Jpeg or RAW ( & Why) June 2013

Started Jun 8, 2013 | Photos thread
walkaround Senior Member • Posts: 2,551
Re: Straightforward answer to your question

gardenersassistant wrote:

There is a full size out of the camera JPEG here .

There is a full size RAW (DNG) version of the image here . (For the avoidance of doubt, they were captured as a pair from a single exposure - JPEG + RAW.)

The areas shown below in red are all blown to white in the JPEG version - that is, the Red channel value is 255, the Green channel value is 255, and the Blue channel value is 255.

It is not possible to recover detail from the blown areas of the JPEG. For example, pulling down Highlights gives the rather nasty effect shown below on the right (with the OOC JPEG on the left).

The RAW version does not have blown highlights. As shown on the right below, if you pull down Highlights in the RAW version more detail is revealed in the areas which are blown in the JPEG version. (The RAW file as imported into Lightroom is shown on the left.)

This example was shot specifically to illustrate the issue to a photography group I run. However, it is not an isolated artificial case. I mainly photograph flowers, and I have a lot of examples where petals have blown areas in JPEGs, but not (or much less so) in RAW versions.

Here is an example. First the OOC JPEG on the left, showing blown areas, and on the right showing the effect of pulling down Highlights.

Now, the RAW version of the same capture, showing a tiny amount of blown highlights on the left, and on the right showing the effect of pulling down Highlights.

It is not just a matter of blown highlights. There is also an issue of lost details.

Here is a 100% crop of an ISO 800 image (from a small sensor travel camera), showing the OOC JPEG version on the left, and the RAW version on the right.

The JPEG version has had details smudged away by the noise reduction applied by the camera. The RAW version has significantly more detail. The RAW version also has more noise. By using the RAW version I can decide how to handle the tradeoff between noise and detail retention, and can if I wish retain more detail than is in the JPEG version.

Yes, your examples show the typical "HDR" look to "recovered" Raw files. And the lack of "detail" in your camera's jpegs can be due to a simple contrast and/or NR adjustment. Most of these parameters are adjustable in-camera.

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