ULF video clips - 12x20

[Andre Noble]

I think one has to be practical about tripod placement with $10,000 worth of gear potentially taking a soak.

[tgtaylor]

I like the idea of defining the coating parameters with rulers and will adopt that in my own work when printing 5x7 negatives on 8x10 paper. It should result in more even size boarders.

Thomas

[pound]

I think this video has been shared before but it is quite inspiring to watch again. If I were to take a trek up to the hills with such equipment, I would be proud of any shots that I might took. Just for the efforts!

[Fr. Mark]

Inspiring videos. Are we really worried about volatilizing metal salts with hot air blown over them? Is there data that they get loose or are we having chemo-phobia? I was an organic chemist and I was under the impression that most metal/salt compounds would decompose (and still not volatilize the metals) at temperatures you can't get to with a hair drier and if you volatilized them, you'd need a torch which would be the end of the expensive paper. I could be wrong and I do want people to treat heavy metal compounds with respect, but I still have my doubts its a big deal.

[Jim Noel]

I guess I am not as healthy as the doctors say, since I have been using a hair dryer to dry my coated papers for more than 60 years.

[Tin Can]

I'll go with that Jim.

[tgtaylor]

Are we really worried about volatilizing metal salts with hot air blown over them? Is there data that they get loose or are we having chemo-phobia? I was an organic chemist and I was under the impression that most metal/salt compounds would decompose (and still not volatilize the metals) at temperatures you can't get to with a hair drier and if you volatilized them, you'd need a torch which would be the end of the expensive paper. I could be wrong and I do want people to treat heavy metal compounds with respect, but I still have my doubts its a big deal.

It's been a while since college chemistry which I didn't major in but took along with physics for a degree in mathematics but I recall that atoms are in a state of constant flux - they constantly vibrate and bump into one another and each collision results in kinetic energy being exchanged. As a result of these collisions some of the atoms are close to the kinetic energy required to escape from the surrounding medium which the hair dryer provides.

Thomas

[Fr. Mark]

It's been a while since college chemistry which I didn't major in but took along with physics for a degree in mathematics but I recall that atoms are in a state of constant flux - they constantly vibrate and bump into one another and each collision results in kinetic energy being exchanged. As a result of these collisions some of the atoms are close to the kinetic energy required to escape from the surrounding medium which the hair dryer provides.

Thomas

Someone with more credentials than I have may disagree, but in a word, "no." Otherwise everything (rocks, steel implements, glass etc etc) would evaporate. What you said is true of some simple compounds with lower molecular weights and relatively lower intermolecular forces, even water. But many covalently bonded materials, particularly polymers, and ionic materials, too, just aren't going to volatilizatize at temperatures most people can generate at home with or without a welding torch. These materials will demonstrate molecular vibration and you could take in dangerous quantities of powders of metals (and other things) particularly when humidity is low.