[Schmidt]

I recently downloaded Corel AfterShot Pro 2 (it's currently at version 2.0.3.25) for use with my K-50 Raw files. Initially I was impressed with its renditions, until some 'pixel-peeping' at 200% zoom showed some strange bands or horizontal artefacts occuring in almost all of my images (some worse than others). I also had noticed these lines consistently occurred between about the Y-coordinates 2559 and 2563, inclusive (with the camera oriented horizontally, or in standard 'landscape' orientation). Sometimes the horizontal line or lines spanned the whole picture, at other times broken up into segments ... But always in the same range. At first I made the assumption that there was something wrong with my camera's sensor. But then I downloaded some Pentax K-50 DNG files from imaging resource and, lo and behold, AfterShot Pro rendered them too with the same artefacts! The images were converted to TIFF files and retained the same problems. I then opened the same images in other raw converters, and none displayed the problem that was evident in AfterShot Pro 2.
Has anyone any experience with ASP2 and a Pentax K-50 on either Windows, Mac or Linux? I really like this converter due to its speed, but this problem may be too serious to warrant a change at this time. BTW, I tested ASP2 out Ubuntu 14.04, and am curious as to whether the same problem exists on other platforms as well.

[Schmidt]

After some further experimentation with AfterShot Pro 2 (ASP2) settings under Ubuntu 14.04 Linux on my machine, I've come to the conclusion that unchecking (i.e. disabling) OpenCL acceleration under the preferences menu seems to solve the problems of on-screen appearance and final rendition to Tiff and Jpeg formats. The default mode for OpenCL under ASP2 is disabled, but I recently had switched it on to take advantage of my hardware... Who knew the bug would actually alter ASP2's Raw rendition process and affect the actual output files. Be interesting to know if this bug is relevant to other Pentax models and Raw formats...

[Schmidt]

I recently downloaded Corel AfterShot Pro 2 (it's currently at version 2.0.3.25) for use with my K-50 Raw files. Initially I was impressed with its renditions, until some 'pixel-peeping' at 200% zoom showed some strange bands or horizontal artefacts occuring in almost all of my images (some worse than others). I also had noticed these lines consistently occurred between about the Y-coordinates 2559 and 2563, inclusive (with the camera oriented horizontally, or in standard 'landscape' orientation). Sometimes the horizontal line or lines spanned the whole picture, at other times broken up into segments ... But always in the same range. At first I made the assumption that there was something wrong with my camera's sensor. But then I downloaded some Pentax K-50 DNG files from imaging resource and, lo and behold, AfterShot Pro rendered them too with the same artefacts! The images were converted to TIFF files and retained the same problems. I then opened the same images in other raw converters, and none displayed the problem that was evident in AfterShot Pro 2.
Has anyone any experience with ASP2 and a Pentax K-50 on either Windows, Mac or Linux? I really like this converter due to its speed, but this problem may be too serious to warrant a change at this time. BTW, I tested ASP2 out Ubuntu 14.04, and am curious as to whether the same problem exists on other platforms as well.

After some further experimentation with AfterShot Pro 2 (ASP2) settings under Ubuntu 14.04 Linux on my machine, I've come to the conclusion that unchecking (i.e. disabling) OpenCL acceleration under the preferences menu seems to solve the problems of on-screen appearance and final rendition to Tiff and Jpeg formats. The default mode for OpenCL under ASP2 is disabled, but I recently had switched it on to take advantage of my hardware... Who knew the bug would actually alter ASP2's Raw rendition process and affect the actual output files. Be interesting to know if this bug is relevant to other Pentax models and Raw formats...

Reviewed a few more Pentax K-50 DNGs in AfterShot Pro 2, and switching off OpenCL acceleration has seemed to have done the trick. I'll call it problem solved -- or at the least, bug uncovered.
Oh yes ... My system specs are: AMD A10 CPU, 8 GB RAM, AMD Radeon HD 8570 discrete graphics card, Ubuntu 14.04 Linux x86_64, AfterShot Pro 2 X64

Last note: Bug also affects Windows builds of ASP2 on my computer, but a few others with different video hardware have reported no problems.