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Can rawtherapee can be used to create an image like a DSLR camera in bracketing mode?

I noticed that rawtherapee has many controls under the exposure tab. I was told that just changing the exposure alone would not be the same as if I used a camera in braketing mode.

Thanks.

Emad-ud-deen
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2 Answers2

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It depends what you're trying to achieve from bracketing.

There's three basic variables that set your exposure - shutter speed, aperture and ISO.

Shutter speed and aprerture both have optical effects on the image that you'll know. Bracketing will usually change one of these, and you can't replicate that pos-capture.

ISO on a digital camera doesn't have optical effects. It acts like a volume control on an amplifier - you can amplify small signals, you just get more noise, and if you overamp a large signal it starts clipping. There's no reason you can't change that in bracketing if you're unsure of exposure levels or want a specific combination of ISO and shutter speed for any reason, and any raw converter will be able do a passable job at replicating that effect by changing the processing settings. It won't be as good as if you'd nailed it in-camera, but it won't be terrible.

eftpotrm
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No, because no camera can do exposure bracketing without side effects.

The camera has to change one of the three to get different exposures:

  • shutter speed: will influence motion blur from moving subjects
  • aperture: will influence depth of field
  • ISO: will influence noise

The side effects depend on the camera used, the lens and the subject.

It's not feasible to try to recreate those in post processing.

null
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  • Thanks for the answer. It was wishful thinking because I purchased HDR Pro and it needs bracketed images to do it's processing and I have many photos taken without bracketing. Most of the photos I now take are bracketed so I can make HDR images of them. – Emad-ud-deen Jul 28 '16 at 23:44
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    @Emad-ud-deen: that would never work, because HDR is based on gathering the dynamic range of many exposures. Artificially creating multiple exposure from a single one doesn't add any new information to the existing data. – null Jul 28 '16 at 23:49
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    but you can create separate exposures from a single raw file and use them in HDR software: http://photo.stackexchange.com/questions/683/how-can-i-get-a-good-hdr-image-from-a-single-raw-file – MikeW Jul 29 '16 at 00:01
  • If you have the raw files you can develop them in a series of dark to light exposures and gain some of the benefit of HDR. If your HDR software allows you to work on RAW files you can do a single frame HDR that will allow you to map the entire dynamic range of the raw file into an 8-bit jpeg. See http://photo.stackexchange.com/questions/42244/why-not-make-hdr-from-a-single-raw-automatically/42254#42254 – Michael C Jul 29 '16 at 00:06
  • @MikeW♦ given the intention of the OP, I'd suggest closing this question as duplicate of either your or Michael's linked question. – null Jul 29 '16 at 00:13