HDR photography

[jude]

I'm interested in this. I know I should be learning the fundamentals of photography, what with having just gotten into it a matter of a few weeks ago or so, but I saw references to "HDR" on a photography site, had no idea what it was, looked it up (thought some of the HDR photos I saw looked amazing), saw an app referenced called Photomatix, downloaded the Photomatix trial, and immediately had to try it.

Notes: I just downloaded Photomatix today. I do have colorblindness, which might make for some odd choices that affect color--so maybe odd to you, but that I can't tell might be odd to you. This first example set is obviously inordinately boring, consisting of the building across the street from my office (in an industrial park). The watermarks on the HDR image(s) are from the Photomatix trial version (I'd like to know what other options are out there before I purchase this to mangle more photos with.

)

I did an auto-bracketing (-2 EV-->0-->+2 EV) three-shot set (handheld), then ran it through Photomatix, playing with the manual adjustments along the way. This was a relatively simple task, taking of all of five minutes or so (including the taking of the photos).

I'm having a hard time digesting what it is this first test constitutes, but it intrigues me enough to want to do more.

Oh, here's that first test set (it's all I've got right now):

[size=small]This photo (below) is the center-exposure shot of the three-shot bracket. It would represent the typical single-shot auto-exposure photo.

[/size]

[size=small]This photo (below) is the Photomatix'd HDR result of the three-shot auto-bracketing set (the above photo representing the center-exposure shot).[/size]

So, again, I'm not sure what exactly (if anything) I accomplished or ruined, but I'm feeling like this HDR--with appropriately high-dynamic-range scenes (which this set isn't)--could result in some interesting, fun shots. I imagine someone here has to be expierienced with HDR photography, and can offer suggestions on software, techniques, etc.

(Note: I think these photos were taken around 20:00 EST, or thereabouts, and so the HDR photo lighting level is actually more representative of what I was seeing with my naked eye. It was definitely more shadowy and dark in real life than the auto-exposed single photo represents.)

 

[laxx]

That's pretty good. The first time I tried an HDR it came out like poo, lol. I kind of gave up after that... but at the same time, I was using Adobe CS3's HDR function.

 

[JadeEast]

I made a couple of screen grabs of the images you provided and added histograms. I compensated for the lack of top end in the HDR with a simple levels adjustment in photo shop in the third shot.

 

[jude]

Oh, wow. Did you go from the original shot in my post above, or did you pull from a larger version from my Flickr?

Thanks--yours looks much better. I'll try playing with the histograms on the images I take this weekend.

So, JadeEast, is HDR something you do much of? Also, which version of PhotoShop are you using?


Quote:

Originally Posted by JadeEast /img/forum/go_quote.gif I made a couple of screen grabs of the images you provided and added histograms. I compensated for the lack of top end in the HDR with a simple levels adjustment in photo shop in the third shot.

 

[JadeEast]

For the example there I just used your post pic. The version of Pshop that I'm using is cs3. I've only played around a bit with HDR but have an pretty good working understanding of color correction and digital imaging from the video side of things.

*edit I see that you're newer to digital photo so I add a bit of info on a couple of concepts when I get a chance to.

 

[intoflatlines]

Photoshop has a merge to HDR automation thing but I don't think it gives very good results (Photoshop CS2 in my situation). You're better off doing it manually, in my opinion. Those samples look like a good start, though.. probably better than what Photoshop would give you.

A thumbnail of a sort of HDR I made manually via Photoshop CS2. The foreground isn't part of the HDR, the sky is. It was really tough to get an exposure that looked good with the cloudless sky in the horizon, the dark clouds, and the red/orange lit clouds.

Full size

HDR is great but I think it's become so much of a trend it's common to see lots of less than quality HDR images out there. Good luck on your HDR quest. I can't do it all that well.

 

[necropimp]

i've played around with it... my last attempt was not really a wow image but i go more for the idea of making the colors of things match what i see with my own eyes since my camera doesn't do the greatest job of it

 

[JadeEast]

Quote:

Originally Posted by jude /img/forum/go_quote.gif So, again, I'm not sure what exactly (if anything) I accomplished or ruined, but I'm feeling like this HDR--with appropriately high-dynamic-range scenes (which this set isn't)​ ​

​

​

I posted earlier that I was going post a bit of info about digital imaging and will do so in a basic way around HDR photography. It's basic stuff and not meant as an insult to anyones intelligence if it's already know information.

