Film vs Digital - Dynamic Range

Anyone who has uses a DSLR and shoots film knows how much more lattitude film has. You shoot it, you got it. With a DSLR you have to resort to all sorts of work arounds such as underexposing to save the highlights, then lightening the shadows in photoshop. Or, shooting multpile images at differing exposures in PS and combining the images later in photoshop, using HDR. Either way is a pain in the *ss for me. I wish they would start automating some of this in the DSLR's processors, like they do in the Point and Shoots now. Hell, while I'm on this rant, why not add face detection for autofocus and exposure, really good AF tracking, etc. like in my FX150??? After all, a DSLR is MUCH more expensive, it should have these features.

I agree; nice job Mauro.

 

But I also agree with Pedro, that these tests should be done with a full-frame camera. The pixels on a 5D are 8.2 microns in size, whereas Canon's 20MP (including the 5D II) have pixels 6.4 microns in size. I'd be interested to see some tests comparing DR between the 5D & 5D II... but, regardless, I'm sure a 5D would fare better in DR than a 40D.

 

Also, Mauro -- did you try, for the 40D image, to set 'contrast' to -4 in DPP? This typically brings out shadow detail.

 

Of course negative film has an advantage in highlights as exposure of film leads to clusters of reduced metallic (black) silver which makes penetration of light more and more difficult through the layers of film as exposure increases. It's a beautiful system, really, chemically. Too bad no one's thought of how to do it on silicon chips... yet. But I do think that digital is quite capable of shadow detail, and I'm wondering if lowering the contrast or using 'fill light' will bring that out in your digital image better than it would in the film image (using 'fill light' on film scans typically exaggerates grain very quickly).

 

Of course, digital underexposure is really bad, given the # of bits available for shadow detail. Also, you don't want to end up with banding like that which is typical of certain Canon CMOS sensors (http://www.photo.net/canon-eos-digital-camera-forum/00RBTe). But I do think that the shadow performance could be made better by different post-processing in your 40D image above.

 

Cheers,

Rishi

"Anyone who has uses a DSLR and shoots film knows how much more lattitude film has.."

 

You mean like Kodachrome, Velvia, or Provia....? Those films have about 6.5 stops of dynamic range. A professional digital camera will have at least 8, and some of the newer ones 10-12. If you mean negative film - then, yes, negative film it has about 12 stops of dynamic range.

 

You shoot a digital camera like transparency film - I don't see the problem with that ...you have to know how to use the equipment for its inherent performance ability whether the workflow is film or digital.

I don't see how someone can say that Film camera gear is more expensive than Digital camera gear. Don't factor in the

lenses, because they are the same. Brand new Nikon F6 - $1600, Used, but perfect condition Nikon F100 - $350, Used but

perfect Nikon F80 - $90, Brand new Nikon D700, $2500 - 3000, D3 $4500. Cost of buying new digital camera because

current one is now obsolete or sensor is worn out and has too many hot pixels, $2500 - $5000. Film purchasing and

development costs during that same timeframe, considerably less. I love film, and I love digital. I use both for different

reasons. I would never venture to say that digital is less expensive than film, because pro quality top-of-the line film

camera gear (including medium and large format) can be had for much less cost than mid level digital gear (such as D300

or EOS 50D)

Stuart:

"To be honest I would not want to use either film or digital with this amount of under exposure. Just much easier to expose correctly and get good image from either medium than to jump through hoops to rescue bad digital or film images"

 

You can decide how to expose the picture but you can't control how many stops the scene has.

Pedro, I didn't have a full frame digital handy last night, it would be interesting if someone else can run a test and add to the comparison.

Matt,

"As usual, the limitations are more with the photographer, not the gear or materials. There are plenty of fancy tests that come to the opposite conclusion as the OP here"

 

You are looking at the ACTUAL pictures, if there is a conclusion out there that states Ektar100 shouldn't have that much latitude, or that the 40D should have more.....then that conclusion is wrong.

Howard:

 

"Mauro: I shot all of the Ektars since the eighties, and they didn't have that much dynamic range, really."

 

Then the new Ektar is much improved.

Dave:

 

"Mauro - Did you use multisampling on the 9000 to reduce noise. When I used to scan Astia with a 9000, I used 16X multisampling and it did wonders to reduce noise further in the shadows. In my opinion, it was like gaining an extra stop in noise."

 

No I didn't, I will try tonight and post for you.

Steve,

 

"The middle grey is not reproduced same between the digital and film images. This could be scanning or exposure - either way there is no control point in the "data." For photography and what you're attempting to do, that would be a 10-step grey scale with the middle grey reproduced to the same level for each system being tested.

 

The means you cannot draw conclusions from what you've done as you have no control point that can be compared as equal in each test."

 

Both cameras were shot in the same setup, shutter speed, fstop, tripod, and lighting, one burnt the highlights and the other one didn't. No white/gray balance will change that but feel free to experiment and post results.

Apart from slide film, the negative or digital image is only a step towards the final stage which is a print, either traditional or inkjet or an image on a screen. Should we not be more concerned about the dynamic range of these than the film or CCD/CMOS device?

Roger;

 

"What I don't get is why you'd use analog gain to dig out shadows in negative film. Are you *reducing* hardware exposure to preserve detail in the clear parts of film? "

 

This is just the terminology of the Nikon Scan.

Rishi,

 

"Also, Mauro -- did you try, for the 40D image, to set 'contrast' to -4 in DPP? This typically brings out shadow detail. "

 

Good point, I will try this.

Steve,

 

"Apart from slide film, the negative or digital image is only a step towards the final stage which is a print, either traditional or inkjet or an image on a screen. Should we not be more concerned about the dynamic range of these than the film or CCD/CMOS device?"

