Sunday, February 20, 2011

Converting RAW files for HDR

Important thing we can not allow any software used to do the RAW conversion on any uncontrolled interference in our file conversion parameters. In the case of Photoshop, this means avoiding the "auto" in the fields: Exposure, Shadows, Brightness and Contrast, and to prevent the white balance settings, "Auto " and "As Shot" white balance if it was set to "Auto" for shooting.

Thursday, February 17, 2011

How many exporures for HDR?

Amount of radiation needed obviously depends on the scene, but before that in many cases insufficient 3 exposure in increments of 1.66 or 2 EV Minor strokes do not recommend, it makes no sense to play in an EV. In theory, would make a measurement point in the brightest and darkest parts of the scene, the quantity needed to calculate radiation, etc. In practice, the usual (using, D-SLR) doing an irradiation, roughly in line with the measurement matrix, and then check the histogram if it points to the clear shift towards overexposure / underexposure change parameters and perform another trial. If it is correct as far as erasing pictures, run bracketing, attach the hose and doing a series. If possible, you may want to change the way the camera's way of making a series of bracketingowych so as to begin from underexposure, and the middle performed exposures, and ended with an X-ray (-, 0, +). The Canon's default is different (0;-;+) and then hinders orientation. The pictures of a strong light source in the scene usually requires more of the radiation, I am often in such cases, the fifth.

Monday, February 14, 2011

Shooting for HDR

The basic condition for obtaining an image in HDR technology is to have several versions of an image of the same scene made with different irradiation parameters (possibly several TIFF files, or JPG also obtained from the various call one RAW file.) The best solution is to implement a number of irradiations of the same scene camera mounted on a tripod. Mounting must be as stable, so that the images did not differ from each other the frame, even minimally.
The individual exposure should be made as soon as possible because of the changing landscape elements during such as clouds, waves, moving in the wind, branches or podrygująca boat on the waves. Forgive me, I had to mention it even though it probably did this kind of situation does not meet. Know that I am "łódkofilem" And nothing will change.

Friday, February 11, 2011


Bracketing, an option available on most SLRs involving the execution of a series of shots of the same scene at a fixed aperture and the changing times, with the specified increments. This stroke and the number of shots depends on the type of camera, for example, in Canon EOS 5D is 3 frames with a maximum 2 EV increments, the Nikon D200 to 9 shots with maximum increments of 1 EV. This feature originally had another use but has proved very helpful in the performance of individual radiation needed to complete the picture in the HDR.

Tuesday, February 8, 2011

Dynamic Range Increase

Dynamic Range Increase (DRI), increase the tonal range, the method consisting in the appropriate application to each other and contain several layers of masking the same scene exposed in different ways. The most important difference, in a simplification, of course, is that DRI is a lot in practice, replacing one image with different stretches, these parts are relatively large, sometimes it can be an inch piece of heaven, while the HDR changes are occurring in each pixel image.

Saturday, February 5, 2011

High Dynamic Rang

High Dynamic Range (HDR) - method of obtaining images of a much wider tonal range than recorded by the camera in a single frame consists of creating a file, usually about 32-bit color depth, formed by the combination of several images of the same scene in different ways irradiated So that the individual frames correctly register all ranges, from light to shadow. Creating such a file requires several input files, their number depends on the tonal range of the recorded scene, from my experience that 90% of cases, sufficient 3 files recorded in increments of about 2 EV, in practice, we highlight three of the same time changing the aperture relations x0.25, x1, x4.

Wednesday, February 2, 2011

Dynamic Range

Dynamic Range (DR), Tonal Range, the ratio of the image brightness of the party's brightest to the darkest, he is limited on the one hand by the possibility of recording equipment (eg digital camera sensor) and secondly by the possibility of an image display device (monitor, printer). This ratio for the average matrix is 500:1 (~ 8 EV), for the printer 250:1 (~ 7 EV), and a monitor 500:1 (~ 8 EV) The approximate course, have to illustrate the concept. The values found in the real world date back to 100 000:1 (~ 17 EV) and our eye sees 10 000:1 (~ 14 EV).