Originally posted by ozlizard I read on here somewhere that by using multi exposure on the K 20 you can acheive the same effect as using an ND filter with long exposure times. An example of this is to get that silky water look. I have tried this technique out myself and was very impressed with the results using 9 exposures. Anything moving (water, clouds) had that dreamy look and anything static (rocks etc) were as sharp as a tack. Great effect! Now there is a question at the end of all this....how does this feature differ from the 3 shot HDR on the K7?
(BTW I explained this technique to a local Canon dealer and he couldn't believe it...never heard of a camera that could do that he said...chalk another one up for Penatax and the fab K20!)
The silky look with moving water etc is done with either multple exposures (with the same exposure levels) or with a long shutter time on a tripod.
HDR is something different. It has been discussed several times before on this forum.
HDR stands for high dynamic range. Dynamic range is measured in "stops".
In the old days a lens would have aperture stops, while on the camera there would be a dial that had shutter speed stops. Changing 1 stop creates less or more what we now call Exposure Value (Ev). A typical APS-C sensor has approximatly 10 to 12 stops dynamic range.
A camera sensor can only "see" a limited range of light and darkness at any one time. Your eye can see a much wider dynamic range. And LCD screens and printers are even much worse in their dynamic range.
The idea of HDR is that by under-, right and over exposing an image you can combine these images into one image. The underexposed one will add extra high light DR, and the overexposed extra dark/shadow area details.
In order to enable more DR in an image also a special file format was introduced. Your Pentax camera is not using that.
After the HDR image is created, you have all this extra high light and shadow detail. Now you want to see it in a JPG image on your screen. Since both JPG and much more your screen / printer cannot cope with that DR, you will need to do dynamic range compression (tone mapping). Most HDR software packages have plenty bells and whistles to this, creating this special HDR look.
My K-7 has no parameters to manipulates its hdr algorithm. Unfortunalty.
If you'd use your K20D and an HDR software package, you will see that the results can be much better than what comes straight out of a K-7.
I hope this helps you understand HDR somewhat better.
Here is a K10D HDR example:
- Bert