One of the idea of HDR is to compensate for the the limited dynamic range available to a digital camera. Just like in digital audio when something is clipped it's gone there is no info there, the math stops. Looking at the histogram of Judes middle exposure you can see that the full range of the available dynamic range is being used it stretches from absolute black on the left to absolute white on the right. It's a well exposed picture, but you can see that at the high end there is a slight amount of clipping.

There will be a loss of detail at both ends, there is information that is beyond the sensors response the cameras can roll off these clipping and make them softer but the info is gone. By taking different exposures HDR post processing lets one recreate an image that goes beyond the level detail that the camera could hold in the highlights.

Just to take a regular picture were pushing the image sensing chip pretty hard. Film and the human eye react to light in a similar way where as a digital sensors doesn't. A digital sensor needs to have it darker tones boosted to look right to our eyes, noise and garbage get boosted in this process. This added noise and artifacts hides detail in the shadows.

By bracketing the shots we take the highlight details from the underexposed clip, the shadow detail from overexposed clip and the rest of the data from the proper exposed one. How one mixes the tones is a mater of taste.

I think HDR imaging can look amazing and can work with some real problems that the digital sensors have. I have very little doubt that it will become more incorporated in camera in the future. It works great with B&W too. I've been pretty happy with the results of a single image shoot in raw and haven't felt the pull to really dive into HDR.

It's possible to try to emulate the look of HDR but it doesn't accomplish the same thing as multiple exposures. Here is a test I did to bring up the detail in the shadows on a single exposure, and you can see the noise gets pushed.

 

[terrymx]

Should have thought about this when we were taking photos to sell the house. I'm trying it out, really cool, but I can't afford the $99 pricetag to rid of the watermark text.

 

[infinitesymphony]

Quote:

Originally Posted by jude /img/forum/go_quote.gif I did an auto-bracketing (-2 EV-->0-->+2 EV) three-shot set (handheld)...

How did you take three identical shots without using a tripod?

 

[Edwood]

Auto bracketing is perfect for creating HDR images. But in the end, it does require manual work to make it look good.

I use Photoshop CS3 Extended. I find that a true multiple exposure bracketed HDR image is limited to static landscape/architectural type images with the use of a tripod.

However, you can do "pseudo" HDR with RAW images. RAW images captures a good deal more dynamic range than a processed JPEG. So, you can usually recover or extend highlights and shadow detail that is normally tossed out with a processed JPEG.

Basically in Camera Raw, move the exposure and brightness slider controls to get the sky or ground details (at the expense of other parts of the image). Do this a couple of times (2-3 versions of the same image will usually suffice). Then just shift+drag all the images into one, use layer masks to hide the areas you don't want in each image version. For instance, one version has the sky nicely exposed, but the ground and shadow areas are too dark. You would mask and hide the ground and shadow areas. On another layer, there is a version where the ground and shadow areas are nicely exposed and brightened, while the sky is completely blown out to white in many areas.

HDR is kind of a gimmicky term for a technique of merging multiple images that has been around for a long time.

-Ed

 

[diredesire]

Quote:

Originally Posted by infinitesymphony /img/forum/go_quote.gif How did you take three identical shots without using a tripod?

There is an auto-align function in PShop, also, you might try a sandbag or desk as a support system. Remotes are a good way to achieve this.

 

[Wil]

As Edwood has mentioned, it is possible to create a HDR from a single raw. Just play ard with exposure settings via PS. I do that and merge using Photomatix.

But even then it is not considered by purists as true HDR because it lacks the real dynamic range of multiple-bracketed shots.

Then again, it is useful for creating HDR shots of scenes with moving objects in them.

Here is one of my earlier efforts creating a HDR from a single RAW file.

 

[Csidinim]

while we are on the subject of raw, what exactly is the difference between in-camera processing and software processing when speaking about exposure. when you take a raw image, cs3 or the camera bundled software will let you adjust the exposure as post process. I assume that is the same thing that is done in camera when you take a jpeg- except with raw, the extra information is still available to rebuild the image within a range of exposures. what is the difference

 

[necropimp]

file size