Re: [H] Question on DPI and toner
At 02:09 AM 17/09/2014, Harry McGregor wrote: Yes, as long as all of the dots use the same amount of toner, ie as long as the intensity is the same. If the intensity changes, IMHO, that is not directly related to the DPI, but some printer makers may take advantage of the smaller dots and take advantage of those in a low dpi mode to lower overall toner use. Very interesting. So there's a chance that the people decreasing their DPI to save toner are actually using more. :) T
Re: [H] Question on DPI and toner
On 09/15/2014 04:58 PM, DSinc wrote: Harry, We continue to disagree minorly. I understand your position. I just do not agree. :) But, FINE, inthe end we sorta get our prints at either 1200dpi or 600dpi. I still do not comprehend your use of 'Grayscale.' Sorry, I just do not get this. If it works for you, fine. I just do not comprehend r what you are talking about. In my world, 'Grayscale' is a photographic term ONLY. It is not part of a xerographic laser printer. Laser printers (mostly) WRITE WHITE. I rendered the image in 8 bit grayscale, but I only looked at pixels that were white. I counted all other pixels as black. Technically I should render it as 1 bit color (Black and white). Here are the numbers with 1 bit color. hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 1200dpi_A.tif -format %c -depth 1 histogram:info:- | egrep '(white|black)' 232834: ( 0, 0, 0,255) #00 black 1207166: (255,255,255,255) #FF white 144 Total pixes, which is 1200x1200 Taking the number of white pixels and dividing by 4 (since it takes 4 of these pixels to equal the size of 1 600DPI pixel) = 301791.5 hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 600dpi_A.tif -format %c -depth 1 histogram:info:- | egrep '(white|black)' 58449: ( 0, 0, 0,255) #00 black 301551: (255,255,255,255) #FF white 36 Total Pixels, which is 600x600 If we subtract the number of 600DPI white pixels from the number of same as 600DPI 1200 DPI white pixels, we get 240.5 extra 600DPI sized white pixels when printing with 1200 DPI then when printing with 600 DPI, which necessitates, that we saved 240.5 600DPI pixels worth of toner, or 962 1200 DPI pixels worth of toner, by using 1200 DPI instead of 600DPI to print the very large letter A. The laser is turned off or delflected to leave a 'black dot' or printable area. This latent image is what the toner cartridge helps to deliver to the incoming page of paper. The fuser fixes/melts the latent image to the paper fibers. The result is a printed page. Yes it still seems like magic to me after all these years! But, I see the magic each time I print a page. It's a lot of very cool technology, but I think the way HP listed resolutions with a print style together with the resolution, like 600DPI Econo Mode and 1200DPI HiRes have warped the thinking on this. As long as you don't change the intensity or amount of toner per pixel, the 1200DPI is less toner, once you start messing with the intensity, all bets are off. The reality is the amount less is so little, it really does not matter. If you can stand reading econo mode it saves toner, beyond that, don't use hi res or other very high quality settings, and you won't use too much extra. -Harry Best, Duncan On 09/15/2014 18:33, Harry McGregor wrote: Hi Duncan, I think we are basically talking about the same thing. A lot of people confuse DPI with print quality. You can have a 1200 DPI, 1200 DPI high quality, 600DPI and 600DPI Draft settings. The 1200 DPI high quality will be visibly darker, the 600 DPI draft will be visibly lighter. A standard 1200DPI and standard 600 DPI setting on the same printer should use slightly less toner on the 1200DPI setting. I can do a print to file or a print to paper, the upside with a print to file is I don't have to count the dots. Grayscale is still the most common laser printer, color lasers are more common then before, but no where near the level of grayscale. I could do the images as black and white only, all that is going to do is slightly increase the white pixel count, as some of the gray pixels will fall to white instead of black, it won't really change it much. My background with this is about 12 years ago, I implemented a print quote system that actually took into account the coverage on the page to charge the student accounts the right amount. Ie if some stupid student decided that they liked reading white text on a black background, they would get billed about about 20x as much as printing black text on a white background. When you setup the environment you tell the system the cost per toner cartridge, the rated coverage from the MFG, the cost per sheet of paper, etc. The software was called printbill, the most recent update was in 2006... http://sourceforge.net/projects/pqadmin/files/printbill/4.2.1/ looks like the official website is gone, but this page has some info on it: http://linuxappfinder.com/package/printbill and the archive.org version of the official site: https://web.archive.org/web/20090202073731/http://ieee.uow.edu.au/~daniel/software/printbill -Harry On 09/15/2014 03:10 PM, DSinc wrote: Harry, I will give you what you believe. No harm, no foul! I just don't get your discourse. I only did 33 years supporting these beasties; and yes, 'Print Quality' was the primary service call. But still, I could be wrong. Will not be the first time! Yes,
