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June 09, 2005
[ DIGITAL vs FILM ]
NOW THAT DIGITAL PHOTOGRAPHY is a mature technology the time has come to face up to the ultimate question: is digital as good as film?
Digital sceptics argue that there are not enough light receptors on any existing digital sensor to begin to reproduce the subtle gradations of film. Which raises the question: how many pixels are needed to equate with a 35mm film frame?
Film doesn’t have pixels but Brad Templeton at pic.templetons.com calculates that there are 20 million "quality" pixels in a top-quality 35mm frame. “That's a shot with a tripod, mirror-up, with a top-rate lens and the finest-grained film, in decent light. 12 million are more typical for ‘good’ shots. There may be as few as 4 million ‘quality’ pixels in a handheld shot with a point-and-shoot camera or camera with a poor lens.”
Michael Reichmann at Luminous Landscape makes a more modest comparison. He says that there are 14 million pixels in a well-lit, well-exposed, well focussed 35mm frame. The recently discontinued Kodak digital SLRs have 14 megapixels and Nikon and Canon make cameras that come close. But for cameras costing less than $10,000 the pixel count is more typically between 4 and 8 million.
We loaded Kodak’s High Definition colour negative film, rated at ISO200 into an Olympus OM2 -- 14 million notional pixels -- with a Nikon D70 digital SLR -- 6 million actual pixels -- set to the same ISO speed. Both cameras were tripod mounted and photos of the same subject in the same lighting were taken with both cameras set to Program -- that is the cameras were left to determine the best combination of shutter speed and aperture.
The subject was lit by available light coming through an open window. This means that both cameras had to calculate the correct white balance in the shade. The Nikon image was captured in RAW and processed using Pixmantec’s RawShooter Essentials, our favourite RAW converter. The image file had to be enlarged slightly in Photoshop to bring it up to 25cm by 30cm.
Because the film camera forces the photographer to set the exposure and focus and then hope for the best, without any chance to review the shot, we used the Nikon digital camera in the same way.
The digital sceptics are not just doubtful about pixels and resolution. There is also a suspicion that the dynamic range of digital sensors is not as wide as film and therefore there will not be as many steps in the grey tone scale between black and white. Our experience suggests that this is a valid concern. It is more difficult to keep detail in the extremes of shadows and highlights in a digital image than in a film image.
There is also a belief that digital prints will look like low quality digital video images on television, with elevated edge sharpness and an artifical look. In our experience this is not a problem, even with relatively inexpensive cameras.
We took the film negative and the digital file to a Kodak Express shop equipped to produce 25cm by 30cm silver halide prints from any image source. When we examined the 10cm by 15cm prints straight from the automatic printer it was obvious that the Kodak film over-compensates for open shadow and the pictures have a yellow-green cast. This produces an unpleasant tinge to skin tones. It is something we could spot in the digital camera’s preview and correct on the spot by resetting the white balance. Score 1 to digital.
Looking at the enlargements we were surprised at how much smoother the gradations are in the digital picture. Skin tones are more natural and smooth. Film tends to flatten the skin surface. Of course this is mass produced film processing and printing and the results would be different from a professional laboratory, but our intention is to compare film and digital as they will be used by amateur photographers.
Neither print has accurate colour. The digital image is closer to true colour but it is over-saturated. Contrast in the digital image is much more natural than in the film print which surprised us, although it is a low contrast subject at which digital excels. Detail is good in both media but the resolution of the film beats digital.
Our conclusion is that low speed fine grain film will produce better prints if all the elements of white balance, exposure, lighting and so on are just right. But in the real world where cameras are pointed and squirted digital will win on averages.
So, the answer to the question: is digital as good as film? If the question means: does digital have the resolving power of film then the answer is no. Does it have the colour fidelity? In perfect conditions -- no. In real everyday situations -- yes. Is the dynamic range of digital as wide as film? Again, in perfect conditions, no. In the real world, yes -- because compensations can be made in the computer, particularly when shooting RAW.
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Posted by terry at June 9, 2005 06:30 PM
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Comments
Sorry Terry, but your methodology is flawed.
You say "If the question means: does digital have the resolving power of film, then the answer is no."
Unless you have magically managed to adapt your Olympus lens to your Nikon Camera or vice versa then your comparison of resolution has no meaning. The lenses are different, hence the comparison is invalid.
As to processing the images in Pixmantec's Raw Essentials software, which setting did you use? As you are aware, there are umpteen different settings that will affect the outcome of the result. Even
without tweaking the various controls for exposure compensation, fill light, shadow contrast, highlight contrast, saturation or hue, the
results can be altered by the choice of any of the seven different appearance settings. Then you can get into sharpening and noise and colour noise suppression - all of which affect the appearance of the final result.
