"Film has more dynamic range than digital." -- true?

I've never seen an Ansel Adams print, zone system and all, that couldn't have it's dynamic range improved with a little Photo Shop.

I don't know where Johnson gets his numbers; my own experience is somewhat different than what he is reporting. I use 5x4 and a one degree spot meter. All that means to this discussion is that I can accurately measure the subject brightness range (SBR) in a scene. For example, this scene measured 11 stops of SBR:

http://www.achromaticarts.com/big_image.php?path=flowers&img_num=2

I made this photograph in June at about 2:00 in the afternoon. IOW, in the brightest conditions that occur where I live. The film is 5x4 160PortraVC which I drum scanned. I can verify that the film was linear for the full range of the exposure, with no color shifts (film has gotten better in the last 25 years ;-).

I made a matching exposure with 5x4 Tri-X developed in XTOL 1:3 which is similarly linear. This was years ago, but IIRC the Dmax was around 1.6 which is very dense for me (I aim for a Zone VIII density of around 1.0 since I'm scanning).

So what I saw was no shouldering, excellent linearity, no color shifts, and 11 stops of SBR. This well exceeds Johnson's 6-7 stops for color negative film.

With digitial sensors, much depends on the size of the individual CCD sensor wells. The bigger wells translate into less noise and greater dynamic range. Phase One is claiming something on the order of 10 stops for the P45 MF digital back which has a very large sensor. Mike Collette of Better Light told me years ago that their sensor design let them capture 12 stops with their scanning backs (color, not infrared). This is possible because the backs make three separate exposures for each pixel as they scan -- the scan array is two dimensional at three pixels wide (an R, a G, and a B sensor) by however long. I don't doubt that their newest backs do even better.

So... it depends. The better digital solutions with the bigger sensors and therefore bigger sensor wells can nearly equal negative film's ability to capture a wide SBR. The smaller sensors in DSLRs seem to fall somewhere between slide film and negative film. The very small sensors in digital point-'n-shoots seem to be closer to the slide film side of dynamic range.

Anyway, that's my take on it.

My opinion... is that negative FILM does, slide film does not, and wet process print paper does not.

Kodak gold 100. I'd think there's more than 7 stops in this scene.

Dynamic range should be based on the range that can be captured on film. This is enhanced considerably by toe and shoulder effects and low and high exposures respectively. This is not to be confused with the contrast range of the output (image on film or paper). Velvia, for example, has deep blacks to nearly transparent results, but a relatively shallow capture range. Negatives appear quite flat by comparison.

Based on characteristic curves (*) published for various films, Fuji Velvia (reversal) has a useful dynamic range of 3-1/2 stops. Fuji Provia has a range of 5 stops. Representative negative films include Reala (8 stops) and NPS160 (10 stops). Tri-X has a range of 10 to 12 stops, depending on development.

Modern DSLRs have a dynamic range of about 7 stops (D2x) to about 8 stops (Canon 1dsMkII), based on test results published on DPReview.com and my own experience (D2x). These sensors have a 12 bit range of capture, expressed in the RAW mode.

Many MF digital sensors have a true 16-bit sensor. Hasselblad/Imacon claims a 12 stop dynamic range for their CFV back. Having seen the results, I'm inclined to believe it.

*The abscissa of the characteristic curves is logarithmic - divide the extrapolated range by log2 (0.301) to express the difference in f/stops.

Stephen Johnson comes to that conclusion gets from intense practice and empirical evidence.

How does the rendering of glare in a 2D RGB color environment get translated into dynamic range?

Just my own unscientific observation but I can't see dynamic range in the images posted because of this emulation of glare which doesn't necessarily translate to wider dynamic range from my understanding of the term. Using bounced lighting will change the entire dynamics of each of those images and so how can that be attributed to the dynamic range of film.

I can't understand how you can measure dynamic range using a Stouffer step wedge when light in real world shooting conditions doesn't behave that way nor does gauge measurements translate into how much useable detail can be captured.

How does knowing f-stop ranges allow you to predict how much detail will be captured in a real world scene?

With my entry level Pentax K100D DSLR all I have to do is expose darker and reduce the contrast setting and my histograms of a back lit tree taken in the shade at noon never clips to black and the hazy sky in the background doesn't either. Now the tree looks solid black on the camera's tiny LCD, but if I view zoom in on it on my calibrated display there's tons of detail captured. The lowest black setting bottoms out at 6 as read in PS's info palette.

That means my camera can map the glare of a brightly lit noon day smack in the middle of 255 levels of RGB luminance. What's the dynamic range of that?

Great stuff. I am marking this thread for further study.

I'm not arguing film vs digital here in regards to dynamic range. But I have to admit from my limited and frustrated experience using neg film on a Yashica SLR 50mm and Canon and Minolta P&S's from the mid '80's to the present, I could never get the dynamic range, definition, color accuracy and sharpness with no noise what so ever as seen in the Pentax DSLR capture at the bottom. I'm sure an expensive scanback would give even better results.