Re: [H] Question on DPI and toner
At 03:20 AM 16/09/2014, Harry McGregor wrote: If we subtract the number of 600DPI white pixels from the number of same as 600DPI 1200 DPI white pixels, we get 240.5 extra 600DPI sized white pixels when printing with 1200 DPI then when printing with 600 DPI, which necessitates, that we saved 240.5 600DPI pixels worth of toner, or 962 1200 DPI pixels worth of toner, by using 1200 DPI instead of 600DPI to print the very large letter A. Harry, are you saying that at 1200 dpi, you're saving toner over printing at 600 dpi? That's the reverse of what I've read up to this point. T
Re: [H] Question on DPI and toner
On 09/16/2014 03:38 AM, Thane Sherrington wrote: At 03:20 AM 16/09/2014, Harry McGregor wrote: If we subtract the number of 600DPI white pixels from the number of same as 600DPI 1200 DPI white pixels, we get 240.5 extra 600DPI sized white pixels when printing with 1200 DPI then when printing with 600 DPI, which necessitates, that we saved 240.5 600DPI pixels worth of toner, or 962 1200 DPI pixels worth of toner, by using 1200 DPI instead of 600DPI to print the very large letter A. Harry, are you saying that at 1200 dpi, you're saving toner over printing at 600 dpi? That's the reverse of what I've read up to this point. Yes, as long as all of the dots use the same amount of toner, ie as long as the intensity is the same. If the intensity changes, IMHO, that is not directly related to the DPI, but some printer makers may take advantage of the smaller dots and take advantage of those in a low dpi mode to lower overall toner use. -Harry T
[H] Question on DPI and toner
I've heard recently that decreasing the DPI on a laser printer will save toner. Thinking about it, I can't see how the savings would be that great, if any. Does anyone know if this is true? T
Re: [H] Question on DPI and toner
Thane, Quite correct.Not truly quantifiable, but if you normally use 1200dpi, reducing the resolution to 600dpi equates to a 50% savings per image/page. Reducing resolution to 300fpi equates to a 75% savings per image/page. But, I do not know how to compute these savings into dollars and/or cartridge life. In our modern world this may be a good trail/error user test with their printer. I have never done this-I still run default resolution; and, grumble about cartridge replacement costs. I spent too many years at Xerox reading memos and such printed on our laser printers stuck at 300dpi and never had trouble reading the printed traffic. Yes, some fonts printed worse than others. Pictures/pix could be pretty bad(lack of fine detail), butacceptable for normal business. I do not use reman cartridges. I buy new. I do not refill used cartridges. Hope this helps, Duncan On 09/15/2014 09:20, Thane Sherrington wrote: I've heard recently that decreasing the DPI on a laser printer will save toner. Thinking about it, I can't see how the savings would be that great, if any. Does anyone know if this is true? T
Re: [H] Question on DPI and toner
At 02:12 PM 15/09/2014, DSinc wrote: Thane, Quite correct.Not truly quantifiable, but if you normally use 1200dpi, reducing the resolution to 600dpi equates to a 50% savings per image/page. Reducing resolution to 300fpi equates to a 75% savings per image/page. But, I do not know how to compute these savings into dollars and/or cartridge life. In our modern world this may be a good trail/error user test with their printer. I have never done this-I still run default resolution; and, grumble about cartridge replacement costs. I spent too many years at Xerox reading memos and such printed on our laser printers stuck at 300dpi and never had trouble reading the printed traffic. Yes, some fonts printed worse than others. Pictures/pix could be pretty bad(lack of fine detail), butacceptable for normal business. Thanks Duncan, that's a significant savings per page. I wonder what resolution is being used when manufacturers calculate the number of pages from a toner? T
Re: [H] Question on DPI and toner
