Can film get too cold -80c (-110f) or -77k

[snaggs]

My friend has a lab so I can store some film at -80c for nothing, or -77k for about $150 a year to cover LN2 consumption. Anybody else looked at this? What do I use for radiation? Are full lead containers required? I wont be stored with the nuclear isotopes but in the bio storage, so im only concerned with background radiation.

Daniel.

[MartinP]

Hmmm . . . . -77K ????? Really?

[-80C would be approximately +193K, if I recall my physics correctly]

[snaggs]

Yeh, LN2, maybe I mean 77K.

[Alan W]

How long are you planning on storing this film?

[brianmquinn]

It is routine to put X-Ray film at -80C to make it MORE sensitive to radiation (and thus fog).

This has been known since the 1950s.

http://iopscience.iop.org/0508-3443/...3_7_10_410.pdf

Also no amout of lead will save your film from cosmic rays.

I suggest you store it a -20 to lessen chemical degredation. You should get 5 years past the date for 400 speed, 10 years for 100 speed and maybe 25 years for 25 speed.
I suggest unless the film you have is no longer made and can not be replaced just buy more small batches.

[Gerald C Koch]

You can still buy Agfa camera film years after they stopped manufacture. They stored their uncut rolls at -10 C. I would assume that Agfa had studied long term storage and arriived at this temperature as optimal.

Other factors are beta, gamma and cosmic radiation. An inch or so for beta radiation and several inches of lead to reduce any gamma radiation. You would need to store film in a deep salt mine to reduce cosmic rays.

BTW, the Kelvin scale does not go lower than 0^oK which is absolute zero so a temperature of -77^oK is noonsensical. Whether a symbol is capitalized or not is important in science. A capital K is used for Kelvin temperature.

[pentaxuser]

[QUOTE=Gerald C Koch;1394858]You would need to store film in a deep salt mine to reduce cosmic rays.QUOTE]

J. S. limited or was that unlimited but a largely one man business used to offer this service free of charge to the right or was that wrong people. He insisted they stayed with the film all the time

Fortunately J.S. went bust in 1953. Good news sometimes when that kind of service disappears

pentaxuser

[Steve Smith]

BTW, the Kelvin scale does not go lower than 0^oK

It also doesn't need the degree symbol.


Steve.

[Gerald C Koch]

It also doesn't need the degree symbol.

Curious Fahrenheit, Celsius, and Rankin all use the degree sysmbol. As you say Kelvin doesn't. Never thought about it before. As someone once remarked, "The nice thing about standards is that there are so many of them."

[lxdude]

It's common to say degrees Kelvin, but incorrect. The reason is that it is an absolute scale rather than a relative scale. It's stated as (for example) 5500 kelvins (small k), or 5500K. Essentially, 'kelvin' replaces the word 'degree'.

It used to be called degrees Kelvin, but that was changed.