Film vs Digital - Dynamic Range

[a_petkov]

The fact that negative film has better range than digital sensors or slide film is common knowledge.

Another fact however is that a tonal range does not a picture make.

[mauro_franic]

Thank you all. Roger and a couple other people have downloaded the RAW files I posted to see if they could rescue the detail in the brightest stop of the 40D using software. Stay tuned for the results.

[StuartMoxham]

Mauro the TMAX 100 shot with the blown highlights is that a scan or a traditional B&W print.

[mauro_franic]

Just a scan. I didn't tinker with it much since the Coolscan does a good job at it. The scene was so bright I couldn't look at it directly and the surroundings were almost pitch black. I think it was one of those rare exceptions were TMX got out-ranged.

[StuartMoxham]

I wonder how much would burn in if you made a traditional darkroom print.

[bernardwest]

I had a brief play with your 40d highlight raw. I only had a <i>brief</i> play as my wife is monopolising our computer

for work, and I didn't have much time. I will try and post the results tonight when I get home. Briefly, some

interesting things I found: Doing 'linear' processing, I found that DPP doesn't make full use of the sensor's data (this

is something I knew already anyway). The Linear dcraw and lightroom processing shows a little bit more detail

(though not anything like a stop's worth) than the linear DPP. I was fairly impressed with DPP's ability to regain

some highlight detail using a contrast of -4. The main problem I have with DPP is not knowing what's going on under

the hood. The exposure adjustment seems to be some sort of combined exposure and highlight recovery tool. Also

when I developed linearly and boosted the shadows, it was clear there was some shoddy noise reduction going on,

even though I had noise reduction set to 0. The real interesting (and unexpected) thing for me was the seeming

quality advantage of dcraw over lightroom in the shadows. Although, I will try to confirm this with a bit better

processing tonight (last night I was rushed, and our computer is acting like it has the weight of the world on it's

shoulders i.e. it's chugging along). Mauro, I wonder if you could post the 40D shadow raw, as I would like to see the

difference between the three processors, and compare to the film scan. I feel somewhat positive that dcraw could

dig a fair bit of detail out of the shadows.<p>

 

Below is a quick preview of some of the results. These are a bit hapazard, as I was rushed and the computer kept

crashing. From memory, the DPP image was converted as srgb (coz I couldn't figure out in a short time-frame how

the hell to output the damn thing in prophoto). And the dcraw image from memory is probably still in prophoto. Top

image is DPP no exposure adjustment, white balance as shot, faithful or neutral picture style (can't remember which

one), -4 contrast; bottom image is linear dcraw initially no white balance, imported to lightroom as 16bit prophoto tiff,

fill light 100, white point set using positive exposure (nb. dcraw default white clipping point is higher than the 40d

pixel saturation point as far as I can tell), then exported to photoshop and a quick-and-dirty two-click curves white

balance adjustment (as some of you may or may not know, the linear image off the sensor is green). Tonight I will

try and process the dcraw image in dcraw itself as much as possible. This should make a bit of a difference as

white-balance and exposure adjustments post-demosaic is not an optimal approach. In summary: notice the little bit

of extra detail in the shadows and the highlights of the dcraw vs dpp image.<div></div>

[mauro_franic]

Probably the best way to have saved it would have been with a little pulling in development and using TMAX DEV instead of XTOL.

[mauro_franic]

Thank you for the work Bernie.

 

It still looks like 3-4 stops have areas with clipping beyond recovery although you dug up important detail. I'd say Ektar has at least a 4 stop advantage on the bright side over the 40D since even the f64 frame was not enough to compromise the highlights.

 

Here is the raw file with the shadows:

 

http://www.yousendit.com/download/TTZuS3dqMGMwMEZjR0E9PQ

[bernardwest]

Thanks Mauro. I'll have a play over the next few nights. You're right about the improvement; the 40D will never match negative film.

 

One query I had - your initial results you show, what settings did you have for the 40D dpp image? When I open it in dpp, it opens with +2 contrast and +2 or so saturation. What settings did your initial posted images have (including what picture style)? Cheers.

[mauro_franic]

Those are the settings. I did not touch the raw at all to either post or send to you.

[mauro_franic]

Please check against the post on your monitor to double check.

[j_a]

Mauro,

 

You have my apologies for my earlier posts. They were off base and frankly I came off sounding like a bit of a crank.

 

My criticism of your comparison still stands however. You're trying to compare two radically different technologies. You can compare trains and trucks, they do the same thing (move things) but they do it in different ways. But the comparisons will always fall short. Digital cameras and film cameras both capture light, but they do it in different ways. Both benefit from inherent strengths as well as inherent weakness. And the most notable of both technologies weaknesses is the first steps after exposure.

