Film vs Digital - Dynamic Range

[douglas lee]

James Johnson -- : the canon 1D Mark II is a 8mp Full Frame so the sensors are a lot larger then the newer Full Frame

cameras."

 

The 1D Mark II is not full frame. Just a clarification.

[s_j_goffredi]

Mauro,

thank you for an interesting article. Ignore the insults, articles like yours are much of the reason I like photonet.

[manuel barrera houston,]

While not exactly brand new to photo.net, what has not been brought about before. I have using digital for years and only now have started playing with film, first a T50 with a 50mm FD mount, liked the results and bought a used Canon EOS 1V to use with my lens (after reading the article and the comments). So Maruo ignore the insults and thanks again.

[charles_hightower]

What about if you bracket your shots and merge to a HDR image? Oh, but I can scan my bracketed film exposures and do the same thing in Photoshop. Yeah, yeah but I can stitch enough 6.3 mega pixel images together to rival 4x5. Oh, yeah I can also whip out my 4x5 camera, shoot multiple angles, scan and stitch them to rival Jesus. But what about Phase One or Better Light backs? Think of the turn around time as a pro. Yeah but I ENJOY developing 4x5 ortho under safelight. It's well, fun. Oh, nooooooooo! What will I do! From all of this B-I-T-C-you-know-whating I'm convinced I have to choose! I guess I will smash my Crown Graphics with a sledge then go tuck my DSLR in at night. Please. You are all limiting yourselves. Shoot what you have to for a job. Shoot what you enjoy for fun and end this already.

[mauro_franic]

VERY SIMPLE:

 

There is an easy way for people with better DSLRs to find out whether theirs could have provided better results.

 

Just set a subject with lighting at measuring f64 with the sphere of the meter pointed at the camera, shoot it at f8 and see. It takes two seconds, much less to write what it could be.

[mauro_franic]

Also can shoot (always at f8) with lighting measuring f8 and f1 to get comparable results to the center and boundaries of the test posted.

[mauro_franic]

DON'T FORGET to shoot the same shots with Ektar to compare.

[Dave Luttmann]

Mauro,

 

Thanks for the updated multisampled scan. Does indeed look better. Ignore the insults from some of the posting trolls. The most laughable of which were the comments of one on how Ellis had "piad his dues." Maybe.....but he was wrong.....and didn't have the courtesy of coming back and admitting it.

 

All in all, the thread has been pretty civil. Like I said, if you posted results showing film is better at DPReview, you'd see the knives come out pretty quick......normally from those who have never tested ;-)

[mauro_franic]

Thanks Dave.

 

Here is a picture "Shot by me" where some of the highlights were blown. It was shot with TMX100. The point is that there are some scenes with more dynamic range than even negative film can capture. The number of stops in a scene are beyond the photographer's control.

 

http://shutterclick.smugmug.com/gallery/3639504_X4XUj#382039618_mcLcC-X3-LB

[stephen_pitts]

Patrick,

 

Keep on saying it. Its much appreciated because while some of the conclusions seem pretty accurate, the Kodak 200 gold comparison is silly. As a whole, I have always thought I liked the way digital performed in low light (its not "murky" like film) but yet Mauro has done a fantastic job at challenging that assumption. Kudos to him and you.

 

Cheers,

 

Steve

[Dave Luttmann]

I ran some Fuji Acros 100 when I was photographing at Spider Rock in Arizona. I had just run through a roll of Tech Pan exposed at iso 6. I then loaded the Acros and forgot to change the iso....effectively over-exposing the first couple of shots by 4+ stops. No blown highlights at all. Try that with a DSLR and see what you get.

 

Regards,

[Ed_Ingold]

The objective way to measure dynamic range is to plot the output of the medium vs the input (light intensity).

DPReview routinely measures the dynamic range of the cameras under test using a calibrated step wedge with 41

stages 1/3rd stop apart and plotting the results. A similar test is reported in most technical data sheets for film,

plotting exposure (absissa) vs density (ordinate), as the "characteristic curve". The absolute level of exposure is not

important, just the range or ratio of the steps.

 

There are no objective claims of a 12 stop range for a small-format digital camera. The results for the Canon 40d are

reported in (http://www.dpreview.com/reviews/canoneos40d/page20.asp), citing a dynamic range of 9.6 stops. The

same test for a Nikon D3 concludes a dynamic range of 8.6 stops. DPReview states their assumptions and criteria

for adjuging the dynamic range (starting from the 2% level or noise floor, whichever is greater). In my view, this is over-

generous. It is more realistic (IMO) to measure the range from the intersection of the slope at the inflection point with

the noise floor, which gives a dynamic range of about 7.5 (comparable to Reala).