Thane, There is a complex formula and special page image that most priter companies use to help them compute (fabricate/lie) about their printed pages/catridge. Please note that this business does NOT use 100% coverage. I just do not know many folk that print fully black pages. I have to claim age/time/forgetfulness for not recalling what the 'coverage' percentage was/is. But I do recall that there is a specification about this the all printer makers try to meet/exceed. And, alot of this has do do with various makers 'image generators.' HTH, Duncan On 09/15/2014 13:27, Thane Sherrington wrote: At 02:12 PM 15/09/2014, DSinc wrote: Thane, Quite correct.Not truly quantifiable, but if you normally use 1200dpi, reducing the resolution to 600dpi equates to a 50% savings per image/page. Reducing resolution to 300fpi equates to a 75% savings per image/page. But, I do not know how to compute these savings into dollars and/or cartridge life. In our modern world this may be a good trail/error user test with their printer. I have never done this-I still run default resolution; and, grumble about cartridge replacement costs. I spent too many years at Xerox reading memos and such printed on our laser printers stuck at 300dpi and never had trouble reading the printed traffic. Yes, some fonts printed worse than others. Pictures/pix could be pretty bad(lack of fine detail), butacceptable for normal business. Thanks Duncan, that's a significant savings per page. I wonder what resolution is being used when manufacturers calculate the number of pages from a toner? T
Re: [H] Question on DPI and toner
At 02:58 PM 15/09/2014, DSinc wrote: Thane, There is a complex formula and special page image that most priter companies use to help them compute (fabricate/lie) about their printed pages/catridge. Please note that this business does NOT use 100% coverage. I just do not know many folk that print fully black pages. I have to claim age/time/forgetfulness for not recalling what the 'coverage' percentage was/is. But I do recall that there is a specification about this the all printer makers try to meet/exceed. And, alot of this has do do with various makers 'image generators.' Hi Duncan, Yeah, I know about the page used (I've seen a copy from Lexmark). I was just wondering if they are printing this page at 300dpi or 1200 dpi when they come up with the number of pages a toner will print. I was sitting down with graph paper trying to figure out the dot coverage, so I appreciate your help. :) T
Re: [H] Question on DPI and toner
Thane, My past understanding is/was that 'they' print those pages at their marketed DPI. Fudge factors notwithstanding post further computational anomalies. HTH, Duncan On 09/15/2014 14:15, Thane Sherrington wrote: At 02:58 PM 15/09/2014, DSinc wrote: Thane, There is a complex formula and special page image that most priter companies use to help them compute (fabricate/lie) about their printed pages/catridge. Please note that this business does NOT use 100% coverage. I just do not know many folk that print fully black pages. I have to claim age/time/forgetfulness for not recalling what the 'coverage' percentage was/is. But I do recall that there is a specification about this the all printer makers try to meet/exceed. And, alot of this has do do with various makers 'image generators.' Hi Duncan, Yeah, I know about the page used (I've seen a copy from Lexmark). I was just wondering if they are printing this page at 300dpi or 1200 dpi when they come up with the number of pages a toner will print. I was sitting down with graph paper trying to figure out the dot coverage, so I appreciate your help. :) T
Re: [H] Question on DPI and toner
I don't agree that it has a direct relationship. I really depends on how the printer deals with it. If the printer does 600 vs 1200 DPI by skipping dots, then lower DPI would save toner. ie (linear only, not showing the other axis) 600 DPI skipped X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Vs 600 DPI Big XX XX XX XX 1200 DPI may use a bit more or a bit less toner depending on the way the printer renders it, but in most cases I would not expect a significant change unless the printer was sill using 1200DPI dots, and skipping pixels. -Harry On 09/15/2014 11:15 AM, Thane Sherrington wrote: At 02:58 PM 15/09/2014, DSinc wrote: Thane, There is a complex formula and special page image that most priter companies use to help them compute (fabricate/lie) about their printed pages/catridge. Please note that this business does NOT use 100% coverage. I just do not know many folk that print fully black pages. I have to claim age/time/forgetfulness for not recalling what the 'coverage' percentage was/is. But I do recall that there is a specification about this the all printer makers try to meet/exceed. And, alot of this has do do with various makers 'image generators.' Hi Duncan, Yeah, I know about the page used (I've seen a copy from Lexmark). I was just wondering if they are printing this page at 300dpi or 1200 dpi when they come up with the number of pages a toner will print. I was sitting down with graph paper trying to figure out the dot coverage, so I appreciate your help. :) T
