Following your questions, I suspected a wrong fixing or washing. Because it’s true that I didn’t use a fresh fixing solution (made 1 week ago), and I washed the plate quite fast. Because it was a simple test.
So I did a new fix solution, and I tried to fix again the plate, and do a good wash.
The result is exactly the same, I still have this brownish stain.
It’s not the first time I have that kind of stain. See this sample attached.
The circle in the center of the image, it’s camera’s reflection.
For the parking’s test I did today (from 5 to 20 secs in bromine), the result for 10 seconds is absolutely marvellous : very strong contrast, perfect exposure (for my taste : I like blue tones in highlights, withs details in shadows). The image is perfect : middle tones are not blue, but neutral (the image posted above was made by a bad scanner). I’m very happy, except for the brown haze.
I have almost no black spots, but still have white ones, and 2 or 3 very big. But it’s better. It’s because I polished the same plate several times, and I think alumina residues begins to disappear.
I did a fast picture of the plate, using my digital camera. You can see the strong and beautiful result.
But for that brownish stain, it’s a mystery. I’m disappointed by this awful stain!! See the green circle on the picture. The other red stains are… the reflection of my face!
And I have no chance : each time I do a test, it’s quite good. When I try to do a “real” image, the result is bad!