Labs

Home all-in-ones

All-in-ones require a considerable amount of testing, as they can print, scan, copy and, sometimes, fax. We use an amalgamation of our usual inkjet and scanner tests, as well as introducing copying tests for automatic document feeders, and directly from the flatbed scanner.

Print timings are taken from the moment the printer picks up the paper until the last page hits the out-tray; scan and copy timings are taken from the moment the button is pressed until the copy hits the out-tray or the scan is displayed in Photoshop. For quality tests, each printout or scan is judged independently by two members of the PC Pro team.

Print tests

We measure print speed using the official ISO 24712 document, which consists of five A4 pages: a "5% coverage" letter, three text-and-graphics pages and one diagnostic page. To calculate standard mono print speed, we print ten greyscale copies of the letter page at both draft and normal (or default) quality using the default driver settings; for colour, we print one copy of the full five-page document at normal quality.

To assess photo quality, we print a selection of five 6 x 4in photos featuring a wide variety of colour tones, indoor and outdoor scenes, landscapes and macro shots. We also print our usual A4 photomontage, in all cases using manufacturers' recommended paper at the best possible quality settings. Photo print speed is based on the time taken to print one 6 x 4in photo and our A4 photomontage.

Scan tests

We rate each scanner's performance based on both speed and quality, just as for the print engine, and we first allow the lamp to warm up to ensure fair results. We then time how long a full-platen preview takes, followed by an A4 colour text-and-graphics scan at 150ppi. Next is an A4 glossy print of a pair of mounted candles, patterned cloth and holly against a green material background. We scan at 300ppi and pay close attention to small details such as the texture of the cloth and petals of a yellow flower, as well as examining colour and white balance accuracy.

Lastly, and most importantly, we perform several scans at different resolutions of a 6 x 4in photo (the outdoor scene, pictured left). At 600ppi, we scan it twice: once with all enhancement settings disabled, so we can assess the raw capability of the scanner, and again with the default settings enabled to see how well each device processes the image. Finally, we scan it at 1,200ppi, with enhancements off to check for fine detail reproduction.

Copy tests

Manufacturers' cpm (copies per minute) ratings are misleading, as once the scan is complete the rate is dependent largely on the device's print speed. We prefer to judge a copier by the time taken for the whole scan-print process of one single copy. We use the A4 text-and-graphics document from our scan tests (professionally printed on coated paper), and make one mono copy at both draft and normal settings, then another in colour at Normal settings. Finally, we also make one copy of our 6 x 4in scan test photo, using best-quality and borderless settings where possible.

Where an ADF (automatic document feeder) is present, we copy a four-page DTP document (which includes the page from our flatbed copy test for comparison) onto plain paper at normal quality in both colour and mono.

The ratings

At the bottom of each review are five scores: Quality, Speed, Features & Design, Value for Money and a final Overall rating. The Quality and Speed ratings are determined by combining the scores for all of the tests outlined above, with print results weighted slightly higher than scan and copy results to reflect the likely day-to-day use of most users.

The Features & Design score is a mix of objective and subjective assessments. We take into account support for memory cards, the capacity of input and output trays, and the size of the LCD. We also judge the general usability of hardware and drivers, and award extra marks for duplex units, network ports, automatic document feeders and fax capabilities.

To calculate Value for Money, we combine the purchase and delivery price, and factor in the cost per page of each printer using quoted ISO page yields as a guideline. Quality, Speed and Features & Design scores are also factored in to produce a final value rating. The weightings for home and office devices are slightly different, with the latter's Value for Money score favouring features a little higher than speedor quality, due to the higher prices involved.

The Overall score is simply a straight average of the other four ratings, although it may appear higher or lower than expected due to rounding.