How Does a Photon Become a Film Photo?

The chemistry behind film photography is pretty fascinating. How do film cameras help us turn light into a physical image?
Thumbnail Credit: Don O'Brien commons.wikime...
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Sources:
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Ascher, Steven and Pincus, Edward. The Filmmaker’s Handbook: A Comprehensive Guide for The Digital Age. Plume, New York: 1999. Pp 16, 76, 111,112-113, 189
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[@SciShow]

Yes, this is a reupload. Thanks for pointing out our blunder. We got distracted by the photons!

[@SolarWarden666]

SciShow you guys should do a video on eidetic memory.

[@photonicpizza1466]

+Nikolay Sones There's a video about that on the SciShow Psych channel

[@alexlawson4173]

Regardless, Ive never seen it yet. So Thanks. :)

[@SolarWarden666]

Photonic Pizza Thanks man

[@MichaelManus]

SciShow dang you work fast!

[@KingsleyIII]

A photon is checking in at the airport, and the bag lady asks "Do you have any bags to check?" The photon says "No. I'm traveling light."

[@MeTriviSlipKlokDriva]

phewwww

[@laggingjaeger1148]

*ba dum tssssssss*

[@MephLeo]

Yeah, I mean, photons really have zero rest mass...

[@Jonathan-th4wz]

That NDT joke tho

[@KennethDAstonJr]

LOL I have to use that one

[@poorplayer9249]

This video brought back memories of photography club in 4th grade. Learning how cameras worked, experimenting with exposures, etc., and working in the darkroom to develop and print pictures...1967. Thanks SciShow!

[@PlagueRiddenBlightSpawn]

As a huge film photography fan, I really enjoyed this episode!

[@SamanthDarling]

I was really into film photography and chemistry at the same time so this brought back some good memories! Still sort of miss when my school uniform would smell like developer

[@naytrevejo3996]

I Still develop negatives and photos in a dark room. The work in a photo in my opinion feels more personal than doing it digitally in a computer. I'm glad this video exists because it demystifies all the process, it's just to know math and chemistry, and control your times. Great video guys, even if is a re-upload.

[@Diceyed]

ah, i was wondering how they made a negative into a positive larger image. also on a slightly unrelated topic, i remember someone pointing out the reason why vampires can't see their reflection in a mirror or in a photo is that Silver was used in film cameras and in older mirror's and silver was known as a holy metal that could not bare the image of vampires.

[@DasUmami]

You small negative and large positive paper and project negative on to positive and then use chemicals to convert (develope) positive into actual photo

[@debashreekonwar4321]

😂

[@RobinKirbyGatto]

ABSOLUTELY AMAZING!!!!!! I have been looking through a gazillion videos to find someone who could teach this process adequately and coherently and finally found this one! Keep on keeping on you do great work and have a great teaching gift!!!

[@ketsuekikumori9145]

I can't recall if they did this one, but how does colored film work?

[@RealLuckless]

Much the same as black and white film, but with far more layers to the emulsion and also making use of filters along with coloured dyes in the reactions.

[@ketsuekikumori9145]

kinda figured as much, though filters didn't occur to me. thought it was just using the natural quirk of light of different wavelengths to hit the different colors.

[@777sillydog]

Ketsueki Kumori you use colored filters in the enlarger when you are printing. The film has layers of colored vegetable dyes as well as silver halide in it. Formaldehyde is used in the development process so that they remain stable. Photographers keep their film in the fridge so the film doesn't change color/ fresh like veggies. Hope that helps.

[@MaxwellStarr]

Color film works similarly up to a point, but has 3 layers stacked on top of each other, each containing a Red filter, Green and Blue filter which filter the light going to the 3 layers of Silver Halide. Each layer also contains a dye that activates during developing that converts Red to Cyan, Magenta to Green and Blue to Yellow. When developed, the developer washes away the Red/Green/Blue filters and the dyes only activate around the ionized silver particles, giving you a negative colored image. A bleach step then converts the developed silver particles back to silver halide crystals which are dissolvable in a chemical (called a Fixer) that removes all the remaining silver particles leaving only the dyes behind on the film, giving us a color negative. Color Positive films (ie: Slide film) work the same way but the dyes on the Red/Green/Blue layers instead come out the same original color.

