Barrie, all I can say is that the Force was with you for this picture

Thanks Barrie. I clicked on the link and found myself in an Indiana Jones movie !

What a difference. Super image.

They are crackers Peter

Liking no. 5 a lot

I don't think the camera is at fault as it works fine with your 15mm lens. Perhaps there is a problem with the connectivity of the Tamron mount. I have seen instances where the mount is not made of the correct material and throws the cameras electrics haywire.

I would suggest you try https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/ Someone there must be using this lens and may have some suggestions.

How does the camera behave with a modern lens ?

I suggest first giving the mount on the camera and the mount on the lens a clean using microfibre cloth and some alcohol. Pay special attention to the contacts.

Re USER modes Steve has given a good example. I have something similar. I have two USER modes set for photographing moving beasts whether they be my dogs or wildlife.

Both are set for TAv mode and continuous shooting Medium burst. One is set up with AF-C and Expanded Area AF points (tracking). The other is set up with AF-S and single select AF point. So for example I will use the first when following a moving subject. But when it stops I can quickly switch to the second mode and use the focus and recompose method to get my shot without having to fumble with adjusting AF mode.

First, the reason I asked is that there are a number of camera settings (Autofocus points; drive mode; Autofocus modes plus many more) which will be retained in that USER mode when saved. Colour space for jpeg output is one of these. So although it does not seem to be the case for you, it is worth pointing out for all that if at any time one saves a change in colour space (AdobeRGB) while in a USER mode, changing the setting back to sRGB while using the camera in Av mode for example, has no effect on that USER mode. Anytime you use that USER mode again you will be producing AdobeRGB output.

Yes a forum limitation not only on this site. If you want to display larger images get yourself on a hosting site like Flickr and you can link directly to it.

ps. Uploading an image 6736x4502 is not too helpful either....

1 Most forums will just downsize it for you as this one has.
2. Those that will display a full sized image may take a long time to load for the viewer (especially on a mobile device), and will resize the image to fit the screen view, with an option to view the larger image zoomed.
3. Although 4k screens are becoming more popular, most folk on a photographic forum will be viewing on a much lower resolution screen. I have a 27" monitor with 2560* 1440 resolution, larger than most I suspect. So even if your image was displayed in full resolution by a webpage, you are relying on my software in my computer to downsize the image by a factor of roughly 1:3 to display in full screen mode. Now I am confident my software will do a good job but you cannot rely on everyone to have good equipment, and even if they do, such downsizing can affect sharpness of an image. My suggestion is to post your images to a web hosting site like Flickr, but do so in a resolution that is a good compromise. Something like 1440 pixels tall will be sufficient for most folk viewing on their monitors.

Certainly applies to dogs !