[HN Gopher] The OpenFlexure 3D printable microscope
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The OpenFlexure 3D printable microscope
Author : enceladus06
Score : 174 points
Date : 2024-11-12 13:18 UTC (3 days ago)
(HTM) web link (openflexure.org)
(TXT) w3m dump (openflexure.org)
| hifikuno wrote:
| This is amazing. I think this would be a fun project for me and
| the kids to make and have a useful tool to help them with their
| curiosity.
| dekhn wrote:
| This scope is nontrivial to build and run. I recommend buying a
| cheap stereoscope and spending more time enjoying looking at
| things before jumping to diy.
| ahmadmijot wrote:
| btw, the OpenFlexure forum link is 404.
| earthtograndma wrote:
| Working now. https://openflexure.discourse.group/
| roflmaostc wrote:
| There is a similar project called UC2 where the emphasis is on
| modularity of the different configurations (simple building
| blocks) https://github.com/openUC2/UC2-GIT
| moffkalast wrote:
| I'm wondering now there if are any cheap entry level stereo
| microscopes or at least any microscopes that work with indirect
| reflected light instead of through-slide illumination. LEDs have
| gotten laughably strong, so if we can turn a night forest into
| day, surely we can illuminate some microbes?
|
| These standard ones are certainly useful for high magnification,
| but they don't really work at all for anything opaque. For the
| average person doing this on a hobby level, looking at random
| objects slightly beyond macro level is far more interesting than
| having to painfully prepare slides for things you aren't even
| sure are actually there or not.
| buescher wrote:
| Cheap is relative, I guess. You can find a used stereo
| microscope on eBay for well under $100, maybe under $50.
| Building one out of a pair of binoculars is a classic but
| relatively advanced DIY project. I'm pretty sure there's a
| detailed write up of one in either the old Edmund's optics
| books or Scientific American's amateur scientist collections.
| Something like this:
| https://web.archive.org/web/20190123040421/http://www.funsci...
|
| If you're thinking of something like a metallurgical
| microscope, those are more involved and expensive, but again,
| eBay.
| Zobat wrote:
| Bought mine at our local "biological" museum for about $150 (in
| Sweden where everything is a little more expensive). 20x/40x
| magnification, indirect or through slide illumination, solid
| construction.
|
| The leds could be better and/or brighter but works for looking
| at stuff and for photography with a 3D printed phone holder on
| one of the ocular lenses.
| dekhn wrote:
| The cheap stereomicroscopes don't have "indirect reflected
| light" but it's not hard at all to add a ring illuminator or
| just arrange a flashlight or other led light that comes in from
| the side. I emulate darkfield using a side illuminator all the
| time. You can also replace the installed LED with an LED matrix
| (like the tiny one adafruit sells) and just illuminate the
| outermost ring of pixels, this will emulate dark field mask.
| geokon wrote:
| This is outside my area of expertise .. But I'd be surprised if
| you can easily best a phone camera without paying obscene dollars
| for special sensors
|
| A bit of an anecdote, but a lab in our building got some
| expensive fancy digital microscope. But we noticed that if you
| took a cheap old school microscope and stuck an iPhone on the
| lens the resulting images were infinitely more crisp vivid and
| high-res
|
| The only obstacles are getting consistent colors and calibration
| as well as making a mount to hold the phone at the right distance
| from the lens
| addaon wrote:
| Many of the best cell phone sensors are off-the-shelf Sony
| sensors that individuals can buy in reasonable quality. The
| "magic" of cell phone cameras is the combination of these
| decent sensors, a lot of processing (that you don't want), and
| really amazing lenses (that, in a microscope application,
| you're replacing with your own -- better to go microscope
| optics to focal plane than microscope optics to cell phone
| optics to focal plane). Certainly at the hobbiest level cell
| phone cameras are amazing, but I suspect even "advanced
| hobbiest" or whatever would prefer the same sensor in a C
| mount.
| geokon wrote:
| A raw sensor is clearly not easy to just hook up to a
| computer.
|
| For example look at the top end Raspberrypi sensor. It's a
| pathetic 12MP. That's like a ten year old phone or so?
|
| I think the processing is also not to be entirely dismissed.
| There is frame stacking that extends the dynamic range and
| there is compression and other complex DSP going on that is
| necessary (b/c 50MP of raw pixel data is a ton of raw data to
| pull off the sensor). Realistically you probably can only do
| some of that in software
| billyjmc wrote:
| You _can_ do all of these things in software, and it is
| done. It's important thing to have control over the process
| so you can get quantitative data at the other end, and not
| just a pretty picture. Also, noise should not be discounted
| as a very good reason to use lower megapixel sensors. If
| you want a pretty picture, by all means use a cellphone,
| but you can't reality use or trust the result for many
| scientific purposes.
| dekhn wrote:
| High pixel count cameras aren't that useful in microscopy.
| Big low noise pixels are better. For every sensor there is
| already a breakout board with USB. Mostly intended for
| machine vision.
|
| Edit: added link to Arducam USB cameras :
| https://www.arducam.com/product/arducam-64mp-motorized-
| focus... is a 64MP camera although note it's 1FPS. Instead
| I would prefer
| https://www.arducam.com/product/presalesarducam-8-3mp-
| imx585... which has C-mount that's perfect for scopes, it's
| 4K for still images, and the sensor is specifically
| designed for low light, when tends to be common in
| microscopy at higher magnifications./
| teamonkey wrote:
| A 4K TV is 8.2MPix. You would need extremely good optics
| and a very high resolution display to make full use of a
| 12MPix camera, let alone more.
| AlanYx wrote:
| >But we noticed that if you took a cheap old school microscope
| and stuck an iPhone on the lens the resulting images were
| infinitely more crisp vivid and high-res
|
| That's the core reason why the Foldscope is so popular. It
| really does work well.
| RobotToaster wrote:
| People have been mounting off the shelf cameras to microscopes
| since before digital cameras existed.
| julianstirling wrote:
| (Note I am an OpenFlexure Maintainer) Camera sensors are very
| rarely the limiting factor for a microscope unless you are in
| pretty exotic modes where speed, timing, or low light
| conditions are important. The key reason it is better often to
| use something like a Raspberry Pi camera than a phone is you
| know exactly what sensor you have and can design for it. Also
| there are benefits of not having the lens in front of it where
| you then need extra lenses to act as eyepieces to view a
| virtual image. But using the picamera and either using a
| microscope objective and a tube lens (or in the low cost
| version just the picamera lens and a spacer) we can get
| diffraction limited performance in a really small, light
| footprint. (More detail on the optics for nerds:
| https://build.openflexure.org/openflexure-microscope/v7.0.0-...
| )
|
| However, the camera/sensor isn't the clever bit. The main
| benefit of OpenFlexure is the automated stage. The range of
| motion is small and the motion is slow so it really isn't the
| right microscope for looking at something like a bug leg. But
| if you want to take loads of high resolution images with a high
| powered objective and stitch them into a composite image (or
| take time-lapses automatically autofocusing regularly) we are
| considerably smaller, more affordable and more customisable
| than commercial alternatives. With lots of options for
| scripting.
|
| As an example of what is possible, check out this multi-
| gigapixel composite image of a cervical smear, and the
| resolution when you zoom in:
| https://images.openflexure.org/cap_demo/viewer.html Note, this
| is collected with an experimental branch of the software (of
| course open source). We need to do some tidying and bugfixes
| before it is ready for release.
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