Sean DeMerchant
Inactive
I have been working this image (actually a series of images) as the sun set over the Carbon River for over month and I am still not happy. I have tried half a dozen RAW converters and still the CA is giving me grief.
Sunset Over The Carbon River, Mt. Rainier National Park, USA
Artistically, being 3-5 weeks earlier to the locale may have yielded batter light (nice direct backlight down the valley) or it may have been submerged. This local is currently gone in this years flooding but it will be back once the waters recede.
You can find the problem file at:
http://www.envisagement.com/opf/SPE25921.CR2
The problem is that Canon's EF-S 18-55/4-5.6 lens has serious optical problems in the corners in contrasty light. Depending upon the RAW converter there is an issue with CA* in 2 or 3 corners of the image.
The upper left has CA in the trees against the sky at a moderate distance from the lens.
The mountain at upper right has CA on the top of the ridge above the clouds at an extreme distance from the lens.
And in some converters the contrasty edges between the dark sand/silt and reflected skylight off the water yields CA issues at a relatively short distance from the lens.
Add in the that the DR of this image pushes the limits of a RAW file on a Canon CMOS sensor and this makes a nice problem file.
I was originally shooting for HDR, but the CA makes fixing each frame time consuming. My current solution is to do 3 RAW Conversions with CA corrected for each problem area separately and then combine them with layer masks to get a good converison. Doing it for 11 shots (33 RAW conversions) seems a bit excessive and time consuming to do HDR and I was hoping people might share their expertise and see if one cannot get a single clean conversion and show how they did it.
thanks,
Sean
*CA -> Chromatic Abberations
Sunset Over The Carbon River, Mt. Rainier National Park, USA
Artistically, being 3-5 weeks earlier to the locale may have yielded batter light (nice direct backlight down the valley) or it may have been submerged. This local is currently gone in this years flooding but it will be back once the waters recede.
You can find the problem file at:
http://www.envisagement.com/opf/SPE25921.CR2
The problem is that Canon's EF-S 18-55/4-5.6 lens has serious optical problems in the corners in contrasty light. Depending upon the RAW converter there is an issue with CA* in 2 or 3 corners of the image.
The upper left has CA in the trees against the sky at a moderate distance from the lens.
The mountain at upper right has CA on the top of the ridge above the clouds at an extreme distance from the lens.
And in some converters the contrasty edges between the dark sand/silt and reflected skylight off the water yields CA issues at a relatively short distance from the lens.
Add in the that the DR of this image pushes the limits of a RAW file on a Canon CMOS sensor and this makes a nice problem file.
I was originally shooting for HDR, but the CA makes fixing each frame time consuming. My current solution is to do 3 RAW Conversions with CA corrected for each problem area separately and then combine them with layer masks to get a good converison. Doing it for 11 shots (33 RAW conversions) seems a bit excessive and time consuming to do HDR and I was hoping people might share their expertise and see if one cannot get a single clean conversion and show how they did it.
thanks,
Sean
*CA -> Chromatic Abberations