Photoshop: 32-bit Tone mapping

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  • Updated 6 years ago
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I would like to be able to keep my image as a 32 bit file after one mapping.

At present, just after tone mapping a 32bit file, the title bar flips to 16 and back to 32bit and you're left with a 16bit image in a 32bit file.

cheers,

Steve
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Steve Herridge

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Posted 7 years ago

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Brett N, Official Rep

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Can you describe your workflow in a bit more detail?
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Steve Herridge

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no probs.

I have a 32bit file (rendered) image.
I use the hdr tone feature to bring in highlight detail and lighten the dark areas.
(Theres a separate issue here in that the default settings apply a tone mapping solution of it's own, when I'd really like to start with the base image).
When I click OK the settings are applied but if you watch the title bar of the document, (where you can see the name of the file, at what scale and the colour mode/bit depth) you see the 32 change to 16 and then back to 32.
This is now actually a 16 bit image which is sitting in a 32 bit file.
What I would like is for the image to remain in 32bit, like you get in some other tone map packages.
Hope this explains things.

Cheers,

Steve
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Brett N, Official Rep

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Thanks for the added details. However, I'm not seeing the same behavior on my side... Are you using the Extended version of Photoshop CS5? There are some limitations with 32-bit editing in the Standard version.
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Chris Cox

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In CS5, there are no 32 bit limitations in standard.
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Steve Herridge

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no probs.

I'm using the extended version.

Do you have any overbrights in the 32 bit image you have tested?

If so, you can test whether your hdr toned image is now 16 bit:
Run the hdr toning but leave the overbright areas alone.
If your image is still 32bit you will be able to pull these areas back in if you run hdr toning again or use something like the exposure node to pull the highlights back in.
If the image has been compressed to a 16bit image (still sat in the 32bit image) when you try to pull the highlights in there will nothing there and those areas will go light grey-ish.

Cheers,

Steve
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Chris Cox

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Tone mapping is the process of taking HDR data and bringing it all into the 0..1 range. After tone mapping, there are no overbrights, or super darks, even if you remain in 32 bit/channel.
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Steve Herridge

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Hi Chris,

thanks for the info.

I would, however like to stay in 32bit after I have made these adjustments so that when I carry out any further colour tweaks this is across millions of colours per channel and not thousands. This way I will avoid any clipping.

For example, HDR Expose allows one to adjust dark and light areas, along with other features, but keeps the image in 32bit.

Cheers,

Steve
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Rich Powell

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You probably know that 32 bit images aren't displayable on a monitor (or printer). Tonemapping is the process of creating a displayable or (printable) image. You can't do this and still have a 32 bit image. Similar to rasterising a vector image or creating a grayscale image from a color one. It is a destructive process.
However it might be possible to create a tonemapped thumbnail or preview and associate it with the original file.