An example of highest level single image HDR (NSFW)

[Daniel D. Teoli Jr.]

This is a single image HDR from a 6x6 BW negative . It is a 3 exposure HDR done in post processing (-1,0,+1,) and it has additional contrast grading done in Lightroom. It is a good example of what can be achieved with single image HDR and contrast grading.

Single image HDR is often looked down upon as not 'real HDR' since traditional HDR is done in-camera with multiple exposures. While it is true single image HDR is not as good as traditional, multi exposure HDR, you can still benefit from single image HDR as many times it is not practical to shoot multiple exposures of a subject. 

 

Sunlit Slipper 1974 L.A. - photo and post processing by D.D. Teoli Jr.

[Bruce Greene]

Daniel, this a beautiful photograph.  Thank you for posting!

But, just to avoid confusion here...  "HDR", for still photography, refers to capturing a wide dynamic range and compressing it into an SDR image or photographic print, as Daniel has illustrated very well here.  Usually by capturing multiple exposures of the same image and combining them.  Or, in this case, by multiple exposure scans of the negative.

"HDR" in motion pictures refers to capturing a wide dynamic range image (usually in one exposure) and presenting it in a wide dynamic range display or projection.  Which is a related, but different concept.  It's unfortunate that the two concepts both use "HDR" to describe themselves.

[Perry Paolantonio]

3 hours ago, Daniel D. Teoli Jr. said:

Single image HDR is often looked down upon as not 'real HDR' since traditional HDR is done in-camera with multiple exposures. While it is true single image HDR is not as good as traditional, multi exposure HDR, you can still benefit from single image HDR as many times it is not practical to shoot multiple exposures of a subject. 

If I understand correctly what's happening here, a single scan is split into three versions, each with a "-1, 0 and +1" (stop?) exposure, then merged together in the same way a multi-shot HDR would be?

If this is correct, while it may have some effect on the image, it's basically just a post production grading technique that could also be done with curves or multiple-layer or multiple node color correction. It's not really extending the dynamic range, or getting any of the benefits of scanning the film at two or three exposures and merging them. There is a significant difference.

With a true HDR scan, you get three things:

1) Extended dynamic range by scanning for the dense, normal and thin areas of the film, then merging them into a single SDR image. The end result is detail in all three ranges. A scan done for the shadows would blow out the highlights, and vice versa. 

2) Depending on how it's done, for color images you get more bit depth in the resulting file than you would with a single scan

3) Reduced noise (if there's noise in the scan in dense areas of the film, an HDR scan will pretty much eliminate the noise from the scanner's sensor, by pumping more light to it, and creating an image well above it's noise floor. 

-perry

[Daniel D. Teoli Jr.]

Thanks Bruce

Yes Perry, this was done with 3 exposures from a single neg in post. Using 3 exposures (-1,0,+1) allows for more range than you get just by software HDR. At least that was how it was in 2012. Scanning at different exposures was not an option when I did it.  

Maybe new software can do better than the old software, don't know.

You can only get what is in the neg or chrome Perry. Single image HDR allows you to get more of what you could not get without it. Think of it this way. There is gold in seawater, but you wont get it without special processing. Same with single image HDR. You wont get the range without special processing.

Maybe you could get the same thing with Photoshop, dunno. I'm an old film photog, I don't know how to use Photoshop, so I make due with Lightroom. But contrast grading alone would not produce the results as shown. And HDR software (at that time) without contrast grading would not produce the results as shown. But when combined, they allowed for maxium dynamic range Perry. 

Do you have any good HDR before / after samples Perry? If so, lets see them, post them here or make your own thread.  I'm always interested in seeing what can be done with HDR.  Anyone for that matter, lets see your before and after HDR samples.

When you do HDR scans Perry, how much extra does it cost for 3 scans over 1 scan? Is there a discount since the film is already set up to scan or does the post processing for HDR make any setup discount inconsequential?

(I should say, the exposures may have been -1.5,0,+1.5. I did it 7 years ago and didn't take notes. But I normally use -1,0,+1 in most cases.)

Edited July 11, 2019 by Daniel D. Teoli Jr.

[Perry Paolantonio]

I guess what I'm getting at is that it's not an HDR scan if you're starting from the same, single scan. It's kind of mimicking what you'd get with HDR, but it's only able to work with what's in the initial scan. A true HDR scan, made from multiple images, works by making different exposures for each at the time the scan is made. that means for really dense areas of the film, more light gets to the scanner's sensor, and more detail, if it's there, is extracted. And for the thinner areas of film, a normal exposure is made, which ensures nothing gets blown out. But if you start from a single scan, you're only able to work with what's in that scan, it's not able to pull out detail in areas where the scanner didn't pick it up.

What you're describing should be doable with any good photo editing software, but it's not an HDR scan. 

We're working on a web site redesign, which will include more HDR samples. Our current scanner does 2-flash HDR only, though we'll have a 3-flash scanner within the next few months. It's more expensive because the machine has to run twice (or three times, for 3-flash) as slow, in order to capture all the images. the scanner handles doing that, and it outputs a single SDR image. The basic idea is the same as what you're doing (at least algorithmically), except that instead of starting from one scan, it's starting from two or three. 

[Daniel D. Teoli Jr.]

Yes, that is true. Different exposure were not made at the time of the scan.

Looking forward to seeing samples of the output at your website comparing the no HDR, the 2 scan and 3 scan machines. You know the deal...a picture is worth more than...