9600 dpi vs 4800dpi printers - can you tell the difference at A4??

Hi all,

A pretty random question but I'm happy with the results out of my Pixma ip7250 although ink prices (and paper for that matter) are increasing all the time.

The newly announced Canon G1510 with its refillable ink tanks looks to be a way of saving some money over time but only has a max print resolution of 4800dpi even though it seemingly has the same FINE print heads as the ip7250.

So, whereas I cannot see Canon bringing out a range of duds, can anyone with experience please advise on whether you really can tell the difference between the 2 print resolutions at a maximum of A4?

With many thanks,
Dave

A4 seen how far away? Inches away with a looking glass....or across the room? Viewing distance makes a huge difference in the needed dpi for a smooth looking image.

http://resources.print​handbook.com/pages/dpi​-for-printing.php

I think the "A" plus number method is kinda a UK thing or a European thing, perhaps? . Anyway, I had to look it up on Google just to know what size it really is.

For others who have no idea what these letters and numbers mean, the actual size of an A4 print is 8.3 inches by 11.7 inches.

Now for your question. . My eyes can only resolve about 150 to 200 DPI on a print, even when viewing at about 12 inches away. . I use 12 inches because my eyes will not focus any closer than that. . 12 inches is my personal MFD!

So no, I would not be able to tell any difference on an 8.3 inch by 11.7 inch print between the printer with 4800 and the printer with 9600.

But isn't printer DPI independent of print size, anyway?


.

9600 vs 4800 DPI is splitting hairs: there isn't much perceptual differences between them, and they can both handle 300 DPI images fine. They're a type of rating for how print dots are arranged (print dots aren't arranged in a square pattern), and so print resolutions are now often quoted as 9600x2400 or 4800x1200. Nowadays, the main features to look for in a pro printer are number of colors (for better color range) or dye vs pigmented inks (pigmented have been known to be able to be more archival, but certain dye inks are getting better).

According to Qimage, the printing program that reads the printer driver's calculations, Canon printers print at the resolution of about 600x600 DPI, where a Dot is the printed picture element that renders an image's pixel. In other words, it's the pixel's equivalent on paper. When you launch a printing process of a given size, the driver calculates the number of Dots it is going to put down to fulfill your order and resizes the incoming image file so that the number of pixels exactly matches the number of planned Dots.

For a Dot to appear in the exact same color as the pixel it is rendering, the Dot is formed by a cluster of droplets of available ink colors. The high resolution numbers from the specs are actually the number of those droplets per inch.

A higher number of droplets per inch (and therefore per Dot) won't help resolve more detail. Along with smaller droplet volumes it allows to create Dots of high color fidelity from a smaller number of ink shades (thus dismissing Light Cyan and Light Magenta as well as reducing the number of levels of Gray ink).

For those that might be interested the A series paper sizes are an international ISO standard, not just a British or European thing. The most important thing about the A series is the aspect ratio, which is 1:Root 2. By having this ratio if you halve the paper by cutting it in half through the long axis you always keep the same 1:Root 2 aspect ratio.

The numbering starts at A0 and this is a sheet of paper that is of the specified aspect ratio, and is exactly 1 square meter in area. The dimensions being 1.1892m by 0.8409m. The area of any particular size is 1/2^N m², where N is the number of the size. This means that A4 is 1/16 m² and is 297.3×210.2 mm.

The A series of papers are actually very useful, since I can use exactly the same page layout to produce an A5 leaflet as for the A0 poster. I believe that there are also at least 2 m² and 3 m² sizes to match if you need even bigger sizes.

Alan

I just finished 'testing' my new Canon Pixma Pro 100. I took a full Canon 5D4 image, resized it in PS CS4, and printed the entire, non-cropped image through the Lightroom print dialog onto several 3" x 5" sheets of Epson Premium Semi Gloss paper. (Not that it matters to this test, but I profiled/calibrated the printer using an i1 spectro and included software). I found that extremely fine details in the image printed smaller and clearer at 1,200 PPI than at 600 PPI, but were slightly less clear at 2240 PPI (6720 pixels into 3").

These results are the result of LR and/or the Canon print software massaging the image data before spraying ink droplets.

I then repeated a test I did on either an Epson 1280 or R1800, I don't recall, from many years ago.

