Ensoniq; great glasses ! the actual glass part is sticking a bit through the frame, but that was probably what you were tlaking about fixing.
Because youre using a texture to create the shadow, the shadow is of quite low quality and maybe a bit too smooth at the bottom. Maybe you could try using a higher resolution texture? or mixing the texture with real shadows..
Cheers $imon. Yep, the poor lens-to-frame fitment was indeed the issue I was referring to, corrected in the render running at the moment. I agree about the shadow texture. The resolution is reasonably high, at 1000x1000px, but I have resampled it to 1500px square. The main issue is the blurring being incorrect, and not accurately emulating a soft shadow effect. The blur was done manually, using a Gaussian blur effect, and I think I was a bit heavy handed around where the bottom of the frames are resting on the table top. I have reworked the texture considerably, and hopefully the final render will look a bit better.
In theory I like the idea of mixing the baked texture with real shadows, but ART always treats every object as solid and casting shadows, unlike Scanline, so the lenses would cast full shadows. Also, preliminary render tests indicate that the render time would be something like your own 3.5 days, and I just can't spare the time. By comparison the baked shadow method takes about 8 hours to render.
I am working on formalising the method used to create a baked shadow that can incorporate caustics (or a rough simulation of them) to minimise the amount of manual work involved, hopefully making it more a science than an art, so to speak. I won't be able to apply the formal method to this image in time for the comp, but I hope to be able to make up a basic tutorial in the future.EDIT: Re-render added to original post. See above.