David Kilpatrick wrote:I have moved this from the Gallery section which is intended for links to on-line image collections.
I don't use the PC platform, so the software you mention is not something I can comment on. Using Photoshop's HDR functions on Mac, it seems that no matter what levels of darkness/brightness I set for two source files via raw export, the HDR system always reports there is not enough range present to create an HDR file. I conclude it may be necessary to use a tripod and take widely bracketed exposures, as a single raw file isn't giving enough info.
Beakydave wrote:... it was a rather hasty effort, using only three 'exposures', just to prove that CS2 can do HDR from a single raw.
01af wrote:Beakydave wrote:... it was a rather hasty effort, using only three 'exposures', just to prove that CS2 can do HDR from a single raw.
Actually, it cannot.
All you have proven is that Photoshop CS2's HDR feature can be misused to create DRI images when tinkering with the EXIF data. You mustn't confuse HDR and DRI. HDR is about capturing wide dynamic input ranges into more than 16 bits/channel. DRI is about compressing those wide ranges into 8 bits/channel.
Raw files from current digital cameras do not contain more than 16 bits per channel of data (usually even less), so you simply cannot create a true HDR images from them. There's a reason why Photoshop normally refuses to work on images derived from one single raw file for HDR. As you have successfully shown, you can trick Photoshop into it but what you'll get is not a true HDR image. Instead you'll get an image in HDR format where many of the 32 bits/channel will be empty, and the tones will be severely posterized. When compressing the HDR-format image into 8 bits/channel in order to be able to look at it, with luck you will compress the empty bits away ... but you may just as well compress non-empty bits and end up with a posterized 8-bit image. You simply have no precise control over the process.
You're using only a fraction of what the HDR feature is supposed to do. It's like using your car to travel a distance of 40 ft---without even starting the engine but just pushing it. If you want DRI then HDR is the wrong tool. The right way to do DRI is layers and layer masks. These offer far better control over the tone mapping than HDR's blunt output function.
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