I use a Centon flash (FG30), which is listed as having a 200V trigger voltage. I've never tested it, so can't say whether my one is this high or not. Obviously I can't say that 200V (assuming my one is triggering at 200V) is safe, but I've used this flash on my K10D and *istD and had no problems. Anyone using the same would do so at their own risk.

A link from that Botzilla page takes you to this thread: http://www.botzilla.com/photo/photoBook/pbook.html#msg200

...which says that Pentax have said their SLRs are safe to 600V, but that the correspondent has problems (not fatal) with a 300V flash gun. However, this was in 2003, so possibly before the first Pentax DSLRs.

Dan

The *istD takes Compact Flash cards (as George well knows, he's just getting on a bit now ), so don't buy SD cards.

As he also says, lenses to suit your shooting preferences! Without knowing what sort of shots you're hoping to take, no-one can advise what lenses you might need. However, a general set would be the 18-55mm standard zoom lens (the Mark 2 variant is apparantly even better than the well respected mark 1), and perhaps the Pentax 50-200mm, which would give you a good basic kit, covering focal length from wide angle to telephoto (the equivalent range of 28mm - 300mm for your Miranda).

Let us know what your budget is, and any particular area of interest to you, and advice can be more specific.

Dan

Other problem I encountered the other day using the infra-red remote was that the camera (K10D) switches itself out of this mode after about 10 minutes. So as I was sat there waiting for a Long-Tailed Tit to come into shot, I discovered the shutter wouldn't fire when I wanted it to.

This may well be a setting in the menu somewhere, but I didn't get round to looking for it. The cable release wouldn't suffer from this though. And George is right, I have over 80 feet of extension for mine, and a cable also means you can camouflage the camera, and not worry about needing line of sight to trigger the shutter.

Dan

I used Avides Media AG through Amazon when I got the grip for my K10D, they were fine and cheaper than anywhere else I could find at the time (about £100 when they were £125 at least elsewhere).

Dan

Doing an animated GIF shows us a cycle through the 4 images, notice how the colour does change slightly between the two showing similar tints, a bit more magenta seems to creep in. Also, the more orangy ones are darker - is this when the FL tube is 'off'?




Dan

I would think it's fair to say that the FL tube will change in brightness as the current goes through its cycle (the number of electrons emitted by the cathode will go through a similar cycle, therefore the amount of fluorescence will cycle too). So the mix of daylight to artificial light will also go through this cycle.

How this actually relates to the half and half effect Iceblinker has found, I'm not sure, but I would imagine that with very careful study, it could be shown that it wasn't just a choice of two options, but a whole range, but to the eye it would look like one tint or the other.

Be interesting to see the results.

Dan

I didn't say it was.

No it's not, it emits elctrons when the current flows to heat the cathode. Hence the flicker.

The colour temp will be constant, but not because of that. It's because a particular element, or compound, will emit light at a particular frequency when an electron jumps from one 'shell' to another ('probability cloud' if we want to get a bit quantum ). It won't emit a different colour if the energy trying to cause that electron to jump shells is less, because the electron simply won't jump. (Before someone comments, I know it's when the electron returns to its normal posittion that the light's emitted. )

Who'd have thought that the original post would have got us here?

Dan

...and John beat me to it.

And Peter made another good suggestion.

Dan

Just to throw a spanner in the works regarding Pentaxian's theory, I believe the way in which the light produced by tungsten and fluorescent lamps is fundamentally different.

Tungsten lamps emit light because the filament is heated up by a current passing through it. The amount of current relates to the temperature of the filament, and the colour of the light produced. Low current, yellow/orange colour (think of a torch with a low battery), high current, whiter light (though still yellowish). As stated, as the current cycles, the filament does not have time to cool down, so the light stays constant.

I believe that fluorescent light tubes work like this:

A cathode in the tube emits electrons when heated, which then strike atoms in the gas, which emits ultra-violet light as a result. This UV light then hits a fluorescent coating on the inner surface of the tube, which then emits visible light. Far more detail (than you could ever wish for) is here: http://en.wikipedia.org/wiki/Fluorescent_lamp

What this means, is that either the tube is emitting light (current flowing), or it's not. The flicker is as a result of this. You would not get the changes in light temperature as the both the UV and visible light is produced due to excitation of electrons, which will result in a given colour of light for a particular material. The combination of phosphors (the fluorescent material) dictate the colour of the light.

Basically, the light temperature is not going to fluctuate.

I am more than happy to be proved wrong.

Dan

...but your actual competition entry is gorgeous, so perhaps it was for the best.

Dan