Digital or 35MM?

Written April, 2000.

Digital cameras are great. They're great fun, and they give pictures instantly. But I still shoot on 35mm and scan everything to digital form. Here are some of the various advantages of each format.

This essay considers the trade-offs between digital and 35mm. It assumes you plan on scanning most or all of your 35mm, so doesn't discuss the many advantages of the "digital darkroom" which you get from either medium.

Resolution, Resolution, Resolution

If you shoot on film, this is almost always the reason, though there are others. Really good film shots on 35mm can have as many as 20 million pixels, though in reality they range from 8 to 15 million. The best digicams have about 3 million at the time of this writing, and 1.3 and 2 are more common. In addition, the film pixels, sampled by a good scanner are 36 bits or even 42 bits -- 12 to 14 bits of range per colour.

Digicams sample just 8 bits per pixel and interpolate the others. The interpolation is good but nothing beats the real thing.

20 million pixels takes a good shot, but even a lousy film shot will usually have 5 to 6 million with all that range. Cheap 6 million pixel scanning is now available with developing. To get your 20 million you need to buy or rent a 4000 dpi scanner, currently about $1400.

So why is resolution so important?

You don't need more than a digicam resolution if all you will ever do is display on a screen, put on a web page or print in a 4x6 or even a moderate quality 8x10 from 3MP. So why do you want more?

Scale-Down

First of all, even if this is all you do, more resolution produces a better scaled down picture. You get better colour, closer to those 36 bits from film. You avoid "moire" patterns when fine patterns (like textures) interfere with the size of your pixels.

Zoom or Crop

Why throw away information? With more resolution, you can zoom in when viewing on screen, and also crop shots and still have them at good resolution. Even if you fill your monitor, do you never want to see more?

Larger prints

You may think you only want 5x7 prints right now, and the digicam does this. But you're thinking the old way. In the old way, you took a few rolls of snapshots a year, and printed them at the drugstore for 4x6 prints. Rarely you got an 8x10 from them. You put them in an album and stored them on a shelf.

Pro photographers never get 4x6 prints, except as proofs. They go out and shoot 3 rolls of the same subject, print none of them at first, and then go and look at them to find the best one. The best one they print really big.

The best shots

Digital photography with its low per-shot cost made me think like a pro photographer. Shoot lots of shots, and savour the best ones. But then you want the best ones at full resolution. Catch-22. If you can't afford to shoot lots of film (there are ways to make it cheap) you probably can't afford a digital camera setup either. I figured I could afford it, since digital photography changed me into thinking like the pro -- shoot a lot, and treasure the few really great ones. Leave the rest for occasional viewing on the computer

The Future

The computers, and digicams of just a few years ago now look clunky and ancient. Guess what? The same will be true of today's hottest digicams. But you won't be able to go back in time and take that great photo at the future's "standard" for good resolution. Unless you shoot on film, where you can rescan up to the film's limit.

You only want your picture at screen resolution today. Will you always be viewing it on today's level of screen? Will web bandwidth always be at today's levels?

Low Light

Today's digicams can't do long night exposures. That will change, but today there are just some shots you just can't get with a digicam. It would be a shame not to get them. (Of course they generally require a tripod.)

Range

Today, film has more range that most digital cameras. It can record darker shadows and brighter highlights at the same time. Particularly negative film. Slides don't have as much range but still surpass digital. Digital also can't handle super high-constrast images with very bright sources. CCDs will "bloom" from the bright source. So they can't shoot an eclipse of the sun as I did on film.

Fancy body features

Right now most digicams don't have the features of some fancy SLR bodies, like nice flash control, exposures to 1/8000th of a second, fancier, faster autofocus systems etc. This will change, though.

Fast Action

Interchangeable lenses

Consumer digital cameras don't have interchangeable lenses right now. Some day they will, and pro digicams in the $4K range do, but they use 35mm lenses that are way bigger than needed, and artificially zoomed (or more precisely cropped.)

Digitals won't have interchangeable lenses until they settle on a size for the imager. (Currently a CCD but it may move to another technology.) To manufacture lenses efficiently, you want to know how big an image they will be tuned to form. That's in flux so if they did sell such lenses today, they would be obsolete in 6 months, and who wants to buy something like that?

Film Anywhere

You can buy 35mm film anywhere, cheaply, and shoot forever. For hiking trips, you can carry and shoot lots of film but carrying battery power and flash memory for that much shooting in digital would not be tenable. Cheap microdrives or writable optical disks may change this.

Cost

This is the most interesting issue. Film costs lots more per exposure. About 6 cents/frame for a film like Superia 100. And about 7 cents for a lab to develop it. If you want prints they are anywhere from 4 cents at a CostCo to 50 cents in some location.

Slides can be bought and developed for about 19 cents/image.

Scanning is available for $8.50/roll at Dale Labs at 3000x2000, however their service is both slow and error-prone in my experience, or on Kodak Picture CD at 1500x1000 for $9/roll just about anywhere. I shoot rolls of 37, which means it's 23 cents to develop and scan. Or around 30 cents/frame, total.

