[toooldtocare]

I updated the firmware for my K5 trying to fix this. Apparently I some how set my lower limit ISO to 160. Even when I chose C-1, Expanded Sensitivity, 2 (on); which should set the ISO to 80-51200, I cannot set ISO to less than 160, even though it should be 80. When I chose off, my lower ISO is then limited to 200, instead of 100. I must have some other setting messed up, but I cannot find where. Any ideas?

I have had this camera for 2 years and love it, but this one has me stumped because I know that at one time it did work correctly. Thanks for any help.

[LaurenOE]

Try turning off the highlight correction, and turning off auto ISO.

[toooldtocare]

Thank you, worked as advertised. I just turned on highlight correction yesterday to experiment a bit, did not connect the two.

Wayne

[LaurenOE]

Thank you, worked as advertised. I just turned on highlight correction yesterday to experiment a bit, did not connect the two.

Wayne

Been there, done that. Obviously.

[tabl10s]

Try turning off the highlight correction, and turning off auto ISO.

How does Auto ISO affect it?

[LaurenOE]

How does Auto ISO affect it?

The only way auto ISO would affect it, would be if the user set the range manually.
I assumed (correctly) the fix would be in the highlight correction setting as most people play with that, and if not, the user would find out that he/she had set the range manually.

Sometimes it takes too much time/effort to explain everything, and mental shortcuts help the user find their own answers (sometimes).

[IchabodCrane]

How does Auto ISO affect it?

With Highlight Protection, the camera captures the image with one stop underexposure and it does that by clandestinely halving the ISO and then boosting the JPEG image in camera (other than the highlights it's trying to suppress). Therefore, with Highlight Protection on, you can't set the ISO to less than 2X the lower limit otherwise the HP procedure wouldn't work.

Important note -- Highlight Protection is a JPEG function so if you're shooting RAW, it doesn't make sense to turn it on and end up with underexposed images.

[toooldtocare]

That makes sense, thanks.

[Giklab]

Important note -- Highlight Protection is a JPEG function so if you're shooting RAW, it doesn't make sense to turn it on and end up with underexposed images.

Sorry for barging in like this, but could we get some clarification on this? The last time Highlight Protection was discussed it was said that HP also affected RAW.
And I can't help believing this, due to two things: a) the RAWs are fine even with HP on (and seem to have a bit more DR), and b) Pentax would have no problem tweaking RAWs (like NR above ISO 3200).

[IchabodCrane]

Sorry for barging in like this, but could we get some clarification on this? The last time Highlight Protection was discussed it was said that HP also affected RAW.
And I can't help believing this, due to two things: a) the RAWs are fine even with HP on (and seem to have a bit more DR), and b) Pentax would have no problem tweaking RAWs (like NR above ISO 3200).

The RAWs really are underexposed by one stop (just checked it again taking two shots... one with HP on and one with it off). It shows up in any image editing app that doesn't detect the tag for highlight protection, signaling it to boost exposure by one stop.

When trying to learn more about HP not too long ago, I found a discussion about Canon's implementation which appears to be identical to Pentax's. It was rather emphatically claimed there that HP doesn't accomplish anything in RAW images, only JPEGs, that you can't do yourself by just underexposing and then manipulating in PP.