HDR High Dynamic Range Examples

[Emre Yildirim]

This discussion has been really interesting so far.

But serously, do either of you really care that much about which one has more dynamic range?

This argument has turned personal, as much as either of you like to deny it.

All I can say is that digital has gotten much better in this area, and I don't think anyone can deny this.

[David Luttmann]

Sorry Matthew,

Convenient? I have shown you the digital test before. I believe with the Canon 20D. You harped on and on about how a digital source couldn't have 10 stops of dynamic range. I believe I had shown you about 9.9 stops. Now you want me to dig up old Imatest results?

Sorry, I don't have time to waste for people like you. Reason being, when I showed you the results from a DSLR, you denied them to be accurate....in other words, no matter what test results I show you, you will call them to question unless they agree with your bias towards film.

As to the extra 1/2 to 1 stop for neg film from a drum scan....I did say you could go to a digital back to get between 11-12 stops.....but I'm sure you call that into question as well.

I think I'll leave it at that. Go do your own tests and quit trying to find a conspiracy with everyone who provides you with tests that don't agree with your opinion.

[Ken Lee]

You can find a nice discussion of the technique, with sample images and Photoshop info, on Luminous Landscape.



Like so many techniques, it's good to know in case you need it.



Some day soon, they might come up with sensors that accomodate a wider range of brightness - or incorporate some kind of fast multi-sampling. In electronics, a fraction of a second can be a rather long time, and it wouldn't surprise me if it were possible for a camera to actually shoot several images in quick succesion, and overlay them instantly, when the contrast level calls for it.



As for me, TMY + Pyrocat HD + Ansco 130 gives a fairly long range already.

[Jack Flesher]

>>Half all the tonal range of a digital SLR is in the top stop, half the remanining tonal ranges are in the "next to top" stop. So, 2 stops uses up 75% of all the available tonal range, 3 stops, we used up 87.5% of the total tonal range available. Now, regardless whether its 12 bit, or 14 bit capture, after maybe 4 stops of digital capture, there is so little tonal range remaining, <<

WG: Where are you getting this -- Ahemmm -- information?

[Frank Petronio]

All I know for sure is that some of you guys are full of it. The problem is I don't know which of you guys are! (But I have some ideas...)

Back to the origianl question - anybody have any web links to HDR - Zone 14 images?

[bglick]

Jack, this "information" is readily available in any RAW tutorial....most notably in Bruce Fraziers book called Camera Raw, it explains RAW files, the digital capture process (Bayer sensors), and Adobes Camera Raw software....it's a good read... and based on your post, I think you would strongly enjoy it. :-)

It seems this little gem of information has somehow eluded most digital fans...something I am sure the makers of Bayer sensors surely do not want to shed light on. They have done an excellent job keeping it under wraps. AFter you read up on it, I am curious as to your comments, as it was s tough pill for me to swallow a few years ago when I first read about it.... so be careful, and absorb it in - small doses! :-)

I explained this in detail in posts awhile back, but don't have the time to dig it up... and yes, even today, I am still bothered by the fact there is 3 stops of data that contain 87% of all the tonal ranges available, that leaves the lower stops, say 5 or 6 which can not record an 8 color step wedge, or even worse for R and B, probably not even a 4 step color wedge....

[Jack Flesher]

>> Jack, this "information" is readily available in any RAW tutorial.... <<

I thought you might say something like that...

So now please do us all a favor and explain the differences between the linear RAW file and the converted RAW file as it relates to DR -- after all, they are significant.

[Jack Flesher]

>> I knew from experience that I needed far more than 1 digital exposures to get a similar feel to what I was achieving conventionally in 1 shot c41 capture. <<

And because of comments like this, all Dave and I are suggesting is that perhaps some film folks have not yet learned how to process digital files properly to achieve maximum USABLE DR...

The big difference in DR is NOT the total DR available, but how the DR that is there gets distributed. The "automatic" settings in most raw converters do not do the total digital file justice. Hence, one must tweak the converter to achieve the desired result -- and that result can get very close to replicating C41 emulsions in latitude, color and tonal distribution. Heck, we can even replicate the grain once we pull the file into Photoshop

Cheers,

[tim atherton]

"Half all the tonal range of a digital SLR is in the top stop, half the remanining tonal ranges are in the "next to top" stop. So, 2 stops uses up 75% of all the available tonal range, 3 stops, we used up 87.5% of the total tonal range available. Now, regardless whether its 12 bit, or 14 bit capture, after maybe 4 stops of digital capture, there is so little tonal range remaining, I wonder how valuable the remaining stops are. I think this point is being overlooked, and its one area neg film still is superior as the tonal ranges remain higher throughout the same image exposure lattitude. How much? I don't know, but I would love to see this analzyed by someone :-) "

this is the sam for a raw scan from colour negative is it not? Do not the linear files from both follow this?

"It seems this little gem of information has somehow eluded most digital fans...something I am sure the makers of Bayer sensors surely do not want to shed light on. They have done an excellent job keeping it under wraps. "

Conspiracy theory...! - hmm not exactly a big secret. We were discussing this 10 or 12 years ago at least

[Frank Petronio]

I seem to get good images from both color neg and my raw DSLR files, darn it. What am I doing wrong?

I do know that if I need to work with a 2-stop underexposed image, I much rather have a underexposed RAW file than a 2-stop under color neg.

Since just about every form of repro involves compressing the tonal range of our images, even from color chromes, at best we're going to see a little more shadow and highlight detail from a longer toe color neg, raw digital file, or 14-bit HDR. What bothers me about the HDR images I've seen is that the jpg (8-bit) on screen I see seem to place Zone II shadow detail at Zone IV (and Zone VIII highlights at Zone VI). Is this just poor judgement on the image-maker's part or are they simply trying to cheat things so that you can tell they are using HDR? I'd still love to see a practical application that makes a beautiful image.