Gordon, did you see this (in the other forum)?

Started May 3, 2013 | Discussions thread
GordonBGood Veteran Member • Posts: 6,306
Re: Gordon, did you see this (in the other forum)?

Kerusker wrote:

ewelot wrote:

.....I found - to my big surprise - that the black point issue didn't show up and dark frames exhibit a nice gaussian intensity distribution! It appears that accessing the in-memory raw image data of the camera via PC control software offers data at a less processed state and - most importantly - the image pixel mean intensity is not shifted to zero level. ......

This should be the link:


Gordon, I would like to know what you draw from the thread over there.

From my K-5, it seems to me that the black point is uncompensated up to ISO 1600, but it is a while since I have checked it and it may have changed with the latest firmware updates.  All of these cameras will definitely have a zeroed black point for ISO's of 3200 and higher where the ISO's are achieved by shifting of underexposed ISO 1600 captures, and I assume that is why the ISO 1600 and higher sensitivities are black point zero compensated:  to prepare for the shifting operations.

I didn't know that the K-5 II(s) would be any different and don't have access to one, but I guess I can check from the raw images posted on Imaging-Resource.

When I get some time in the next day or so, I will do a quick check of K-5 II(s) raw images and report back here.

Interesting that the PKTether type programs would be able to capture the raw data at a different stage in the processing pipeline.

Regards, GordonBGood

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