I created an image consisting of a vertical, a horizontal, and a 45 degree single-pixel line, in each of CMYK and RGB fully-saturated colors. Abut each of these characters at the lower left corner to get an idea: |/_ .

I created these images at 300 PPI, 600 PPI, ans 1200 PPI. When printed, the 600 PPI lines were half the thickness of the 300 PPI lines, but the same saturation. The image at 1200 PPI had lines about 2/3 the thickness of the 600 PPI lines, and around half the saturation. (The printer cannot print at 1200 PPI, but does a fair job trying too). I then downsampled the 1200 PPI image to 600 PPI using CS4, and Bicubic Sharper. Surprisingly, this restored the color saturation while only slightly increasing the thickness of each single-pixel line from the size it was at 1200 PPI.

I achieved similar results with the Epson printer, long ago...

IOW, these inkjet printers can resolve solid, saturated details at far smaller physical sizes than most photograpers can imagine.

I also didn't see any reason to upsample an image to get sharper details. This might change if you are printing at less than 300 PPI.

As an aside, this new Canon shades yellow tree leaves without visible black in droplets. The same print, from the Epson R1800, has naked-eye visible black droplets in the same leaves. I don't know if this is due to smaller dye droplets from the Canon, vs the pigment droplets from the Epson, or some other technique... Both printers were profiled/calibrated on the specific paper used.

The print test can be seen at https://imgur.com/a/4w​MlF

Why is it that the question posed was about DOTS (of ink) per inch, yet some responses are about PIXELS (of captured photo) per inch

???

Dave,

As for your question about 9600 dots of ink vs. 4800 dots of ink, it is a simple thing to select the quality of output for a printer at time of printing (via the printer software selection) Then view each print under an 8X loupe (or simply use an 50mm lens if you have no loupe) to view the same area of a print, to determine the ability to see dots of ink on one print (at 9600) vs. the other (at 4800). You can determine for yourself at normal viewing distance vs. under 8x magnficatiuon, the 'value' of one ink resolution vs. other other, and the relative greater cost of ink in the quality vs. cost tradeoff.

YOU HAVE DECIDED TO IGNORE POSTS BY Wilt If you want to see the posts, the ignore list removal command is here.

I was going to reply. When I logged in, I realized why your response was inappropriate.

The human eye is said to resolve one minute of arc. At 12" viewing distance, that is 0.00384" of resolution. That is equivalent to 287 Pixels per inch when viewing a print from 12" distance (viewing the proverbial 8" x 10" print viewed at 12", which is assumed for most DOF calculators. That is HALF the image resolution provided by a 5DIV.

If we print ONE pixel at 9600 dots per inch, we have one pixel represented by 33.4 dots of ink,
If we print ONE pixel at 4800 dots per inch, we have one pixel represented by 16.7 dots of ink.

So expressed in terms of human visual acuity, 9600 dpi is about 33X the visual acuity of the human eye, while 4800 dpi is about 17X the visual acuity of the human eye, at the 12" viewing distance. You cannot really appreciate the difference in dots of ink unless you view the print at magnification with a loupe, and even with a 8X loupe you will scarcely be able to differentiate the two. It is only the tonal representation of a single pixel which could benefit from more dots of ink per pixel, but it actually needs to be viewed under magnification to even begin to be appreciated by the human eye.

If you produce a 32" tall print with 300 pixels per inch (as a lot of commercial printers insist upon as resolution of the original image file) you could view the 9600 dpi print from 12" away, it still has 9600 dots of ink for a single pixel, but (assuming you resized your original 5DIV image by 2.15X to produce a 9600 x 14400 pixel image demanded by the printer) the detail resolution of the upsized image is still no better than the original 4480 pixel tall sensor image (regardless of the ink dots used to portray each pixel.

Wilt wrote in post #18562139
The human eye is said to resolve one minute of arc. At 12" viewing distance, that is 0.00384" of resolution. That is equivalent to 287 Pixels per inch when viewing a print from 12" distance (viewing the proverbial 8" x 10" print viewed at 12", which is assumed for most DOF calculators. That is HALF the image resolution provided by a 5DIV.

