I mentioned a few days ago about overexposing film. I got to thinking about this.
An experiment will have to wait on this, but I had the perfect way to at least try parts of my workflow to see how it works: a developed film leader. The leader on film is the bit that sticks out from the film cassette to let you go and load the film into your camera. The film leader is exposed to broad daylight (or, indoor light, or whatever) as you’re loading it.
To say that the leader is overexposed is understating the matter by a lot. Normally an exposure is measured in a small fraction of a second with a fraction of the light going through the aperture of the lens. The leader is out for minutes at a time. Then there’s the bit of film that you pull out when you’re loading the camera. It too is also exposed to full light as you’re loading the film.
Both should be fogged.
Let’s take a look…
Yep. pretty much black. (I’ll talk about the marks in a moment… :-) )
Ok, the outside isn’t enough, let’s try brighter!
Well, look at that, there is a noticeable density difference on the film. The film on the right is the always exposed leader and on the left is the film I exposed as the film was being loaded into the camera. Interesting!
So film can store information about the difference between a few minutes of exposure compared to just maybe a half a minute. Fascinating!
Can my scanner tell as well?
As it turns out…
you can tell the difference quite plainly.
The black mark was scratches I put in to signify roughly where the density difference was in case the scanner wasn’t able to differentiate between them. (Also, the film was woefully abused and left out next to the sink which is why there’s so much other damage)
I think we’re onto something! Film’s Dmax (Density Maximum) is well within the reach of my cheap-ish scanner. Next up: trying this with real pictures!