 

In the case of digital (raw or not) the software used to view the image has a direct effect on the image itself. Raw just leaves all the info there, it still needs to be interpreted by a software in order to be viewed. Some software's do this better than others. You need to list what software you used and the setting used by that software.

 

Let me take a step backwards with film and begin by stating the first inherent weakness' is in the actual material. Film, relying on chemistry and not physics is subject to a number of factors that could alter the exposure: age, temperature and humidity in storage, manufacturing quality control and handling. Then there's developing process itself. Every strip of film run thru a developer is going to be minutely different than the preceding strip.

 

So the first part of my critique of your comparison is the potential for +/- errors in the comparison samples.

 

My next criticism of your comparison was touched on by another poster. Limited scope and simplistic labeling. Your comparison specified one digital camera and one type of film. You simply can not make a sound claim that, "negative film has a wider dynamic range than digital SLRs." If every digital SLR had been tested and compared you might be closer to making that claim, but not all the way.

 

The next problem with your comparison is in making the assumption that all things are equal. They aren't. I'll explain by way of example. I own a Nikon D200 and a Nikon D300. You might think that, all things being equal, that ISO100 on the newer and greatly improved D300 would be better than ISO100 on the D200. You'd be wrong. In fact, or at least in observance, the D200 out performs the D300 at ISO100 and ISO200. However at ISO400 and above its no contest the D300 wins hands down. The same problem with not all things being equal is in effect in your comparison. You compared film ISO versus digital ISO. The way a digital camera defines ISO is just too different than the way film handles ISO (ISO being originally introduced as a measuring tape for the sensitivity of light sensitive chemistry has been shoehorned into use for light sensitive physics). As a stark example of the difference I'm referring to simply compare an images shot on 3200 speed film to a image shot on a D3 at ISO3200. No contest, the D3 will produce far superior images. The same contest at ISO100 will may produce different results.

 

My last (thankfully eh?) criticism of you comparison is you have a built in bias as evidence by your previous posts and website. That bias may have colored your research and skewed your conclusions. Its a lot like asking someone who sells Ford's for a living to make a scientific comparison between Chevy's and Ford's.

 

In summary, your comparison suffers from too many faults.

 

I have no doubt you tried to make a sound argument for film. Its just that it is a flawed argument, such as I've seen hundreds of times on Pnet (hence my crankiness). But I do encourage you to keep trying. For if nothing else we've learned that at ISO100, Ektar100 beats a D40 in dynamic range.

[mauro_franic]

All good J A.

 

"So the first part of my critique of your comparison is the potential for +/- errors in the comparison samples"

HERE IT IS NOT ABOUT MAKING THE IMAGES COMPARABLE BUT TO UNDERSTAND THE POINT WHERE INFORMATION IS NO LONGER RECORDED. WHEN YOU RECORD PURE, THERE IS NOTHING TO RECOVER IN RAW PROCESSING.

 

"You simply can not make a sound claim that, "negative film has a wider dynamic range than digital SLRs." If every digital SLR had been tested and compared you might be closer to making that claim, but not all the way."

 

TRUE.

 

"My last (thankfully eh?) criticism of you comparison is you have a built in bias as evidence by your previous posts and website. That bias may have colored your research and skewed your conclusions. Its a lot like asking someone who sells Ford's for a living to make a scientific comparison between Chevy's and Ford's."

 

GOOD POINT. THOUGH I TRY FOR MY TESTS TO BE AS OBJECTIVE AS I CAN (SO I CAN PICK THE BEST MEDIUM LATER AND BECOME EDUCATEDLY BIAS FOR IT).

 

DIGITAL IS SUPERIOR THAN FILM IN MANY ASPECTS. IN RESOLUTION AND DYNAMIC RANGE LOW SPEED FILM STILL HAS AN EDGE. DEPENDING WHAT IS IMPORTANT TO YOU, YOU MAY SHOOT ONE OR THE OTHER, OR BOTH (LIKE ME).

 

"For if nothing else we've learned that at ISO100, Ektar100 beats a D40 in dynamic range."

 

CONCLUSION WELL PUT.

[j_a]

Mauro,

I should explain that somehow I logged in under a very old account and I'm the a-hole Eric that bit your head off for no particularly good reason. Again, my apologies. Sometimes my bad day shows up in my posts.

[mauro_franic]

No problem. I like your J A side better.

[dallalb]

Hi Mauro, I'm afraid that so many people took your test as the ultimate match between digital VS film!

I understood the reason of your test: I shoot film and scan it with a CoolScan 5000 ED and I'm amazed by the tone richness I achieve from some negative or B&W film. But I stop here. Film and digital are two different technologies to record the light of a scene with their strong and weak points... Then all is filtered by our eyes and... our brain... and the result is always different from reality. And it differs from person to person. The comparison may be useful but I prefer to understand how taking advantage of these technologies to express my vision, rather to worry about something that is always a limited medium.

