[Brightcolours]

I am not sure that lens design is all that much different between film and sensor other than rear element reflectance and therefore coatings?

Sensors do behave differently than film. In front of the sensels are micro lenses which try to direct the light towards the pixels. Light hitting them at big angles does not all reach the sensor, so with wide angles at "large" apertures you see more vignetting (light fall off) than with film.

 

Some sensors/lens combinations show colour shifts and even severe resolution loss.

As for lenses having to be better for digital that is clearly a laugh!  The onset of low resolution digital allowed for the proliferation of (poor) quality zoom lenses and only now are designs (of zoom lenses) doing justice as sensors improve.

Huh? With film, we did not get very high resolutions on 135 format. One of the reasons why MF was so popular when resolution mattered.

Zoom lenses of poor quality are something from the 1980's and 1990's, before the digital SLR age.

What are the zoom lens designs doing justice to, if not the "digital sensors"?

 

With digital, we all pixel peep. Before digital, you would just look at your small prints of vacation snapshots you got back from the 1-hour service.

I am only interested in FX (I have DX also) as it is here where the buck stops.  Poor lens quality shows.

Before you seemed to say that lenses do no not need to be better for digital, and now poor quality shows?

OK you can go out and buy a £1800 zoom that has great quality (professionals and photo-journalists do) but Joe Public could do with something cheaper.  Only Samyang are fulfilling this market and only part-way (lacking AF).  Don't let that hold you back though focussing manually is easy (easier?).

What are you talking about? Samyang does not offer ANY zoom, let alone any quality zoom. Besides Samyang, there are many companies offering affordable prime lenses, most of which offer AF (voigtlander (MF only), Nikon, Canon, Sony, Sigma, Tamron).

 

And Nikon, Canon, Sony, Sigma, Tamron and Tokina all offer relatively affordable zoom lenses with AF too.

Samyang have been criticised about decentering and this is the only aspect that half holds me back.

The Samyang 85mm f1.4 is the least sharp 85mm available. It does however render things nicely. The Samyang 24mm is not great. The Samyang 14mm is sharp but has a LOT of distortion.