I have been a keen photographer for all my adult life, and a teacher and examiner of photography at all levels in schools and university. Another long-standing interest has been collecting and repairing antique watches. As you can no doubt appreciate, the gradual onset of Parkinson's over the past ten years, with an increasing tremor, would be, for me, the very worst of afflictions imaginable. Well, that was how I had imagined it would be. But it hasn't quite turned out like that. I still have the tremor. It's persistent, very noticeable and extremely annoying; but my photography is now better than ever. With my current digital SLR camera* I achieve far sharper hand-held photos than I ever could back in the 1970s, with my, then, state-of-the-art equipment.
Parkinson's enables unexpected insights into the quiet advance of technology. In this case, it's principally the image-stabilising systems built into many camera bodies, and continuous improvements in the design and production of image sensors. Factor in the consideration that once you've got the kit, it costs virtually nothing to take photos, and of course you can delete as many shots as you like as the odd blurred image creeps through. As a final resort you've got image-sharpening software. Last year I took pin-sharp action shots of the Manx Grand Prix [with a hand held 600mm(35mm equiv.)lens. That's a big lens, and would have been a real challenge for an able-bodied professional 15 years ago!]
On the negative side, I have been forced to give up watch repairing. But I still take pretty good macro shots of them!
*Pentax K5. I have had Nikon, Olympus and Panasonic Lumix in the last five years, but personally prefer the current Pentax in-body vibration reduction system. Experimenting can be very expensive, so thorough research is recommended. Image stabilisation is variously called IS, OS, etc., and in some systems (e.g. Nikon VR) is built into the lenses.
I was diagnosed with PD 33 years ago, and I have for more years than that been a keen photographer. I still am, and I can still take good pics. And I have had pictures printed in a book As far as I am concerned I will continue to do the things I love doing and that is it. I see no reason why PD should take a skill I thoroughly enjoy away from me.