Hi there. Something weird seems to be happening to my digicabi dry cabinet.

When turning the knob to the minimum setting all the way left, the RH shows as ard 48%, and when turning it all the way right, it becomes ard 42%. is such a small variance common? i am using a digital hygrometer so the chances of it being spoilt should presumably be lesser.

Second, just want to ask whether it makes a difference whether the RH is too low. we all know the optimum is 45-55%, and i assume that anything higher results in risk of fungus appearing. however if i set the RH below 45% is there any adverse effects to:

1. Camera Equipment
2. Camera Lenses
3. Negatives stored in the dry cabinet.