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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

HDRx samples...

Thanks Jim, beauty!

More please :)
 
Peter Matthes said:
Yeah ... That's exactly what I was getting at.

If you could keyframe the blend of the two exposures over the length of a moving shot ... that would be insane. :thumbsup:
Click to expand...

I was about to say that wouldn't be necessary exposure-wise but then I thought about Magic-Motion™ and I saw the genius. Brilliant. Yes please on this one.
 
I have a question about HDRx.

Let's say you take an HDRx shot where the under is perfectly exposing the darker parts of the image but not clipping the highlights, just overexposing them; and then the over is exposing the highlights perfectly but not clipping the shadows, just underexposing them. In this situation HDRx makes perfect sense to me as the blend should create an image where everything is properly exposed.

Now let's say you take an HDRx shot where the shadows and highlights are further apart. The under is perfectly exposing the shadows but the highlights are significantly clipped; the over is perfectly exposing the highlights but the shadows are significantly clipped. I figure this is pretty typical. So what I don't understand is how this would have the same effect as in the previous example… because now the clipped shadows, whether they were barely out of the exposure range or very far out of the exposure range, are blending in as if they were all the same color (black); and the clipped highlights, whether they were barely out of the exposure range or very far out of the exposure range, are blending in as if they were all the same color (white). So now any part of the blended image that was blended with either clipped shadows or clipped highlights is still getting "half clipped" if that makes any sense.

For instance, let's say a wall is filling the frame, and the wall is being lit in such a way that one side is in shadow and the other side is brightly lit, and it gradually changes from one to the other so that the middle of the wall is 50% as dark as the shadow side and 50% as bright as the well-lit side (so the wall is a linear gradient). Using HDRx, wouldn't the resulting blend have a consistent, linear ramp up from the dark to light in the middle of the wall where neither the under or the over was clipping, but then once you get to far enough in either direction that either shadows or highlights are clipping, the change in apparent exposure would no longer account for the clipped values?

If that doesn't make any sense, think about it like this:

100 = white
000 = black
1XX = clipped highlights

(assume the pattern remains the same over this imaginary gradient)
OVER|UNDER: BLEND
020|069: 44
026|075: 50
032|081: 56
038|087: 62
044|093: 68
050|099: 74
056|1XX: 77.5 ("should be" 80)
062|1XX: 80.5 ("should be" 86)
068|1XX: 83.5 ("should be" 92)

Hopefully that makes sense. As you can see (?), once you get to the part of the gradient where there is clipping in either the under or over image, the blend becomes increasingly inaccurate.

So my question is: does HDRx take note of what is being clipped (whether it be in the under or the over) and compensate in the blend by replacing clipped values with "super white" or "super black" values which are calculated using the exposure metadata and values from the other image (under or over) in which that part of the image was not clipped?

I'm not trying to figure out how you've done what you've done from a technical standpoint (I am interested, but I know you have to keep it close to your chest), but rather, I'm trying to determine the limitations of HDRx. I'm assuming you do somehow compensate for this issue, but if not… couldn't you? Using a system like the one I described in the previous paragraph?
 
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It's really an amazing tool. And I'm also impressed with the DR in the normal exposure !
 
DISCLAIMER:
I know this is an 8-bit JPEG. I know that playing with these images is not really representative of what you can actually do, and I am not pixel peeping, I promise. I am just showing these because I am impressed with just the 8-bit JPEGs. Not scrutinizing, just having fun. :}

Here are the levels in Photoshop, and the part of the range I am "throwing away" to brighten up the image. Lots of headroom to play with.

levels.jpg


Here is a before and after. Even though I am throwing away a lot of the subtle little details, You can still see a lot of highlight detail is left in the image. "1" is before HDRx™, "2" is after HDRx™ and the new levels adjustment.

grade.jpg


Here is my own creative grade. Just for fun, took me 5 minutes. Loved the location.

MYGRADE.jpg


Any more images to play with, Jim? :D
 
David Quinn Carder said:
I'm not trying to figure out how you've done what you've done from a technical standpoint (I am interested, but I know you have to keep it close to your chest), but rather, I'm trying to determine the limitations of HDRx™. I'm assuming you do somehow compensate for this issue, but if not…*couldn't you? Using a system like the one I described in the previous paragraph?
Click to expand...

Think Graeme Nattress. :-)

Jim
 
Thanks for posting, Jim.

I'm excited to see (and use) HDRx in the way it was intended.

I'm also curious to experiment with it an see what else it can be used for...
 
This is an exciting new aesthetic being born. Man, I can't wait! 21st century filmmaking is beginning to have a look all its own. All that film had and much more. This is going beyond film-- if we want it to.

Do you have any idea how long I've waited for this!?
 
Jannard said:
Think Graeme Nattress. :-)
Click to expand...

No doubt. : ) But the question remains—and maybe Graeme can come in and give an answer when he has time—are those clipped values being compensated for (I won't ask how) or would an HDRx image have the flaw I described? Again, I'm guessing they are compensated for, either with a system like the one I described or by some means I haven't considered (the latter being far more likely), but if it's not being compensated for I'd like to know.

To be honest I hadn't even thought of the problem until this thread, but now that it's dawned on me I think it's an important issue.
 
Looking back at my first post, I did mistakenly state that my question was how it was being done, not if it was being done. That was a mistake—I'm not prying!
 
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