You can use older flash guns in A and M modes only.

Dedicated TTL does not work (the K10D does not support TTL, only P-TTL).

With really old flashes you would be wise to check the trigger voltage - some have very high levels that were ok with manual cameras but not the newer breed. If you have access to a volt meter, just measure between the centre pin and the edge (but watch your fingers as some have up to 300V!).

So it's kind of yes and no
Matt

Not a problem with the Pentax one
The body has absolutely no idea of the focal length - you have to manually enter it (which is a pain to work out 1.7x in your head).

Only snag is that it won't work so well for zooming...

Matt

The Pentax 1.7x AF converter can be used to convert manual focus lenses to autofocus.

However, you can just as easily use it with an autofocus lens - to some advantage! Because the focus is entirely inside the AF1.7x the lens never moves. You just manually set a rough position (say infinity) and the converter will do the rest.

In practise it works extremely well - I've used it with the SMC-F 70-210 and the SMC-FA 80-320

Matt

AJ,
That's reasonable. Cokin and Kood do a round circular polariser for the Cokin P holder. It fits between the lens and the first filter (you'll notice the P-holder has the first notch slightly wider).

With the 12-24mm you can just about get away with using the P-holder with a tiny amount of vignetting on the corners. It becomes more obvious if the holder isn't at 90 degrees to the camera. (It's also the aperture of the filter holder that gets in the way - a friend of mine filed his out to make it slightly larger)

Even with the Lee and Cokin X-Pro you can get some vignetting at 12mm if the holder isn't at 90 degrees!

But yes, for landscapes, a polariser and one ND grad should be ok. If you add more than one Cokin/Kood/Hitech filter you'll get magenta tinges appearing

Matt

AJ,
The Lee one is this:
http://www.leefilters.com/CPTS3.asp?PageID=134

You then have two filter holders with the front one connected to the rear - the front can then rotate independently.

Upside down sounds good though...
Matt

(It's just there are all kinds of people who read here - I don't think they'd appreciate buying a linear and finding they can't focus )
Matt

Of course - just rotate the whole holder
But... it doesn't work if you want a polariser AND an ND-grad. Then you need either a round polariser, or stack two holders together (Lee filters can do this, not sure about Cokin).

Matt

Absolutely not correct. (But maybe you were joking... but just in case someone gets the wrong idea...)

Both circular and linear need rotating. The linear polariser will stop the autofocus from working. You need a circular polariser.

Matt

I have three Wacom Graphire tablets and a Volito

The Volito is a bit "plasticy", and only has a single switch on the barrel (the Graphire has an eraser and two buttons on the barrel).

However, if you compare "No Volito" vs "Volito" - there's no comparison It'll make Photoshop/Elements much, much easier to use. I usually keep the left hand on the keyboard and the right on the pen.

Matt

Thought you might like to hope over to this link and check out the review for the AT-X 535 50-135mm f2.8 Tokina lens:
http://www.optyczne.pl/index.php?art=57&&roz=1

What's interesting is that it's about £440 - resolution is very high. Problems with flaring, but then once Pentax get their hands on the optics and give it the "star" treatment, I strongly suspect we'll see a completely different beast
(And probably a much higher price)

But it'll give you an idea of the size and build. 67mm filters is nice! I think the Pentax are lighter than the equivalent Tokina builds (comparing 10-17s for instance or 12-24)

Of course, the Tokina will be Canon and Nikon mount only. Will have to wait for the Pentax version, but I feel the LBA starting to bite

Matt