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Old Mar 4, 2010, 5:35 PM   #11
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Originally Posted by vvcarpio View Post
that is, HDR in its technical definition as high-dynamic-range. If so, I agree.

In this context a RAW is a high-dynamic-range compared to a jpg.

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I haven't purchased any new modleing programs in a long time.
You don't need to now ... download the absolutely amazing Blender 2.5 ... completely free and in many respects better than its commercial equivalents costing thousands. It is particularly instructive experimenting with lighting, including ambient occulsion.

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Originally Posted by MartinSykes

I think that before you can say you're for or against HDR
How can anyone with an open mind be "for or against" any technology ? What is more relevant is to have some sort of rules of thumb as to what technology will bring out the best in various situations. The "Best approach" thread is an attempt to determine the most appropriate technology for one particular scene that has a high dynamic range. Any "best result" will really be for that particular style of scene, with that particularly user using his tools efficiently. My feeling is that a well edited RAW in this situation, will produce at least as good results as HDR or exposure fusion ... I'm very happy to be proved wrong.
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Old Mar 5, 2010, 2:33 AM   #12
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I have a further question. If you take 3 exposures of a scene and the middle one doesn't contain any blown highlights or clipped shadows because the scene isn't that extreme, then what value do the other exposures add? I can see the extra exposures might be useful on extreme scenes where the camera can't cope, but they shouldn't be needed in every situation. Is everyone using multiple exposures because that's how the current software solutions require it or because the problem of shooting HDR inherently demands it?
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Old Mar 5, 2010, 5:28 AM   #13
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After shooting something as simple as stained glass windows I believe HDR approach will improve any given lighting situation no matter what it is. It will never make it worse. Some situations like a dull overcast day with very weak shadows will not show the effects of the HDR as much as a bright sunny days with deep dark shadows but there will be some improvement. Light is so subtle and so complete from absolutely blinding white the the deepest darkest blacks. And present equipment cannot record it in all its glory.
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Old Mar 5, 2010, 10:05 AM   #14
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Just my opinion, but the only reason I use HDR software is when I can't capture all of the detail I want in a single picture. If I can push the shadows without introducing an unacceptable amount of noise, then I'll use Lightroom or Photoshop. I may do that anyway and run it through a noise reduction software program, as long as I don't have blown highlights, though I've found the results with a series and HDR software is often better. Again, just my opinion but if a single frame has no clipped shadows or highlights then it's not "high dynamic range". I also don't think HDR software should be used to compensate for exposure errors, though auto bracketing is extremely useful when in questionable situations (and provides a series for HDR if the scene really is beyond the dynamic range of the camera).

I've been interested in the results of Martin's program, it definitely is picture enhancing software. But in my opinion only, it isn't really expanding the dynamic range, it's just recovering what the camera took (and doing it quite well, too). I've used HDR software on occasion when I didn't need to, mostly either out of curiosity or else because I thought the scene was beyond the range of my camera's sensor. Sometimes I've been really pleased as it's gotten me where I wanted to go with less work, but sometimes it has done some strange things to certain colors/features.

I'm not at all dogmatic about what HDR is or is not, it's just my opinion. Anyone is free to have a totally different opinion of what it is and how to use it - but this is just how I see it. I don't think it's "wrong" to use HDR software when it's not needed - just like I don't think it's "wrong" to use levels instead of curves when adjusting contrast in photoshop. It might be unnecessary, but it's not "wrong". If it gets you a good picture, who cares what method you used - if it's good I want to know as I might want to use it down the line sometime.
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Old Mar 5, 2010, 3:29 PM   #15
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Quote:
Originally Posted by MartinSykes View Post
I have a further question. If you take 3 exposures of a scene and the middle one doesn't contain any blown highlights or clipped shadows because the scene isn't that extreme, then what value do the other exposures add? I can see the extra exposures might be useful on extreme scenes where the camera can't cope, but they shouldn't be needed in every situation. Is everyone using multiple exposures because that's how the current software solutions require it or because the problem of shooting HDR inherently demands it?
That's been my question, too. I'm using 3 or 5 exposures because all the books I see say so.

