I've been photographing Pyramidal Orchids (Canon 5DMKII and 100mm Macro f2.8) and been getting some awful results. I always shoot RAW and convert to DNG using Lightroom. Most of the images exhibit distinct posterization.
I'm assuming this is something to do with these flowers in particular - probably iridescence. I'm guessing they strongly reflect UV and IR (one of which, or both) which are interfering with the capturing of tonal levels. If it's IR then I'm assuming that the amount reflected is too much for the sensor's IR filter to cope with??
Anyone experienced this, looked into it, identified the exact problem, found a solution???
Link is to a desaturated crop of the image to show loss of tone in flowers....
What does the color histogram look like? The red channel is probably blowing out. You would have to reduce overall exposure so the red channel doesn't clip.
The histogram for red channel shows no clipping. Shadow tone is blocked a bit in the blue channel but nothing obvious in the image data to suggest a problem.
Rob - thank you, yes, images are shot in RAW and I do all the editing in DNG within LR and generally export as 16 bit TIFF for any local editing in PS.
Any chance you could try another RAW converter and/or not converting to DNG? I don't really think that's the issue, but it helps to eliminate possibilities.
Also, what color space are you using? You might want to try Pro Photo or sRGB to see what kind of difference that makes.
Discussion
4 repliesI've been photographing Pyramidal Orchids (Canon 5DMKII and 100mm Macro f2.8) and been getting some awful results. I always shoot RAW and convert to DNG using Lightroom. Most of the images exhibit distinct posterization.
I'm assuming this is something to do with these flowers in particular - probably iridescence. I'm guessing they strongly reflect UV and IR (one of which, or both) which are interfering with the capturing of tonal levels. If it's IR then I'm assuming that the amount reflected is too much for the sensor's IR filter to cope with??
Anyone experienced this, looked into it, identified the exact problem, found a solution???
Link is to a desaturated crop of the image to show loss of tone in flowers....
Cheers
Dave
Cheers,
Rob
The histogram for red channel shows no clipping. Shadow tone is blocked a bit in the blue channel but nothing obvious in the image data to suggest a problem.
Rob - thank you, yes, images are shot in RAW and I do all the editing in DNG within LR and generally export as 16 bit TIFF for any local editing in PS.
Also, what color space are you using? You might want to try Pro Photo or sRGB to see what kind of difference that makes.