Developed film -- how susceptible to light damage?

[rhaytana__tim_adams_]

I know I need to protect unexposed and undeveloped film from light,

but how about after I get the negatives back from the processor?

 

Why I'm asking: I scan the film in a room with many windows, and

fret a bit about the light pouring through on the film strips lying

on my table. I now carefully protect the film strips from light,

but that's only because I don't know how sensitive they are to light

damage. Perhaps I needn't be so careful with developed film.

 

Thanks.

[steve_levine]

Color films,are merely vegetable dyes(food coloring basically) suspended in gelatin,thats been attached to a strip of plastic.Like all dyes,light will degrade and fade these.A color slide mounted in direct sunlght will show loss of color in a month or so.Color films on a desk for a few hours in direct sunlight,I wouldnt worry so much about,(but I wouldnt make a habit of leaving them in the sun).Non chromogenic B&W films,contain silver,rather than dyes,and have much greater permanance.However,these too will fade in direct sun for any length of time.

[lex_jenkins]

If you don't mind spending hours searching Kodak's labyrinthine website, you'll eventually find some highly technical studies on the light-keeping, dark storage and other archival effects on films.

 

These studies, among others, are the sources for assertions that certain negatives will keep in dark storage for X number of years while one particular slide film will keep in dark storage ten times that long, as well as how long backlighted transparencies for continual public display will last, etc.

 

It is possible that by now Kodak has tested the effect of the particular wavelengths present in typical scanners on negatives to compare them with the known effects of, say, the halogen lamps used in dichroic head enlargers.

[rowland_mowrey]

Steve;

 

The dyes in color films and papers are not vegetable dyes. They are a special class of insoluble azomethine dyes. Vegetable dyes are soluble in water generally. Boil a carrot and watch the water turn yellow.

 

The dyes are not in gelatin alone. They are dispersed in special solvents that surround the dyes and have other addenda in the solvents. These dyes, solvents and addenda are adjusted to minimize sensitivity to light, moisture, heat, and oxygen. In other words, the dyes are in protective capsules which are suspended in gelatin.

 

The dyes do fade. Current estimates on the EK web site state that Endura paper will last for 200+ years.

 

Now, as to your question Tim. Any form of light that strikes the film and has in it a wavelength complementary to the dye will initiate fading. Red light fades cyan dyes, etc.

 

UV light fades all dyes, and infra red (heat) fades all dyes.

 

The question is, how fast. The light from a scanner is just about like a light in an enlarger or printer and therefore should affect the film about the same. Laser light in a laser printer is more intense but briefer. Sunlight on film is the most intense and lasts longest during your handling negatives.

 

I do my scanning in a room with no windows, and use a tungsten lamp to look at and select negatives or slides. Then I scan. Scanning is the least problem. Worry about heat, humidity and sunlight.

 

Ron Mowrey

[rhaytana__tim_adams_]

Thanks, all, for the responses. I think I'm going to continue to play it safe and continue to protect the developed negatives from sunlight, as much as possible.

[lex_jenkins]

Tim, you got the next best thing to researching Kodak's site and with a heckuva lot less effort: Ron Mowrey.

[rowland_mowrey]

Lex;

 

Thanks very much. I'm nothing special. I just try to give accurate answers based on my experience. If that helps people, then it makes all of us better off.

 

I trust your trip went (is going) well? I have no way of knowing if you are back and how your mother is doing, but I hope things turn out well.

 

Warmest regards.

 

Ron Mowrey

[lex_jenkins]

Ron, I'm still in Savannah for a few more days, hoping to duck outta town before the G8 Summitteers roll in with all politicking and posturing blazing.

 

There's a strong police presence around downtown and the historic district but they're friendly folks just doing a difficult job - watching out for potential trouble while trying to make sure everyone else enjoys a good time.

 

A few locals have scheduled some protests which they say will be peaceful, and I believe that's their intent. I'm just hoping everyone respects the other side and airs it out without things degenerating to the disastrous events of Seattle a couple of years ago.

 

For the most part I've been able to photograph freely, with only one request from a police officer to not photograph a particular building. Actually, I was trying to photograph a backlighted employee struggling to hoist a bag into a dumpster in an alleyway, but apparently the alley was between a bank building and courthouse, hence the restriction.

 

Otherwise I've burned as much film as I can stand between street shots along the downtown market district, river walk, historic homes, squares and whatever else I can think of. Savannah is a gorgeous city - I could spend a month here just taking photos. It would take that long because the skies aren't particularly cooperative - sometimes the cloud cover doesn't burn off 'til late in the day.

 

Mom is hobbling around reasonably well using a walker, is finally on schedule for routine physical therapy and even has transporation lined up to and from the clinic. So I'll feel comfortable returning home next week.

 

And I think I've meandered enough from this thread's original topic!