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Beeftweeter
Jun 28, 2005


holy shit this os has cinepak?!?!?


tef posted:

got a 150mm f/2.8 large format lens :2bong:

hell yeah

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echinopsis
Apr 13, 2004

tef posted:

got a 150mm f/2.8 large format lens :2bong:

I like the big number combined with the small number

echinopsis
Apr 13, 2004

420mm lens at f/6.9

akadajet
Sep 14, 2003

tef posted:

got a 150mm f/2.8 large format lens :2bong:

perfect for mounting to a gameboy camera

HAIL eSATA-n
Apr 7, 2007

shooting this wedding on saturday :ohdear:

wet cold and gray outside
inside will be lit with something

using only a 17-55 f/2.8-4 without a flash

plan to set it to 55mm/f4 ~200ss and let the ISO free

requesting thoughts and prayers

echinopsis
Apr 13, 2004

protect your highlights

and if youíre iso is free, at least work out where your iso becomes unusable noise and keep that in mind.



and good luck

tef
May 30, 2004

-> some l-system crap ->

big scary monsters posted:

f2.8? drat, all my lf stuff is f5.6 or slower. what size film are you shooting?

4x5

echinopsis
Apr 13, 2004

echinopsis
Apr 13, 2004

holy poo poo mate



just as a matter of curiosity what does a 4x5 bit of film cost

big scary monsters
Sep 2, 2011

-~Skullwave~-
it's a good size. the cameras are still just about manageable to carry so you can actually get to cool places with them. although i remember a cool video of this japanese guy who went hiking in the forest with a 14x17 or something over his shoulder

big scary monsters
Sep 2, 2011

-~Skullwave~-

echinopsis posted:

just as a matter of curiosity what does a 4x5 bit of film cost

it's been ages since i shot any but i remember b&w a couple USD a sheet, colour at least $5. i bought a load of well expired colour negative film on ebay and developed it b&w. worked ok and ended up way cheaper

Corla Plankun
May 8, 2007

improve the lives of everyone
how does over/under exposure work in film?

it occurred to me that i have always had a digital sensor in-the-loop for the entire time i've been learning about photography (even real film got scanned by a negative reader with some pretty obvious sensitivity/noise issues when i worked in a drugstore photolab). i assume that film still has some kind of limiting factor and there can't be an image with 200 stops of dynamic range or whatever, but i have no idea what it looks like

akadajet
Sep 14, 2003

Corla Plankun posted:

how does over/under exposure work in film?

it occurred to me that i have always had a digital sensor in-the-loop for the entire time i've been learning about photography (even real film got scanned by a negative reader with some pretty obvious sensitivity/noise issues when i worked in a drugstore photolab). i assume that film still has some kind of limiting factor and there can't be an image with 200 stops of dynamic range or whatever, but i have no idea what it looks like

in my experience I can over expose portra 400 a ton and it still looks good when scanned

Sagebrush
Feb 26, 2012

Corla Plankun posted:

how does over/under exposure work in film?

it occurred to me that i have always had a digital sensor in-the-loop for the entire time i've been learning about photography (even real film got scanned by a negative reader with some pretty obvious sensitivity/noise issues when i worked in a drugstore photolab). i assume that film still has some kind of limiting factor and there can't be an image with 200 stops of dynamic range or whatever, but i have no idea what it looks like

like, on a physical level? or just aesthetically?

physically, film (black and white for simplicity) is made of grains of silver halide crystals glued to plastic film. when light hits a crystal, there is a chance that a small area of the crystal (a few atoms) will be transformed into metallic silver. this silver particle is invisible, but when you put the film in a developing solution, the presence of that metallic speck triggers a chain reaction that causes the entire affected crystal to turn into silver. this makes the grain turn dark. this is statistical chemistry, so the more light you shine on a given area of the film, the more of those crystals will be triggered to turn dark.

after developing, the fixer washes away the unexposed silver halide, with dark particles of silver left behind in areas that were brightly exposed, forming a black-on-clear negative image.

if you overexpose the film, all of the particles will have been triggered and the whole area is black. if you underexpose, none of them will have been triggered and they will all get washed away.

aesthetically, due to the statistical nature of this reaction, overexposure is better than underexposure. there is a long exponential tail where you keep adding more and more light, but most of it is just already hitting grains that were already exposed, so it isn't doing anything, and those last few unexposed grains just keep getting missed. this means that film continues to retain some detail even into severe overexposure.

however, if the film is underexposed, you have a problem. the film cannot record any detail below the threshold that causes a crystal to change. there is a certain minimum level below which light is basically just ignored, and you have no detail at all because the crystals just get washed away even if some photons did hit them. this means that film is bad at recording underexposed scenes.

in contrast, digital sensors are the reverse. a digital sensor records every single photon that gets into its wells, so it's good at underexposed scenes. but if you fill up the well, everything beyond that is simply clipped and ignored, and it isn't a statistical effect. all of the pixels will wash out simultaneously. so don't overexpose digital.

