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I'm glad VLC worked. The image quality looks pretty good on these.
I can't wait for the DVD to come out  I think the term "Captive Audience" doesn't even come close...
Lens caps and cable releases can become invisible at will. :D
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In post #26, I show the coating blade in actual use, but I'm still getting off-line comments and questions about this re: how does it really work and why is it better, or something to that effect.
Well, first, the blade has a well that is 1/2" deep by the width of coating desired + a fudge factor for selvedge. So, an 8" blade is actual 8.25" wide and the well is therefore 1/2" x 1/2" x 8.25". The well will hold about 40 ml allowing gaps of the endcap up to 20 or 40 mil. This is to allow coatings of carbon which requires more fluid.
The edge towards the operator is heavy. For an 8" blade it weighs about 2 pounds (1 kg). That serves two purposes. One is to keep the motion smooth from inertia and another is to keep the paper spread out and level as the blade advances. The end cap is adjusted to have gaps from usually 5 mil to 20 mil or even higher, but above about 20 mil, the surface tension is not enough to hold the emulsion in the well and it will leak.
It is designed to work with between 5% and 12% gelatin for optimum coating and is designed to work at about 65 - 75 deg F. If you overheat, the paper will wrinkle and the emulsion will run especially on film support. The blade should be at about 105F when you pour in the emulsion. A cold blade will set up the emulsion and cause streaks and defects.
The tolerance of the blade is 0.001" and any blade out of tolearance is a reject.
Now, if the leading edge towards the operator were to be missing, that is if it was just an undercut blade and not a contaniner, then the puddle of emulsion poured on paper will spread and will cause swell and create a huge defect at the start of the 'run'. As the paper swells, the paper moves closer to the blade and the blade scrapes off emulsion leaving too little causing streaks in the middle. If the blade is adjusted unevenly, you will see more or less emulsion at the edges. But, basically the blade is designed to allow surface tension of gelatin with the right viscosity to 'pull' the emulsion into evenness. Doing this takes practice. So this is why I suggest and demonstrate on the DVD, the use of the blade in the light with dyed gelatin to learn before you commit with emulsion.
These blades were used at Kodak in the 20s to coat up to 42" wide film and paper with trough coaters. I am currently coating up to 16"x20" sheets and I admit that beyond 8x10 the difficulty goes up. Typically, with an 8x10, I use an 11x14 sheet to allow for edges and over and under run.
The bottom line is that this is an art and takes practice, and the larger the blade the more practice.
PE
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Ron,
Absolutely fantastic that you are making this technology available to us. Can you hear my audible drooling for the DVD? I think I have all the chemistry on hand including about 100 gms of cadmium chloride inherited from my grandfather. Now to just move this farther up the todo list. Many thanks.
Richard
Richard
Why are there no speaker jacks on a stereo camera?
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Well, 3 more hours today, and another 2 or so tomorrow should pretty much wrap things up.
Today, we finished the taping of the ISO 40 ortho film and iso washing. I will have stills of that tomorrow or the day after to post. We also have a lot more to show.
PE
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Ortho emulsion being made
Here are some pictures for you.
The first is of the reactor ready for addition of silver nitrate and ammonia. The reactor contains KBr, KI, and PA Gelatin. This is a special gelatin that allows washes to be done more easily.
The second is a picture of the emulsion being washed. The coagulum (emulsion + gelatin) is hanging as a mass from the stirring rod while the salts remain behind in the water. This wash is repeated several times with cold distilled water, and then the emulsion is reconstituted and diluted to the proper concentration and then sulfur sensitized and coated.
PE
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Ron,
This stuff is Fascinating!!! Can't wait for the DVD. Thanks!
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I am ordering two! One to store, and one to wear out from watching it.
Bob M.
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Two hours of tape finished today at 12:30 PM. We will have to reshoot some scenes and edit, so a finish date of mid February is in sight. I'll post some interesting pics here as I go through the footage (meterage?).
PE
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PE,
I have to ask....is a book of some sort going to accompany the release of the DVD?
Bob M.
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Oh, I thought I said this before. The DVD and book will be sold together.
PE
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