H&W Control Developer
If you are wondering why you have never heard of an American factory where "H & W" film is manufactured, the explanation is simple. In fact, Holden and Weichert simply created "H & W Control Developer" which is an exceptionally low-contrast formula. This allows one to develop an inherently high-contrast, fine grain, high-acutance emulsion to yield a normal pictoral tonal range.
The films they were repackaging under the VTE branding were said to be Agfa microfilm emulsions.
This concept became somewhat better known thanks to Kodak's Technical Pan 2415. This was also a high acutance, thin emulsion film, with inherently high contrast when shot at an exposure index of ~100 and processed in conventional developers. But extremely soft-working Technidol developer would yield a normal photographic tonal range and essentially grainless images when Tech Pan was exposed at E. I. ~25.
Separately, "H & W Maximal Developer" is also offered for developing conventional films, with a boost in effective ASA speed. Many such developers have been hawked over the years (as they are still today) usually with a tradeoff in some other attribute such as grain visibility.
H&W Control Developer
If you are wondering why you have never heard of an American factory where "H & W" film is manufactured, the explanation is simple. In fact, Holden and Weichert simply created "H & W Control Developer" which is an exceptionally low-contrast formula. This allows one to develop an inherently high-contrast, fine grain, high-acutance emulsion to yield a normal pictoral tonal range.
The films they were repackaging under the VTE branding were said to be Agfa microfilm emulsions.
This concept became somewhat better known thanks to Kodak's Technical Pan 2415. This was also a high acutance, thin emulsion film, with inherently high contrast when shot at an exposure index of ~100 and processed in conventional developers. But extremely soft-working Technidol developer would yield a normal photographic tonal range and essentially grainless images when Tech Pan was exposed at E. I. ~25.
Separately, "H & W Maximal Developer" is also offered for developing conventional films, with a boost in effective ASA speed. Many such developers have been hawked over the years (as they are still today) usually with a tradeoff in some other attribute such as grain visibility.