[@tjmaxwell21]

Excuse me the preferred phrase is "film of color"

[@RealLuckless]

Developing black and white film at home is actually way easier than a lot of people realize, and a dark room is not actually needed. Sure, it can be handy to have one, but you can do a lot with film work using only a changing bag, daylight development tanks (Containers that you load the film in while it is in the dark, but can then handle the tank on a work bench in the light to pour chemistry in and out), and a film scanner. Working with medium and large format negatives is kind of a neat treat.

[@s0matando]

It's interesting that you brought this up. I had photo classes in college and forgot that kids nowadays may not even know that we used film before, or how it worked! Slowly it's making a comeback, like the LPs maybe. My niece bought a Polaroid camera for instance! =]

[@alveolate]

there is only one reason to go back to film - to get super-high resolution photos without buying a super-expensive high-res DSLR. as long as your focal length was correct, a film camera would take the photo with extremely high resolution - the pixel-size is literally down to the molecular level. this would require perfect lens focus, of course, which is not that easy to achieve at that level of precision; but if you get close enough, you would get a photo with far higher functional resolution than you could get with standard CMOS chips. that said, there aren't many applications that require such high resolutions. also, there's the DSLR trick of stitching multiple shots together to achieve higher resolutions (but it only works with still portraits and can require a lot of work to get the focus and distortion correct on each shot). developing film conventionally is also slightly risky, as the chemicals are slightly toxic (don't rub your eyes after touching them). as for the "polaroid experience", there are portable printers which can wirelessly connect to cell phones. these little guys can be loaded with high quality photo paper, and produce prints in seconds like a polaroid. in terms of product quality, portable printers are superior in every way to the old polaroids - there is literally no reason at all to go back to polaroids other than irrational nostalgia.

[@rydaddy2867]

I had a photo class in high school...can kids even take a film photo class anymore?

[@Andrewsarcus]

How about the glass plates used for early photography. Especially Astronomy and how modern laser scanning techniques enable research to show just how sensitive the early photo emulsions were. Scanning a glass photographic negative over 100 years old at 6 million DPI can show detail that the original astronomers could only dream of.

[@Cadwaladr]

It's essentially the same process, just an emulsion on glass instead of film.

[@robertdraxel7175]

I express my thanks for people making such channels on youtube a reality! Thanks!

[@zombieblood1675]

My mom "son back in my time they didnt have collor tv " ME"i can write you a presentation on the history of tv and pictures" MY mom "bet you cant" Sci show uploads this 20 seconds later. Thanks

[@justingasparino9204]

zombie blood colour*

[@RevolutionGamersHD]

Random Person colo(u)r*

[@yayu984]

RevolutionGamersHD you both are right. color is the american way to spell colour

[@camicus-3249]

Of course, but we can all agree it isn't "collor"

[@RustyTube]

Back in my time we didn’t have any TV at all.

[@Samuel-ge7im]

Great Job Sci show! Your Videos are always informative and interesting! Keep it up!

[@Babarudra]

Wow, great job explaining the basics of photograph development in 3ish minutes!

[@Cadwaladr]

If the silver grains in the negative are large enough they can appear shiny. If you look at the negative in bright light against a dark background, you can see a positive image.

[@Ahhh714]

The camera was always the one invention where we were always so close to created throughout history even in antiquity. There was so much experimentation going on in optics, the missing piece was perfecting light sensitive material. Really could have been invented a lot sooner and should have been invented as late as the 1600s.

[@alexlandherr]

I’ve always wondered about the development process of film, thanks SciShow!

