A few points here:
- When I first started I measured the height wrong, so the bowl is the wrong shape. It’s so important to do the first measurements accurately.
- I took a few specular hightlights to be white, and set the tones on the basis of this. This was a mistake. You need to ignore the small areas and set the tone for the larger areas.
- The lighter areas are HB but you can’t see that at all in the scan, so perhaps I should stop using HB. Perhaps I’ll use white, 2B and 6B. But I don’t think this will be enough to make the object real. The above drawing looks like it is three tones (beacuse you can’t see the difference between HB and white), and it looks flat. Three tones don’t allow scope for detail. The trouble with the above was that the background was black, so I couldn’t use 6B on the bowl, just the background. You need to factor in the tone value of the background when planning the drawing. In this situation perhaps I could have used 6B on the bowl, even though there is nowhere on the bowl as dark as the background. Aonther option is to use 2B, 4B and 6B and white. I’ll try that.