
Cheap microscopes: Yours to cut out and keep - feelthepain
http://www.economist.com/blogs/babbage/2014/04/cheap-microscopes
======
ColinWright
This deserves to be better known, and the project deserves success. Here are a
few previous submissions of the story, each with its own slant and its own
take on the topic. Some have comments, most don't, I've only marked the
largest discussions.

[https://news.ycombinator.com/item?id=7503554](https://news.ycombinator.com/item?id=7503554)

[https://news.ycombinator.com/item?id=7495183](https://news.ycombinator.com/item?id=7495183)

[https://news.ycombinator.com/item?id=7448294](https://news.ycombinator.com/item?id=7448294)
: 13 comments

[https://news.ycombinator.com/item?id=7407449](https://news.ycombinator.com/item?id=7407449)

[https://news.ycombinator.com/item?id=7385509](https://news.ycombinator.com/item?id=7385509)

[https://news.ycombinator.com/item?id=7384131](https://news.ycombinator.com/item?id=7384131)

[https://news.ycombinator.com/item?id=7377213](https://news.ycombinator.com/item?id=7377213)
: 58 comments

[https://news.ycombinator.com/item?id=7369558](https://news.ycombinator.com/item?id=7369558)

[https://news.ycombinator.com/item?id=7367503](https://news.ycombinator.com/item?id=7367503)

[https://news.ycombinator.com/item?id=7365903](https://news.ycombinator.com/item?id=7365903)

[https://news.ycombinator.com/item?id=7363305](https://news.ycombinator.com/item?id=7363305)

~~~
frozenport
You can get a children's microscope for $5 dollars that has the same resolving
power, but it still hasn't changed healthcare.

I got tired arguing with people that the cost of healthcare is not the
microscope.

Its either the people or the disposable goods. For example, it is difficult
and costly to prepare the following slides:
[http://cdn.dogomedia.com/system/ckeditor_assets/pictures/532...](http://cdn.dogomedia.com/system/ckeditor_assets/pictures/5329b83f1860e0297c0020b4/content_Prakash-
Foldscope2014_copy.011.jpg)

At the end of the day $757,000 could have been used to dig 1000 wells.

~~~
vacri
I remember seeing a talk by an antarctic scientist researching anti-freeze
oils in fish, for use in the food sciences. Down there with his crew and
expensive equipment, boring a hole through the ice to catch fish... and the
most fundamental bit of equipment they used in the process was the fishing
rod. They couldn't find a short rod easily (Australian, no culture of ice
fishing) so they ended up using a toy Snoopy-branded rod, all of about 30 cm
long...

~~~
foobarian
Why on Earth did they happen to bring a toy Snoopy-branded fishing rod with
them on an Antarctic expedition?

~~~
vacri
It was purchased as part of the mission equipment. Australia doesn't have ice
fishing, so there aren't really any sources for short fishing rods. The toy
rod was available, and did the job!

------
chrisBob
I think it is a great product, but the numbers are a little misleading. In
microscopy the most important number is usually the resolution not the
magnification, and 1µm is what you expect from a 20x objective. The 2100x
specification doesn't help much and confuses people, but to be fair, a good
20x objective starts in the $200-400 range.

~~~
EpicEng
I work on digital microscope scanners and I have always thought that 1um was
the general value for a 10x objective (because that is always what it is on
scanners.), 0.5um for 20x, etc. I realize that many factors contribute to
effective magnification (and resolution), but your statement makes me want to
look more closely at standard microscopes.

~~~
chrisBob
The resolution is given by 1.22λ/NA.

λ can be rounded to 500nm and the NA of a standard 20x objective is .4 giving
1.5µm. This is good because I was worried you caught me just making things up
for the internet. A 40x with a .65 NA gives just under 1µm resolution.

Resolution is also a slightly fuzzy spec depending on the audience. I go with
the Raleigh criteria: You can't distinguish between two particles separated by
less than the resolution distance. You can however, see particles much smaller
than that, and there are many variations, most of which give you better
resolution numbers. We occasionally use other specifications when we need to
say we met a specific target.

