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No HDR, please
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This group is for pictures made out of different exposed versions only.
I will start to delete all this HDR/Photomatix pics in the pool.
Posted at 9:06AM, 8 March 2006 PDT
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Then you have to delete lots of stuff... The Photomatix pics are like an invasion ;)
btw, is there a clear definition of what is HDR and what is DRI? Apart from the visual effect like the halos around objects and so on. i just can't get to the bottom of it.
Posted 76 months ago.
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You're right fotofrog.
The look of tone-mapped and generated hdr-picture is getting popular.
I can't give you a clear definition, but i'll try to write down what i think makes a picture pool-worthy.
DRI pictures are hand-made.
DRI pictures have long exposures.
DRI pictures are mostly night-shots.
Posted 76 months ago.
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Most HRD images looks fake like some graphic made for computer games. I agree with icon0815 about DRI pics are handmade but they are not necessarily have to be long exposure or night shot.
Posted 76 months ago.
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thanks icon0815 for the attempt of an explanation. But as maran stated, long exposures or night shots are not necessary to create a DRI. In my opinion, the hand-made process is also no criteria. I can write a PS-macro that basically replays my hand-made steps and will get me a satisfactory result in many cases. On the other hand, the photomatix effect is based on a process that you can reconstruct manually in PS (this is a guess as i don't know the HDR algorithms).
Your definition is good enough for the pool-worthyness because you may have a certain idea how a DRI has to look like. That's perfectly OK for me because i'm doing DRI according to your definition.
But sometimes i'm a nitpicker and so i have to fathom this.
Posted 76 months ago.
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maybe you can tell me your definition?
i have deleted all pictures tagged with photomatix in the meanwhile
Posted 76 months ago.
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Surely the essential point here is that you have an initial scene where you want to capture details from both very bright highlights and dark shadows, so you're using a technique (typically involving blending two differently exposed images) to create a single image that combines the two.
From the Luminous Landscape tutorial page:
"In nature when doing landscape work that includes sky, especially early or late in the day, the contrast range encountered often exceeds that which film or imaging chips can handle. It's therefore necessary to find a way to reduce the contrast range to something that the camera can handle so that the highlights don't burn out and the shadow areas don't turn inky black."
This photo was taken just before sunset. A straightforward photo would have either exposed for the sky or the buildings. The Nikon RAW image has 12 bits of data per pixel compared to 8 bits in jpeg, so I was able to process the raw image to create two jpegs at different exposures, then I recombined them in photoshop elements to create the image above.
This was taken as a single jpeg; it has been processed in photoshop elements with layer masking and soft light to darken the sky and brighten the bushes - I think this technique also counts as a dynamic range increase.
I switched from the 'hdr' group to this one because they insist on images which have been generated using a specific narrow set of tools.
Posted 76 months ago.
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HDR is a form of DRI. What distinguishes HDR from other forms of DRI such as blending is that an HDR image uses 32 bits per channel per pixel, whereas blending uses 8/16 bits/channel. Given that a camera sensor has at most 14 bits per pixel, the only way to make a true hdr image is with multiple exposures, whereas DRI can more generally be achieved by blending on a single exposure, whether raw or jpeg.
Until display devices are capable of showing 32 bit images I think that blending is a more convenient technique because it requires only a single exposure and if you shoot raw then 2^12 is already plenty of dynamic range compared to the 2^8 available in jpeg.
Posted 76 months ago.
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Blending does not require multiple exposures, but you get the best results using them.
Posted 75 months ago.
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I'm still very unclear on the difference between HDR and DRI, other than the aforementioned notion that to be "HDR", an image must be made using very specific tools (i.e. Photoshop CS2's HDR feature) -- though I don't think those groups (or at least not all of them) require that that specific software be used, so long as it's basically the technique we're talking about, which, to my understanding, involves:
(1) Obtain multiple exposures of the same scene at different levels of brightness
(2) combine these images somehow to create one image which has highlight detail and shadow detail that couldn't be achieved from a single exposure.
Now, some say that splitting up a RAW file into two exposures would qualify... and I won't say whether I agree or disagree without thinking about that a bit more, but I will say that that initially seems to me like something that's still just one exposure... Couldn't some creative use of curves, perhaps combined with some dodging and burning or the like, maybe generate the same image from that initial RAW file? Perhaps I'm mistaken, but it seems like it ought to be possible, whereas with true multiple exposures, you can combine shadows and highlights in an image, both with detail, that migth be MANY stops different.
I'm only just beginning to tinker with this process, and I'm far from having results I'm pleased with, but I've been shooting for it, in preparation for that day, often with 8 stops or more difference between my lightest and darkest exposures (though I may only end up blending a few of those, I don't yet know).
Just the two cents of a newbie, so take it as you will. :-)
Cheers.
Posted 75 months ago.
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hchalkly: the second DRI image you posted in this thread looks overdone to me. it's too obvious and contrasty.
Posted 75 months ago.
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I haven't tried this technique yet, but I can at least say that I agree with the above from balaclava9 that the second image doesn't look at all natural.
An ignorant question, if I may? Do you tend to get halos using HDR or DRI?
In my humble opinion it seems like 2 images at different exposures or possibly RAW files (with their increased range that I never knew of before seeing this post) would be needed to achieve a realistic image. It sounds like the DRI technique is the one that can do that, not HDR.
Thanks to all who contributed to this thread and my education. :-)
Originally posted 74 months ago.
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Stew Stryker edited this topic 74 months ago.