Re: [H] Question on DPI and toner
Harry, I am so glad you disagree'd. But, you miss the point. Itis not 'skipping dots'! It is how many dpi the printer does. The 'inch' is a fixed number. On my old BrandX printers we did 90K dots/sq in. This produced a totally black square 1in.x1in. The way the printer 'IT' is how the IG 'draws' IT. I accept your pix of two resolutions, but I do not agree. Our 1 inch/square printed 'targets' just got lighter; nothing more. There wasnohorizontal/vertical difference. Thank you for your () add, but the other axis is quite part of this whole equation. All your pix shows me is 'character spacing.' That is totally IG control. Has little to do with resolution. HTH, Duncan On 09/15/2014 15:26, Harry McGregor wrote: I don't agree that it has a direct relationship. I really depends on how the printer deals with it. If the printer does 600 vs 1200 DPI by skipping dots, then lower DPI would save toner. ie (linear only, not showing the other axis) 600 DPI skipped X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Vs 600 DPI Big XX XX XX XX 1200 DPI may use a bit more or a bit less toner depending on the way the printer renders it, but in most cases I would not expect a significant change unless the printer was sill using 1200DPI dots, and skipping pixels. -Harry On 09/15/2014 11:15 AM, Thane Sherrington wrote: At 02:58 PM 15/09/2014, DSinc wrote: Thane, There is a complex formula and special page image that most priter companies use to help them compute (fabricate/lie) about their printed pages/catridge. Please note that this business does NOT use 100% coverage. I just do not know many folk that print fully black pages. I have to claim age/time/forgetfulness for not recalling what the 'coverage' percentage was/is. But I do recall that there is a specification about this the all printer makers try to meet/exceed. And, alot of this has do do with various makers 'image generators.' Hi Duncan, Yeah, I know about the page used (I've seen a copy from Lexmark). I was just wondering if they are printing this page at 300dpi or 1200 dpi when they come up with the number of pages a toner will print. I was sitting down with graph paper trying to figure out the dot coverage, so I appreciate your help. :) T
Re: [H] Question on DPI and toner
Hi, So I went a step farther, I generated two grayscale images. 600x600 DPI, 1 inch 1200x1200 DPI, 1 inch In each is a rendered letter A, and it was saved as an LZW tiff, so no lossy compression involved. I only looked for White pixes, counting anything with any shading in it as using toner, which is a little overkill. hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 600dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 300762: (255,255,255,255) #FF white hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 1200dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 1205231: (255,255,255,255) #FF white I took the white pixels in the 1200dpi and divide by 4 to get the equivalent area coverage of 600: 1205231/4 = 301307.7500 I subtracted the white pixels of the 600 DPI image from the white pixels of the 1200 DPI image, and found: 301307.75-300762=545 So that means the 1200 DPI image has more white in it, but not by much. If you want to look at the grayscale aspects you can as well, but overall, unless the printer is printing lighter at 600 DPI (ie using the 1200DPI size pixels, and leaving space between pixels, which printers tend to only do when in Draft mode), lowering the DPI does not save toner. This does not take into account waste toner, and some printers, especially color lasers have more waste toner collection then others. Most grayscale printers don't have waste toner collection, and instead the waste is re-used within the toner cartridge. -Harry On 09/15/2014 01:44 PM, DSinc wrote: Harry, I am so glad you disagree'd. But, you miss the point. Itis not 'skipping dots'! It is how many dpi the printer does. The 'inch' is a fixed number. On my old BrandX printers we did 90K dots/sq in. This produced a totally black square 1in.x1in. The way the printer 'IT' is how the IG 'draws' IT. I accept your pix of two resolutions, but I