Kodak Ektachrome E100GX

E100GX is the warm-balance twin of E100G, launched together by Kodak in 2003 as the replacement pair for the older E100S and E100SW. The X is the warm tag. RMS granularity sits around 8, low enough that 35mm scans cleanly on a Coolscan or a flatbed without grain becoming the dominant texture. T-grain emulsion technology is what gets it there.

The practical character is moderately enhanced saturation with skin tones that lean toward cream rather than pink. If you have shot Provia 100F, the GX sits roughly opposite: where Provia is cool and quiet, GX is warm and slightly louder, though nowhere near Velvia 50's territory. Most photographers who loaded GX were doing portrait or wedding work where the warmth flattered skin without needing an 81A filter. Catalog shooters generally stayed with E100G or with EPN. GX was for people and golden-hour landscape.

Kodak rolled this into the broader Ektachrome contraction at the end of 2009. By then the entire E-6 market had collapsed and most working pros had moved to digital. Surviving stock from 2009 production runs occasionally appears in freezer lots on eBay; the dyes hold up reasonably well in cold storage, though older expired material tends to drift cyan in the highlights.

It shipped in 35mm and 120. No sheet sizes were ever made in this emulsion, which is one reason architectural and commercial shooters stayed with EPP or EPN.

Reciprocity exponent is 1.10, the standard mild number for modern E-6 emulsions of this generation. Past one second Zone Light Meter nudges the shutter time up by a small amount: a 30-second meter reading lands at roughly 35 seconds at the film plane. The math is about correctness more than dramatic compensation. The warm balance does shift slightly with longer exposures, so if you are shooting a nocturne factor in both the exponent and a possible color drift.