Improve back lighted shot with extensions – artifacts?

Hi,

If I want to improve a back lighted shot with one of the plug-ins I see very often blue or red artifacts. I guess this shows something regarding the “planned” changes. But as I´ve not found an explanation for this, what does it show exactly?

Regards,
Ben

Hi Ben,

The blue areas represent the underexposed, that means too dark areas, whereas the red ones are overexpososed areas = too bright. In both cases you will loose details in these areas, as the tone values of these areas have exceeded the possible dynamic range. You can counteract this by increase or reduce the brightness and/or reduce the contrast.

On very high contrast photos, it might not be possible to prevent both blue and red areas, especially with 8-bit JPEG and current 12-bit AD converter used in DSLRs due to the limited dynamic range. More modern DSLRs with 14-bit AD converter in combination with the usage of 16-bit images (e.g. TIFF or RAW) might be a tad better (> 0,5 stop) though.

Best regards

Hoang-Tran