 

I have not seen any objective tests performed on medium format digital sensors, although all of the manufacturers

claim a 12 stop range. My own experience comparing a D2x vs.an Hasselblad CFV vs. Reala is that the CFV back

has significantly better range than either. I have no way at present to put numbers on that observation.

 

The fallacy of Mauro's test is that the figurine has a wide range of reflectivity. There is no documentation of that

range, nor any certification of the linearity of the Sekonic 358 meter over such a wide range of exposures.

Interpretation of this demonstration is skewed because there is tendency to rate the overall "exposure" of the figurine

rather than the true range of reflectivities represented. One can examine the histogram of each figurine, but without

knowing what the values should be, no conclusion can be made.

[Ed_Ingold]

I should expand a bit. The figurine has a wide range of reflectivity. Furthermore there is a wide (and unknown) range of light intensity striking it (at least 1/3rd is in shadow). Therefore you can't know what the reflected intensity should be.

[mauro_franic]

Edward brings up some valid points.

 

"There are no objective claims of a 12 stop range for a small-format digital camera. The results for the Canon 40d are reported in (http://www.dpreview.com/reviews/canoneos40d/page20.asp), citing a dynamic range of 9.6 stops"

- THIS IS CONSISTENT WITH MY RESULTS.

 

"The fallacy of Mauro's test is that the figurine has a wide range of reflectivity"

- AT WORST 100% REFLECTIVITY (LIKE A MIRROR) SHOULD GIVE YOU PURE WHITE AT THE SENSORS LIMIT. I SEE PURE WHITE SPOTS IN MULTIPLE OF THE STOPS. THE TEST IS VALID.

 

"linearity of the Sekonic 358 meter"

- VALID POINT. YET EKTAR AND THE D40 SHOT THE SAME SCENE (LINEAR OR NOT) AND EKTAR DID NOT HAVE BLOWN HIGHLIGHTS IN A SINGLE FRAME.

 

"The objective way to measure dynamic range is to plot the output of the medium vs the input (light intensity)"

- WE WILL HAVE TO EXPLAIN THAT TO THE FIGURINES.

[mauro_franic]

Edward, without being sarcastic, your points are valid pertaining to the ABSOLUTE precision of amount of light reflected. They do not affect the RELATIVE observation that Ektar could cope with it and the 40D couldn't.

[nsfbr]

Can we discuss this from a technical point of view? There are fundamental differences in the mechanisms of film and digital technologies that exist which alter the characteristics in favor of film at present. Specifically, the highly linear nature of the initial step in the flow - the CCD or CMOS element converts photons to signal that is then digitized. At some point, when the gold rush for number of pixels is behind us, and perhaps once noise levels at insane ISOs is fantastic, this will be addressed. The techniques to do so are not difficult - attenuation proportional to signal level is well known, but doing so on a per pixel basis prior to initial digital conversion will be a challenge. I expect that the solution will be arrived at in an unexpected way - linearity is not really a requirement, repeatability is, so there is no fundamental law that says the response to light needs to look anything like it does today.

 

A couple of ideas of theoretical approaches to this:

 

1. Per pixel active ND filtering. This approach would involve an electrically active layer that was in the light path directly above the sensor. A real time feedback system would detect a threshold value in the pixel well below saturation and trigger a darkening of the layer above that pixel for the remainder of the exposure. In theory, the threshold could be set very low and the darkening proportional to the amount above the threshold. This would provide a highly non-linear response which could be converted in whatever form was programmed into the camera (the response curve).

 

2. Rather than inserting a layer above the sensor, the sensor could be actively drained during the exposure. Again, this could start at an arbitrary threshold and in theory could be done proportionally to the amount above the threshold or inversely proportional to the remaining headroom. This is probably a bigger electronic circuit challenge, but a smaller manufacturing challenge.

 

I would note that similar (similar as in analogous) things take place and explain what happens in film. The rolloff in response as I understand it is an artifact of non uniform particle size in the emulsion. An element may have a different depth in the film, a projection in the light path and different absolute sensitivity. Those things create the non linear response that we seek to replicate in digital photography. From my perspective, aesthetically, digital is different than film. Not better or worse, but different, and as a result requires different technique. For those so inclined, it is not technically impossible for the sensor manufacturers to create sensors that behave identically to film. In fact, the fact that there are differences in films tell me that manufacturers could hawk cameras that behave like one film OR another and thus expand the market again as people want a Velvia camera, Ektar, etc. This is Moore's law put to good use in my view.

[Ed_Ingold]

In this thread, there also seems to be a confusion between exposure "latitude" and dynamic range. The OP and

most of the responders appear to refer to "latitude".

