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Film Vs. Digital

Jorgen Udvang

Subscriber Member
Ha ha... that's a man on a mission :)

When that is said, I'm just back from a one week trip with an Olympus OM as one of two cameras, shooting one roll per day. That's the first time for me since I went digital 6 years ago. The last years, film has only been a nice past-time activity, but this time, I took many of the best motives on b&w film only. Film goes to the lab tomorrow. I need a darkroom :lecture:
 

Godfrey

Well-known member
"... Film is not sensitive to gamma rays ... "

Wrong. It's also sensitive to x-rays, and other invisible high energy EM spectra. this is why film stored in even a light lead bag can be fogged by as low power a device as an airport scanner, never mind gamma ray contamination.

Nothing new in this presentation. Film and digital capture are simply two entirely different recording media, each with its own strength and issues. Film has had 100+ years of development behind it, digital about a third that. Lots wrong with both still.

But we can make great photos (and movies!) with either! :)
 

haring

Member
Film can be fogged by as low power a device as an airport scanner... is it true? I thought that is is a problem if the film is over 800 ISO?
 

Godfrey

Well-known member
Film can be fogged by as low power a device as an airport scanner... is it true? I thought that is is a problem if the film is over 800 ISO?
It all depends on how long the film is being exposed to the scanner's illuminating EM radiation. Fast films fog in a shorter exposure, slow films fog with longer exposures. So if you put slow film through a scanner set to a low power quickly, you will be able to detect less fogging than if you put the same film through the same scanner more slowly, or fast film through the same scanner at the same rate.

As long as the intensity of the scanner's illuminating EM radiation is above the minimum activation threshold required by a particular emulsion to activate the chemical reaction, all the films will be fogged to one degree or another.
 

Lars

Active member
It all depends on how long the film is being exposed to the scanner's illuminating EM radiation. Fast films fog in a shorter exposure, slow films fog with longer exposures. So if you put slow film through a scanner set to a low power quickly, you will be able to detect less fogging than if you put the same film through the same scanner more slowly, or fast film through the same scanner at the same rate.

As long as the intensity of the scanner's illuminating EM radiation is above the minimum activation threshold required by a particular emulsion to activate the chemical reaction, all the films will be fogged to one degree or another.
Another thing to keep in mind when traveling is that high-altitude cosmic radiation also fogs film. So lead bags is a good idea even if you can get past security without xray.
 
To build on what Lars and Godfrey have said, exposing film to radiation -- be it x-ray, gamma ray, high altitude radiation in a plane, etc. -- is cumulative. Of course, we are assuming that our digital sensors are immune, which may not be the case.
 

Godfrey

Well-known member
To build on what Lars and Godfrey have said, exposing film to radiation -- be it x-ray, gamma ray, high altitude radiation in a plane, etc. -- is cumulative. Of course, we are assuming that our digital sensors are immune, which may not be the case.
They're not, but it takes a lot higher energy radiation to cause damage to a digital sensor than it does to fog film. Gamma rays or very high intensity Xray at least.

The downside is that film is a 'use once' recording medium so. If it gets fogged You toss it and cry, then put in new film. With a digital sensor, once it's damaged, the best you can do is map out the damage until it's unusable, then replace the sensor. For a still camera, this is a small consideration as we have plenty of pixels to spare. For a video camera, though, the sensors work a little differently and small amounts of damage can prove more significant.
 
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