HC110 with TX. B vs H

[stevew]

OK. I finished some tests to compare effects of the dilution on highlights. Diluting the developer should have a compensating effect on the high values. I shot a street scene last night. Tripod 1/2 sec at f2 for the whole roll. Developed half at dilution B, half at dilution H.

Scanned on Nikon V at 4000ppi with Vuescan as color positive, converted to grayscale in PS.

Left images as reversed so the diffraction patters are visable on the streetlights. In astronomic photography, this is done for studying stars.

The details may not show in web saves. You'll have to trust my impressions from
my views on screen and on print.
B vs H: comparable grain, acutance, and shadow detail.
***Dilution H does show compensating action in the diffraction patterns on the streetlights.***

So if you shoot high contrast bar scenes like Merciful, or night street scenes, you'll see some improvements with Dilution H or 1:100 like GeneW uses.

First image is full frame at Dilution H.
Second: Dilution B crop.
Third: Dilution H crop.
Fourth: Dilution H extreme crop.

 

[stevew]

Dilution H Flipped to positive.

Dilution H Flipped to positive.

Flipped, levels, curves.

 

[stevew]

Further reflection.

Further reflection.

I did some more thinking on rendering of the streetlights on the developing test (I know, it’s dangerous to think too much).

The book “Developing by Jacobson”, mentions several effects that happen on photographic emulsions.

Irradiation: emulsions are a turbid medium (silver halides suspended in gelatin) that scatters light. As a pinpoint (such as the streetlights) is imaged on the surface of the film and begins to penetrate, the image spreads out through the film in a sort of halo because of the particles of silver.

Halation: as the light reaches the base of the film stock, part of the light that is unscattered will seek to exit the film base. The light that was scattered out in the halo will reflect off the film base and rebound (the angle of incidence is equal to the angle of reflectance) to the surface of the emulsion forming a halo around the point of the streetlight. Film manufactures try to minimize Halation by including an anti-halation layer 1)at the bottom of the emulsion at the base interface, 2)at the back of the film base, or 3)dye the film base itself.

The choice of developer also has an effect on the scattering. A energetic, rapid-acting developer (surface developer) will develop the upper part of the image at the film surface thus minimizing the effects of halation. Surface developers have very little compensating effects so are less desirable in many situations.

More diluted, compensating type Depth developers penetrate further in the emulsion and accentuate acutance and adjacency effects (border effect, fringe effect, Mackie lines), assuming there isn’t a lot of solvent effects.

So HC-110-B will work more as a Surface developer. Diluting the developer will cause more of a Depth developing and will have a compensating effect, but it can accentuate Halation in some rare circumstances.

 

[Trius]

Now that's really instructive and interesting. H wins for me.