 

Dynamic range is the range of exposure over which the film or medium can produce a useful range of output (e.g.,

density). Latitude is a convenient "fiction" expressing the deviations from the "correct" exposure which can produce a

useable image or print. Indeed, the "correct" exposure is usually a subjective decision (q.v., the Zone System).

 

"Latitude" is a composite of the dynamic range and the range of light intensity reflected by the subject. Furthermore,

the range of the subject is subjective to the extent of what is important in the subject. It's generally accepted that

some shadows can be featureless black and some highlights (e.g., specular reflections of the sun) can be

featureless white. The range of the subject expands or contracts depending on where you want to see some level of

detail.

[Ed_Ingold]

Mauro,

 

I was careful not to indicate an "absolute" exposure, rather the range or ratio of high to low and (perhaps) steps in

between.

 

The tendency of digital capture to "blow" highlights is well documented, and is comparable to that of reversal film -

about 2 stops middle grey. Negative film is much more forgiving toward highlights than either. In RAW images, it is

rare that all three channels are overexposed. If any one channel is in range, a considerable amount of overexposure

can be recovered through interpolation. This amounts to an as much as additional two stops for a typical scene.

 

I refer to my followup post regarding the confusion between range and latitude.

[mauro_franic]

Agree it seems to be a known fact (although some photographers are not convinced). It is still good to run up-to-date comparisons as sensors evolve and new films appear, as in the future, digital sensors may match or surpass the ability of negative film to retain detail in the highlights.

[mt4x4]

Eric A,

 

I don't see anything wrong with Mauro wanting to do a test of his own, even if it has been done 100 times before. This is all part of the learning process.

 

As far as the subscriber vs non-subscriber thing goes.... if photo.net didn't want non-subscribers to be able to post, then non-subscribers wouldn't have the option. Honestly, I see Mauro as a potential-subscriber, rather than a non-subscriber. He is testing this community out before he decides to pay for a subscription. And unfortunately, responses such as yours, Eric, can deter people from subscribing. Thank god the people who are interested in participating in meaningful, helpful discussion outweigh the ones who want to bite someone's head off for doing something on their own.

 

I would also like to note that I am impressed with Muaro's ability to keep his cool and not return insults after receiving personal attacks.

[mt4x4]

Tim Holte,

 

From what I have read most Professionals use Digital over film because that is what their clients want.

 

I have a feeling that many amateurs are using digital because of the cost savings over film.

 

Personally, I use digital for both cost savings and convenience. Film+Processing can get expensive. I also like being able to run home and pop my flash card into the PC and immediately upload my images.

 

I've honestly thought about picking up a film camera and taking the Intro to Photo class at Montana State University because they teach you how to develop your film in the dark room. Why? Because I think it is something I would enjoy learning.

[mt4x4]

One more thing...

<br><br>

About the Clarkvision test....

<br><br>

The <a href="http://www.adorama.com/US%20%20%20%20314866.html?searchinfo=1d%20mark%20II&item_no=25">1D Mark

II</a> is NOT a full frame sensor camera. The 1D sensor measures 28.7 x 19.1mm.

<br><br>

Its is the 1Ds that has the full frame sensor. I know a couple of Pro photogs who are still using the 1Ds Mark I

because of its full frame sensor and lower megapixels. Plus the fact that it will sync with a flash to 1/500th.

Check out Al Berger's website at <a href="http://www.prorodeopix.com/">http://www.prorodeopix.com/</a>. He uses a

1Ds Mark I with a 300 f/2.8, and I'm pretty sure all of his photos are available light. I had asked him if was

going to upgrade to a Mark III when it came out, and he replied "Why would I downgrade my camera?"

<br><br>

Just thought I would toss that in, because I thought I had saw someone say the 1D was a full frame camera.

[eric_guel]

"I would also like to note that I am impressed with Muaro's ability to keep his cool and not return insults

after receiving personal attacks."

 

That has been very impressive, indeed. And it shows he's got more character than the know-it-alls who

hurl unfounded insults and then disappear into the night.

[sexgun]

Hello all, I shoot digital and still develop my own b&w film. Thank you for the information in this thread. I

don't understand why some individuals would sound as if they are personally offended when others discuss a topic

which does not interest them. I bet they do not try to act like bullies when meeting someone face to face.

[rjpillers]

Mauro,

Thanks for all the effort. Information like this is always useful. I primarily use color film these days, with a little P&S digital ready at all times to catch the kids doing the kids' stuff.

 

I look forward to the time I can ditch the film equipment. I'm hoping that digital full-frame sensors will achieve the dynamic range of film (or better) at a reasonable cost (under $1000) within the next three years. Possible? What do you all think?

Jamie