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wildbillbugman
02-16-2013, 09:10 PM
Hi,
When doing a foging test, I coat a piece of ordinary paper, then let it dry in total darkness. I then cover half of the coated area and expose the other half. I then wet the paper with filtered water, then developer. Lately, only the exposed area that had been exposed becomes black and the unexposed area stays the color of the paper(white). This is as it should be. HOWEVER,If I turn on the lights and therby expose the previously unexposed half, the "unexposed" area, in the course of several minutes, becomes blacker than ithe initialy exposed half. Why?
Bill:confused::confused::confused:

Photo Engineer
02-16-2013, 09:14 PM
In your zeal to keep the unexposed part unexposed, could it be that the original exposure is less than the total exposure given later? And remember that the developer may have been used up or oxidized in the area of the first exposure.

So, have you tried adding fresh developer to both?

PE

wildbillbugman
02-16-2013, 10:56 PM
PE,
When doing this test, I always use "virgin" devloper. Since I have not used fix at this point, would not the "exposed" area gain as much exposure from the white light after development as the initialy unexposed area. Yet the unexposed area eventualy becoms darker than the exposed area. Its as if the first exposure of exposed area is less 'potent" than thesecond time I turn on the white light and expose the entire area. It is as though the emulsion is "faster" in the pressence of developer.
Bii

Photo Engineer
02-16-2013, 11:22 PM
Bill;

You are comparing apples to oranges. Ever hear of reciprocity? Just for one effect, there are dozens of effects that are fighting you in this Compare equal exposure times, development times and then evaluate. Use the same amount of developer and everything else.

PE