Corla Plankun
May 8, 2007

improve the lives of everyone
fascinating!

i was mostly asking about the aesthetics i guess. its easy to pick up on digital over/under exposure due to the simple math/aliasing stuff but i guess i don't have a good enough understanding of the chemistry to be able to guess what a badly exposed (or, come to think of it, too-zoomed-in) photo looks like in a fully chemical development process with no daqs anywhere

Beeftweeter
Jun 28, 2005


holy shit this os has cinepak?!?!?


sagebrush's post is pretty good. if it's still confusing maybe think of it as a physical engraving that you're making, idk, ink prints of. an "overexposure" in that case can be thought of as something with sharper relief: it's simply easier to make copies of

you're making copies of a negative too

echinopsis
Apr 13, 2004

that notion of slowly saturating the grains creating that tailoff in the highlights is definitely the best part of film

I shoot with the highlight priority extra thing enabled and so I very very rarely clip the highlights, meaning I can do what I want with them afterward. clipping on digital bites

Sagebrush
Feb 26, 2012

Corla Plankun posted:

i don't have a good enough understanding of the chemistry to be able to guess what a badly exposed (or, come to think of it, too-zoomed-in) photo looks like in a fully chemical development process with no daqs anywhere

black and white film negative under a microscope:



each black blotch is a little speck of metallic silver that was converted from a halide crystal. overexposed areas have a denser spread of crystals with fewer clear areas in between (because it's a negative, recall). underexposed areas will have fewer blotches scattered across a clear field. it's basically the same idea as a dithered black and white gif, just with randomized "pixel" shapes and a more random distribution.

here are the unexposed halide crystals on the film emulsion viewed with an electron microscope. after processing, each one of them will either be transformed into a black metallic silver dot that is fixed in place, or it will be dissolved and washed away.

Sagebrush fucked around with this message at 05:39 on Mar 30, 2023

tef
May 30, 2004

-> some l-system crap ->

echinopsis posted:

holy poo poo mate



just as a matter of curiosity what does a 4x5 bit of film cost

https://www.freestylephoto.com/category/2-Film/Black-and-White-Film?stock=0&attr%5B%5D=1-4&q=

it's not cheap

tef
May 30, 2004

-> some l-system crap ->

Corla Plankun posted:

fascinating!

i was mostly asking about the aesthetics i guess.

the thing to note is that people routinely over and under expose negatives by a few stops, and then under or overdevelop to compensate


which is how you get "pushing film", or underexposing and overdeveloping, which usually gets you a heavier contrasty look and denser negatives

and "pulling film", or overexposing and underdeveloping, which usually gives you lower contrast and thin negatives

tef
May 30, 2004

-> some l-system crap ->
the thing to bear in mind with film is that, well, it's not always a straight forward relation between "amount of light" and "amount of darkness on the negative"

every film has a so called "characteristic curve" or h-d curve which plots the negative density vs the amount of light hitting it, and it's usually divided up into three sections, the toe, the straight line, and the shoulder

when you expose a film normally, you aim to fit as much of your image inside the straight line section, which gives good tonal separation and hopefully captures the full range of light levels in your shot

if you underexpose, you're kinda moving your photo onto the left side of the curve, the toe. this means that darker tones tend to get lumped in together, but the highlights are still cleanly separated. on the other hand, if you overexpose, you're kinda moving to the right side of the curve, the shoulder, and for this film, this means that the highlights get compressed, but darker tones in your image stand out more

i picked fp4 here because it has a very distinctive curve. it's worth noting that most films tend to have a bit of a toe, compressing the blacks, and not much of a shoulder, which means you can overexpose and still pull out the highlights.

this is where "Expose for the shadows, develop for the highlights" comes from. you work out the darkest part of your image, and position it at the bottom of the straight line section, and then when it comes to developing, you're controlling the final contrast of the negative, trying to ensure that the highlights don't get too toasty on the negative

it's also why pushing film (underexposing) tends to give very dark, moody images, and why pulling film tends to make everything feel a bit flat and low contrast

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tef
May 30, 2004

-> some l-system crap ->

aside, 35mm used to be considered "miniature film", which is why things like 110 and minox are called subminiature. i even found an old book which talks about 4x5 as being medium format, because it's only a little bit bigger than 120, when compared to things like 8x10 or higher.

