When will digital = or better film?

[russell_f]

Recently I've read some contradictory info on this. On the one hand, Phil G on

this website says that the Canon 300D has a digital sensor that's the same size

as 35mm film and produces images that rival a medium-format Mamiya. On the

other, in a random magazine I read on an airplane, the author claimed that while

the new Sony Alpha has a 10-megapixel sensor, it will take about 25 megapixels

before digital matches the best of good old retro film. Was he joking?

 

Image quality and megapixels, as is now generally agreed, I believe, aren't the

same. Can you really enlarge slow, high quality film to the size a 25 megapixel

would produce? And are we already at the level of film or better for at least

one digital model, as photo.net says?

 

Thanks for your input and helping to clear up my confusion!

[russell_f]

Note: I meant the Canon EOS-1Ds Mark II, not the 300D, and Hasselblad, not Mamiya.

 

Shoulda checked the article first!

 

http://www.photo.net/equipment/building-a-digital-slr-system/

[ace_fury]

What difference does it make?

[troyammons]

Most slide film is worth about 5-6 mp per sq inch of film in most cases so it can beat it for color photography depending on what you are comparing.

 

Velvia may be a tad more depending. 400 film a bit less.

Microfilm is a lot more. I shoot bluefire film and with a 5400 dpi scan it returns a 2 pixel edge and is clean. Thats 39mp.

 

The current dslr cameras aready match most 35mm film.

 

I had a slr/c and it matched or beat 645 film shots from a Pentax 645 on a regular basis.

 

One place where digital falters is DR except for the kodak slr cameras, but clean high iso is a plus for digital.

 

Also I prefer B+W film compared to B+W digital. To me there is nothing more boring than a B+W flat gray scale digital enlargement.

 

Also comparible at an ultra expensive price is the Phase One P45 back to 4x5 film.

[emwalker]

Some good, fine grain pro b/w film will give you >20MP of usable resolution. Crappy comsumer color 400 speed film will give you <10MP. Some digital cameras are <6MP. Hasselblad makes a 39MP digital back.

 

The biggest difference is in grain, which is absent in digital. Good digital sensors give very low noise (somewhat equivalent to grain) at low ISO values.

 

My 20D produces more usable information than Fuji 400 consumer film, in my experience, but cannot come close to IlfordHP5. So, as always, it depends on how you look at it, and which digital camera you compare to which film.

 

And no, medium format film (the fine stuff) will still outcapture the 35mm frame digital.

[richard_cochran]

Which film are you talking about? 8x10 Velvia? Or Kodak Max in APS format? Are you more concerned with ultimate resolution in a detailed contrasty area, or grainless smooth rendition of blue skies? What technique is being used?

<p>

For many purposes, the best 35mm DSLRs are already better than typical 35mm film. But the best film, used with good technique, still can have some advantages over even high end DSLRs, especially when the output medium is something other than digital. No projected 25 megapixel digital matches a projected 35mm or medium format slide that was taken with optimal technique. But then, nobody views projected slides over the web, so you can't point your web browser at a valid comparison of projected slides versus projected digital.

<p>

Digital cameras are unlikely to ever beat large format, at least not at anything approaching reasonable cost competitiveness and convenience. There's little demand for such high resolution, meaning low market size, and the low volume means they have a hard time recovering the high development costs.

<p>

But beating run-of-the-mill 35mm ISO 400 film? DSLRs have been there for quite a long time.

[keith_van_hulle1]

Is there a pi$$ing contest somewhere that makes this necessary? Have you ever shot with a DSLR? Maybe done some KR25 and internegs? And then done test prints under controlled circumstances for both types? Side by side prints is the only way you're going to answer this. And that will still be subjective based on the viewer, the subject, the lighting, the display, etc.

 

Why does one have to beat the other? Both are worthwhile mediums. Think about before the world of digital - where do you think big enlargements came from before. I don't see people running around trying to redo the same shots BIGGER just because digital is available. As previous posts have stated film MIGHT have an edge in raw MPs. If you think that's all there is to this and will judge the final answer based on that, too bad.

[neal_shields]

You will find a lot more opinions on this than test data. All the quantifiable test data I have seen puts 200 asa 35mm film at about 16 meg pixels.

 

The best documented test data I have seen is from the FBI.

 

http://www.fbi.gov/hq/lab/fsc/backissu/july2001/swgit.htm

 

I have taken microphotographs of both sensors and film grain and as the grain or die clouds are several factors smaller than even the smallest pixels, I suspect that it is physically impossiable for digital to ever equal film for a given sized sensor.

