Originally posted by cem.kumuk In built HDR at K-5 is not a real HDR application. I can call it pseudo HDR only. Because a real HDR must be at least made of 3 or 5 frames with ev differences about 1,5 or 2 in between each. Than dedicated softwares like Photomatix combine these frames to built a real HDR photo.
cem, nice photo indeed
However, I cannot agree on what you write. I see where you are coming from but I think you confuse two different things here.
The first is stacking. Multiple photos are aligned and stacked into a single one with a dynamic range which is 4EV or 8EV larger than any of the original ones, when using 3 or 5 photos 2EV apart each. Photomatix allows to save the result from stacking as a single hdr file. Actually, the demo version allows you to do so without restriction and it stamps no demo label into images if you are doing so. The result is a single hdr file you can further process in other applications.
The second is tone mapping. Tone mapping compresses the high DR into 8EV. Photomatix allows to load any hdr file to allow tone mapping. Most people are not aware of the two steps because they don't save in between.
A raw file from the K-5 can be considered a true hdr file because it well exceeds the normal DR we used to see from digital cameras. It should compare well with 3 image bracketed hdrs from other cameras. You can convert it to 32 Bit in PS and save as a true hdr file to be opened by, e.g., Photomatix.
Moreover, the built-in hdr application in the K-5 does a 3 image bracket with 3EV steps IIRC, aligns, stacks and applies one out of a choice of four tone mappings. Of course, Photomatix or other packages offer more control.
The last raw for the city gate (at -2EV) is more than sufficient alone to recreate the full HDR version shown as the first image. No need for the other two shots with a K-5. At least not at ISO 80. Just save as 32 Bit file in Ps (all settings and black level 0 upon ACR import!) and open in Photomatix.