Digital has a very low incremental cost, the battery power and flash memory usage. Around a penny or less per shot typically.

The hidden cost of digital is fast depreciation. A $1000 hot new digital camera will be worth $500 in a year. That's enough to shoot and scan over 1500 photos -- 40 rolls -- on a film camera that cost less to start and depreciates much more slowly.

So if you shoot less than 1500 photos/year, film could be cheaper than digital. If you shoot more, digital will be cheaper.

It's worth noting that this also alters the question of when to go digital. Normally with any computer technology, it will always be available cheaper if you wait, so you have to buy sometime. However, with cameras, film is always an option. Even a quality point and shoot for under $200 and some scanning may do the trick better than the $1,000 digicam.

Funsaver

While not related to the choice of what to shoot, digital will probably never easily replace the concept of the disposable camera you buy for $9 in the store. These have many applications, like keeping on in your car for emergencies, giving them to people at weddings and quick "I wish I had a camera" moments. They shoot as well as digicams, assuming the focal length is suitable.

Instant Feedback

This is the one greatest advantage of the digital camera, and the one that will eventually cause it to win. Instant feedback is not only fun and impatience-satisfying. It can make for better photography. When you get to see the shot right there (assuming a good digicam with a zoom on the LCD or a nearby computer) you get to see if you got a good shot. You can take it again if you didn't.

With digitals there is no need to guess the exposure, or play games bracketing to see what's right. You shoot, and you know it's right, or you shoot it again right there. There are shots I've missed on film because I didn't realize I bumped the camera or didn't bracket enough. Digital wins big here.

It also does give that instant gratification. And the cheap scanning I list above requires mail-order developing, and takes 10-15 days. Picture CD is available in some places like Wolf in a couple of hours, but it has problems. You can also have your own scanner.

(My usual technique has been to get Picture CD on all rolls, and use my own scanner for higher resolution on particular shots.)

Scanning sucks

Scanning at home sucks. It is time consuming, hard to do, and dust is always a problem. Scanning at a large lab is the way to go. They scan the film before it has had a chance to see dust. They don't do colour correction well, but you can fix that. Someday they will just give you the raw data and let you do all the important stuff.

Scanning at home does give you short-term gratification combined with 1 hour developing.

Scanning at minilabs like Wolf Camera also sucks because they do not have clean facilities. After they take your negs out and dry them they get dust.

Also, with a poor scanner, negatives will show noise in the highlights.

Automatic adjustments

Digital cameras can white balance right there, and you can correct it if it's not right. They can meter better because they have the whole CCD to meter with. You can colour correct film after the fact too, but not with the subject right in front of you.

Future enhancements

Digitals will really win when they start playing cute tricks. Nikon's "best shot selector" is a really cool feature that lets you shoot handheld until you were still enough to get a good shot. This will allow digitals to outdo film at handheld shooting. Digitals will be able to take multiple exposures of the same thing at different focus ranges and different exposures to provide artificial depth of field and wider range than even the human eye.

Smaller, lighter

Because of the smaller imagers in today's digital cameras, they get to be smaller, and have smaller lenses. With imagers 1/3 the size, they can have lenses 1/3 the focal length, 1/9th the area and 1/27th the weight in the glass. Overall much smaller. Who doesn't want that if you can get the resolution?

Though don't discount cameras like the Olympus Stylus Epic at $90 or the Cannon Elph, which while only APS, still is better resolution than digitals, and currently smaller.

Depth of field

Smart lenses

A little bit today, and more in the future, digitals will have smart lenses they understand fully. They will know and correct for lens errors like light fall-off and distortions like barrel or pincushion or the non-rectilinearity of wide angle lenses.

They may also correct for some types of chromatic aberration and other problems that simple lenses need correcting elements for. Simpler lenses means cheaper, lighter and more contrast.

What do digitals need?

I will go back to digital for some work, mostly because of the hassle of scanning, but I am looking for:

1. At least 2400 pixels wide, ideally 3000 or more.
2. 12 bits per pixel rather than 8, and a way to use it through a CCD-RAW style format.

The upcoming Canon SLR Digital comes close to meeting this.

Those are on the must-have list. On the wish list are:

1. A low noise CCD that can do 30 second exposures.
2. A fast interface to the computer, USB or better 12 megabit IRDA to avoid cables.
3. A great lens able to fully resolve, with a wide range, or interchangeable lenses or quality lens add-ons.
4. Cheap portable storage like Sony Minidisk, mini CD-R, or microdrive.

We're getting closer and closer to this.

Medium Format

Of course, this is only a debate between digital and 35mm. People who are really serious about resolution and willing to give up the convenience of 35mm to get it shoot on medium or even large format. They won't go digital for a long time. For them, resolution is vital, and digital isn't even within 2 orders of magnitude of what they are looking for.