I find the green button works pretty well Pete, particularly when I use my BPM bellows which of course has to be in manual mode.

All metering systems average the scene to a mid grey (18% grey in film terms) so the ubiquitous white cat in snow will alway be underexposed and the equally ubiquitous black cat on coal will always be over exposed, which is why they have exposure compensation built in.

The green button, just like any other metering mode, will sometimes need compensation which works in exactly the same way.

Using wide aperture is not always the best way to go especially if you are using hyperfocal focus (pre setting the focus using the DOF scale), stopping down increases the range of whats in focus.

Using manual mode and 'presetting' the camera frees you to concentrate on the subject (particularly useful with sports) and was the way we all used to work back in the days of the Spotmatic, and is still useful today especially with studio flash, its still my preferred way of working.

Pentax A lenses (which have the all important 'A' position on the aperture ring) can be used in any mode, everything, except of course focus, is still automatic.

Pentax M and M42 lenses (with an adapter) you will have to use stop down metering. I tend to use Manual mode, set focus with the lens wide open and the viewfinder image is at its brightest, then stop the lens down say to f8, pressing the Green Button will force the camera to take a reading showing the shutter speed for that light level and aperture combination. This will appear in the viewfinder and on the top screen, the camera will set this shutter speed at this time, if the shutter speed is too slow alter the aperture and press the Green Button again.

On both types of lenses you can pre-set the focus using the DOF (Depth of Field) scale that is on all these lenses.

Using this is tricky to write down, but here goes, on the lens you will see the DOF scale just below the focus scale which alters as you focus the lens (usually calibrated in feet and Meters) it will look similar to this

22, 16, 11, 8, 5.6, 4, 3.5 | 3.5, 4, 5.6, 8, 11, 16, 22

If you envisage an average focus distance of say 10ft then set that to the centre mark by altering the focus ring, by reading left and right along the scale to the aperture you set, you can see the minimum and maximum distance that will be in focus. So you can snap away knowing that within those limits the picture will be in focus and just use the (dim at small aperture) viewfinder to frame the shot. Its one of those things that is far easier to show you rather than it is to describe.

Pressing the Green Button just before taking a shot will 'update' the shutter speed as the light varies. And will usually give the correct exposure.

One final tip some of the M42 adapters have a flange on the front of them, with some lenses this 1/2 a mm extra distance from the sensor to the lens will stop you from focusing on infinity (I know its a tiny distance, but thats how accurate the lens to sensor dimension has to be). On some older lenses its no problem as they can focus past infinity, but on others it will make the difference. The Genuine Pentax adapter fits flush with the front of the camera mount which eliminates this problem.

As you can tell using these old lenses is not as quick as using lenses with the 'A' setting, but image quality particularly with any Takumar lens will be superb.

There are a few Sigma 70 - 200 f2.8 EX lenses on eBay as they have brought out a newer version that focuses down to 1 meter (the older one is 1.5 Meter) so some owners are upgrading. I got mine for just under £300.00 last month. Superb image and build quality, and being rear focus it focuses in the blink of an eye.

PS doesn't update the Histogram display automatically (it would take resources away from everything else) so its just the display that's lagging behind, clicking on the yellow triangle forces PS to update the display and the combs disappear. Rest assured that the combs aren't there in the file its just the display that hasn't 'caught up'.

You can do a lot with a B&W in PS. I hope you don't mind but I did a little 'tinkering' with your picture.




Once you've converted to B&W select part of the image say the sky with the Lasso Tool and feather lots, pull up a Levels Adjustment Layer and adjust the sliders, do the same for any other part of the image. You can also use a Curves Adjustment Layer and increase contrast on just the part of the picture selected. I added a glow to the water beyond the people, but I could only go so far with this small file.

If you shoot Raw and open as a 16bit file its amazing the detail you can extract.

For highest quality convert your Raw files to 16bit Tiffs. Theres a lot more information for PS to work with.

The Metz 48 AF-1 is only £139.00 at SRS, its a very good PTTL flash with a swivel head. It also has USB update, but as there are no updates for the Pentax version needed I don't know how useful this is.

True

It is an easy fix Matt, but you really shouldn't have to. Even on the Metz (I have the 48 AF-1) you have to make sure you wind the locking ring right up to the flashes body to make sure the locking pin is withdrawn properly.

Macros of Orchids are tricky, you need lots of DOF. Its a good effort.

One tip is to carry a small piece of black felt in your bag when you go flower hunting, drape it on the plant behind your subject, gets rid of any distracting 'blobs' of flowers in the background and if you use flash it kills the reflections which can give a colour cast from the foliage.