One other reason why I'm hesitant of using a scanner is it requires so much handling of these delicate pieces. Soft pastel is easily damaged, so to be dragging a sketch across a scanner to ultimately stitch together sections is not going to happen. Spraying a fixative on the sketches is also not an option as the varnish and calcium carbonate share a very similar refractive index, so as you spray, the sketch disappears! Not so simple, eh... There is also a huge risk with the larger pieces that with so much handling that the paper will be creased or damaged. I've handled enough paper to know no matter how careful you are, the more you handle it the greater the likelihood of damage.
I do understand what is being said about what scanners can offer, and I've been rethinking scanners as a result. I also understand the nature of my pieces and what I can and can't do with them. Like everyone, I'm not going to put my work at risk.
Annette, you've presented a good alternative - stitch photos together.
My care for my work extends to how I store them. Finished pieces are not left to languish in the sketch pads. I've even devised contraptions that help me control dew while I'm sketching, so now just the heaviest of dew stops me, as it would stop everyone's own efforts at what they do. So I am very familiar with handling my stuff. I say this so you have a little insight into not just the production but also the care that goes into these pieces. There's even a little materials science thrown in for good measure!
What will happen is more experimentation. I will look into scanners all the same, including large professional units to see what will cause the least compromise to my work. I'll also try different cameras and Photoshop - I never thought I'd be using astro-inspired mosaic software with my sketches!!
Alex.