Scott Kroeker wrote: gdanmitchell wrote:
To clarify, exposure blending is not necessarily HDR. What we normally think of as HDR accomplishes a very different thing - a sort of local contrast enhancement throughout the frame - while exposure blending is closer to using GND filters in concept and result. It also tends to be a lot more labor-intensive since the blending work is typically done manually by \"painting\" on layer masks.
See for me any time you take more then one photo to capture DR is HDR. The problems is that so many people have confused tone-mapping with HDR. IMHO they are 2 different things but so much misinformation and wrong terminology used on-line we have a backwards perception of the term HDR. HDR today is mostly associated with over tone-mapped and cooked to death images. The to me, they should be categorized as tome-mapped not necessarily HDR as you can tone map any image. But to try and get the masses to change their way of using this terminology is pretty much a lost cause at this stage. Which is sad because HDR has gotten such a bad rap because of grotesquely tone-mapped images.
Scott, that may be your definition, and I can understand your logic, but the term HDR came into existence recently (after exposure blending had been around for quite a while) specifically to refer the the technique in which the software does a sort of luminosity averaging across the scene based on algorithms that operate on the enter image to increase local contrast.
I\'m sure I\'ll get push-back from at least a few people, but I think that it makes the issue simpler to think of two things:
1. Exposure blending - which is a sort of super-charged version of what we used to do with GND filters.
2. HDR - which is an analytic software process that increases local contrast using data from multiple captures.
This is not meant as a judgment of the value or appropriateness of the techniques, but rather an attempt at clarifying something that often gets confusing.
Scott Kroeker wrote:
But, taking 2 or more exposures for DR and then manually blending (painting) them together in photoshop is still HDR as you have captured higher dynamic range then you could in one image.
But Scott, the use of the GND also lets you \"capture a higher dynamic range\" than you could in a normal single image.
Let\'s say I\'m shooting the classic \"bright sky above darker foreground image.\" In Case A I use a two stop GND (let\'s say) with somewhat narrow transition so that half of the image is effectively shot two stops differently than the other half. In Case B I make two exposures separated by two stop and then combine the two images using a mask with a somewhat narrow transition so that the result is the same.
I don\'t see how one is HDR by your definition and the other isn\'t.
Of course, if you want to play our your logic all the way, a lot of things that are done to handle large dynamic ranges would also have to be regarded as HDR. Dodge the shadows a bit in the darkroom? HDR. Use a CP filter to darken sky or control reflections? HDR. Burn down the highlights? HDR.
Get my drift? :-)
Take care,
Dan
Jun 25, 2012 at 01:53 PM
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