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I would like to thank Mbrelax for posting 3 HDR pictures thus pointing out why we go to the effort of increasing Dynamic Range manually (British sarcasm comes over me again)
Posted 73 months ago.
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Ricardo Galvão (f0t0gr4fi4) [deleted] says:
See my tutorial by handmade HDR or DRI
here
Posted 73 months ago.
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uhh, they're gone ;)
Posted 73 months ago.
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I know I'm a "little" late to this discussion, but since I made first steps into HDR/DRI world only recently, it's still fresh and interesting for me.
IMHO HDR and DRI mean the same thing - by definition. It's just one step of the process that makes them look different: HDR (as most people understand it and most examples in flickr show) uses tone mapping and DRI uses only, huh, dunno the right expression ... exposure blend? Averaging? (I'll use "DR compression".)
So using different TLA's for basically the same thing is quite misleading (IMHO). Should only be tone mapping that is disputable. Some people like it, some don't. I like it only as artistic effect - when done tastefully. Wouldn't call any tone-mapped image a photo anymore though.
So, what difference does it make if some DRI was hand-made, done with Photomatix or whatever there is?
This image:
was created in Photomatix. (I know it's a pitiful example, but that's not the point.) Only used DR compression (or light/shadow correction, as Photomatix calls it). No tone mapping
So how would you classify it?
BTW: lindes asked himself if making two pics from a single RAW and blending them, would qualify.
IMHO it would - by definition: RAW has higher dynamic range than JPG. So by splitting and merging one does achieve what DRI is all about - compressing dynamic range from some format (unsuitale for direct use) into 8-bit LDR format of JPEG, because current SW and HW doesn't allow us to view and share HDR formats directly.
And I agree that splitting and re-merging RAW photos is probably unnecessary. I don't know enough PS, but working with 16-bit depth images and adjusting some appropriate curve should do the trick of compressing the range to the 8-bit depth. At least theoretically. If someone knows how to do it, I'd love to learn it.
(Hope I wasn't too annoying with chewing over the same old cud.)
Posted 73 months ago.
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I thought the same thing about taking two exposures from a single RAW - why not just do it with curves?
That assumes that you want a uniform mapping of RAW value to JPEG value, which isn't always the case.
Here's my first attempt at this technique, using a single RAW file:
I created a "bright" and a "dark" JPEG from the RAW file. The "light" version was completely blown out on the water and in much of the sky; and the "dark" version had no detail in the shadows.
I could work on these individually, before combining them as described in the text of the photo.
Multiple exposures would undoubtably have yielded better results, but the moving water may have presented problems. I may try manipulating a 16-bit conversion of the RAW file to see what I can do with that, once Pixel handles 16-bit properly (too poor for PS!).
Originally posted 73 months ago.
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Mark Tranchant edited this topic 73 months ago.
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It seems to me, also, that HDR and DRI are the same thing. But a lot of people are using tools like Photomatix without full understanding how to use it. They use some default settings and get a cartoony effect with strange halos -- an effect a lot of people find very pleasing. People have incorrectly come to call this effect, "HDR," when in fact it should be called, "Using the default settings of Photomatix to get wacky visual effects." If I am understanding correctly, then people here in this group are using the term DRI to mean, "using HDR to achieve photos that look more realistic." It's a difference i can certainly appreciate.
The idea of HDR is to show the full dynamic range of tonality in an image that would be available to the human eye viewing the original scene. Due to technological limitations (because the cameras we have today can't capture detail both in extreme shadow and extreme highlights in the same photograph) it entails taking multiple images of the same scene, taken at different exposures, and combining them into a single image (aka exposure blending). An HDR file uses 32 bits of information (this is an insane amount of information, btw, capable of capturing all the dynamic range we could ever need, and then some) in each of the red, green, and blue color channels, rather than the 8 bits or 12/16 bits available in a jpeg or raw/tiff file, which sometimes does not suffice for capturing the full dynamic range of a scene.
It seems to me that splitting a RAW image into multiple exposures and recombining them using Photomatix or Photoshop HDR is not true HDR. At the very least, it's unnecessary; all of the information is already in the RAW file, and--as has already been pointed out--the same effect can be achieved by someone who knows how to use the Curves tool in a piece of software like Photoshop. Exporting separate images and then recombining them is just taking the long way around. Plus you're throwing away a lot of information by converting the RAW (12 bit) to a jpeg (8 bit).
You're doing yourself a much bigger favor by taking multiple photos exposed at 1.5 stops or more apart (although this is admittedly impossible with anything but a stationary scene or object unless you want a blurred final product), combining them with photoshop or Photomatix into an actual HDR (32 bit color) file. This allows you to actually end up with a higher dynamic range than any one (or even two) of the original RAW files you took, and then use tone mapping to get the final look you want.
Something else people either forget or don't realize is that HDR technique does not always guarantee a better photograph. In fact, it could even be considered a necessary evil, useful only in situations where any one exposure you make with your camera loses information in the shadows, the highlights, or both. The ideal situation is one where you take a single exposure that clips neither the shadows nor the highlights, and can usually be achieved by adjusting he exposure compensation on your camera up or down a bit. If you're not clipping information at either end of the dynamic range of the scene, then combining it with additional exposures of the same scene is not adding any information that wasn't already there in the original well-exposed image.
Tone mapping is the process of approximating the appearance of a true HDR (32 big) image in order to display it on a monitor or other medium that can't display that much information. You can end up with realistic or unrealistic images as a result of this process. It's all a matter of how you apply it. All of the "HDR" and "DRI" images on flickr are necessarily tone mapped.
-dave
Posted 71 months ago.
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