5. Images from Pixel phones newer than Pixel 5 count against Drive limit just like any other data. I guess Google is no longer funding the Drive division for supporting Google hardware adoption.

It was very convenient to document my projects with my phone camera as it is usually nearby. But being generous with the shutter also meant I was quickly filling up my Google Drive quota. With the flood of nag mail demanding I pay money to increase my quota, I was motivated to migrate from cloud-based storage back to local storage on my TrueNAS array. And if I’m doing that anyway, I might as well dust off my Canon EOS M100 camera. Shown here with a lens for up-close photography and a wrist strap (*) far less bulky than the standard neck strap.

Convenience of cloud backup was a major reason why my M100 had been gathering dust. Now that Google has made it less enticing, I’m returning to the superior photography capability I’ve already paid for. The M200 is the current successor but I don’t feel a need to upgrade yet. Even this older M100 has sensor and lenses that easily outperform a phone camera, even more so when dealing with projects like my Sonicare HX6530 circuit board.

Credit to the Pixel 7 camera design team, it performs well with subjects at normal ranges. But I would not call my usage pattern normal, and I’ve highlighted problems before.

Above is a serviceable picture taken by the Pixel 7, below is from the M100.

When scaled to blog post size, they’re pretty close. But when I want to crop, the M100 sensor delivers more pixels to work with. Here are 1:1 pixel crops from original resolution of above images:

The M100 gives me more pixels to crop closer to the subject. The Pixel 7 is quite competitive here looking at the center of the image, but it falls behind when we start looking towards the edge:

Both lenses degraded as we move away from the center, but the EF-M Macro lens does a better job. And while the phone camera couldn’t focus much closer than these pictures here, the Canon lens can focus far closer. So close, in fact, that the lens itself casts a shadow blocking surrounding light. Which is why it has a built-in ring light to handle those cases.

So a dedicated camera has a better sensor. In front of that better sensor is a better lens, which can be swapped out for different lenses optimized for specific scenarios. And in front of that lens is a finely threaded mount for lens filters, which adds even more capability. For my electronics project photography, adding a polarized filter is a magical transformation.

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(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.

Several recent posts focused on small things like a damaged ESP32 module. Trying to document these projects presented a challenge because it’s been difficult to take good clear pictures of fine detail. I did the best I could with what I had on hand, but the right tool for the job is a camera lens designed for macro photography. When one such lens for my Canon EF-M camera was on sale during the holiday shopping season, I could not resist.

Here’s the LED on the Introduction to SMD kit, with the entire image scaled down to 1024 pixels wide.

If I crop out the center of the original picture instead, this is what I see:

A lot of detail are visible, certainly far better than what I could get before, but I think the focus could be a little sharper. I hope the lens is limited by operator skill rather than optical characteristics, because I could learn and improve my skill.

Here is a picture of the LED array from my recent freeform SMD experiment, again scaled down to 1024 pixels wide. The solder joints – which I could barely manage with the naked eye – look really uneven at this magnification. But wait – there’s more!

Here’s the cropped-out center of that image. Tiny beads of solder look like monstrous blobs of invading space aliens, not at all attractive. But the wire inside the left side LED is clearly visible, and multiple diffractions of the right side LED can be seen. This picture represents a combination of two novice skills: freeform SMD soldering and macro photography. I’m pretty happy with the detail and clarity of these pictures, but not at the quality of these solder joints. That’s OK, it just means I have lots of room for improvement.