[Ed_Ingold]

Neal,

 

Your comparision of pixel dimensions to dye clouds is invalid.

 

If you read the MTF curves for color film (http://www.normankoren.com), you will notice that the contrast falls off at higher frequencies, with a corner frequency of about 20 lp/mm, whereas a DSLR sensor has a corner frequency of about 85% of the Nyquist limit (or about 80 lp/mm for a D2x). Resolution of a process is estimated by extrapolating the MTF curve to zero contrast. This is higher for film, but only when applied to very high contrast targets (e.g., resolution charts), not practical situations.

 

This falloff is due to scattering of light within the emulsion, and proximity effects of the chemistry, which limit resolution. Digital sensors have much higher acuity than film because there is little or no scattering of this sort - less than 1 pixel. The lens has no significant effect if its resolution is 3 or 4 times better than the medium under test - which is not hard to accomplish.

[russell_f]

Thanks to everyone for your responses, which have been very educational.

 

To explain a bit- it wasn't my intention to set up a simple comparison, but to understand the two technologies side by side. Compared to you all I'm a fairly casual snapshooter, just recently upgrading from a Yashica T4 point and shoot to a Fuji F30 digital point and shoot, and wanted to understand why my shots look the way they do on each. I don't have first hand experience of slide film, or medium format, or large format, or slrs, or enlargements bigger than 8x10.

 

That, and I'd just read these comparisons made by others and wanted to resolve them.

 

I had no idea it was so hard to say how many "megapixels" your top of the line film emulsion has.

 

Anyway, I better understand the terrain now, but I'll have to continue to learn. Thanks.

[robert lee]

"...just recently upgrading from a Yashica T4"

 

Hope you kept that little gem. The T4 had one of the finest lenses on a point & shoot. Loved that little "waist level" finder as well.

[russell_f]

Definitely keeping the T4. There's something about its images that digital doesn't replicate. To be honest, though, despite that, I'm not sure when I'd want to use it instead of the Fuji.

 

No waist-level finder, sadly. The model I have is the original black one- I believe the T4 Super has the second viewfinder.

[stephen_steele]

Hi,

 

I know Ken Rockwell does have his critics here at PN. However, he does make a very valuable point. This is to say that once a picture is taken with an 8MP camera, its always an 8MP picture. However, a film will increase its resolution in line with scanner technology.

 

I feel that this is a very important point. At the current rate of improvement, who's to say that there won't be a drum quality consumer scanners some time in the future?

 

It is right to say that its not only the resolution that counts when comparing the two formats, its also the look of digital and film. Some professionals hate the way digital pictures look, and for this reason won't use the media. However, I have to say that film will only be a minority interest, though I notice that in the UK at any rate, the price of medium format equipment seems to have stopped falling.

 

Stephen

[robert lee]

"However, a film will increase its resolution in line with scanner technology."

 

No. The film itself is also limited.

 

Let's run the numbers on Velvia 50's curve from Koren's site. 50% MTF for this film is about 50 cycles/mm. For a 36mm by 24mm frame, this is about 8.6 million pixels. Even this is more generous than the 85% MTF number that Edward benchmarks for the typical DSLR silicon imager. At MTF85, Velvia measures about 35 cycles/mm, or just about 4.2 million pixels.

 

This is why current generation DSLR's are roughly equivalent to 35mm film in resolution. Current DSLR's are in fact superior to 135 format Velvia in almost all other respects as well: latitude, sensitivity, and noise.

 

Fundamentally, it does not matter how perfect of a film scanner used to scan the film. The upper bound on realizable resolution is constrained by these numbers, i.e., by the emulsion itself. In fact, the digitization process itself contributes only losses: large if using a cheap flatbed, insignificant if using a $100k drum scanner.

[stephen_steele]

Hi,

 

I don't have the knowledge to agree or disagree with your analysis - so I won't do either.

 

What I will say, is that there doesn't seem to be a widely held consensus in relation to what are equivalant digital/film resolutions in terms of mega pixels.

 

For example, I shoot in 645, and so far I've heard its equevalant to 8mp,10mp, 12mp,16mp and 22mp. I've also been told you get different answers depending on the calculation you make. Also, as stated above, it seems logical that the type and make of film must play a part too.

 

However, as I've mentioned in other threads, I feel people are going to be very sorry in years to come when they have lost all their digital pictures.

 

Stephen

[nick_morris1]

Well yeah,

sony is coming up with some really awesome cams of late.

