A Repulsive Suggestion

[willie_901]

Convenience or Information Content

Convenience or Information Content

...

As always, your thoughts… Anything else jpegs can tell us?

No.

JPEGs images by definition contain less information than raw files. It is physically impossible for a single JPEG to offer unique information.

When exposure, post-acquisition rendering settings and the white-balance parameter are perfect the raw file's higher information content has no value. As exposure, post-acquisition rendering settings and the white-balance parameter approach perfection, the value of the raw file's higher information content decreases. The reverse is true as well.

The sole purpose of shooting JPEGs is convenience. In some circumstances JPEGs increase versatility. This is most common in older cameras with slower data processing performance. But this is not the case for newer cameras where buffer memory sizes and, or data transfer rates are high. One example where JPEGs offer a practical advantage is when professional sports photographers wirelessly send images to editors in real time.

 

[Doug]

OOC JPEGs are more "trustworthy" in a news or documentary context, aren't they? Difficult/impossible to conceal manipulation?

 

[willie_901]

JPEGs can be manipulated as well. However, it is true the extent of modification is limited since the intrinsic information content is lower. I am unaware of any way to insure a JPEG is strictly an OOC JPEG. Even OOC JPEGs can be manipulated (see below).

In terms of "news or documentary context" I think the situation is very complicated.

Committing outright fraud such as adding or deleting objects is equally problematic with raw and OOC JPEGs.

Raw files provide more opportunity to influence viewer emotions by enhancing image perception aesthetics. One example would be selectively increasing shadow region brightness. Such an image would not represent a scene as it appeared to an in-person viewer. Another example would be darkening or increasing the contrast of smoke in a sky. I can imaging a war photographer creating sets of custom, in-camera, JPEG rendering parameters to achieve image enhancing effects for different types of scenes.