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“At what dpi should I scan?” “At what percentage?” “My software says ppi and not dpi, what’s that mean?” “What is screen resolution?” “What is print resolution?” “How do I make the best scan?”

These are questions I’ve heard many times. And while there’s no definitive, completely foolproof answer - I hope that this article will at least clarify many of the terms and provide you some tips so that you can use your scanner to its fullest.

For any of you out there that already have your own way of scanning and resizing your images, I encourage you to quit reading and keep using whatever method you’ve developed that works for you. But for those of you who are just a tad perplexed by the various settings in your scanning software, and even more so once you have the file in Photoshop, I offer the following tips that may help you to “think in pixels.” In addition, I offer some tips about your scanning software and Photoshop that will help you achieve the best-possible scan from your negatives or prints.

DPI/PPI: There are two abbreviations that are used interchangeably these days - DPI and PPI.

DPI, or dots per inch, and PPI, or pixels per inch, are for all intents and purposes the exact same thing with respect to your digitally scanned image. Both DPI and PPI are a measure of density. The higher the number, the greater density of information in your file. But please note: don’t let your printer’s DPI rating throw you. Your printer’s dots are different than a scanned file’s dots. In other words, scanning a file at 2400dpi and printing it on your 4800dpi printer simply does not mean anything - they’re apples and oranges, so to speak.

PERCENTAGE: Most scanner software offers various percentages at which you can scan

your file. Percentage in this case is a measure of the “physical” size of the final scan. For example, at 100%, a Holga neg would scan in at roughly 2.25”x2.25” (6x6cm). A 35mm negative scanned at 100% would be 36mm by 24mm. As I’ll explain further, I recommend you set this at 100% and forget about it.

RESOLUTION: This is probably the most difficult term to nail down, because the same

term is often used to describe a number of different things. Your screen resolution, your printer resolution, the resolution of that .jpg file you posted... But when you’re talking about scanned images, resolution is for all practical purposes the same as the dpi/ppi measurement.

SCREEN/PRINT RESOLUTION: Screen resolution for most personal computer monitors, TVs

and other video devices is 72dpi. Some PC users may cry foul and say, “Mine is 96dpi!” and while that is true for the output from the video card, if you’re using a CRT, the resolution is 72dpi... For many “consumer” inkjet printers, a perfectly acceptible print can be made from a file that is 150dpi, although 200-400dpi may be best for your specific printer. For example, the Epson 2200 makes the best prints from 360dpi files (thanks Susan B!). And finally, for most professional printers of magazines, packaging and books - commonly called offset printing - 300dpi is the standard resolution of a file that is acceptible. There are exceptions to all of these - for example, fine art books and prints are often made at 400+ dpi for offset printing - so please consider these numbers as a rule of thumb, and not the gospel truth.

DPI/PPI and PERCENT size are related in that together they determine the TOTAL NUMBER

OF PIXELS in your final scan. So in order to make sense of this chaos, it is quite simply easiest to think in terms of number of pixels. The total number of pixels in your file determines how it can best be presented - on the web, inkjet printed or offset printed.

To illustrate the inter-relationship between DPI, percentage and the various resolutions, I offer this example (please pardon my American usage of inches):

If you scan a 2.25” square negative at 100% and 72dpi - you get a 162px by 162px image (2.25 inches multiplied by 72 pixels per inch). Scan the same neg at 100% and 3200dpi, you get a 7200px square image (2.25x3200). Photoshop will report both images at 2.25x2.25in. (because they were scanned at 100%), but the the pixel sizes are obviously drastically different. In this example, the fi rst image would be best utilized on the web, and would not make a very good inkjet or offset print. However, your 7200x7200px image would be would be more than adequate for 300dpi offset printing. In fact, it would print at 24” square at a professional outputter (7200/300=24). Further, your 7200px scan is going to be inkjet printed at 36” square if you size the fi le to 200dpi (7200/200=36), or a whopping 48” square when sized at 150dpi (7200/150=48).

In this example, I hope that you can clearly see the relationship between total number of pixels and the physical size at which your image will print in various media. If you can do this relatively easy math, you’ll never be in the dark again about what size your fi nal image will be, because now you’re thinking in pixels.

YOUR SCANNER SOFTWARE

So what are the best settings to use when I make a scan? When you scan a fi le on MOST scanners, go with the highest resolution at which the hardware (not the software) is rated - say 2400 or 4000 dpi - and keep the percentage at 100%. This is typically the best-possible scan... If you scan at a dpi setting higher than your scanner is rated, OR at the highest hardware dpi AND a percentage higher than 100%, the scanner will resort to software to “make up” (interpolate) the information. This can often result in a lack of sharpness since the software is making up extra info by implementing a scaling algorithm. However, some software packages are better than others, so some experimentation with this would be prudent.

SPEAKING OF PHOTOSHOP...

Armed with your new knowledge, the Image Size menu item in Photoshop takes on a whole new meaning. It makes “doing the math” unnecessary when resizing your images. This is due to one feature that many people ignore - the check box for “Resample Image.” By checking and unchecking this box it’s easy to manipulate both the pixel and physical size of your image.

Unchecking “Resample Image” leaves the total pixels unaffected and changes only the physical size - the pixel size is actually locked against change. This is useful to scale your 2.25” Holga negative scanned at 3200dpi to a much larger fi le for printing. Simply input your printer’s preferred dpi and the image will “scale” to this size without affecting the actual pixels. If, however, you leave “Resample Image” checked, you will change the pixel dimensions. This is useful to scale your hi-rez image for

publishing on the web. The same 7200px Holga neg would take quite a while to upload - so changing it to 72dpi will drop a hefty amount of the pixel information and give you a 2.25” image that is appropriate for the screen.

It is my hope that this article illuminates for you a method by which you can dispel your confusion and begin to think in pixels, so that you may perpare your images for the various media we all

now use to publish our work. TEXT BY

MIKE BARNES

Toy camera user: 3 years Member of tc.com: 3 years

What motivated you to start shooting toys initially? My original inspiration came from seeing photographs taken with Diana cameras - I was searching for images that would give a vintage, timeless quality about them, the crappiness was an added bonus. Inspiration for continuing is sharing philosophy, comradery, and enthusiasm from other tc shooters.

Was there a photographer that inspired you to shoot toy cameras? Don Brice

Is there a particular toy camera photographer that inspires you now? Dominic Turner... Tread... Gordon

Do you have a favorite toy camera? Dories/Diana clone - warps images, significant outer blur, challenging - love/hate relationship

Do you have any personal words of plastic wisdom you can share with us? Get close, then get closer. Eliminate the crap. If in doubt tape it up. Know your camera. Don’t give up. Do you have any advice for someone who is just starting out with toy cameras? Taking photos with a toy camera at first can be like searching for a pearl amongst a sea of oysters. Get to know your camera, and be selective with your shooting, but don’t think too much. When you go for a shoot, load your camera, and finish the roll, don’t let it sit. Sometimes those “end of the roll” shots tend to be the best.

Anything else you’d like to add? HAVE FUN. Don’t expect to be taken seriously from super sharp obsessed photographers. Do it for yourself.