Wikipedia:Reference desk/Archives/Computing/2014 September 19

= September 19 =

Network Printer doenst recognise pcs
Here at work we have a ricoh 8000 printer, this printer is connected on the network, by a network cable.

Until yesterday we were able to print from this printer. But now the printer doenst recognise pcs.

If I ping to the printer ip using a pc, it doens nothing, the same happens if I try to ping to a pc ip using the printer (yes, this printer has a ping function).

What can be the problem? This problem came out of nowere.201.78.206.50 (talk) 12:46, 19 September 2014 (UTC)
 * I found the problem. The ethernet wire was the problem.201.78.206.50 (talk) 12:57, 19 September 2014 (UTC)

recording

 * [[File:Qc-fenêtre.oga]]

Hello, there is a "boom" at the end, can you remove it please ? Fort123 (talk) 17:53, 19 September 2014 (UTC)


 * Someone might want to help you, but that's not really what we do here. You can use the free program Audacity_(audio_editor) to do it yourself. SemanticMantis (talk) 19:34, 19 September 2014 (UTC)


 * If this is for use in a Wikipedia article, you could ask at commons:Commons:Village pump. -- BenRG (talk) 00:11, 20 September 2014 (UTC)

Confusion with printing sizes and DPI
I went for the first time to a printing company, because i would like to print out some computer designed images as "Digital Art". I explained that for starters, i would like to have some prints made at 12" x 12". We did a little talking and i mentioned i wanted these printed at the highest DPI they have to offer. I am not used to how printing works, and i told the person at this company that i mainly work with pixel resolution. I said to them that i can produce the image at literally any pixel dimension needed, and asked "What pixel resolution should i give you to get a 12" x 12" image at your highest DPI?" They told me i should shoot for about 750x750 pixels. They then showed me a 24" x 24" poster of some football stuff, printed on the same printer that does their highest DPI.

Wanting to know as much as i could about this, i looked up DPI conversion as soon as i got home. According to formula #1 here:

Pixels / DPI = Inches 750 / ? = 12

This means the DPI would need to be around 60 (to produce 12.5 inches), which is only the DPI of a CRT monitor! Choosing the option in the converter of this site of "300 DPI (Laser/InkJet)" gives that my image would only give a 2.5" square print! Worse yet, at "600 DPI (Hi-Res Inkjet)" the image would be 1.25" square! At the 300 DPI i would need an image (according to the SECOND converter on this website) of 3600 pixels, and at 600 DPI i would need 7.2k pixels.

Whats going on here?!? I didn't notice anything wrong with the poster i was shown, it appeared pretty good quality! Maybe i don't know it and their "best" printer has really poor quality?!? Or perhaps its specially made for posters, which for some reason have really low DPI? Was there miscommunication?

It is hard for me to understand this issue. I *generally* understand DPI but it seems we weren't talking the same language or something. On top of that, the Photo-quality printing article talks about DPI starting around 2,400 DPI for more professional prints.

The person i talked to said they didnt know what DPI the printer had. What type of DPI should i expect from a company, for decent grade art prints? I want them to look great, but know what demands are reasonable! Surely i need more than a 750x750 pixel image?!?! What went wrong in my conversation with this person? Should i look for another company?

Bewildered and confused,

216.173.144.188 (talk) 17:54, 19 September 2014 (UTC)


 * Me too. But 60 DPI gives you about 0.4 mm pixels - definitely visible up-close. The ancient Apple Laserwrite had 300 DPI B/W, and that's still quite ok. I'd suggest you go with that and get a galley proof to see if it meets your expectation. --Stephan Schulz (talk) 18:40, 19 September 2014 (UTC)


 * According to a friend i just talked with, people working at printing companies often have no idea what a pixel is, because they don't necessarily work with DIGITAL images. (Really?!?!?!)


 * What i really want to avoid is that my image is too big or small for 12" x 12", and the person resizes the image to fit. This will cause distortions in the image. When a normal image off a camera is resized **slightly**, there is little or no difference noticeable in the quality... probably because neighboring pixels have similar hues. In my situation, there are intricate details and edges, and also situations where a single orange pixel may be alone in a sea of black background. This detail could get screwed up badly if the image is resized, am i right? At least, i don't think it will be good at all, so i really don't want the image resized! ... But if these printer people know nothing of pixels, it feels awkward to pay them so i can help them do what i need.