do not agree. Our 1 inch/square printed 'targets' just got lighter; nothing more. There wasnohorizontal/vertical difference. Thank you for your () add, but the other axis is quite part of this whole equation. All your pix shows me is 'character spacing.' That is totally IG control. Has little to do with resolution. HTH, Duncan On 09/15/2014 15:26, Harry McGregor wrote: I don't agree that it has a direct relationship. I really depends on how the printer deals with it. If the printer does 600 vs 1200 DPI by skipping dots, then lower DPI would save toner. ie (linear only, not showing the other axis) 600 DPI skipped X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Vs 600 DPI Big XX XX XX XX 1200 DPI may use a bit more or a bit less toner depending on the way the printer renders it, but in most cases I would not expect a significant change unless the printer was sill using 1200DPI dots, and skipping pixels. -Harry On 09/15/2014 11:15 AM, Thane Sherrington wrote: At 02:58 PM 15/09/2014, DSinc wrote: Thane, There is a complex formula and special page image that most priter companies use to help them compute (fabricate/lie) about their printed pages/catridge. Please note that this business does NOT use 100% coverage. I just do not know many folk that print fully black pages. I have to claim age/time/forgetfulness for not recalling what the 'coverage' percentage was/is. But I do recall that there is a specification about this the all printer makers try to meet/exceed. And, alot of this has do do with various makers 'image generators.' Hi Duncan, Yeah, I know about the page used (I've seen a copy from Lexmark). I was just wondering if they are printing this page at 300dpi or 1200 dpi when they come up with the number of pages a toner will print. I was sitting down with graph paper trying to figure out the dot coverage, so I appreciate your help. :) T
Re: [H] Question on DPI and toner
Harry, I will give you what you believe. No harm, no foul! I just don't get your discourse. I only did 33 years supporting these beasties; and yes, 'Print Quality' was the primary service call. But still, I could be wrong. Will not be the first time! Yes, spurious toner isa problem. I don't speak to this. I assume the developer housing seals are OK.Please let's not have a tomAtoes/tomahtoes disucssion. OK. Why 2 grayscale images? Grayscale seems to be some special setting. What does 'grayscale' prove? Why not print a 36 point (or even larger) 'A' at both 1200dpi and 600dpi? There should be a visible difference. I'll assume you have an eye-loupe or a magnifying glass. JMHO, Duncan On 09/15/2014 17:28, Harry McGregor wrote: Hi, So I went a step farther, I generated two grayscale images. 600x600 DPI, 1 inch 1200x1200 DPI, 1 inch In each is a rendered letter A, and it was saved as an LZW tiff, so no lossy compression involved. I only looked for White pixes, counting anything with any shading in it as using toner, which is a little overkill. hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 600dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 300762: (255,255,255,255) #FF white hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 1200dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 1205231: (255,255,255,255) #FF white I took the white pixels in the 1200dpi and divide by 4 to get the equivalent area coverage of 600: 1205231/4 = 301307.7500 I subtracted the white pixels of the 600 DPI image from the white pixels of the 1200 DPI image, and found: 301307.75-300762=545 So that means the 1200 DPI image has more white in it, but not by much. If you want to look at the grayscale aspects you can as well, but overall, unless the printer is printing lighter at 600 DPI (ie using the 1200DPI size pixels, and leaving space between pixels, which printers tend to only do when in Draft mode), lowering the DPI does not save toner. This does not take into account waste toner, and some printers, especially color lasers have more waste toner collection then others. Most grayscale printers don't have waste toner collection, and instead the waste is re-used within the toner cartridge. -Harry On 09/15/2014 01:44 PM, DSinc wrote: Harry, I am so glad you disagree'd. But, you miss the point. Itis not 'skipping dots'! It is how many dpi the printer does. The 'inch' is a fixed number. On my old BrandX printers we did 90K dots/sq in. This produced a totally black square 1in.x1in. The way the printer 'IT' is how the IG 'draws' IT. I accept your pix of two resolutions, but I do not agree. Our 1 inch/square printed 'targets' just got lighter; nothing more. There wasnohorizontal/vertical difference. Thank you for your () add, but the other axis