Are 1-frame HDR's really 'good as HDR'.

[480sparky]

It was mentioned in yet another thread that taking one frame and creating a -2 and a +2 EV to combine with the original 0 EV to create a 'good enough' HDR.

So I decided to put that claim to the test. I scrounged my hard drive for a 'suitable' set of -2/0/+2 frames, and found this one:

So, I used one of the the original NEFs to create a -2, 0 and +2 version and used those to make a 1-frame HDR. This is what I ended up with:

Then I took the actual three NEF frames that were exposed -2/0/+2 in camera on-site. Using those 3 frames, I created this HDR:

These have not been edited at all.... this is how they came straight out of the HDR processing. Obviously, both need some color correction, but that's not the issue here... it's whether a single frame can be adjusted in post to -2 and +2 exposures and create the same image as a 3-frame build.


All settings are the same for both builds, save for having to manually set the EVs for the 1-frame build.

You can view the full-size images by clicking here:

1-frame HDR.
3-frame HDR.

Keep in mind I'm working with the original raw files. Working with JPGs alone may produce different results


Thoughts? Comments? Suggestions?

.

 

[Bynx]

I think it depends on the range of light in the image as to whether a single shot will do. Your example here doesnt have extremely bright or dark areas so this limits the number of shots that might be needed. Try the same procedure but with the sun shining and dark shadows present, or maybe a shot of the living room with a lamp on and very bright light coming through the window.

 

[analog.universe]

Perhaps someone can correct me if I'm wrong here, but if I understand the theory correctly, couldn't the same result be achieved by simply applying a more complex tone curve to the original RAW? Normally when you HDR, you have different exposures because the camera can't fit all of the dynamic range of the scene into one. So you take a few, and then the HDR software creates a file with more information in it than any of the originals had. If you're just processing your raw into 3 different outputs, and then recombining it with HDR, you're not actually gaining additional information, you can't synthesize more data. What you do get is a different output curve due to a difference in processing method. However, since you have the same input data whether you've split the RAW into 3 exposures or not, you should in theory be able to reproduce the output of the HDR by only manipulating your raw converter, since it has just as much data as the HDR program did. Yes? No?

 

[robertandrewphoto]

While they both have a similar result, the true HDR shot is much better

The sky is better, the detail in the rocks at the bottom are better, the shadows in the building are exposed better, there is no haloing....and that is just what I can tell with a quick glance.

In my opinion, there is no replacement for a true HDR and I won't ever process a single shot to have an HDR effect and call it HDR....It should just be called FHDR

 

[SlickSalmon]

That's a really interesting experiment. Thanks for conducting it.

 

[480sparky]

Personally, I think using a single frame simply cannot create a true HDR. One frame simply cannot record enough dynamic range if the scene is outside the capability of the camera/sensor to record. If the dynamic range of a scene is 12 stops, I doubt you'll ever get a good image using one frame. And the wider the range of the scene is, the results will become even worse.

 

[cgipson1]

This is from a single frame (0) that I ran though PS, and changed the brightness to -2 and +2......

so it does work (Photomatix seems to do it best).

Here is the original (O) that I shot.... Major difference.. and to the good of the photo...

 

[480sparky]

.....so it does work.......

It really just looks like you increased the brightness.

Now, try three in-camera -2/0/+2 frames so we can see the difference. We really can't compare an apple to an orange when we only have one of them.

 

[Josh66]

Personally, I think using a single frame simply cannot create a true HDR. One frame simply cannot record enough dynamic range if the scene is outside the capability of the camera/sensor to record. If the dynamic range of a scene is 12 stops, I doubt you'll ever get a good image using one frame. And the wider the range of the scene is, the results will become even worse.

I guess it depends on you definition of HDR, but I would tend to agree that one frame cannot produce a true HDR. After all, if you can do it in one frame, how is that more dynamic range than a 'normal' picture?

One-frame HDR's are just 'special processing' to me - there isn't really anything about the dynamic range that is higher than normal...

I have not yet seen a 'one frame HDR' that couldn't have just as easily been done with some curves adjustments...

 

[cgipson1]

.....so it does work.......

It really just looks like you increased the brightness.

Now, try three in-camera -2/0/+2 frames so we can see the difference. We really can't compare an apple to an orange when we only have one of them.

I will see if I can get some shot.... . As far as the pics above.. look at the red bricks to the left of the car outside of the shadow area. basically the same "brightness" on both of them...

 

[480sparky]

........I will see if I can get some shot.... . As far as the pics above.. look at the red bricks to the left of the car outside of the shadow area. basically the same "brightness" on both of them...

Are you going to edit your post again if I tell you what they look like?

Yes, it's better, but IS IT HDR? I can do the same thing, even without creating -2/+2 frames and going through the entire HDR process. With 'true' HDR, the highlights on the car and in the clouds would not be washed out.

 

[cgipson1]

........I will see if I can get some shot.... . As far as the pics above.. look at the red bricks to the left of the car outside of the shadow area. basically the same "brightness" on both of them...

Are you going to edit your post again if I tell you what they look like?

Yes, it's better, but IS IT HDR? I can do the same thing, even without creating -2/+2 frames and going through the entire HDR process. With 'true' HDR, the highlights on the car and in the clouds would not be washed out.

Sorry about changing pics.. but had put the wrong ones up.. didn't have the real "0" on that set...

I did these the the very first day I had photomatix so they are a little rough...

 

[manaheim]

Think of it this way...

The human eye can see something like "21-23 stops of dynamic range". Cameras can see like 7-9.

HDR is intended to give you as close to what the human eye can see as possible, so you want to get as close to 21-23 as you can.

A single RAW image gives you approximately 4 stops of leeway- 2 in each direction.

This takes you from 7-9 to 11-13... about 1/2 of the 21-23 we're looking for.

So, no, it's not as good, and no you can't use tonal curves to achieve the same thing... unless, as bynx said, it happens to be a very low dynamic range scene to begin with.

 

[Josh66]

Is a low dynamic range scene really in need of HDR processing anyway?

I don't do a lot of HDR's... (I do employ it occasionally though.) It seems to me that there are three types of HDR...

True HDR - truly high dynamic range.

Cartoon HDR - you know what I mean.

Faux HDR - HDR that is really just tone mapping or creative use of curves.



It's been a while, but this is one of the last HDR's I've done... 2 exposures (I felt that was all that was required):


IMG_6172_and_IMG_6177 by J E, on Flickr

Not perfect, I know. It is an example of a photo that would not have been even remotely possible with one exposure though.

edit
These are the two frames that went into it:


IMG_6172 by J E, on Flickr


IMG_6177 by J E, on Flickr

 

[cgipson1]

Personally, I think using a single frame simply cannot create a true HDR. One frame simply cannot record enough dynamic range if the scene is outside the capability of the camera/sensor to record. If the dynamic range of a scene is 12 stops, I doubt you'll ever get a good image using one frame. And the wider the range of the scene is, the results will become even worse.

I do agree with this totally, for true HDR. If the detail is not in the images you are working with.. you can't pull it out of the under's / over's and put it into the photo.. it doesn't exist. As pointed out, our camera only "see" about 10 stops... for true HDR, you have to have photos that encompass a wider range than that 10 stops... or it isn't really HDR. I will concede the photo I posted above is more like a brightness fusion, than true HDR.