I don't think you have quite understood what I suggested, the point is that you don't want the camera to fire until focus is correct.

Impotentspider, the wording as I remember it is that SR is less effective in the macro range. I have found it to be good for at least 2 stops with my Tamron macro at 1:1, where I might expect 3 or 4 at longer ranges.

I think trap focus might work with a DA lens if you set the camera not to focus when the shutter is pressed, since the DA lenses have full time manual override. I haven't tested that though.

This idea occurred to me last week when I was taking hand held macros. I expect many of the very clever people here have already thought of this, but I'll post it anyway in case I'm not the only one who's never thought of it before.

First, the problem. SR is great, it gives we Pentaxians something which Canonites cannot have and Nikonians must pay top dollar for. That is, a stabilised Macro lens. Hand held macro here we come!

The problem is that SR can only take care of your shake in two dimensions, and you are moving in three. At normal shooting distances DoF is large enough that this is irrelevant to even the pickiest of us, but at macro distances keeping the subject in focus while hand holding is a nightmare.

What we need is a way to fire the shutter at the precise instant the image comes into focus. Enter Trap Focus. Unfortunatly for the rich among us, this will only work with older Manual focus macro lenses, though it may work with newer lenses if you turn off AF when shutter button pressed in the custom menus (I haven't tried this as my Macro lens is MF).

1. set the camera to AF-S mode

2. Frame the subject slightly out of focus. Unfortunatly the point of focus must be centred since you can only use the centre focus point with an MF lens. If this is not a satisfactory composition you will have to correct it with cropping.

3.Press and hold the shutter button. Nothing should happen

4. Still holding the shutter button, adjust the focus very slowly, either using the focus ring or Krytens Patent Manual Zoom mode (move your head closer to the object).

When the portion of the subject in the centre focus point comes into focus, the shutter should fire, and if all goes well you should have a nicely focussed hand held macro shot. It's not perfect, but I have found this method improves my hand held macro hit rate significantly.

hope this helps someone out

I would expect a lens as expensive as the Bigma to be built well enough to handle a pro grade focusing motor TBH. True the K10 has a more powerful motor than previous Pentax DSLRs (at least the later *ists anyway, I've never used an original *istD) but that shouldn't be the end users problem.

I must admit that most of my butterflys this holiday were taken in a tropical butterfly house, so I've been cheating a bit in that respect

Further to this, I am using an old Tamron 90mm SP with 2x flat field converter to give me 180mm F5. It's great for bug shots in the wild and the pair set me back about £60 on evilbay. If you can get the KA version of the mount then it should be fully operational on all Pentax DSLRs. I am using the KM version with my K10D with pretty good success dispite the metering issues (discussed repeatedly in other threads).

I'll probably be posting a few butterflys from my holiday soon, so keep an eye out if you're interested in what this lens combo can do.

the 18-55 is certainly not a pro grade optic, even stopped down. Even at F8-F10 (which seems to be where mine is at its best) it is no match for either my SMC-A 50 1.7 or CZJ 35 2.4. Admittedly comparing a kit zoom to primes of that caliber could be seen as unfair, but I'm just trying to qualify my statements regarding this lens. I regard it as the best of the kit zooms, certainly it is better than the Canikon offerings, I have never seen it directly compared to the Oly or Sony kit lenses. Still beating the Canon EF-S 18-55 is hardly a stellar achievement.

In many cases it's "good enough", but you do have to ask yourself, is that REALLY good enough?

I already have an 18-55 because it came with my DL2, so it is filling that role in my kit bag until I get around to affording a replacement for it. I don't do wide angle very often so it doesn't bother me a great deal. If I was without a lens at that focal length and wanted to buy one tomorrow, the 18-55 would not come into the question, but I'm really not sure if the Sigma 18-50s F2.8 would end up beating the Pentax 16-45s 16mm and SMC.

I have a very similar debate, TBH I think baring a lottery win I'll eventually end up with the Sigma DC Macro 18-50 F2.8. The DA* 16-50 would be excellent, but I'll have a hard time justifying that much money on a standard zoom and the 16-45 F4 just isn't quite fast enough.

For now I'm sticking with the 18-55, which does a good enough job stopped down a bit. My more pressing desire is a nice long tele since this makes up most of my summer time photography and my 80-320 just isn't quite up to what I want.

when you say you're interested in ~20-60 F2.8, have you taken the crop factor into account?

If so then your options are basically the Pentax 16-50, Pentax 16-45 F4 (much cheaper but F4) or the Sigma offerings.

if you're looking for something a little less pricey, the Pentax SMC-FA 80-320 is a great lens for the price. I am using it right now in Canada as my long tele, it compliments the K10D very well.

Saying that, I am also considering getting a Sigma 135-400, or maybe it's big brother the 170-500. With SR these lengths are reasonably hand holdable (given good technique) so suddenly they have become much more interesting.

In their deffence, scientific tests of this system are nearly impossible.

All I can say for sure is that I now consider 1/60th at 320mm easily do-able, whereas before it was on the very limit of shots which I would fire off anyway without real hope of them working out.