 

 

nickmorris

[nano_burger]

Quoting someone famous, "What you put behind the lens isn't nearly as important as what you put in front of the lens." Unless you are using a pinhole that is...

[jrjacobs]

Another point is being missed here. Current DSLR's have very limited lattitude - and at best are equivalent to slide film. Most color negative and B&W film has about a 5 stop advantage in lattitude over digital sensors.

 

I believe digital will eventually have similar lattitude, but it currently does not.

[godfrey]

Arguing and debating qualities of the capture medium on theoretical, technical bases is

fruitless. They are different capture mediums with different properties, and different

techniques are required to exploit them to maximum advantage. Exploiting them to

maximum advantage is the key ...

 

For my purposes and needs, digital capture became on par with 35mm film capture in

2002. Later developments obviated my medium format film equipment in 2003 and 2004.

I get equivalent resolution and tonal quality out of the digital capture medium now, with

less expensive equipment and more productive workflow.

 

For some work, medium and large format film, and subminiature film, remains a superior

capture medium, but those types of work are not my usual concern. When they are, I use

film.

 

Godfrey

[chromatic-aberration]

Stephen... With the increasing standardization of computer formats, your fears are less and less founded - especially now that there are so many people with a vested interest in maintaining continuity. Once things begin to go obsolete, there'll be mechanisms for conversion to whatever comes next. Digital has it's drawbacks, but so does film. Just try to archive the same negative in two places at once so that it'll survive a fire or other catastrophe.

[patrick_viebey___orlando__]

There's lots of cool technical details here.

 

But, OTOH, this harkens me back to the 'vinyl record versus CD' debates. I never could hear a difference, and was quite happy with going to CD.

 

Frankly, I would say it likely depends on what you're gonna do with it. My little Pentax 5Mb does a quite nice 8x10. I can do a lot better with my D2x. But, I'd also be careful about making say a life-size print for close viewing with it (like I'm ever gonna do that)...

 

So, I'd say personally, for MOST users digital is quite adequate. A lot of pro's now only use digital and it's working quite well for them, so no matter what the technical details, it's working for them!

 

OTOH, again, I'd still say it depends on what you want to do with it - those medium film cameras still have a use (although those 39Mb digital backs are way cool!)

 

pat

[patrick_quinn1]

I don't think digital will ever beat film for monochrome work, without a completely new digital image file format. Currently, a monochrome digital image has just 256 steps, black being 0 and pure white 255 (RAW might have more but current printers won't handle this). Film, being analogue, has in effect thousands of steps. Black and white film prints show much more detail. Digital is a lot more convenient though!

[ned1]

Digital will rival film (and will probably exceed it) when you have a sensor that is full frame medium format sensor CMOS chip that has six sensors per pixel: two each of red, green and blue. One of each pixel sensor is normal and the other one is HR, like the Fuji. Oh, and each pixel sensor should be large so as to reduce noise (hence the MF format). I'll contend that the six sensor arrangement is more important than megapixels since so many megapixels are lost to color smearing in a normal chip. The HR sensors and CMOS shold give you 7 stops in latitude, which rivals film. Without the RGB sensors you will never get true colors. My only fear is that a chip like this will never be developed because too many people are content to settle for inferior products.

 

Your opinion?

[godfrey]

<i>Patrick Quinn: <br>

> I don't think digital will ever beat film for monochrome work,<br>

> without a completely new digital image file format. Currently, a<br>

> monochrome digital image has just 256 steps, black being 0 and<br>

> pure white 255 (RAW might have more but current printers won't<br>

> handle this). Film, being analogue, has in effect thousands of<br>

> steps. Black and white film prints show much more detail. Digital<br>

> is a lot more convenient though!</i><br>

<br>

That's amongst the most ridiculous notions I've heard claiming that film is better than

digital in quite a while. No disparagement to you intended, but it's obvious that you're not

understanding digital B&W work at all. <br>

<br>

B&W in digital capture is a rendering process. It has the same tonal resolution, or more, as

color ... which is a combination of the capture sensor's analog dynamic range combined

with the capture sensor's quantization space ... because it is achieved by combining or

mixing the color channels down to a monochrome representation. You have exquisite and

explicit control of the spectral response through the mixing of color channels, and work is

done in a 16bit@channel color space, not 8bit single channel. <br>

<br>

Printers suitable for exhibition printing use quadtone inks to mix to B&W as well as color

inks to produce far more than 256 distinct levels of tonalities. <br>

<br>

Godfrey<br>

[._._z]

What film did they use in their "study" Neal? On what films did they perform measurements?