Bloody
Mar 3, 2013

Sagebrush posted:

like, on a physical level? or just aesthetically?

physically, film (black and white for simplicity) is made of grains of silver halide crystals glued to plastic film. when light hits a crystal, there is a chance that a small area of the crystal (a few atoms) will be transformed into metallic silver. this silver particle is invisible, but when you put the film in a developing solution, the presence of that metallic speck triggers a chain reaction that causes the entire affected crystal to turn into silver. this makes the grain turn dark. this is statistical chemistry, so the more light you shine on a given area of the film, the more of those crystals will be triggered to turn dark.

after developing, the fixer washes away the unexposed silver halide, with dark particles of silver left behind in areas that were brightly exposed, forming a black-on-clear negative image.

if you overexpose the film, all of the particles will have been triggered and the whole area is black. if you underexpose, none of them will have been triggered and they will all get washed away.

aesthetically, due to the statistical nature of this reaction, overexposure is better than underexposure. there is a long exponential tail where you keep adding more and more light, but most of it is just already hitting grains that were already exposed, so it isn't doing anything, and those last few unexposed grains just keep getting missed. this means that film continues to retain some detail even into severe overexposure.

however, if the film is underexposed, you have a problem. the film cannot record any detail below the threshold that causes a crystal to change. there is a certain minimum level below which light is basically just ignored, and you have no detail at all because the crystals just get washed away even if some photons did hit them. this means that film is bad at recording underexposed scenes.

in contrast, digital sensors are the reverse. a digital sensor records every single photon that gets into its wells, so it's good at underexposed scenes. but if you fill up the well, everything beyond that is simply clipped and ignored, and it isn't a statistical effect. all of the pixels will wash out simultaneously. so don't overexpose digital.

tyvm for this post. how does the negative become a print

tef
May 30, 2004

-> some l-system crap ->

Bloody posted:

tyvm for this post. how does the negative become a print

you take a photograph of it

echinopsis
Apr 13, 2004

thanks for the filmsplanation

Sagebrush
Feb 26, 2012

photo printing paper is treated with (basically) the same silver halide solution as the film. you put your negative in an enlarger -- a vertical slide projector with variable focus and magnification -- and project the negative image onto the paper, exposing it just like film. when the paper is processed you get a negative of the image that was exposed, which was already a negative, so the paper now contains a positive.

Megabound
Oct 20, 2012

Bloody posted:

tyvm for this post. how does the negative become a print

You go into your big reverse camera room and expose some paper that has been treated with the same chemicals as the film to a projection of the negative.







The chemicals you use to develop the paper are the same ones you used to develop your film.

Megabound
Oct 20, 2012

Your editing process is the same as in lightroom but physical. If you want to add or remove contrast you change filter, the paper has 2 layers of sensitive silver and they're reactive to different colours of light so by adjusting the colour of the light coming out you can adjust contrast.

If you want to make a part of your image darker or lighter then you can dodge and burn, which is using physical objects to block parts of the image from exposure to expose parts for less or more time.

If you want to crop you just make the picture bigger on the easel, or move the borders around.

If you want to alter perspective you can tilt the head of the enlarger and tilt the easel you print on, like keystoning you see in a projector.

HAIL eSATA-n
Apr 7, 2007


                /


55mm isn't enough! it's not enough!

HAIL eSATA-n fucked around with this message at 15:10 on Mar 30, 2023

echinopsis
Apr 13, 2004

go wide and you wish youíd have died

go long and youíll get that shot

thatís a rhyme they used to tell around the table at lens conventions in the 70s and itís still true today

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echinopsis
Apr 13, 2004

https://www.lensrentals.com/blog/2023/03/how-your-camera-and-image-processor-determine-colors/


this seems to be a very good article on camera or something

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