

How Your Camera Works - adamnemecek
http://www.objc.io/issue-21/how-your-camera-works.html

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alkonaut
How your _phone_ camera works. It's a well written article but it seems odd to
cover how a camera works and leave out Aperture because of the edge case of
having a fixed aperture as in a smartphone. With a longer description of
aperture and some picture examples of aperture controlling DoF and exposure
this would have been a complete introduction to digital photography, now it's
a complete introduction to fixed-aperture digital photography...

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DanBC
> because of the edge case

Edge case? Phone cameras are very common and more common than DSLRs and
probably more common than digital point and shoot.

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saiya-jin
True, but title is really misleading, and from true photography point of view,
smart phone cameras are edge case, on low quality end of spectrum.

Also, most people with smartphone will never care for more than point & click,
so suggested slight enhancement of coverage would make much more sense
(although it doesn't put in anything that isn't already written out there
1000x times).

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danieleggert
Thanks for the feedback. The reason I picked this title is simply because
"your camera" for most people will be their smartphone. A bit too catchy for
people with a DSLR.

But as other people have noted: Most photos today are taken with smartphones.
I touch upon aperture, and linked to Wikipedia for those interested in in-
depth information.

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chestervonwinch
I recently started looking into computational photography. I didn't realize
how much of the imaging acquisition process I was ignorant of: color theory,
exposure, shutter speeds ... It's all pretty intuitive, but I feel like need
to learn optics to really get it all!

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adamnemecek
There's this Stanford projects called Frankencamera [1] which is pretty jaw-
dropping. They do a bunch of cool stuff but the one feature that really stood
out was that you can take a photo and then focus it in post-production.

[1] [https://frankencamera.wordpress.com](https://frankencamera.wordpress.com)

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AceJohnny2
Post-production focus? That sounds like Lytro, another Stanford spin-off (but
based on a grid of lens): [https://www.lytro.com/](https://www.lytro.com/)

~~~
adamnemecek
interesting, thanks for the link

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ShinyCyril
I highly recommend a read through of Barbara London's Photography book [1].
Apparently this book is still commonly used for photography classes even these
days.

I have the 3rd edition which is pretty old, but all of the information is
still applicable - film and digital cameras share the same basic principles.

[1] [http://www.amazon.com/Photography-11th-Edition-Barbara-
Londo...](http://www.amazon.com/Photography-11th-Edition-Barbara-
London/dp/0205933807)

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semi-extrinsic
Here's a great article giving an even more indepth look at camera sensor
technology:
[http://www.olympusmicro.com/primer/digitalimaging/cmosimages...](http://www.olympusmicro.com/primer/digitalimaging/cmosimagesensors.html)

~~~
wluu
Though that only describes the Bayer array (which is used by most cameras
except for Fujifilm and Sigma).

Fujifilm's mirrorless cameras use what they call X-Trans CMOS sensor tech -
[http://www.fujifilm.eu/uk/products/digital-
cameras/interchan...](http://www.fujifilm.eu/uk/products/digital-
cameras/interchangeable-lens-cameras/model/x-pro1/features/fujifilm-x-trans-
sensor-technology/)

And Sigma uses the Foveon X3 CMOS sensor -
[http://en.wikipedia.org/wiki/Foveon_X3_sensor](http://en.wikipedia.org/wiki/Foveon_X3_sensor)

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Leibo32
I have been trying for years to make sense of how to use my digital camera. I
usually just fumble around good article getting me going the right direction.

~~~
bobbles
you should check out Tony Northrup on youtube. he does awesome guides to using
certain model cameras (rather than just a review, an actual 'how to use your
camera' guide)

Even if you dont have the camera in the video you learn so much about how they
work

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padde
This is great explaining, very neat, thanks! I'll definitely link to it from
time to time when friends or colleagues don't grasp the basics of capturing
images and colour processing.

~~~
danieleggert
Thanks. Glad you liked it.

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huuu
Can someone explain to me how ISO on a digital camera works? Are several
pixels combined (the resolution lowered)?

I always think it's odd to have ISO settings on a digital camera.

~~~
dietrichepp
No, the ISO setting adjusts the analog gain before conversion to digital. As
you would expect, this raises the noise floor. It is natural and expected to
be able to adjust speed on a digital camera, because the dynamic range of a
ADC is limited, and you want to be able to use that range optimally.

For example, suppose your camera has a dynamic range of 10 stops. If you are
shooting a scene with a dynamic range of 8 stops, then you get +/-1 stop of
latitude where mistakes in exposure can be corrected digitally. Overexpose,
and the signal will sometimes be above the range of the ADC. Underexpose, and
the signal will sometimes be below the range of the ADC. You can adjust either
the exposure (aperture, shutter speed) or the signal gain (ISO) to get the
signal into the right range.

You do the same exact thing when you're recording digital audio: you adjust
the gain so that you use most of the range of the DAC. As in photography, you
can try increasing the gain afterwards, but you might get problems with noise.

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peterwwillis
Before going on a long vacation of sight-seeing I thought, I should buy a nice
camera to memorialize the trip, but I don't know what to buy. Three days of
research later and I figured out how the sensor type & size, shutter speed,
aperture size, ISO level, and magic proprietary software combine to create a
good picture in different environments. I couldn't explain it to you, but I
can now find the best point-and-shoot camera for the lowest price.

I never did end up buying a camera, though.

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galago
I can't downvote, but this seems a bit thin for HN.

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DanBC
Noone can down vote submissions.

As far as I know most people can flag submissions so if you think it really
doesn't belong here you could flag it.

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jwcacces
Why is this page so wide?

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rcthompson
> Click! Your camera just turned photons into bits.

Click! Your camera just made a skeuomorphic sound.

~~~
Sharlin
My camera has a reflex mirror and a mechanical shutter.

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fennecfoxen
Reflex mirror??!? Get out. Rangefinders forever, baby!
[http://instagram.com/p/i35NJLQAeM/](http://instagram.com/p/i35NJLQAeM/)

