LightRoom 4 problem

I have been working on some DNGs, recently taken with my K-5 and (mostly) the DA* 16-50, in LR4, and have been disappointed to discover a mysterious intermittent failure by LR (in the Develop module, program fully up to date) to identify the DA* 16-50 at the Lens Correction panel. On ticking, as usual, “Enable Profile Corrections” in the lens correction panel, it automatically displays the correct make & model correctly under “lens profile” most of the time, but has started occasionally responding with “None” in the Make and Model boxes, and persists with this fault however many times I try in that panel, including closing and reopening the entire program (Furthermore, there is no record of data such as white balance or exposure in the Basic panel for these photos.)
The workload is 400- 500 photos from a recent visit to Turkey, and this glitch has occurred in maybe 10-20 cases. Apart from the 16-50 I only had the 12-24 (an unfortunate necessity as I was having to travel light) but 95% of the time I used the 16-50, and it is just the 16-50 that features in these failures of recognition.
It'd be interesting to know whether anyone else has had experience of this, or maybe has an understanding of what underlies this malfunction, and whether it is likely to be indicative of a significant flaw in camera, lens, or LR?

I have found this also, but.....it only happens with jpegs, not DNG's....at least in my case. I thought it was just a feature of Lightroom that it doesn't recognise the data from jpegs.

Puzzled....:

Lens correction panel?

Just when I thought I was starting to get to grips with LR4

Must open that instruction book one day.

Carl

I'm assuming that the workings of the lens is okay (lens pins making contact with the body's contact terminals), so next thing I'd look at on the "faulty" DNG's is the exif data, to see if there is perhaps a data corruption that LR4 is unable to read. After that, I ain't got the foggiest, honest guv'nor!!

LR4 has never recognised the 55-200 WR automatically, but as soon as I manually tell it that it's a Pentax, it understands! It will recognise the non-WR version without intervention from a human...

It also does not have a profile for my Sigma 170-500mm at all, I tend to go to the closest match and trust to luck...

The DA* 16-50, the 18-55WR and the 10-17 F/E are all picked up automatically.

Having now discovered this tool (thanks Duncan)and watched a tutorial - I get 'none' every time and Pentax is not even listed so I can not even manually state Pentax - although according to the adobe list - they have profiles for every lens I own!

Maybe I am doing something wrong but have followed step by step instructions and tried every variation allowed

Carl

The Adobe web-site lists all the lenses that are in the "supported" category for LR4. If they are on the list, they should show when you open the "lens correction panel", and tick "enable profile correction" with "setup" at "auto". All my Pentax lenses are on the supported list and do show, most of the time.

I have just taken a few shots with a lens that I checked was on the list - and still 'none'

I may have to follow Derek's advice and re-load.

If I do this - does it impact the 'library' I have saved in LR4? - anybody know?

Carl

Thanks for that advice, but like FTD, I dread the potential side effects of reinstalling

Hmm, curiouser and curiouser...

I've re-installed LR4 at least twice, but the lenses I mentioned above have always been treated as described. Some sort of bug, perhaps?