Measure! Do not use drops! Drops are not an accurate way to measure. Are you using US Standard drops, Metric drops or Imperial drops? With PhotoFlo 200 one needs 5ml of PhotoFlo in one liter of water. Really, how hard is it to measure 5ml and 1 liter?
Heck, Kodak gives a "capful" as an acceptable measure. I don't know about you, but I find the Photo-Flo caps to be rather difficult to measure with...
A drop is a drop. 20 to 25 drops = 1ml. No, it's not precise. My dropper might not drip like your dropper. If absolute precision is necessary, you don't measure in drops of course. But for this application, the margin of error is so small that it's not going to be the determining factor as to whether or not your film has drying marks. 5ml of PhotoFlo per liter of water, should work as well (or as badly) as plus or minus "a few drops."I do. So are you using US Standard, Imperial or Metric drops?
FWIW ,there are about 12 drops in a ml of water.Actually, drops are an extremely accurate way to measure small amounts of liquid. Medicines in Europe are commonly dispensed by number of drops. For any particular viscosity, a drop will always be the same volume as long as it collects and falls on its own from the source (eyedropper or small spout or whatever). One could easily find the number of drops of Photo Flo concentrate in, say 1 or 2 ml and calculate the volume and then the number of drops needed to make small amounts of working solution. Heck, Kodak gives a "capful" as an acceptable measure. I don't know about you, but I find the Photo-Flo caps to be rather difficult to measure with...
Best,
Doremus
FWIW ,there are about 12 drops in a ml of water.
But surfactants are more viscous than water so that does now apply. Measure 5ml of PhotoFlo and then add one liter of water.
...or figure out how many drops of Photo Flo it takes to make 5ml (it'll be the same every time if you let the drops form and fall by their own weight). Then you can just add that many drops to one liter (or half that many drops to 500ml) and save yourself the trouble of getting out the graduated cylinder and measuring every time.
Best,
Doremus
or you could make a more concentrated stock solution of fotoflow and then water that does to the right ratio; or just use a drop or two and be done with it....or figure out how many drops of Photo Flo it takes to make 5ml (it'll be the same every time if you let the drops form and fall by their own weight). Then you can just add that many drops to one liter (or half that many drops to 500ml) and save yourself the trouble of getting out the graduated cylinder and measuring every time.
Best,
Doremus
I would rather get out a graduated cylinder and be right than deal with stained negatives.
Sirius,
What I'm trying to point out (hopefully in a good-natured and humorous fashion) is that drops are really accurate, as accurate as measuring with the graduated cylinder, especially for smaller amounts where measuring error with the graduated cylinder is much larger. One method is no better than the other. Both are "right" and will not result in stained negatives.
If one uses an eyedropper or the like and lets drops slowly form and fall under their own weight, each drop is, within a very small margin, the same volume. The margin of error measuring a ml or so in a graduated cylinder is likely much higher unless one uses a thin graduated pipette or syringe (which I do for developer stock solutions where I need 5ml or more). I find it more convenient at the Photo-Flo stage to simply measure out the requisite number of drops with an eyedropper. I'm confident that my measurement accuracy is well-within the margin of error for mixing that particular solution. Point being: I'm not being slapdash or sloppy here.
Here in Europe, many very strongly-concentrated medications are sold to consumers in bottles with a drop-dispenser top. Doses are given in number of drops. Some of these medicines contain opiods, etc., which need rather careful dosing. The drop method, again, does the job within the margin of error for that particular application.
My point is simply that drops are accurate and could present a more convenient method of measuring out Photo-Flo or small amounts of other concentrated stock solutions than using a graduated cylinder for many. I use drops for mixing bleaches, wetting agents, developer additives and small amounts of other aqueous stock solutions. I use syringes for volumes from 5-10ml or so. I have a battery of different graduated cylinders in sizes from 15ml to 2 liters. I use what I feel is most accurate and appropriate for the task at hand.
Best,
Doremus
There are 3.5 splashes in a milliliter.Yes, but there are some here that state that is ok to just dump a splash in. That invites problems.
There are 3.5 splashes in as milliliter.
if I need accurately measured small amounts,Sirius,
What I'm trying to point out (hopefully in a good-natured and humorous fashion) is that drops are really accurate, as accurate as measuring with the graduated cylinder, especially for smaller amounts where measuring error with the graduated cylinder is much larger. One method is no better than the other. Both are "right" and will not result in stained negatives.
If one uses an eyedropper or the like and lets drops slowly form and fall under their own weight, each drop is, within a very small margin, the same volume. The margin of error measuring a ml or so in a graduated cylinder is likely much higher unless one uses a thin graduated pipette or syringe (which I do for developer stock solutions where I need 5ml or more). I find it more convenient at the Photo-Flo stage to simply measure out the requisite number of drops with an eyedropper. I'm confident that my measurement accuracy is well-within the margin of error for mixing that particular solution. Point being: I'm not being slapdash or sloppy here.
Here in Europe, many very strongly-concentrated medications are sold to consumers in bottles with a drop-dispenser top. Doses are given in number of drops. Some of these medicines contain opiods, etc., which need rather careful dosing. The drop method, again, does the job within the margin of error for that particular application.
My point is simply that drops are accurate and could present a more convenient method of measuring out Photo-Flo or small amounts of other concentrated stock solutions than using a graduated cylinder for many. I use drops for mixing bleaches, wetting agents, developer additives and small amounts of other aqueous stock solutions. I use syringes for volumes from 5-10ml or so. I have a battery of different graduated cylinders in sizes from 15ml to 2 liters. I use what I feel is most accurate and appropriate for the task at hand.
Best,
Doremus
It's called Photoflo 200 for a reason: the diluition must be 1:200
Yeah but, it's really 1+199.I am glad that at least one person gets it!
No, that's just listed as "typical dilution":It's called Photoflo 200 for a reason: the diluition must be 1:200
Nope this one actually says add 5 ml Photoflo to one liter of water. 1:200 is Kodak for Ilford 1+200. It means one part in 200 parts. Quoting PE, "Use 2 ml of Photo Flo 200 in 400 ml of water and this should fill most tanks for film development. Your bottle will last you probably your entire life."Yeah but, it's really 1+199.
Nope this one actually says add 5 ml Photoflo to one liter of water. 1:200 is Kodak for Ilford 1+200. It means one part in 200 parts. Quoting PE, "Use 2 ml of Photo Flo 200 in 400 ml of water and this should fill most tanks for film development. Your bottle will last you probably your entire life."
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