The standard objectives I am quoting are Olympus Plan Acromats, different
systems have different tube lenses which cause you to get a different
magnification out of the same objective. That is why the NA is the important
factor. Otherwise I would just use a 1m tube lens and get 5x higher
magnification numbers to report similar to what we see with the paper
microscope.

~~~
EpicEng
Ok, that makes sense. We tend to use high NA objectives for our applications,
and the light path is a bit longer than in standard scopes (though not too
long as to introduce too much empty magnification.) shows how much I still
have to learn about optical systems even though I've been writing control
sofwtware for these things for almost five years now.

------
dm2
How do I purchase one?

Is it possible to attach to a phone to take a picture?

Here is their website: [http://www.foldscope.com/](http://www.foldscope.com/)

Why would the initial test to 10,000 if it only costs $1. I would gladly pay
$5 (if that includes shipping). If there is a version 2, I would gladly pay $5
to purchase that one also.

This reminds me of the Cartmanland commercial, "awesome new themepark, and you
can't come!"

~~~
Aardwolf
I wonder if it's also possible to make it yourself from paper?

Or 3D print it?

Not that the makers don't deserve the money!

~~~
yitchelle
Maybe not from paper, but the research paper is here[1], so no obstacles.
Right? :-)

[1] -
[http://arxiv.org/ftp/arxiv/papers/1403/1403.1211.pdf](http://arxiv.org/ftp/arxiv/papers/1403/1403.1211.pdf)

~~~
Steuard
Side note (as a scientist who uses the site): there are lots of different ways
to share an arXiv.org link, but in almost every case the best option is this:

[http://arxiv.org/abs/1403.1211](http://arxiv.org/abs/1403.1211)

That links to an abstract page for the same paper you linked to rather than
the full PDF, and it's a lot shorter to type (and less specific about format).
This form often avoids accidentally linking to an outdated version of the
file, too.

------
cheetahtech
Here is the Ted Talk on the Microscope.

Its quite incredible.

[http://www.ted.com/talks/manu_prakash_a_50_cent_microscope_t...](http://www.ted.com/talks/manu_prakash_a_50_cent_microscope_that_folds_like_origami)

~~~
gcb0
So it is a lens, CR232 batteries, and a LED... and you are invited to use and
throw it away with the battery? not very clever.

~~~
dhaivatpandya
I think this comment exemplifies the "HN negativity syndrome".

Completely disregarding the years of effort poured into developing a paper
lens, etc., you simply dump the innovation into the "not very clever" pile?

~~~
gcb0
paper lens?! are you trying to signify the other side of HN that upvotes
kickstarter links without even reading? :D

~~~
dhaivatpandya
See research paper:
[http://arxiv.org/abs/1403.1211](http://arxiv.org/abs/1403.1211)

When I said "paper lens", I meant the idea of embedding the lens into the
paper.

------
VLM
Note that this is a different meme than the popular "you can make your own
working general purpose camera out of cardboard". That meme is moderately
popular and has been successfully implemented many times.

This is a different concept, of a precision manufactured, very cheap, single
use, very specific medical test microscope generally revolving around a
projection display technology.

I'm not saying its not cool. It is cool and is a net gain to humanity etc. Its
just probably not what you're thinking it is based on the short description.

I think a general purpose "print/fold at home" microscope for educational
purposes would be interesting, along the lines of numerous successful
cardboard photographic cameras, and maybe even useful. The linked article,
although also cool, has nothing to do with that meme, and is almost the
precise opposite other than common construction material.

Also this is an old story, even if newly reported. I remember watching the TED
talk from the TED RSS feed during a blizzard some months ago. As per Colin's
post this is the 12th time its been featured on HN.

~~~
pcl
The article didn't mention anything about it being a single-use device. And
from the description, it sounds like the intention is that the device would be
printed professionally for best results, but assembled by anyone (hence the
focus in simple instructions that don't require any test).

Also, the article mentions projection capabilities, but as a non-standard
modification.

~~~
VLM
Watch the TED talk from a couple months ago, it was pretty good, better than
the average ted talk and I mean that as a compliment to the presenter not as
trashing the rest of ted, or read the other 12 HN postings, I am correct in
those assertions, at least as presented.

