You can of course use the DOF preview (or take a test shot) to check depth of field well before the bat flies into view... or whatever it is you're photographing! You could experiment in daylight to see how big the dof is with the camera at various aperture and focus settings.

With some film cameras you could focus on the nearest point you want in focus, and the farthest point, and the camera will automatically work out the appropriate focus and aperture setting to ensure everything within that range is sharp.

This would be an awesome and easy to implement feature for a future Pentax DSLR!

Well, I posted details of this on an astronomy forum (I joined up specifially to do so - how sad!) - and this is how the site moderator responded:

And later, when he had looked at the specs in detail:

The price is actually incredibly reasonable, when you consider it also functions as an astro-tracker... not that geo-tagging or atro photography are things I am personally interested in...

An extraordinary device, well done Pentax! Astrophotography's a bit 'niche' but this could make Pentax the go-to brand for astrophotography. Hopefully a lot of units will be sold, and a lot of astrophotography enthusiasts will upgrade to or buy a Kr/K5 because of this little device.

Well it's a free world, innit?

I have to admit though, i'd be tempted to buy a readymade, and recoup the costs by selling the k7 to someone who will really love it!

Well in the end I have given in to temptation and bought a PZ70. It should be fully compatible with all Pentax lenses from K to DA. Finding that CR5 batteries only cost £3 a pop helped make up my mind!

Is the aperture ring set to A?

Should do, and it'll be fully functional (except for focus) if you put it on the A setting.

Quite right too! There seems to be a resurgence of interest in film... a few 'hip' young people I met last year at friends weddings were into it... one girl was even shooting Super 8 film!

I have trouble with contrasty black and white digital images... the clouds never quite look 'right'... so I am thinking of trying out some B&W film with a red filter....

Very cool. Makes you think about getting a W90!