Kodak reports t© laboratories on; a great day for photography . . . lowering the dilution limit for alkyd resins. identifying very meagre samples
Faster, faster
Where this man sits and writes pam phlets about photography 15 footcandles hit his face. That's just with in the lower limit of illumination recommended for office work. N o body, of course, snapshoots at that low a level. But good gracious, this picture was made with a $6.95 cam era (our esteemed Brownie Hawkeye) , unassisted by any additional light source, at its one and only set ting of Z/15, l/40th of a second! Imagine w h a t an adjustable camera would have done under the circum stances. H o w in the world, etc.? The catch is that our Brownie was loaded with a new kind of film, Kodak Tri-X Film. Not really a catch, for it can now be bought at any film count er. Such husbandry of photons! Currently available in N o . 620, No. 120, No. 135-36 exposure rolls, and No. 523 film packs. N o sacrifice of graininess. Exposure index nomi nally 200 b u t not too meaningful be cause latitude is of a type the definition-framers h a d n ' t anticipated. This is quite an announcement. W e also have a companion an nouncement about color. A new 35mm color film with approximately thrice the speed of Kodachrome Film has just gone o n the market. To process it to full-color transparen cies calls for no major capital appro priation a n d no chemical engineer ing talent but merely for a Kodak Ektachrome Processing Kit, Process £-2, priced at $1.80. (It's really op erable at the home darkroom level, but if you'd rather not bother, your Kodak dealer can handle it for you for p r o c e s s i n g b y p r o c e s s o r s equipped t o do the work.) This new film we identify as Kodak Ekta chrome J35 Film (for 35mm minia
t u r e c a m e r a s , 20 e x p o s u r e s for $1.85) and Kodak Ektachrome 828 Film (for cameras like the Kodak Pony and Bantam, 8 exposures for $1). Photographic characteristics have been changed substantially from the sheet and roll film Kodak Ektachrome because the new film is intended to be viewed at large mag nifications, as in projection, and the other isn't. In sum: 1) The scope and even the style of black-and-white photography have been vastly extended by dispensing with the need for added light in many situations and in others per mitting flash or flood lamp to bite far deeper into the gloom than ever before. 2) Color photography by 35mm camera can now be done in much less light than before, with results ready for inspection 65 minutes after the last shutter click. If s a great day for photography.
letter t o Shell. Turned out they hadn't realized that concentrated glycerol mono-oleate, with diglycerides, triglycerides, free fatty acid, glycerine, and soap all wrung out by molecular distillation, was avail able at around 40^ a pound as our Myverol Distilled Monoglycerides, Type 70. Which m a d e Shell's invention work better—straight mono or the mono-di mixtures? There followed some earnest comparisons in both our laboratories and theirs. De pression of dilution limit and viscos ity were measured with various resin formulations a n d at various temperatures. Naturally, our straight mono won every race. If you would like to see the data, write for a copy of "Distilled Monoglycerides as Alkyd Resin Dispersants" to Distillation Products Industries, Rochester 3, Ν. Y. {Division of Eastman Kodak Company).
Infrared beam squeezer
Thin and odorless Anybody who keeps up with events in the paint and lacquer business knows that the Shell Oil Company is the pre-eminent producer of odor less solvents. One of the principal ways to push upward in that field is to cut viscosity and keep it down during storage so that the paint will be easy to spray and brush. To the uninitiated it might appear that all you need do is use more solvent, which should be perfectly dandy for Shell. It doesn't work that way. You bump into something called the "dilution limit." Dilute more and your alkyd resin kicks out in the form of a gel. Now a bright lad in one of our sales departments was digesting his lunch one afternoon when his eye fell on an item in Chemical Week reporting Shell's finding that mix tures of glycerol mono- and dioleates act as dispersants for alkyd resins in odorless formulations. Since it is the young man's job to sell our monog\yc&ndes and since he has faith that a straight mono can d o anything a mono-di mixture can do, only better, he called in his young lady forthwith and dictated a
The lens you see here is not glass but silver chloride, which is transparent all the way out beyond 17μ. in the infrared. W e use such lenses not as magnifiers but to constrict one of the beams in a double-beam infra red spectrophotometer so that all its flux can be put through a 0.75mm χ 3.5mm aperture. Then a second AgCl lens collimates the beam again. T h e samples, frequently weighing 50 micrograms or less, are handled b y grinding them with a little potassium bromide and com pressing to a narrow strip. You can do it, too. For $102 we*ll sell you a pair of these lenses coated with a black AgoS smoke that cuts out radia tion below 7μ, plus τι similar planeparallel plate for the reference beam. The deal is with Eastman Kodak Com pany, Special Products Sales Division, Rochester 4, Ν. Υ. Prices include Federal Tax where applicable and are subject to change without notice.
This is o n e o f a s e r i e s o f r e p o r t s o n t h e m a n y p r o d u c t s a n d s e r v i c e s w i t h w h i c h t h e Eastmcan K o d a k C o m p a n y a n d
its divisions a r e . . . serving laboratories everywhere VOLUME
3 3.
NO.
7 ·
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FEBRUARY
14,
1955
661