------
dm2
I found this DIY microscope for smartphones if anyone is interested:
[http://www.instructables.com/id/10-Smartphone-to-digital-
mic...](http://www.instructables.com/id/10-Smartphone-to-digital-microscope-
conversion/)

~~~
Lambdanaut
I saw this in action at a local maker faire. It uses a laser pointer's lens as
the refractor, and works pretty well! Definitely a clever hack, and the bonus
is you can easily take pictures of what you find!

------
zafka
I did a quick search on the glass spheres, and the only place I could find to
buy them was Edmund Optics for $15.00 each. Does anyone have a decent source
for the lenses?

~~~
chrisBob
Edmund has good prices. That is probably your best bet in small quantities.
One of the nice things about ball lenses is that they are made in batches, so
large orders scale well.

------
gradi3nt
Can anyone comment on the more technical optical properties of this
instrument? How does it perform compared to a traditional microscope with the
same magnification and resolution?

~~~
twistedpair
I'm a dev, but got my degree in optical engineering not that long ago.

The reason this is not news is that good microscopes cost money. Saying "hey,
I've achieved 2100x magnication!" is pretty meaningless. Anyone who's ever
used a nice camera can instantly realize the difference in the photos you get
with a $500 Canon lens compared to that disposable camera you bought for $5.

The pictures they've supplied are wonderfully blurry. Three cheers for poor
light sources, spherical aberration and diffraction blur. If you're doing
slides with results of great import, such as various health tests, you want an
accurate image. We don't get to see any shots of optical calibration targets
here, which would demonstrate just how poor the optics are. As a rule of
thumb, anything over 1000x is usually poor and 1500x is considered the
practical limit of optical microscopy (without some really expensive tricks
like conjugate points and fluorescence which gets you a $100K+ kit).

So yeah for cheap microscopes!, but I had a $5 one as a kid. Nothing new here.
Plus, training people to properly prepare the slides and interpret the images
correctly is a far larger problem. I've watch Harvard and other labs haul away
truck loads of old equipment to the dumps. Let's send that to anyone in the
3rd world that wants it, but not waste too much time doing what's already been
done.

------
nathancahill
This is based on a ball lens. There are several ball lens hacks floating
around the internet, like this "iPhone Microscope" research paper[0] and this
DIY[1] to build your own. Ball lenses are cheap and you can attach it to
cellphone camera lens with a little M3 tape.

The cutout paper part seems to just hold the slide, and pane it in front of
the lens.

[0]
[http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...](http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0017150)

[1] [http://www.instructables.com/id/Cheap-and-easy-iPhone-
micros...](http://www.instructables.com/id/Cheap-and-easy-iPhone-microscope/)

------
netcraft
Did anyone get in the initial test that can comment on the quality and
performance?

~~~
tedsanders
Yes. What would you like to know? The devices are cheap and durable and they
work.

~~~
netcraft
Do you have any pictures of the whole device? What is the overall size? How
long does the watch battery last? I would assume quite a while since it is an
LED

~~~
tedsanders
It's like 6" by 3" by 1/4".

You can see the size in the TED talk or on the website:
[http://www.foldscope.com/#/scienceeducation/](http://www.foldscope.com/#/scienceeducation/)

Honestly, I'm not sure how long the battery lasts. I've mostly worked with the
versions that have no backlight (to use them, you hold them up to a lightbulb
or to the sun).

------
RankingMember
Wow, this is awesome. I've been looking for a cheap microscope to just have
around the house and noticed that they indeed haven't changed a lot in
cost/features in quite some time.

------
davexunit
Please tell me that the specifications will be released under a free culture
license.

~~~
popey
From their FAQ, which to me means "no".

" Is Foldscope an open hardware project? Do you have plans for the same?

We are currently exploring best possible ways to provide quality tools to
largest number of people. We have two missions; one in healthcare and one in
education. We are exploring all possible options to bring this tool to the
masses and exploring licenses that allow us to do this in a sustainable
manner. More information about this will be available here soon. "

~~~
davexunit
Thanks for that. It's counterproductive for a project like this to not be
free/open hardware.

------
neals
Are there any images of what a 2100x magnification looks like?

~~~
neals
I found this page that shows various levels of magnification:
[http://www.grayfieldoptical.com/selected-
examples-1.html](http://www.grayfieldoptical.com/selected-examples-1.html)

~~~
chrisBob
This is exactly why the 2100x spec is a bad one. The 1µm resolution they claim
is no where near as good as the resolution in the linked 2000x images here.