If we print ONE pixel at 9600 dots per inch, we have one pixel represented by 33.4 dots of ink,
If we print ONE pixel at 4800 dots per inch, we have one pixel represented by 16.7 dots of ink.

So expressed in terms of human visual acuity, 9600 dpi is about 33X the visual acuity of the human eye, while 4800 dpi is about 17X the visual acuity of the human eye, at the 12" viewing distance. You cannot really appreciate the difference in dots of ink unless you view the print at magnification with a loupe, and even with a 8X loupe you will scarcely be able to differentiate the two. It is only the tonal representation of a single pixel which could benefit from more dots of ink per pixel, but it actually needs to be viewed under magnification to even begin to be appreciated by the human eye.

If you produce a 32" tall print with 300 pixels per inch (as a lot of commercial printers insist upon as resolution of the original image file) you could view the 9600 dpi print from 12" away, it still has 9600 dots of ink for a single pixel, but (assuming you resized your original 5DIV image by 2.15X to produce a 9600 x 14400 pixel image demanded by the printer) the detail resolution of the upsized image is still no better than the original 4480 pixel tall sensor image (regardless of the ink dots used to portray each pixel.

Wilt I'm going to disagree with you on the number of dots of ink in a pixel. On paper a pixel is a two dimensional object, and as such you really need to look at the print two dimensionally. Most printers seem to be asymmetric with ink resolution. Often being limited to only 2400 DPI in the direction that the paper travels.

In such a printer, with a resolution of 4800 DPI in the other direction you actually get 122 dots of ink per two dimensional pixel at 300 PPI. 9600 DPI then gets you 256 dots per pixel, as in most specs I have looked at in the past the other resolution stays firmly at 2400 DPI. My Pixma MG5150 is asymmetric in this way, at 9600×2400 DPI.

To be honest I don't really profess to have much idea just how the printer choses to lay down those 256 dots of ink per pixel, but what I do suspect is that the higher resolution allows for a better mixing of the ink, especially when using more colours like the Photo Cyan and Magenta, to better, and more consistently match the correct tone for the pixel.

Alan

Wilt, the printer's image-forming resolution (one image pixel to one printed dot) is 600x600 DPI.

The figures 9600 and 4800 specify droplets per inch, which (especially if combined with reduced droplet volumes) only help increase color accuracy and color smoothness, as they take place within each of the 600x600 pixel-related Dots.

A droplet is not a picture element - it's a technology that creates the requested color for the Dot, which is a picture element.

The number of droplets per inch has no impact on the printer's detail resolving power.

Of course, brainf*rt, dots are arrayed in two dimensions, so a single pixel is the product of horizontal dots and vertical dots (at the two densities are not the same in the printer) and not a single dimension to 'make a pixel' with ink.

Relative to the human eye's ability to resolve detail, we should consider a single dimension for the measure of the ink dots or pixels presented, so my 33 dots per pixel (in a single direction for 9600 dpi) stands.

agedbriar wrote in post #18562195
Wilt, the printer's image-forming resolution (one image pixel to one printed dot) is 600x600 DPI.

I have never seen that specified. Can you point me to a source for that dpi count? I have heard of Epson using one dpi and Canon using another dpi within their software, based upon the 'native resolution' of the print heads, yet tests have shown no direct correlation between the 'software dpi' assumption (e.g. 360 dpi in Epson's case) and 'best quality'.
Epson has published some specs, such as for its Stylus injet printers https://www.epson.eu …ducts/mainunits​/faq//4011

• 360 dpi "Select for medium-quality, standard text printing."
  
• 1440 dpi "Select for high-quality, photographic printing."
  
• 2880 dpi "Select for top-quality, photographic printing."
  
• 5760 dpi "Select for the highest and best print quality, photographic printing"
  ...and the Stylus 1280 has 2880 x 720 dpi output.
  

agedbriar wrote in post #18562195
The figures 9600 and 4800 specify droplets per inch, which (especially if combined with reduced droplet volumes) only help increase color accuracy and color smoothness, as they take place within each of the 600x600 pixel-related Dots.

A droplet is not a picture element - it's a technology that creates the requested color for the Dot, which is a picture element.

The number of droplets per inch has no impact on the printer's detail resolving power.

Indeed. The number of droplets per inch does not change with print size, like the number of pixels per inch will change.