 * 216.173.144.188 (talk) 19:12, 19 September 2014 (UTC)


 * I suspect that whoever told you "750 pixels" was just plain wrong.
 * I'm not too familiar with what's considered "high resolution" among mainstream commercial printers, but if I wanted "highest resolution", I'd be thinking of something more like 600 dpi, and for 12x12 inches that's 12 x 600 = 7200 x 7200 pixels. —Steve Summit (talk) 23:54, 19 September 2014 (UTC)


 * When you said "pixel resolution", you seem to have meant "image dimensions in pixels". Your printing company may have interpreted "pixel resolution" to mean "pixels per inch". If so, the 750 × 750 figure probably means "750 pixels per inch in both horizontal and vertical dimensions", and a 12 inch × 12 inch printed image would use a source image that is 9000 pixels × 9000 pixels. Maybe you can have another conversation with your printing company to make sure you're talking about the same thing. You might confirm what "image size in pixels" you should give them for a 12 inch by 12 inch print.


 * If you want to better understand the pixels and dots conversions, here's some more information I just found.
 * The conversion website you used is assuming a dot is the same as a pixel. But this isn't always the case. Look at Wikipedia's Dots per inch article, section DPI measurement in printing, and look at the picture showing an image of a ball on a screen and on a printer. (Ignore the subsection "DPI or PPI in digital image files" for now. In that subsection, dot means the same as pixel, just like the conversion website you used.) To summarize the section and picture, for black or white images (no grayscale), 1 pixel needs 1 printed dot. But for color images, 1 pixel may need multiple printed dots. This is because printed dots will have a limited color palette, so each pixel needs to use more dots and dithering to match the source pixel colors.
 * Once you understand that, you could ask your printing company about the highest DPI they can print, and how one color pixel ends up in how many horizontal dots by how many vertical dots, then do all the conversion math yourself. This might be helpful to confirm you understand everything correctly and they didn't give you bad information. But if you trust they're doing the conversions correctly, just ask what image size, width by height, in pixels by pixels, you need to give them and you won't need to do any conversion math yourself. --Bavi H (talk) 04:11, 20 September 2014 (UTC)


 * 300dpi is standard. (ppi is the digital resolution, dpi is the printing resolution, though some folks/programs use them interchangeably) ...The image resolution can be adjusted a little higher or little lower, depending on image quality and printer quality. To get substantially higher, like the photo-quality you mentioned, takes a substantially better printer and thus cost. If you give them a 600dpi image and their printer can really only handle 300, the print may end up darker and possibly inferior to the 300 version. So I suggest that you either go back to that print shop and ask for someone else to help you understand it (that's part of their service, their job!) or else go somewhere else. You could even ask for the specifications ("specs") in writing, or where it's listed on their website, which is also standard in this business. And I'm not sure what your friend told you, but anyone working at a printing company should know the resolution details, and yes they do deal with digital images -- unless they are a specialty shop like screen printing or something else old-fashioned, yet  even then they should still know about what you're trying to do. Good luck. And FYI the Adobe forums (e.g. ) are a good place to read up on all this stuff. El duderino (abides) 09:18, 20 September 2014 (UTC)


 * I've had similar problems with print shops - and the bottom line seems to be that they simply can't guarantee 1 pixel on-disk == 1 dot on the paper. These large format printers seem to resize the image no matter what - and provide processing to sharpen the image, etc, etc.   So all efforts to get exact reproduction in a large-format printer have (so far) failed.   You'd hope that a large-format printer would be able to cope with at least 300dpi - and for the kind of fancy professional stuff those guys use, you'd hope it was more like 600 or 1000 dpi...but there is no way to be sure unless you can read the manual for the printer, muscle the print shop guy away from his PC and do it yourself!
 * SteveBaker (talk) 16:09, 22 September 2014 (UTC)


 * I agree with the earlier comments that many print shop workers simply don't understand pixels at all, and that you want to print at 100% or at least an integer fraction of that, like 50%, 25% or 20% (33 1/3 % could be tricky though). I'd ask to speak to somebody else, or find another print shop, until you find somebody who understands his job. StuRat (talk) 17:00, 22 September 2014 (UTC)