I had all but given up on being able to use the Lightroom lens correction feature with my Sony 18-250 lens, finding myself a long way down the road to utter exifsperation.
Hardly any coverage of Sony lens profiles in Lightroom, no support in Lightroom for search of on-line profiles, and Photoshop CS5 (which does support on-line search) failed to recognise the lens identification EXIF tag because Sony use a proprietary tagging system. When the latter hurdle was finally overcome with the aid of a bespoke tagging utility, there was no on-line profile available anyway, and the only remaining option, DIY home lens profiling, is not really practical for the non-professional.
Thankfully, Tamron have come to the rescue. They have provided profiles for all their lenses and these come bundled with the latest release of Lightroom, version 3.2. So how does that help me when the lens I’m bothered about is a Sony lens? Well, my Sony DT 18-250mm F3.5-6.3 is optically identical to the Tamron 18-250 F3.5-6.3 Di II (Alpha Mount). Sony own a major share in Tamron and the Sony lens is essentially a rebrand of the Tamron with only minor changes such as more rounded aperture blades (for improved bokeh) and different focus screw gearing (for faster focusing).
I tried the Tamron lens profile with my Sony RAW images in Lightroom and it works perfectly. The distortion correction is indistinguishable from PTLens, to the naked eye at least, but with vastly greater convenience, flexibility, and automatic chromatic aberration/vignetting correction thrown in.
I now have a Lightroom user preset which applies the correction for me with one click.
Kudos to Tamron for saving the day. I know there must have been a marketing angle to their efforts but if they were looking for brownie points they have certainly won them, in my book at least.