You are quoting DR numbers for film higher than anything I have ever
seen. What I'm interested in is not the AG dynamic range but what Kodak
or Fuji says about their films.
Numbers I'm familiar with are more like 5-6 stops for slide film and
9-11 stops for negatives. Do you have some non-AG numbers to dispute that?
Chuck Norcutt
On 5/1/2012 6:39 PM, Ken Norton wrote:
>> OK, I'll buy it if you give me the actual dynamic range numbers.
>
> Without jumping to heroics, I was getting 12-14 stops of DR and the
> highlights and shadows didn't go wonky. With heroics (adjusting the
> scanner's exposure times" I'm seeing another two stops lurking in
> there, but depending on the picture, this may or may not be overly
> usable.
>
> That's just with the digitizing process. B&W film in an analog
> environment is unmatched. You can dodge and burn and not get wierd
> things happening because there were too few bits representing half the
> stops of range.
>
> Honestly, with XP2, I'm not sure what the upper limit on DR is.
> However, if you lean too far into the shoulder or toe, you do suffer
> some lack of tonal separation because the S-curve is so flat. (Midtone
> gray is already one full stop into the shoulder). XP2's DR exceeds the
> ability of my scanner to capture no matter what I do. In the darkroom,
> I can do things to pull stuff out that really changes things. Ilford
> Pan-F and Delta 100 have different curves and don't have as much
> absolute dynamic range, but they put what dynamic range they do have
> to better use.
>
> I know what the numbers say, Chuck. 12 stops should be 12 stops should
> be 12 stops. When you do a straight top-and-tail of the histogram and
> hit print, both technologies are going to be similar. But when you
> start pulling those highlights back and lifting those shadows up, film
> behaves totally differently. With the highlights, it's not uncommon to
> have color shifts as well as some nifty rimming effects with things
> like the setting sun or any other bright colored light source. Shadow
> lifting gets nasty, hence the necessity to expose-to-the-right
> whenever possible to avoid having to lift the shadows. Cameras that
> dither the output of the sensor (Olympus E-1, for example) mask a lot
> of those nasties, but at a price. With film, provided the scanner
> (which is a digital camera) is set to adequately capture the full
> dyanamic range of the film (not as easy as it sounds sometimes) will
> start to reveal details in the shadows and highlights that just aren't
> there with digital capture.
>
> My best concert photos have been and remain those taken with Fujifilm
> Press 800, followed closely by NPZ. Colored stage lights do horrible
> things with digital capture. Film is not such affected and that
> shoulder gets leaned into in a way that red lights stay red, purples
> stay purple. With digital, the reds turn yellow, the purples turn
> blue. Yellow lights will turn the performer into Big Bird. (I had
> major Big Bird Badness last week).
>
> When shooting things like weddings, the Portra films are unmatched.
> I've NEVER had a worry, EVER, about capturing the white dress and
> black tux in the most extreme of lighting conditions. Portra 400NC
> (now just straight Portra 400) just nails everything dead on and the
> skintones make you wonder just why we shoot digital?
>
> So, when you compare the DR of Portra 400 with, say, a Canon 5D (which
> remains a DR leader), even though the numbers are close, it's still no
> contest.
>
> Where the DR numbers really do matter is when you compare digital with
> reversal films. Velvia is an obvious one which gives maybe 8 stops on
> a good day, depending on several factors, Provia is about a stop
> better, but isn't as picky. Astia will give another stop and isn't
> picky at all. Ektachromes are all over the boards, but tended to give
> a bit better range than equivalent Fujichromes. Agfachrome really set
> the standard and gave a very wide range. In fact, I have one set of
> pictures of an abandoned farmhouse I could never capture with my
> standard Fujichromes.
>
> B&W films are quite variable. Not only does it matter what brand and
> model of film you are using, but how you expose and develop it. There
> are some fantastic claims of extremely wide dynamic ranges, but those
> require odd exposures and development plans. It's fascinating that in
> the world of B&W, where EVERYTHING is known, that we are still
> discovering new things about the films, developers and methods.
> Especially so, since some information about the films has been leaking
> out of Kodak. (have you hugged your APUG neighbor lately?)
>
> I've got the spec sheets for a bunch of these films, and in actual
> practice, I've found that my usability in scanned images matches these
> specs very closely, but doesn't take into account how much can be
> rescued from the toe and shoulder. I've been able to gain a full stop
> of missing information in the shadows of Velvia. I'm able to pull
> stuff out that can't even be seen by examining the slide on a light
> table. With some curves adjustments, I'm able to usually get another
> full stop of straight-line section from the Fujichromes. In the case
> of negative films, I'm usually having to increase the contrast of the
> image to reduce the effective dynamic range since the images don't
> look "normal" to today's expectations.
>
> I did do dynamic range testing of Ektar 100 compared to the 5D. I'll
> have to go back and look at the images again. I didn't get around to
> publishing the results of the tests since there were some procedural
> things which would be easily skewered, but we were seeing two to three
> stops of additional USABLE dynamic range over the 5D even when a
> maximum amount of highlight and shadow recovery was applied to the 5D
> image. That's not to say the 5D was bad. Far from it. It still remains
> the best digital camera I've ever tested in this regard.
>
> Oh, on an oddly related note. With the big event shoot, Lightroom 4
> was able to very closely match colors between the E-1 and the DMC-L1
> using Auto-Tone. The midtones and skintones almost perfectly matched
> (with a slight adjustment of WB on the DMC-L1 files, but the top and
> bottom edges of the dynamic range were vastly different. Lightroom got
> everything in the middle to match, but sacrificed a lot on the outer
> limits. My new computer (i5 with 6Gb RAM) performed like a champ, but
> boy did it get HOT!!! The cooling exhaust vent was almost too hot to
> touch..
>
> AG
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