There's only one right answer: Buy 'em all!!

Steve

Since the problem is over-exposure, it's not likely to be related to the type of focus motor (PLM, DC, SDM, screw-drive). Does the aperture lever move across its full range and can you see it opening/closing the aperture? On the US forum, some people have reported screws or springs coming adrift and stopping the aperture from working.

Steve

I used to be a scientist, too. Then drifted into engineering circles and discovered 'engineering judgement'. Never did find out what it meant, other than "I say it's X, I'm an engineer, don't argue with me." (Steve now runs for cover to avoid the wrath of engineer members of this forum...).

As for zero artistic talent, I used to think the same about myself. Until the day I went to the opening of an art exhibition to take snaps of some friends who were exhibiting. Got talking to a local press photographer who was covering the event for his paper. I said I had no artistic understanding or talent, unlike the people who had produced the exhibits. His response was 'Nonsense. You've got a camera so you're an artist!'. Who was I to disagree???

Rob - the Irix 150mm macro has internal focusing but not sure whether the subject changes size when focusing with the focus ring as I use a focus rail when taking shots for stacking. As you say, the software has to compensate for change in size (and a lot else, too!) so the more help you give it the better the chance of a good result.

Steve

The camera isn't ruled out yet. Don't bin the 16-85 until you've checked whether it happens with other non-PLM lenses - if it does, it's the camera not the lens. And if you know anyone nearby who has a Pentax, ask if you can try your 16-85 on their camera.

Steve

An interesting pair of stacks. There is indeed not much discernable difference at the image size in the thread. But click on the images and the larger versions are definitely different - the latter (13 stacked images) is much sharper across the whole seed head.

But which is the better? If you want lots of sharp detail everywhere, then it's the second image. But if you want some areas of softness (the seed head is, after all, a soft and fluffy thing), then it's the first image. So whether it's 'the more is better' depends on what you want. As always, the technology must be the servant of the artistic vision!

Steve

Nice to see a song thrush, particularly with young. Haven't heard any from my garden this year.

That wild flower is valerian. Round here, it's not so much wild as rampant and all-pervasive. Nice flower, but the price we have to pay for having a bit of it flowering in a chosen spot in the garden is a lifetime of digging it out of flower beds, borders, nooks, crannies and cracks between paving slabs where you don't want it to be!

Steve

An interesting and contrasting pair of photos that, like many good photos of this type, raises unanswered questions. Such as why it's the man with collar and tie who is wearing hiking boots while the highly polished, smart shoes are being worn by the man with a casual shirt.

As others have noted, the B&W works well. Perhaps it's because of the strong lines in the composition. The vertical lines of the background tree trunks mimicking the vertical lines of the foreground seat was no doubt a conscious choice made by the photographer rather than simply a coincidence .

Steve

It's the voice of experience - including much experience of other members of my family. Within the family, there are back problems due to wear and tear from ageing, auto-immune illness, spinal abnormality since birth and injury. But the one that made me comment above is the experience of a certain member of the family who chose to ignore advice relating to other problems (particularly sports injuries), with the result that they developed back problems which means that they can no longer do the sports which they used to enjoy - avoidable if only they had acted on advice at the beginning.

Steve

Oh dear. Please do as you're told or it might get worse. And make the most of your GR, that iris picture looks pretty good to me!

Did you discuss with the doc how you carry your 2lb monster? I sometimes find that carrying a weight to one side or the other is a cause of aches and pains but carrying it symmetrically (front or back) is OK. And sometimes a K3 plus moderately sized lens slung round the neck can be a problem, but holding it in both hands to take most of the weight off the neck is OK.

Steve

I'm another fan of that second shot in the initial set - a magnificent tree with just enough of the bluebells to support the composition without competing for attention.

Woodland shots like this might be one of those increasingly rare situations when a physical filter on the lens would do a better job than post-proccessing. Use a neutral density graduated filter to cut out some of the light from the top then expose for the average of top and bottom. Must try it myself one day!

Steve