I believe the difference in skintone rendering between HP5+ and TX could probably be attributed to curve shape; HP5+ has a rather straight-line response _way_ out there into really high density, while I believe TX still has some shouldering. I haven't used TX in years nor plotted its curve shape, so that's just supposition.(posted 8766 days ago)The current Delta 400 has somewhat reduced red sensitivity compared to HP5+ and Delta 100; I don't use it when photographing people for that reason. It has a tendency toward darker-then-desired skin tones and showing up blemishes.