Matt has explained it very thoroughly, as always.

TTL flashes produce only one flash to make the exposure after the mirror goes up and the shutter is fully open. In TTL mode, an additional light sensor inside the mirror box measures the light reflected from the film/digital sensor surface. When the correct amount of light has been used to make the exposure the TTL circuitry quenches the flash to stop it producing any more light.

P(reflash)-TTL uses the cameras normal light meter to set the flash power before making the actual exposure when it fires a second time.

Well done Tel. Good price, good camera, good job.

Now let's see some piccies from that 50D

Hoya filters are made by . . . Tokina.

Try adding +0.7 exposure compensation for everything for a while and see how that goes. Adjust the slight overexposure if there is any in PP. I think you'll be happier with the results.

You may be right Stefan, but if it's working in true P-TTL mode, it is supposed to flash before AND after the mirror goes up and the shutter is released.

For info RayHutty:- the P in P-TTL stands for Preflash. A complicated sequence of light pulses are exchanged between the pop-up flash and the wireless slave, the slave is triggered and the camera's light meter measures the flash output to set the exposure and flash power BEFORE the mirror is raised and the shutter is released. After the shutter is open you get the second main flash which actually makes the exposure.

The AF240FT is a TTL Auto + High or Low output flash and will only work in TTL with suitably equipped bodies. The *istD and *istDS are the only Pentax DSLR's that support TTL. All the newer bodies support P-TTL.

This does not make any sense to me. What exactly do you mean?

A wireless slave flash is triggered by light pulses from the pop-up flash. Covering the pop-up flash will render the wireless flash useless as it can't 'see' it's instruction to fire.

And how cool would those titanium (silver really) coloured FA Limited lenses look stuck on the front of it.

I haven't used them myself but I've known the LinkDelight name for many years of ebay trading. I think you can trust them.

Yes they have a few negative FB's but then again they have more than 35000 positives.

If you've got £150 to spend,get a new FA 50mm 1:1.4. You'll not regret it.

Why so many available? It's probably due to the fact that almost every Pentax 35mm manual focus SLR from the MX onwards was sold with a 50mm lens of some sort as standard. That's a lot of cameras and a lot of lenses that have lasted longer than the camera they were sold with and are now available because numpties perceive they don't need them now that they have 'gone digital' .

The most common is probably the SMCP-A 50mm 1:1.7. The f2 version (not 1.2) was sold with later models.

The f1.2 lens was only produced in original K mount and the later A series. It's expensive but if you need the fast aperture for low light it's worth considering.

The bottom line is for around £50 you'll get a very good lens.

Caution: Check the aperture ring of any A series 50mm lens They are prone to sticking due to a broken leaf spring mount. It's fixable, with patience, but best avoided if possible.