@MartinShackletonCeramics I had the camera out to do some product shots so thought I would take a couple of photos to see if I can help you out with the depth of field thing (although the flower thing works really well and does give a sense of scale so if you can’t change the depth of field on your camera stick with that). The only thing I changed between these 2 photos was the f number
that’s f29 which is the deepest my camera will do, the next one is f4.5 which is the shallowest
With the shallower depth of field the back of the rim, foot of the beaker and the rock its sat on are out of focus (its a sake beaker so about 5cm across) and there was an audible difference in length of exposure with the f4.5 being much quicker (but I shoot with a tripod so that doesn’t matter but if you were hand holding it might). The camera was set to auto focus and picked the bright patch front left in both cases, if yours is picking out the back of the rim you could try moving the camera away from the vase a little bit or (with most dslr) if you half depress the shutter release button you can force it to focus on the bit of your choosing and if you keep the button half pressed you can then reframe without it loosing the focus before taking the photo. (its a 28-105mm lens locked into macro mode shooting at iso 800 in case you wanted to know). Let me know if you want me to mess about with the iso rating.
Right back to product shots, I need to re angle my back drop and increase my exposure by the looks of it.