[@CamCakes]

This is JAAAMMMMM packed with a lot of chemistry!

[@jamespurks1694]

Thank you for the post. It contained some things I did not know before.

[@THETRIVIALTHINGS]

I always wanted to know how those film rolls worked. Thanks SciShow!

[@duddernator]

So how do Polaroid cameras work? Is there a chemical reaction happening inside the camera?

[@QuantumLeclerc]

It's basically a mini developer and printer I think

[@RealLuckless]

The film is packed with the development chemistry built in - As the film is passed out of the camera after taking an image it is forced through rollers that squeeze the chemistry against the film, and starts off the reaction. So remember to handle them with care, but that kind of goes for all film really.

[@ajaxhopper9859]

RealLuckless lol, "squeeze the chemistry"

[@eazyzero8215]

@@ajaxhopper9859 ur funny

[@ThisIsTaco1]

3:22That pun was magnificent, i'm not even mad.

[@admanmccombs]

At 0:16, you show the light hitting the mirror of an SLR camera and going through the view finder, not the film that rest behind the mirror.

[@jazzclarinet2006]

Not to mention that it's pointing to the shutter instead of the film.

[@crystall9522]

My high school chemistry class had a photography unit where we made pinhole cameras out of shoe boxes and developed our own photos. It was great!

[@taramas5582]

We did this in 5th grade physics class. It is awesome!

[@BotchedGod]

MIND BLOWN

[@Yellowdigigod]

Even as an upload, you are still the best Scishow host.

[@omnilearners3974]

I have tons of old films around my house. It's nice to know how they worked.

[@MrJdguanguan]

Great Video! Very imformative thank you

[@Nurauq]

That was great! Thank you!

[@Dyslexic-Artist-Theory-on-Time]

Like everything it is photons interacting with the atoms of the periodic table over a period of time!

[@vadse1012]

Now it all makes sense thanks

[@leftlane5085]

you said that "if more photons hit a silver halide crystal, more reactions with the developer can happen, & that spot on the film strip becomes darker." can you explain this? won't the silver halide crystals that took in relatively more photons have LESS silver ions to receive electrons from the reducing agent?

[@Master_Therion]

Always remember, when developing a selfie from a film camera you are "exposing yourself" so you better do it in a "dark room."

[@cup_check_official]

clever boy

[@patrickmccurry1563]

I love how they chose the only presenter that looks like he might have a vintage camera in his closet. That's not an insult, in case anyone's wondering.

[@pinustaeda]

Nice save, re-uploading this. Could have chosen a better picture for the camera though, since the mirror is down in it.

[@BlueyMcPhluey]

very calming voice

[@carnemajoris7316]

can you make a another one about cameras and how it started and developed? really interesting subject. greetings from vienna.

[@zebionic]

Very interesting, and for me especially. Some 25 years ago (when I was a teenager) I developed some photographs myself, but never quite understood the process.

[@iminthatweirdpartofyoutube2687]

Very informative video! I still shoot film, the darkroom is so much fun!

[@nimraaslam7715]

Thanks alot!

[@Fxiry101]

OMG thank you!!

[@yoganusasanam8174]

great video. film forever

[@edgbaston149]

Thanks you so much

[@RobinKirbyGatto]

Just out of curiosity do the reducing agents react with the silver ions or silver atoms, giving an extra electron to them. I believe you mention initially it reacts with remaining silver ions and then you mention it makes them darker with the silver metallic composition. However, when you are showing spoon part, you then say "atoms." Once the silver ion is hit by photons and becomes a silver bromine atom, is that what the reducing agent attaches to, providing an electron, making it darker? Thanks! Robin

[@hpjme]

how does the reaction work with instant film cameras like polaroids and the new instax cameras?

[@kristinag7391]

Interesting. I took a photography class in methacton school district. That was my first experience combining science and art

[@Tenwyg]

Love it, but some model graphics of the reactions would have been super helpful.

