How Exposure Affects Film
OK, so for a while we’ve been wanting to explain a couple of film technicalities that we’re pretty sure will change many people’s understanding of film and exposure.
Alright, take a deep breath ‘cause this stuff is easy but sometimes difficult to explain in written communication.
So the thing is that exposure on film (unlike in digital photography) is not equivalent at all to overall brightness of an image. For example, in the digital photography world when someone speaks of an overexposed image you instantly imagine a bright, all-white image with (probably) clipped highlights. In the film world this is not necessarily so.
Color film’s latitude is huge. Like 2-3 stops for underexposure and up to 6 spots for over-exposure (depending on the film stock). Also clipped highlights are literally impossible on film (straight from the scanner).
Add to this awesome characteristics the fact that brightness can be controlled during the scanning process.
Now this “overexposed = bright all-white” and “underexposed = dark black” rules of thumb start to make less sense right?
So then what’s the big deal with all that “overexposed 1 stop” etc film talk you read everywhere on the Internets?
OK, so we’ve had so many questions about this and we’ve told so many customers on our Wetransfer feedbacks that we decided to shoot some stuff and show you guys how this thing works.
Here’s a shot of our colleague Héctor we shot on Fuji 400H film and a Contax 645 medium format camera.
We metered with our handheld (incident) light meter below his chin with the bulb out facing the shooter. That shot will be considered our “anchor” or “box speed” example, meaning it was shot at 400 ISO not over or under-exposing.
From there we shot in one stop increments down to 6 steps under (all the way to the left) and up to 6 steps over (all the way to the right… yeah, 1/15 handheld at f2 right there!).
We then scanned these on our Fuji Frontier SP3000 at the same brightness level (important).
Make sure you click on the images to view larger and even the upper right hand icon to for full size 😉
Here’s the full spectrum of the 13 stops of the test
Now zooming in on the Overexposure side
And finally the Underexposure side of the test. (yeah, the -6 was Héctor’s profile pic for a while 😛 )
We did the same thing for these shots of our colleague Gloria , but this time in a totally different light situation and on Kodak Portra 400 film.
What conclusions can be made from this test?
Well… first of all… 6 stops overexposed? And it still looks amazing? That’s pretty sweet.
Overall, there seems to be a higher number of usable shots on the overexposure side than on the underexposure side. So what does this tell us? Film LOVES overexposure. Unlike what happens in digital photography, with overexposure film gets a little more saturated and you get more details on the shadows, but definitely no clipped highlights or “all-white” burnt images. That’s why it’s totally safe to say that if you’re in doubt between two possible camera values for your exposure you’ll always be safer on the “over” side than on the “under” one.
It must be noted also that underexposure brings out grain and colors shifts and extreme overexposure will make images flat, contrast-less and with magenta or yellow highlights.
So again, remember that for these tests we scanned all images at equal brightness, so that’s why you get a -6 image full of grainy shadows and a +6 image that’s less bright than you’d expect. So underexposed images can be brightened by “bringing up” grainy shadows (hello VSCO look!) and overexposed images can be “brought down” so they don’t look hyper white-ish.
Also bare in mind that these were scanned and then posted UNEDITED. It goes without saying that with very basic edits the -1 shot can be made to look maybe similar to the correctly exposed one and for example the -3 can be scanned darker and slightly edited to look more “chiaroscuro”-like, but you get the picture, right? (no pun intended;) )
So that’s a lot of info to digest!
Hope this clarifies some doubts that so many of our customers have written to us about and that it helped you somehow to be more confident when you’re shooting and getting you closer to the look you want out of your scans.