What is the best print output resolution for the Canon i9900/i9950?

[richpate]

I noticed that in Canon's Digital Photo Professional software and Photoshop Elements there is an indication, sometimes adjustable in preferences, about the default output resolution for the printer. DPP has a value of 350 dpi already in the preference box, which can be changed. However, I can't find the "ideal" output resolution in my printer manual, just the print-head resolution of 4800x2400 dpi. One website says 300 dpi for Canon Printers, 360 dpi for Epson.

Does anyone know the "ideal" output resolution setting for the i9900/i9950 printer? Thanks.

 

[ghwellsjr]

According to this link provided to me by Grandad35, http://www.ddisoftware.com/qimage/quality/ the native resolutions of these printers is double what you posted.

The i9900/i9950 have two sets of nozzles that are spaced 600 dpi and offset from each other so the effective resolution could be double that but I believe that one set is used when printing in one direction and the other set when printing in the other direction. However, according to Grandad35, the dpi is different from the resolution that an application sends information to the printer. I think the printer is using all that extra dpi to lay down several drops of ink to control colors and shades better.

 

[Tin Ho]

I always resize my image to 300 pixels per inch to print regardless what the image's resolution is. I have some jpg images of file size even less than 150 KBytes. They are really low resolution images. If I print them without resizing to 200 - 300 pixels per inch the print will look soft (low sharpness). But they will look sharp if they are resized to 300 pixels/inch. The interpolation (increasing resolution) does make a difference. I was surprised by discovering this. Perhaps there is something I do not understand about the images. My guess is they were originally high resolution. But the compression reduced their file sizes to really small. When I resized them to 300 pixel/inch (interpolation applies) the sharpness of the images were brought back.

 

[richpate]

Thanks everyone for responding, some good info.

My question was originally spawned by a statement I read in onOne's Genuine Fractals software manual concerning final print resolution which stated, "A common mistake is to set the resolution of the file to the resolution of the printer (4800x2400dpi). The secret is that the human eye can not see much more than 250-300 pixels per inch. So the ideal resolution for your files should be close to this and be an even multiple of the printer's resolution."

So, how should I interpret that statement relative to doing 13x19" enlargements on my i9900 printer?

 

[Tin Ho]

I use Photoshop to print photos. What I do is to go under Image Manual then click on Image Size. It will pop up a small Image Size window in which you can resize your image to fit your 13x19 paper and you can reset the resolution to 300 pixels per inch. Photoshop will resize your image file by interpolation. It will be printed by your printer with no further adjustment of the size and resolution by the printer setup. Unless the image is one that has a resolution too low to begin with this has always worked for me.

 

[richpate]

I use Photoshop to print photos. What I do is to go under Image Manual then click on Image Size. It will pop up a small Image Size window in which you can resize your image to fit your 13x19 paper and you can reset the resolution to 300 pixels per inch. Photoshop will resize your image file by interpolation...

Thanks, Tin Ho. I guess that's the magic word, "interpolation," or I think sometimes called "resampling." It's my understanding (what little I have) that the best output resolution setting (300dpi?) is one that will result in the sharpest enlargement your image-file/printer combination is capable of -- thus a setting requiring the least distortion of the image data during the interpolation process.

Does anyone know exactly how interpolation works and how to "help" the process towards the sharpest enlargement possible? Sounds like the onOne folks are inferring that you help interpolation by using the best output rez setting for your printer, and with it being "an even multiple of the printer's resolution," whatever that means exactly -- the setting or print size? :/

 

[Smile]

Enlarge using Genuine Fractal Print Pro plug-in for photoshop. It will allow to keep the quality as it enlarges by mathematical formulas and avoids pixelation problems like normal enlargement in photoshop or other programs.

Make supre you get at least 300DPI for photographic prints.

What is perhaps most confusing is this 300DPI you see here and there. You have to understand that 300DPI is simply a means to say that an image can be printed to photographic quality standards. These standards are for normal photos.

If you for example tried to print something very delicate like stamps or money, you would need at least 1200DPI. Or better yet 2000DPI because you need to scan them at this resolution.

Resolution can be optical or real print resolution and interpolated what you see on your printer specs etc. This is just marketing to make you buy a printer or scanner that has higher resolution on paper. Real printer or scanner resolution can be found in technical documentation such as service manuals.

 

[Grandad35]

I highly recommend reading the information published on this subject by Mike Cheney (previously referenced by ghwellsjr). Understanding this subject involves looking at how the pixel data is handled by the printers driver. This image:

is a 40 x 60 pixel sample (taken from a larger photo) that has been blown up 10:1. It shows pixellation the individual pixels are clearly visible.

This same 40x60 pixel image was printed at 4x6 inches (10 pixels/inch) on a Canon i9900 using the standard Windows printing package (which just passes the pixel information directly to the printer and is not color managed). The print was then scanned at 100 pixels/inch (to keep the image size down):

Note that the printer made no attempt to upsize the image it just printed each pixel as a large square with a constant color.

The same image was then printed using Qimage, which is set to automatically upsize each image to 600 ppi on my computer (equivalent to upsizing the image in Photoshop or GF, then printing through Photoshop):

It is easy to see that the upsized image gives a much more pleasing result. If you want to get the best results from your images, paying attention to these details will help. It can be argued that a print from a 300 ppi image is as good as a 600 ppi image 99% of the time, but Qimage does it automatically with no effort on my part.

 

[Tin Ho]

Yeb, the higher PPI the better. 300 - 600 are most common. For graphics 600 or higher may be necessary. For photos 300 is the minimum. Thanks, Grandad, always for his professional knowledge and information.