Quote Originally Posted by Bruce (Camclicker)
Is a ratio of 1:2, 1 part X plus 1 part Y to make 2 parts or is it 1 part X plus 2 parts Y to make a combined 3 parts?

Would a PMK developer that calls for combing parts of 1:2:100 yield 100 ml or 103?
When you are working with photographic chemistry, make it easy on yourself and change all the colons ":" to plus signs "+". This is the way it should be expressed anyway.

True ratios will just mix you up, and in reality can't normally be expressed in an easy way when using more than two like quantities (like mls). In other words, the PMK "ratio" is expressed incorrectly simply because it has more than two quantities. It should be 1+2+100, and that's really the only way it makes sense here.

Just in case you want to know, to express a developer dilution of (one part Dektol plus two parts water) in a ratio, it would be written 1:3. The second numeral of a ratio (the three in the Dektol example) is the total of parts needed for the solution. The first numeral (the 1) indicates one of the parts that make up the total, in this case the Dektol. Mechanical ratios work the same way, (think of two pulleys, one three times the size of the other). The larger pulley is three feet in diameter, the smaller one foot. One rotation of the larger rotates the smaller three times. A ratio of 1:3.

If this is all mush to you, just go back to my first sentence and mix with confidence.