Kind regards, Alberto.

[mauro_franic]

Alberto, you are right, the goal is not to beat one over the other but to share information. Even if you shoot digital exclusively, understanding its characteristics can help you produce better results, make educated compromises and ultimately be more effective in realizing your vision.

 

Digital has many advantages of its own and in a short time has dominated the mainstream. It's future couldn't be brighter (fun intended).

[rishij]

Lowering contrast in both DPP and/or LR, along with highlight recovery, does bring back some considerable

highlight detail, but always with the potential for hue shifts & saturation losses:

<p>

Here's the original LR conversion:

<p>

<img src="http://staff.washington.edu/rjsanyal/Photography/OriginalLRConversion.jpg" width=800>

<br>

<a href="http://staff.washington.edu/rjsanyal/Photography/OriginalLRConversion.jpg">Link to Full-Size Image</a>

<p>

And here's what I did to try to recover some highlight detail in Lightroom:

<p>

<img src="http://staff.washington.edu/rjsanyal/Photography/HighlightRecovered.jpg" width=800>

<br>

<a href="http://staff.washington.edu/rjsanyal/Photography/HighlightRecovered.jpg">Link to Full-Size Image</a>

<p>

Still, nowhere near as good as the Ektar100...

<br>

Rishi

[juans eye]

"You shot Jpegs didn't you? -- proving nothing more than your ignorance."

 

DSLR PMS :) Stop hating. Self discovery is a great journey. And the fact the OP is sharing is a privilege. The OP will probably be taking better pictures as he finds insights in his tests. And if all this does not interest you, just hit the back button and try not to bite off heads :)

 

Thanks OP!

[mauro_franic]

Thank you Rishi, that is a very good job.

 

Are the white areas in the second image void of information in the RAW file or is there more detail to be recovered?

[mauro_franic]

Thanks Juan.

[rishij]

What I don't understand, though, Mauro is this (and as a disclaimer, I'm not saying the following in a harsh tone):

<p>

For all your talk & examples of how 35mm clearly outresolves digital (a la

http://www.photo.net/film-and-processing-forum/00RV7N), how come in this particular test, the 40D image, upsampled

(using bicubic algorithm in Photoshop) to the resolution of the Ektar 100 scan (which I take it was 4000 dpi on a

LS-9000?), clearly looks sharper?

<p>

<b>Ektar 100</b>:

<br>

<img src="http://staff.washington.edu/rjsanyal/Photography/FilmVsDigital/Ektar100_ActionFigures.jpg" width=800>

<br>

<a href="http://staff.washington.edu/rjsanyal/Photography/FilmVsDigital/Ektar100_ActionFigures.jpg">Link to

Full-Size Image</a>

<p>

<b>Canon 40D</b>:

<br>

<img src="http://staff.washington.edu/rjsanyal/Photography/FilmVsDigital/40D_ActionFigures.jpg" width=800>

<br>

<a href="http://staff.washington.edu/rjsanyal/Photography/FilmVsDigital/40D_ActionFigures.jpg">Link to Full-Size

Image</a>

<p>

Please view images at 100% to make a fair comparison.

<p>

I understand that local contrast has an effect on perception of sharpness; negative images inherently have less

local contrast, though you do try to tease out local contrast when expanding the tonal range of negative film

from the 'flat' scan (generally I do this myself, as I don't trust NikonScan or Vuescan to make my vision).

<p>

But, I mean, given your last post that basically said a 26MP theoretical digital SLR couldn't even match 35mm

Provia, how come the 10MP real digital SLR here, set up so that the same area is covered as the full frame film

shot, seems to resolve <i>at least</i> what the film resolved?

<p>

Please explain.

<p>

Thanks,<br>Rishi

[rishij]

Mauro,

 

Those white areas seem to be just completely void of any information, according to Lightroom. Of course, I haven't read the raw data off the RAW file myself... but I trust LR :)

 

Really looking forward to your response to my last post!

 

Cheers,

Rishi

[mauro_franic]

No need to apologize Rishi. It is good you question these things. That is why I open the discussions.

 

First since I was not intending to test for detail, the figurines where not perfectly aligned on a plane parallel to the film plane. This, combined from the narrower depth of field, definitelly would compromise detail are fine contrast.

 

Nonetheless, even in these conditions, with some quick sharpening and contrast this is what the Ektar crop you posted looks like.

 

http://shutterclick.smugmug.com/gallery/6616619_YJEwK#425581323_3ygce-O-LB

[mauro_franic]

I don't even have LR but I trust you. It appear the 40D starts clipping highlights at least 3-4 stops before Ektar.