is quite part of this whole equation. All your pix shows me is 'character spacing.' That is totally IG control. Has little to do with resolution. HTH, Duncan On 09/15/2014 15:26, Harry McGregor wrote: I don't agree that it has a direct relationship. I really depends on how the printer deals with it. If the printer does 600 vs 1200 DPI by skipping dots, then lower DPI would save toner. ie (linear only, not showing the other axis) 600 DPI skipped X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Vs 600 DPI Big XX XX XX XX 1200 DPI may use a bit more or a bit less toner depending on the way the printer renders it, but in most cases I would not expect a significant change unless the printer was sill using 1200DPI dots, and skipping pixels. -Harry On 09/15/2014 11:15 AM, Thane Sherrington wrote: At 02:58 PM 15/09/2014, DSinc wrote: Thane, There is a complex formula and special page image that most priter companies use to help them compute (fabricate/lie) about their printed pages/catridge. Please note that this business does NOT use 100% coverage. I just do not know many folk that print fully black pages. I have to claim age/time/forgetfulness for not recalling what the 'coverage' percentage was/is. But I do recall that there is a specification about this the all printer makers try to meet/exceed. And, alot of this has do do with various makers 'image generators.' Hi Duncan, Yeah, I know about the page used (I've seen a copy from Lexmark). I was just wondering if they are printing this page at 300dpi or 1200 dpi when they come up with the number of pages a toner will print. I was sitting down with graph paper trying to figure out the dot coverage, so I appreciate your help. :) T
Re: [H] Question on DPI and toner
Hi Duncan, I think we are basically talking about the same thing. A lot of people confuse DPI with print quality. You can have a 1200 DPI, 1200 DPI high quality, 600DPI and 600DPI Draft settings. The 1200 DPI high quality will be visibly darker, the 600 DPI draft will be visibly lighter. A standard 1200DPI and standard 600 DPI setting on the same printer should use slightly less toner on the 1200DPI setting. I can do a print to file or a print to paper, the upside with a print to file is I don't have to count the dots. Grayscale is still the most common laser printer, color lasers are more common then before, but no where near the level of grayscale. I could do the images as black and white only, all that is going to do is slightly increase the white pixel count, as some of the gray pixels will fall to white instead of black, it won't really change it much. My background with this is about 12 years ago, I implemented a print quote system that actually took into account the coverage on the page to charge the student accounts the right amount. Ie if some stupid student decided that they liked reading white text on a black background, they would get billed about about 20x as much as printing black text on a white background. When you setup the environment you tell the system the cost per toner cartridge, the rated coverage from the MFG, the cost per sheet of paper, etc. The software was called printbill, the most recent update was in 2006... http://sourceforge.net/projects/pqadmin/files/printbill/4.2.1/ looks like the official website is gone, but this page has some info on it: http://linuxappfinder.com/package/printbill and the archive.org version of the official site: https://web.archive.org/web/20090202073731/http://ieee.uow.edu.au/~daniel/software/printbill -Harry On 09/15/2014 03:10 PM, DSinc wrote: Harry, I will give you what you believe. No harm, no foul! I just don't get your discourse. I only did 33 years supporting these beasties; and yes, 'Print Quality' was the primary service call. But still, I could be wrong. Will not be the first time! Yes, spurious toner isa problem. I don't speak to this. I assume the developer housing seals are OK.Please let's not have a tomAtoes/tomahtoes disucssion. OK. Why 2 grayscale images? Grayscale seems to be some special setting. What does 'grayscale' prove? Why not print a 36 point (or even larger) 'A' at both 1200dpi and 600dpi? There should be a visible difference. I'll assume you have an eye-loupe or a magnifying glass. JMHO, Duncan On 09/15/2014 17:28, Harry McGregor wrote: Hi, So I went a step farther, I generated two grayscale images. 