[@AidanRatnage]

That was a super quick re-upload.

[@Senechyn123]

Aidan Ratnage true, what's different?

[@AidanRatnage]

I don't know, it was so quick that by the time I clicked on the original it was already taken down.

[@cup_check_official]

the emulsion. i think they pointed out the viewfinder as the emulsion in the previous video. glad to see they are making sure that the right information is out there

[@hym279]

Excellent video. Just a comment, on the picture of the camera, tje light and circle don't point to the film but to the mirror of the finder.

[@casualcadaver]

Can you do one on different film types and it's comparisons to digital in terms of resolution ?

[@Michael-TheArchAngel]

What about Colored negatives and Positives how is the color information stored and how can one scientifically calculate who accurate the photo is it to the real scene?

[@Otokichi786]

Once upon a time, when Modern and Popular Photography magazines were being published, the whole "how does light turn into a photograph" question was more theory than fact. It's nice to know that this clear explanation about what goes on with film and photographic paper sheds quite a bit of light onto the photochemical experience.;)

[@ischyz7105]

It's no wonder people used to think photographs could capture a person's soul, if alchemists were the only ones who could create them...

[@patrickmccurry1563]

I doubt anyone actually believed that. It sounds too much like what racists using advanced tech would accuse the local "savages" of thinking if and when they saw it.

[@sion8]

Patrick McCurry​​ Some Aboriginal Australian people still do, some Native Americans used to think of it a bad thing but of those some later changed their minds and actually added photos into their funeral rituals and/or a continued link with their dearly departed ancestors, and in Islam it is seen as disrespectful to pray in a place that has photographs in it. The believe seems to come from the fact that in some mythologies (such as Voodoo among others) mirrors were seen as a window into the soul and because early photography and even to this day uses mirrors in order to reflect light so that it can be captured in film or digitally, they thought that it could capture the soul of people.

[@Lttlemoi]

+Patrick McCurry Instead of just assuming racism in everyone, perhaps take a moment to do some basic research? People of all ethnicities have believed and still believe the craziest stuff, ranging from using powdered rhino horn for increasing virility, raping babies to cure AIDS, that people can rise from the dead, turn into bats and suck out the blood of young women, that murdering slaves or volunteers on an altar and cutting out their organs is good for agriculture or that disemboweled dead bodies don't need a brain to survive in the afterlife. Honestly, the idea that photographs capture the soul is rather on the tame side.

[@Logan912]

"Derek, I don't know if you're familiar with the belief that some Aboriginal tribes hold. It's the concept that a photo might steal a part of your soul, and what are your thoughts on that as someone who gets their picture taken for a living?" "Well, let me answer your question with another question. How many Abidigenals do you see modeling?"

[@HarryL2020]

ischyz it's just stupid religious people, they will always slow us down unless we get rid of them.

[@cojawfee]

Can you do a video explaining color photography?

[@CommentCritic]

....dude I have the exact same hoodie. Cool!

[@mahmoodandalibph]

thanks for grat information

[@Yadid1]

Can you make a video on the Camera Obscura?

[@michaeldaugustine9249]

This explains how they made black and white photos. But how did they make color photos using film?

[@DimitrisPapadopoulos1980]

0:21 These are the shutter blades not the film ! I guess that you could find a better picture for this !

[@michaelwalton4017]

FIRE PHOTON TORPEDOES!😮

[@naomifarago8983]

Hank green is the best host of scishow

[@kassepirai5310]

How is music stored and replayed in CD/vinyl?

[@sandmastermaster]

He's whispering like they filmed this 1:00am when mom and dad are asleep.

[@shikhanshu]

no he's not... turn up your volume

[@sandmastermaster]

Shikhanshu Agarwal it's not the volume. It's how he talks, which is not really a daytime voice.

[@mahadeibnsalam6735]

how does the color appear !!!!

[@AgglomeratiProduzioni]

0:15 Is the image correct? I think the photographer sees upside-down there.