 

When detail is gone because you burnt the highlights, IT IS GONE - you can't print it. If it is there, it is always possible to print it with adjustments to match your printer and goals.

Thanks Mauro,

 

I look forward to seeing the multisampling scan to see if it assists as I think it will in the shadows. Ektar seems so good that I can see a number of people putting their heavy, expensive DSLRs in the cabinet only to be used for snap shots.

I'm seeing some really basic confusion in this thread about scanning and film.

 

Howard- how do you know Ektar in the '80s had poor dynamic range? From looking at the negative? Scanning it? Printing it yourself? You're not judging based on commercial lab prints, are you?

 

Dave and Mauro, multisampling is irrelevant for color negative film- are you seeing scanner noise in the film highlights? Remember, the shadows of negative film are clear and CCD noise is not in highlights but shadows.

 

Ditto for adjusting film analog gain. Set it right so as not to blow out the shadows and lock exposure for the roll. If you want more recommendations on maximizing color neg. film scan quality look up Erik Krause's Nikon-based "super advanced workflow" where you use hardware analog gain, rather than software clipping, to subtract the film base. That can help you with color accuracy but probably doesn't matter for this thread, apart from the fact that you need to set exposure properly for the type of film.

 

I strongly agree with Steve that you haven't calibrated your scan or digital file in any meaningful way. Just leaving software settings on the defaults make no sense at all.

 

What you want at the minimum is to do something like use middle gray on your QP card to set middle gray on both images to the same point. Then you can at least more clearly see the difference in shadow vs highlight rendition. This is basically what dpreview does in their dynamic range tests using a blacklit stepwedge.

 

Now, how you map the negative film to your final image is an open question, I think. Negative film compresses highlights, so is the goal to preserve overall tonal relationships, accurately match a backlit step wedge, show how much highlight detail it can preserve before clipping, etc? How you uncompress them is really up to you. What you *don't* want to do is scan with the defaults on and let the scanner software do this for you, and heaven's forbid let it *clip* highlight data in an attempt to increase scene contrast and make it look more attractive.

 

That said- I don't disagree with the basic conclusion that any negative film has a gracefull roll-off of data in the highlights and digital doesn't. That's not news.

Also, has no one read this statement from Canon's own 'Full Frame CMOS' white paper:

 

"Canon’s full-frame sensors have reached another image quality milestone as well. Their gradations and dynamic range are now the equal of the best positive films, and their resolution and lack of grain are superior. No smaller sensor has achieved this level of performance."

 

That was as of 2006. I don't know if their 'highlight tone priority' or whatever they call it has extended this performance. But I seriously doubt Canon was *understating* their cameras' dynamic range.

 

In real-life shooting, in my experience, shadows in digital captures are easier to work with than those from Velvia 50 scanned on an Imacon 848 even. But I can bracket +/- 2 stops with negative film and get the same image from all 3 with enough post-processing. It's kinda ridiculous. But on the other hand, it's the same logarithmic response of negative film that typically makes the images not-so-appealing because of lack of contrast; Velvia is so pleasing because of the enhanced local contrast, which is how our eye-brain system sees things (even though overall we have a logarithmic response to light due to multi-sampling the visual scene that we see).

 

Rishi

Mauro,

Again, thank you very much for very entertaining and selfexplanatory test.

 

Crop vs FF should not make any difference, for the dinamic range of 5D and Canons with smaller sensors is about the same (according to DPPreview)

Error above- should be "backlit stepwedge" and a qualification- multisampling for color neg. film is generally useless but if you do see scanner noise in the lightest areas, give it a try.

 

Here's how DPreview does Dynamic range testing:

http://www.dpreview.com/reviews/sonydslra900/page23.asp

 

Here's how Dxomark.com tests (Rishi- this also addresses your questions of a 40D vs 5D, etc)

http://www.dxomark.com/index.php/eng/DxOMark-Sensor/DxOMark-metrics/Landscape-photography-maximum-Dynamic-Range

 

Both of these sites test digital cameras, but the concepts carry over to film. I'm not sure what the point is of testing film vs digital for dynamic range, but if you think it's useful...

Thanks for the comments Roger.

 

"Dave and Mauro, multisampling is irrelevant for color negative film- are you seeing scanner noise in the film highlights? Remember, the shadows of negative film are clear and CCD noise is not in highlights but shadows."

 

Dave and I are referring to use it for the shadows.

 

I will check Erik Krause's article.

Thomas Wilson , Nov 24, 2008; 10:22 p.m wrote: <p>

<i>

Enough already!</i>

 

 

<p>

+1

so, when do the digital cameras come out with extended dynamic range...what would it take...

One thing regarding testing of DR of digital cameras I can not get. All graphs demonstrate brightness range from 0 to 256, which is 8 stops, therefore 8 stops should be the maximal DR for any digital camera. How can one say that the DR of some cameras is 9.1 or 11 stops?

<i>Pedro Esteves , Nov 25, 2008; 06:22 a.m.<p>

Because the sensor on this full frames is bigger, the DR is wider.

<p>

 

James Nakia Johnson , Nov 25, 2008; 08:33 a.m.<p>

 

Using Full Frame to do the test will be a hard one being that higher MP can lead to highlight clipping</i><p>

 

Where are some of you people getting your information?!?

<i>One thing regarding testing of DR of digital cameras I can not get. All graphs demonstrate brightness range from 0 to 256, which is 8 stops, therefore 8 stops should be the maximal DR for any digital camera. How can one say that the DR of some cameras is 9.1 or 11 stops?</i><p>

 

Because the analogue to digital converter is using 14 bits, or 12 bits on older cameras. These 14 bit dslrs could theoretically be able to manage up to 14 stops, but the reality is that noise kills the lower few stops.