600x600 DPI, 1 inch 1200x1200 DPI, 1 inch In each is a rendered letter A, and it was saved as an LZW tiff, so no lossy compression involved. I only looked for White pixes, counting anything with any shading in it as using toner, which is a little overkill. hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 600dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 300762: (255,255,255,255) #FF white hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 1200dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 1205231: (255,255,255,255) #FF white I took the white pixels in the 1200dpi and divide by 4 to get the equivalent area coverage of 600: 1205231/4 = 301307.7500 I subtracted the white pixels of the 600 DPI image from the white pixels of the 1200 DPI image, and found: 301307.75-300762=545 So that means the 1200 DPI image has more white in it, but not by much. If you want to look at the grayscale aspects you can as well, but overall, unless the printer is printing lighter at 600 DPI (ie using the 1200DPI size pixels, and leaving space between pixels, which printers tend to only do when in Draft mode), lowering the DPI does not save toner. This does not take into account waste toner, and some printers, especially color lasers have more waste toner collection then others. Most grayscale printers don't have waste toner collection, and instead the waste is re-used within the toner cartridge. -Harry On 09/15/2014 01:44 PM, DSinc wrote: Harry, I am so glad you disagree'd. But, you miss the point. Itis not 'skipping dots'! It is how many dpi the printer does. The 'inch' is a fixed number. On my old BrandX printers we did 90K dots/sq in. This produced a totally black square 1in.x1in. The way the printer 'IT' is how the IG 'draws' IT. I accept your pix of two resolutions, but I do not agree. Our 1 inch/square printed 'targets' just got lighter; nothing more. There wasnohorizontal/vertical difference. Thank you for your () add, but the other axis is quite part of this whole equation. All your pix shows me is 'character spacing.' That is totally IG control. Has little to do with resolution. HTH, Duncan On 09/15/2014 15:26, Harry McGregor wrote: I don't agree that it has a direct
Re: [H] Question on DPI and toner
At 06:28 PM 15/09/2014, Harry McGregor wrote: Hi, So I went a step farther, I generated two grayscale images. 600x600 DPI, 1 inch 1200x1200 DPI, 1 inch In each is a rendered letter A, and it was saved as an LZW tiff, so no lossy compression involved. I only looked for White pixes, counting anything with any shading in it as using toner, which is a little overkill. hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 600dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 300762: (255,255,255,255) #FF white hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 1200dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 1205231: (255,255,255,255) #FF white I took the white pixels in the 1200dpi and divide by 4 to get the equivalent area coverage of 600: 1205231/4 = 301307.7500 I subtracted the white pixels of the 600 DPI image from the white pixels of the 1200 DPI image, and found: 301307.75-300762=545 This is what I was attempting to do with my graph paper, and I get the same sort of results. On the other hand, Duncan's experience differs, and he has a lot of it, which is hard to argue with. :) T
Re: [H] Question on DPI and toner
Harry, We continue to disagree minorly. I understand your position. I just do not agree. But, FINE, inthe end we sorta get our prints at either 1200dpi or 600dpi. I still do not comprehend your use of 'Grayscale.' Sorry, I just do not get this. If it works for you, fine. I just do not comprehend what you are talking about. In my world, 'Grayscale' is a photographic term ONLY. It is not part of a xerographic laser printer. Laser printers (mostly) WRITE WHITE. The laser is turned off or delflected to leave a 'black dot' or printable area. This latent image is what the toner cartridge helps to deliver to the incoming page of paper. The fuser fixes/melts the latent image to the paper fibers. The result is a printed page. Yes it still seems like magic to me after all these years! But, I see the magic each time I print a page. Best, Duncan On 09/15/2014 18:33, Harry McGregor wrote: Hi Duncan, I think we are basically talking about the same thing. A lot of people confuse DPI with print quality. You can have a 1200 DPI, 1200 DPI high quality, 600DPI and 600DPI Draft settings. The 1200 DPI high quality will be visibly darker, the 600 DPI draft will be visibly lighter. A standard 1200DPI and standard 600 DPI setting on the same printer should use slightly less toner on the 1200DPI setting. I can do a print to file or a print to paper, the upside with a print to file is I don't have to count the dots. Grayscale is still the most common laser printer, color lasers are more common then before, but no where near the level of grayscale. I could do the images as black and white only, all that