So for what it's worth, I tried the following experiment. I took 5 exposures of the UN Building (today) at +2ev, +1ev, 0ev, -1ev, and -2ev. I then used DPHDR to create the following:

1) All 5 exposures used
2) Just the brightest (+2ev) and darkest (-2ev) exposures used
3) Just the middle exposure (0ev) used for "pseudo-HDR"

I used default values for DPHDR's eye-catching tone-map for all 3 images. I then resized and sharpened the images in PSE7. No other processing was done besides resizing and sharpening in PSE7.

When I shot the 5 images, I wrapped my gorillapod on a metal railing. The camera must have moved between shots because I notice slight misalignments.

For reference, I added the original middle exposure (0ev) image.

#1) All 1,2,3,4,5 exposures


#2) Exposures 1 (+2ev) and 5 (-2ev) only.


#3) Single-JPEG HDR using the middle exposure (0ev).


#4. Original, non-HDR, middle exposure (0ev).


From the resulting images I see that using only the extreme exposures (+2ev and -2ev, #2 image above) produced over-saturation.

While using only 1 image (#3 above) lacks saturation.

So I'd say that the middle exposures help -- at least for DPHDR. I include that last qualifier because (and Martin can correct me if wrong) I suspect it depends on what algorithm the HDR program is using.

EDIT:
The exposures I used are here:
http://cid-7e695c2c0dde32eb.skydrive...t/DSC06997.JPG
http://cid-7e695c2c0dde32eb.skydrive...t/DSC06998.JPG
http://cid-7e695c2c0dde32eb.skydrive...t/DSC06999.JPG
http://cid-7e695c2c0dde32eb.skydrive...t/DSC07000.JPG
http://cid-7e695c2c0dde32eb.skydrive...t/DSC07001.JPG

Last edited by vvcarpio; Mar 5, 2010 at 3:51 PM. Reason: Added links to originals
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Old Mar 5, 2010, 4:24 PM   #16
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Quote:
Originally Posted by Bynx View Post
After shooting something as simple as stained glass windows I believe HDR approach will improve any given lighting situation no matter what it is.
Bynx, I'd be interested to see if you can produce the best looking image using the 3 files in the "Best approach" thread. The scene has a high dynamic range.

vvcarpio,
It looks as though there's a lot of blockiness in the sky on the left in the HDRs, especially with the 2 image HDR, but this may be just a low quality jpg. I'd be very surprised if editing the RAW for the central exposure couldn't produce identical or better results to the HDR. I'm happy to try if you'd like to post it.

I suspect HDR is useful where a scene has an extreme dynamic range and where there is much noise in dark areas, that is not disguised by detail in the scene ... and where there is no movement of any kind, unless blurring of movement is required.

Last edited by amcam; Mar 5, 2010 at 4:40 PM.
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Old Mar 5, 2010, 4:39 PM   #17
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Since I dont have to prove anything to you Im not getting into this. I use Photomatix and its fine for me. Ive proven it to myself through the use of my camera and my eyes. I dont mind helping people which I do all the time here. But not lazy ones who want others to do it for them. Why dont you just do the work yourself and show us the results?
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Old Mar 5, 2010, 4:50 PM   #18
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Hmmm, vvcarpio. Problem is the middle pick shows that you doesn't really need HDR. Look the histogram:

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Old Mar 6, 2010, 2:19 AM   #19
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Quote:
Originally Posted by vvcarpio View Post
So I'd say that the middle exposures help -- at least for DPHDR. I include that last qualifier because (and Martin can correct me if wrong) I suspect it depends on what algorithm the HDR program is using.
I think it probably helps for every program because I'm under the impression that saturation is poor in extreme light/dark so you only get the true saturation for part of the picture where it is properly exposed. You can try to estimate the correct saturation from a poor exposure but the results aren't as accurate and can make the colours look strange. In most situations it doesn't matter but for skin tones in particular it can look very odd.

@ordo, The histogram is a useful guide but you can still get pictures where the overall histogram is nicely balanced but some regions of the image are poor. What HDR should do is adjust the image so that every region has a nice histogram as well as the image as a whole.
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Old Mar 6, 2010, 5:24 AM   #20
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i tried the -2 0 +2 with easy hdr but the image are only small standard settings

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