Tanks for your comments. I am aware that starting as close as possible to the "right exposure" will probably always be best.

Rethinking my question I can say it like this:

In reality the camera does not store a photo, it stores a lot of zeroes and ones in the raw file. The camera or PC software can transform this to a picture.

If I change the aperture one stop and make a new shot, will the data stored in the raw file be the same and only the parameters for changing it to a picture changed? If so, shooting at right exposure should not be that important.... Or wil the data stored on the raw file be different?

Anybody got a link on a 101 on how to use the histogram?

When shooting jpegs I almost always use exposure bracketing to be able to select the best shot afterwards.

But when shooting PEF's I can afterwards adjust the Sensitivity in Digital Camera Utility 5. Does this do EXACTLY the same as bracketing or is it more like an "emergency correction"?

In other words - How do I get the best quality shots when using PEFs:
* by using bracketing as I do with jpegs?
* No bracketing, just correcting Sensitivity in Digital Camera Utility 5

I am using a K-5

Hi All

I am new to Pentax Digital SLR, but have long time used the Pentax ME Super. Now I have bought a K200 and I am generally very pleased. I can with no problem use my old A-series lenses.

Trying to use an old manual 500mm F8 Sigma Mirror Lens I find two options:

1) Just setting the camera to Av seem to give shots under-exposed a little more than two steps (which unfortunately is the maximum automatic exposure correction).
2) Set the use of aperture ring to "Permitted" (Custom setting no 23). Set the camera to manual. Now pressing the green button will set the right exposure time and give correctly exposed shots.

I wonder why the option 1) can't give right exposures when 2) can, but it may have something to do with minimizing costs as suggested in the previous post?

Best regards

Morten Agerlin