is going to do is slightly increase the white pixel count, as some of the gray pixels will fall to white instead of black, it won't really change it much. My background with this is about 12 years ago, I implemented a print quote system that actually took into account the coverage on the page to charge the student accounts the right amount. Ie if some stupid student decided that they liked reading white text on a black background, they would get billed about about 20x as much as printing black text on a white background. When you setup the environment you tell the system the cost per toner cartridge, the rated coverage from the MFG, the cost per sheet of paper, etc. The software was called printbill, the most recent update was in 2006... http://sourceforge.net/projects/pqadmin/files/printbill/4.2.1/ looks like the official website is gone, but this page has some info on it: http://linuxappfinder.com/package/printbill and the archive.org version of the official site: https://web.archive.org/web/20090202073731/http://ieee.uow.edu.au/~daniel/software/printbill -Harry On 09/15/2014 03:10 PM, DSinc wrote: Harry, I will give you what you believe. No harm, no foul! I just don't get your discourse. I only did 33 years supporting these beasties; and yes, 'Print Quality' was the primary service call. But still, I could be wrong. Will not be the first time! Yes, spurious toner isa problem. I don't speak to this. I assume the developer housing seals are OK.Please let's not have a tomAtoes/tomahtoes disucssion. OK. Why 2 grayscale images? Grayscale seems to be some special setting. What does 'grayscale' prove? Why not print a 36 point (or even larger) 'A' at both 1200dpi and 600dpi? There should be a visible difference. I'll assume you have an eye-loupe or a magnifying glass. JMHO, Duncan On 09/15/2014 17:28, Harry McGregor wrote: Hi, So I went a step farther, I generated two grayscale images. 600x600 DPI, 1 inch 1200x1200 DPI, 1 inch In each is a rendered letter A, and it was saved as an LZW tiff, so no lossy compression involved. I only looked for White pixes, counting anything with any shading in it as using toner, which is a little overkill. hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 600dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 300762: (255,255,255,255) #FF white hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 1200dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 1205231: (255,255,255,255) #FF white I took the white pixels in the 1200dpi and divide by 4 to get the equivalent area coverage of 600: 1205231/4 = 301307.7500 I subtracted the white pixels of the 600 DPI image from the white pixels of the 1200 DPI image, and found: 301307.75-300762=545 So that means the 1200 DPI image has more white in it, but not by much. If you want to look at the grayscale aspects you can as well, but overall, unless the printer is printing lighter at 600 DPI (ie using the 1200DPI size pixels, and leaving space between pixels, which printers tend to only do when in Draft mode), lowering the DPI does not save toner. This does not take into account waste toner, and some printers, especially color lasers have more waste toner collection then others. Most grayscale printers don't have
Re: [H] Question on DPI and toner
Thane, NO. I can be argued with forever, but, I do not think I will agree with Harry. If you see results that lean one way or the other, fine. All I can speak is my experience with laser printers. Happy to share, however. Best, Duncan On 09/15/2014 18:52, Thane Sherrington wrote: At 06:28 PM 15/09/2014, Harry McGregor wrote: Hi, So I went a step farther, I generated two grayscale images. 600x600 DPI, 1 inch 1200x1200 DPI, 1 inch In each is a rendered letter A, and it was saved as an LZW tiff, so no lossy compression involved. I only looked for White pixes, counting anything with any shading in it as using toner, which is a little overkill. hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 600dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 300762: (255,255,255,255) #FF white hmcgregor@hmcgregor-Satellite-L75D-A:~/Documents$ convert 1200dpi_A.tif -format %c -depth 8 histogram:info:- | grep white 1205231: (255,255,255,255) #FF white I took the white pixels in the 1200dpi and divide by 4 to get the equivalent area coverage of 600: 1205231/4 = 301307.7500 I subtracted the white pixels of the 600 DPI image from the white pixels of the 1200 DPI image, and found: 301307.75-300762=545 This is what I was attempting to do with my graph paper, and I get the same sort of results. On the other hand, Duncan's experience differs, and he has a lot of it, which is hard to argue with. :) T
