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JPEG Image File Format
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This is to follow up a comment in another thread here -
http://www.shuttertalk.com/forums/Thread...1#pid99251

(Jan 26, 2015, 10:03)EdMak Wrote:  I only shoot .jpg. Ed.

So do I.

There are many erroneous myths being perpetuated about JPEGs, particularly with regard to their editing, so that many newcomers are led to believe that they cannot be real photographers unless they shoot in a raw format.

Those myths are likely left-overs from the days when the computing power in the early digital cameras was minimal, and the speed and storage capacity of their expensive memory cards was very low, so that JPEG images contained little data compared with what modern cameras record. They were therefore quite low in image quality when transferred to a computer for displaying full-screen or for printing, and were prone to deterioration during any further editing and saving.

A typical example is my DSLR from a decade ago - its "high quality" JPEGs are rubbish by current standards. Its raw files contain less than half the data of the JPEGs from my modern DSLR. The only way to get decent images from the old DSLR is to process the raw files in computer software, when they can then be very good.

The are no such issues with my modern camera - the JPEGs are usually at least 10 MB of data, and are of very good quality. They can withstand extensive processing and still retain the capability to produce good prints up to A3, not that they usually need to, because they are of high quality out-of-camera, usually only requiring gentle and subtle tweaking at most.

There is no doubting the maths - there is more data in a raw file, so there is more latitude in processing raw files in computer imaging software, and for correcting mistakes that shouldn't have been made during shooting. But with a modern DSLR it is usually no longer necessary to shoot raw, unless you really want to.

There are some simple but important considerations when photography involves JPEGs -

Shooting:
Set the colour balance and exposure as close to correct as possible - which should be the aim also when shooting raw. (Although despite the myths to the contrary, white balance and exposure corrections can be achieved with high quality JPEGs.)
Study the histogram and, for most scenes except the obvious exceptions where there are no highlights, usually expose to the right, but make sure that important highlight areas are not over-exposed - (Highlight recovery is less effective in JPEGs.)

Processing:
JPEG files can be edited directly in any imaging software, including Adobe Camera Raw!!
Always make a copy of the JPEG file, preferably into a separate folder, and process only that copy - always keep the original JPEG separately. (In some software, editing the original file and saving it will over-write the original.)
Before saving, ensure that the software is set up to save the JPEG file at the lowest compression, i.e. highest quality. (E.g. In PS Elements that is level 12.)
Finish the editing to your satisfaction before saving, so that the edited JPEG file is saved only once. (Repeated saving of a JPEG reduces its quality slightly each time.) Alternatively, if you want to carry on editing the file later, save it in a non-compressed file format (E.g. as a TIFF, or in Photoshop's own PSD format.) and convert it back to JPEG when finished.
If you need to resize a JPEG file, e.g. for the Web, do that only after all other editing is completed.

Most cameras now have the option to save each image in both JPEG and raw formats (Raw+JPEG). That is what I used to do, until I found that the raw file was, literally, a waste of space when using a modern DSLR.

But, as always, "To each his own"! (Edmak)

Cheers.
Philip
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Messages In This Thread
JPEG Image File Format - by MrB - Jan 26, 2015, 12:36
RE: JPEG Image File Format - by EnglishBob - Jan 28, 2015, 11:44
RE: JPEG Image File Format - by MrB - Jan 28, 2015, 18:36
RE: JPEG Image File Format - by Rolf - Jan 29, 2015, 13:29
RE: JPEG Image File Format - by MrB - Jan 29, 2015, 16:51
RE: JPEG Image File Format - by EdMak - Jan 29, 2015, 13:45
RE: JPEG Image File Format - by WDHewson - Feb 2, 2015, 08:09
RE: JPEG Image File Format - by Jocko - Jan 19, 2016, 02:02
RE: JPEG Image File Format - by MrB - Jan 19, 2016, 06:07
RE: JPEG Image File Format - by Jocko - Jan 19, 2016, 07:59

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