BetterPhoto Q&A
Category: Traditional Film Photography

HELP! Ditched Digital for Film SLR!

Sincerely,
Andrew

To love this question, log in above
December 19, 2005

Secondly, stay away from Wal-Mart for your scans. Although I am not sure what type file my lab uses, they can and will supply you with a high resolution file of your prints. Check out www.prophotoimaging.com.

To love this comment, log in above
December 19, 2005

To love this comment, log in above
December 19, 2005

First - yes, one can get decent 20x30 prints from 35MM film, if one uses the appropriate materials and procedures. Since you are talking about a 20x enlargement (spoken of as "20 diameters") I'm sure you can understand where any minor problem, be it blur or dust spot, will get magnified accordingly.

So, first of all, you must use very fine grain film - meaning a slower speed (lower ISO number). In the digital world, setting your CCD to be more sensitive to light leads to so-called "noise"; well, in the film world the same basic issue leads to grain (though for entirely different reasons). That is, the more light-sensitive film is, the more grain it has. So, if you plan to make posters, plan on using 100 or slower film (color, or B&W). WHile 400 speed film is fine for most day-to-day shots, it might prove to be a bit too grainy to allow for sharp and clean poster sized output. And 800 speed (which I assume you just mis-typed as 80 above) will become that much more problematic.

Next, of course, you want to be sure your camera is as steady as possible - so a tripod is virtually necessary. Well, perhaps not if you're shooting at 1/1000th of a second with a moderate telephoto or short lens, but you may not have that option if there's not that much light and you are using slow film (for fine grain, remember?). While the general rule for tripods is to use them any time your shutter speed falls below 1 over the focal length of your lens (in MM), you will still see improvements if you use a sturdy tripod. So, if you're using a 50MM lens, don't shoot handheld below 1/60th of a second. Using a 300MM lens? Well, keep it above 1/250th, at least (more like 1/500th).

Okay, so you burn some slow film with all the right procedures; what next? You will want a high-resolution scan - not from a discount store but rather from a photo lab or friend who has a film scanner. These can go from home units of 2700 ppi to 4000 ppi and up to 10,000 ppi for the Imacon or Leaf drum scanners that cost $30,000.

So now we've got a scan. First, recognize that at 4000 ppi scan resolution your film frame, which is about 1x1.5 inches in size, will have a total of (4000x6000=) 24 million pixels. Without doing anything but altering how many dpi you want on the final print, you can do a decent upsize.

That is, photo printers generally demand about 300 dpi resolution, plus or minus 80. I depends on the printer itself - some are "happier" with 360dpi (certain Epsons), my Kodak 1400 dye-sub printer wants a 301 dpi resolution, and some poster-size digital printers (like Chromiras) use fewer than 300 dpi - like 220 dpi. Also, since posters are not typically viewed from mere inches away, slightly lower resolutions are often quite acceptable.

That said, let's do the math: 4000x6000 ppi scan divided by 300 dpi output resolution give us an image size of 13.333 x 20 inches. Understand, we haven't changed any actual image pixels - we've merely changed their density from 4000 per inch to 300 per inch, okay?

Now, in Photoshop (and Elements) as well as other post-production imaging software you can upsize - it's usually best to do this a little at a time. So scale up by 10% - giving you a 14.66x22 inch image. Repeat as needed - digitized images are able to go quite a ways for upsizing - I've done it through interations to get me to 24x36.

Of course, to the degree that you want to crop out some of the original image, you'll need to enlarge that much more - making grain and movement blur all the more critical. SO be careful!

To love this comment, log in above
December 19, 2005

As an aside, digital cameras (well, the better DSLRs, which use different types of ships than the point & shoot digitals) can also get pretty amazing large images, even though they're not 24 megapixels (yet). This has to do with the way the grain structure of the film is scanned versus the way the DSLR chip creates a "first generation" digital image from the actual scene. So don't let the numbers fool you completely.

Finally - 120 (and 220) refers to a larger size of roll film - rather than coming in a metal cassette like 35MM film does, this is the kind of film that comes on a spool (with a backing paper). The film is about 70MM wide, making for the ability to shoot images that are 60MM at most. Thus, there are Hassleblad cameras that shoot so-called "6x6" - referring to square negatives of 6CM square (i.e. - 60MM by 60MM). And there are other makers, like Pentax and Mamiya, whose cameras make images that are 60x70MM (or "6x7), using the same type of film. And Fuji used to make a real behemoth, the 680, that produced 60x80MM images on that same roll of film (of course, each could take fewer images than the prior on a given length of roll). The difference between 120 and 220 is simply the length - like a 24 exposre roll versus 36 exposures. Oh, yeah, and after all of the above Mamiya and a few others came out with their so-called "645" format - which again uses the same roll of film but places an image that is 60MM by 45MM.

Well, I hope that makes some sense - go forth and shoot!

To love this comment, log in above
December 19, 2005

To love this comment, log in above
December 20, 2005

I recall seeing some other brands out there - but frankly don't know if they are worth their (lower) prices.

To love this comment, log in above
December 20, 2005

Of course, the devil's in the details -in this case, that one word - 'decent'. What is 'decent' photographic resolution and detail to some photographers is highly unacceptable to others, hence, the advice to use a bigger piece of film. 20x30 is stretching the enlargement potential of the small 35mm format (or for that matter, most digital sensors). Even with IS0 25-100 film, mirror locked-up and camera on a hefty tripod. You might be pleased with the results, or you might not.

The style of photograph also has some bearing on the concept of 'decent' - a grainy 35mm or noisy digital B&W 'art' photo of a smoky bar might be very acceptable enlarged to poster size, while a crystal-clear Southwest sunrise landscape might not.

To love this comment, log in above
December 20, 2005