Just to continue picking on you, you set the cameras to Program mode,which means the camera chooses its own combination of aperture and
shutter speed. Even with the same lens there is likely to be a disparity of sharpness between two different apertures so who knows at what apertures the two different lenses were set.
I imagine the the film vs. digital debate is akin to the Holden vs Ford debate. There are those who have taken a stand one way or the other and refuse to be convinced otherwise. I have to confess that I am one of those who thinks digital is so far ahead of film that for all intents and purposes film is now dead.
Cheers
Noelb
Posted by: Noel at June 9, 2005 06:33 PM
Seems a reasonable comparison given a person may own these two types of cameras.
Digital is VERY convenient I can post process and tweak and also output to a Photo printer up to A4 with nice results, however I find dynamic range in digital not as good as film, shadow detail is lacking if highlights are catered for.
Posted by: John Smith at June 9, 2005 09:23 PM
Digital dynamic range is NOT as good so you loose shadow detail even with PP you cant equal film.
Posted by: John Smith at June 9, 2005 10:21 PM
Photographers can debate the quality of film vs digital photography until the cows come home and never come to an agreement.
Each photographer chooses the tools that suites his or her personal style. There are some people out there still using pin-hole cameras just because they love the look and feeling that it imparts to their images.
So rather than debating the quality or merits of one form of capture over another lets get out there and continue developing our creative talents as photographers.
Posted by: aubrey at June 10, 2005 10:24 AM
Please don't laugh at my ignorance, but I often hear of silver halide prints (eg. as mentioned in Terry's post heading up this thread) and don't know what that means exactly. Are they the usual photo prints that we get from the local film processing lab (or processed by Kodak via the pharmacy, etc) or are they something we need to ask for specifically (and presumably pay extra for)?
Posted by: sod at June 12, 2005 12:48 AM
That's a perfectly reasonable question.
"Silver halide" is the shorthand way of referring to conventional photographic materials which use light sensitive silver particles suspended in the emulsion on film and paper. The silver [halide] changes character when exposed to light and that change is exploited and fixed by the chemical processing.
So, in short -- yes, silver halide prints are the ones you get from the photo processing shop. Silver halide prints last longer than prints from inkjet printers and the photo finishers are generally equipped to make silver halide [old fashioned] prints from digital files [very modern!] It's a hybrid, best-of-both-worlds solution.
Posted by: Terry at June 12, 2005 03:32 PM
I had read Michael reichman's article at http://www.luminous-landscape.com/reviews/cameras/d30/d30_vs_film.shtml and I think it pretty well puts an end to the debate, film vs digital.
The thing about Michael's article is that it was written about four years ago and Michael was using a 3 megapixel Canon D30. Common entry level DSLR's are now twice that.
I liked your comments but thought that you should have come out more clearly on the side of digital.
Merely my opinion, of course.
Posted by: Colin at June 14, 2005 10:18 AM
The item on Film vs Digital brought to mind some experiments I did last year. I’m not sure if anyone has done this before but I wanted to compare Digital v Silver using the same lens on each camera.
Please explain!
For the film camera I used a Canon EOS 50 with a Canon 28-105 ultrasonic lens. I shot 200 ASA Fuji neg and had it processed at a Fuji Image Plaza and printed on a Frontier printer.
For the Digital camera I used my newly purchased (at the time) Canon EOS Rebel 300D fitted with the same lens used on the film camera. I took the shots on a tripod using time delay and as near as possible in time to each other. I printed the digital prints on Epson’s R800 which has just been replaced this week by the amazing R1800.
I thought the reason for doing this test was fairly obvious and was surprised that it hadn’t been done before.
The results? Well, let's say that I don’t shoot a lot of film these days. The enlargement is interesting. It represents a print about 30 inches wide.
I come from a commercial photographic background. I owned and operated a company called Photovision in South Melbourne for over 30 years but I can honestly say I saw the light in 2000 and put a "for lease" sign on the building and retired to the Gippsland Lakes.
[DPEXPERT COMMENT: Peter sent the prints that he describes in the text and there is no doubt that the huge enlargement of small sections of the digital and film images show that digital has more detail and greater sharpness than film. It is not possible to show the difference on a PC screen -- you'll have to take our word for it. Our suggestion is that anyone who is looking to pick up a cheap pre-loved Canon EOS50 should contact Peter forthwith.]
Posted by: Peter at June 16, 2005 09:49 AM