[@agxiso]

film forever!

[@FabledThunder]

I'm guessing there was an error with the earlier video.

[@Miimu5210]

Magic.

[@ibrahimdeniz7308]

Anyone else living in constant fear all this knowledge is going to be lost? Or no longer needed? Yeah...

[@AlejandroBravo0]

And how do they add the colour?

[@traceur2793]

How you ever read a comment and think "damn I wish I would of wrote it first"?

[@hritikvaishnav603]

3:10 Wait I don't get it. If you pass light through a negavite film onto a paper, the dark parts should still be dark, because the dark parts of the film blocks light. Then how is the image inverted?

[@dsego84]

I think the photo paper is white by default, so the light "burns in" the darker parts, thereby inverting the image.

[@luisgordillo1695]

Looking for an explanation with Pop up pictures ! please help!😬

[@deejaydubla]

And now I feel old.

[@TheRegret]

but... you didnt describe how to develop a color photo which i think is incredibly interesting

[@KG_BM]

I was expecting this episode to be sponsored by a specific chinese battery company

[@Nmethyltransferase]

Why does ketamine work (whereas memantine fails) for depression?

[@AshishGupta-ql9lq]

what about color photographs?

[@byteofbacon]

Shouldn't it be called Photongraphy then?

[@michelangelou7]

If you believe in photons I suggest you check out Ken Wheeler aka Theoria Apophasis.

[@288theabe]

I'm more interested in how a photon becomes a massive torpedo of death. lol

[@eldstgilmorbarboydodellatb4413]

Forget the photo film just put a spoon in the album 🍽

[@zshanmalik]

do a episode on Earth 2.0 please

[@syn010110]

this makes me feel old

[@sealinski]

Like oils in the vinegar of a **TASTY** vinaigrette

[@TronIILorule]

How does color film work, then? How come red lights are used in developing rooms?

[@Correctrix]

Red light doesn't disable human night vision, so it's a good choice in dark environments, e.g. plane cockpits at night.

[@777sillydog]

CAPTAIN Man the red lights are used because photo paper is much less sensitive to them. You still have to keep them dim. When you develop film the room has to be completely dark. If you are using 35mm film you keep the film dark until you get it onto a reel and into a canister that is made for developing. Liquid can get. In, but light can't. When you print with color paper you have to keep the paper in the dark . It sounds hard, but you get used to setting up everything in the same order every time before you turn the lights off. If you print on the computer the lights are on the whole time. Some things in Photoshop are based on darkroom photography so it is not that hard to get used to. Hope that helps. If it matters, I used to teach photo to kids, have a BFA and got a grant and residency for my photos.

[@777sillydog]

...... Mentioning some of my background so you know I won't lead you astray.

[@TronIILorule]

777sillydog You didn't need to, but thanks. Your explanation was helpful

[@maggus999]

But isn't it kind of misleading to point out the mirror in the cutaway of the housing? That has nothing to do with the actual photo, it's only there to allow you to see through the lens to frame your shot.

[@SandCrabNews]

OK, now tell me about color slide film.

[@xdnewsman7408]

Wow, this sounds crazy complicated...

[@Astronomynatureandmusic]

Sorry, the video goes way too quick for me with no visualization of what actually happens.

[@preethamr7275]

How dose colour films work

[@trienbui9582]

how Picture has colour?

[@cup_check_official]

why the reupload?

[@cup_check_official]

oooh the emulsion thingy

[@user-kv5mx6ro5l]

SCISHOW RULESSSSS❤️

[@Toastmaster_5000]

What I don't understand is how color is involved

[@danames5780]

A Actual informative Sci Show vid ......vs a silly video on human farts.

[@pizzajona]

One of the most confusing sci shows of all time

[@izzyxblades]

Thank you, I thought it was only me ^_^; this is harder to understand than most other SciShow videos

[@The2808erik]

Now explain color film photography