Asked By
cgabriel
10 points
N/A
Posted on - 04/07/2012
Hello there techyv experts!
I am planning to buy a scanner next week for my work.
The problem is, I'm not really into computers and other devices.
I just want to ask you guys your help on these.
What specifications should I look at when buying a good scanner?
Thank you so much.
Specifications on buying a good Scanner
There are several steps to assess the quality of a scanner:
1. Resolution: Mainly measured in optical resolution, more the resolution the more the clear image.
2. Actual resolution: The resolution actually found while you get from a scanner while scanning.
3. Pixel depth: The number of different shades that the scanner can identify and distinguish between them. Good for 8 bits of color channel. Excellent for 16.
4. Dynamic range: This is the most important of all the features. It measures how many different shades it can distinguish at different brightness for full black to full white. Bigger the number, greater is the quality. 3. Color consistency and Random noise.
5.Interface type: It says how it connects to the computer. Three types. Parallel is worst in quality and the slowest.
6. Scanning speed Depends on the resolution. For res 150, a4 sec avg. is required.
7. Maximum scanning area: You should buy one according to your job type.
Caringal Cheong
Specifications on buying a good Scanner
Before you look at resolution, I’ll let you in on a secret: For the vast majority of us who use a printer to print e-mails at home or a nice copy of a photo for Grandma, resolution is not something you need to worry about. Even basic printers have a high enough resolution that your documents will look professional, while photo printers are going to give you great-looking prints. So don’t stress the specs too much.
Dots Per Inch
Let’s look at the basics. Printers print by putting ink or toner onto paper. Inkjets have nozzles that spray tiny drops of ink, while laser printers melt dots of toner against the paper. The more dots you can squeeze into a square inch, the sharper the resulting image will be. So, the most common printer spec is dots per inch, or dpi. A common spec is 1,200 dpi, though some inkjets have a higher vertical resolution (they can put more dots top to bottom than left to right), so you might also see something like 720×360 dpi.
Optimized DPI
Printers can put dots of different sizes, intensities, and even shapes, onto the page, which can change the way the finished product looks. Many printers use “optimized dpi,” meaning their printheads optimize the placement of ink drops to improve the quality of prints. If you see a printer that has a 9,600 dpi, it’s layering dots by passing the same part of page multiple times and putting several dots of different colors in one place. The final result will look rich, but this technique uses a lot of ink and time.
Print at the Resolution You Need
More is not necessarily better. For the majority of daily uses you’d be wasting ink to print everything in the highest possible resolution. When I print out shopping lists, I set my printer to “draft” quality so the document comes out fast. It doesn’t look perfect, but who cares? As long as I can read it when I’m in the supermarket, it’s good enough.
What’s Good Enough?
For a letter or business document (even one with graphics), 300 dpi is going to look fine. If it’s a handout for the board of directors, 600 dpi will look great. For the average photographer, 1,200 dpi is excellent (only pros would need to print something at twice that). All of those specs are well within the means of every decent printer out there. And once you get above 1,200 dpi, it’s going to be nearly impossible to see any difference in whatever you’ve printed.
Ink Makes a Difference
Resolution is more than just dpi, however. The kind of ink used can trump the dpi numbers. Laser printers will make text look sharp because they use toner which doesn’t bleed into the paper like ink does, so if your main purpose in buying a printer is for printing black-and-white documents, a monochrome laser printer will give a page of text that looks crisper than a high-resolution inkjet printer.
Use the Right Paper
Papers are made to optimize the differences between printers and so help create great images no matter what dpi your printer is capable of. Plain copy paper will work well for laser printers because nothing is getting absorbed. But inkjet inks are water-based and so they get absorbed into paper fiber. That’s why there are specific papers made for inkjet printers (and why printing a photo on plain paper is going to give you a limp, wet picture). If you’re just printing an e-mail, use cheap copy paper; but if you’re developing a brochure or flyer, it's worth investing in the right paper.
