In camera processing

[Edalongthepacific]

In a camera that offers both JPG and RAW, once an image has been taken in JPG, are in-camera image adjustments made to that JPG or is a new JPG made from RAW data for the image? If adjustments are made to the JPG file, will it then become a re-saved JPG and lose additional resolution?

[ronkruger]

As I understand it, a JPEG is degraded (though how much is debatable) each time it is opened and saved. When shooting RAW/JPEG, the JPEG is created from the RAW file and is an original JPEG.
I shot this way for a very short while, but decided I could usually do better converting the RAW to JPEG with my computer software, so I shoot nothing but RAW. Saves space all around as well.

[Jeremy Roussak]

In a camera that offers both JPG and RAW, once an image has been taken in JPG, are in-camera image adjustments made to that JPG or is a new JPG made from RAW data for the image? If adjustments are made to the JPG file, will it then become a re-saved JPG and lose additional resolution?

With respect, that's a meaningless question: images can't be "taken in JPG".

The raw data comes off thes sensor and, if your camera offers the facility, may be saved as a raw file. The raw data from the sensor may, if you choose, also be converted to a jpeg in the camera and saved as a JPG file.

Jeremy

[Jonathan Ratzlaff]

Depends on what your camera setting is.  If you are shooting raw or raw and jpeg, then, if your camera allows it, you may retouch the image or develop a raw file.  If you retouch a jpeg then you get a jpeg from a jpeg.  If it is a raw file, you save a jpeg from a raw file with your settings applied. If you are shooting jpeg only you get a retouched version of your jpeg.  Still that is a better way of creating a black and white or toned image than losing the original colour data in a straight monochrome image.  The straighten and correct horizons are useful in some instances.

In camera retouching in no way provides any substitute for camera editing, but in a pinch is better than nothing.

[LKaven]

It's hard to tell what you want to do.

In general, the camera captures RAW data always.  The RAW data is then either delivered as a RAW file, or converted into a JPG using in-camera settings, and delivered that way, or both.  In almost all cases, the camera makes a low quality JPG using the in-camera settings no matter what, and this is used to supply the image that you review on the LCD on the back of your camera. 

If your question involves retouching JPGs in-camera post capture, than I'm not sure what you're trying to do, and perhaps you could explain it a bit.

[Edalongthepacific]

I think I get  it. I had thought that the JPG's original data (the RAW) data may be retained in memory. But that cannot be. That would take up memory space. Once you shoot a JPG you can't go back to RAW.

[ronkruger]

If you set your camera to shoot RAW/JPEG, it saves both files, which does take up more space on your memory card. If you shoot JPEG only, the RAW file is lost. If you shoot RAW only, you can save the RAW file and create a JPEG, TIFF or whatever you want from it in post production. This gives you much more control than letting the camera decide how it wants to process the JPEG.
If you save the RAW file as your master, you can do something else with it at a later date if you want.
Shooting JPEG only is like taking slides to have prints made, and then throwing away the slides.
My adivce is to shoot RAW only.