What do the extra 2 ink-tanks do?

Alright, so the Canon Pixma iP6700D has 6 ink-tanks, the iP8500 has 8 ink-tanks and the iP4300 has 4 ink-tanks, for printing photos.

The question is - what do the extra 2 ink-tanks on the iP6700D and the extra 4 ink-tanks on the iP8500 add? Is it just more contrast?

Thnx.

Oh, and if anyone has an iP6600D/6700D, I'd really appriciate an upload of the text quality!

Most modern, high quality inkjet printers use at least 6 inks, adding a light cyan and magenta to the normal complement of cyan, magenta, yellow, and black.

The purpose of the lighter inks is to produce prints that are less "grainy". As an example, if you're printing an image that has a light blue sky, the printer is laying down very small amounts of cyan (and some yellow) ink. Since inkjet printers can't control the amount of ink deposited (there's either a dot or not), if the printer only has 4 inks, the cyan dots are going to be very sparse, since you want just a little cyan colorant. This causes the print to look grainy since the colored dots are very sparsely deposited. Adding a light color cyan allows the printer to produce more cyan dots, thus reducing the graininess, while still maintaining the same overall appearance.

A second order effect is to allow for a larger color gamut than would be possible with just 4 inks. The extra color gamut comes, not from the additional light inks, but from the fact that the "dark" inks can be made darker (more colorful). Without the extra light inks, the print would be too grainy, since less of the "dark" ink would be needed when printing tints. With the extra light inks, the "dark" inks can be optimised for gamut, while the light inks keep the print from looking too grainy.

That dosent make any sense..

The DPI should be the same no matter how many colors. The only way the print would seem less grainy is if the DPI would increase, but since it dosent, I dont see how the picture will be less grainy.

The only think the photo-cyan would do is create a more contrasted print, is what makes sense.

You are correct, the DPI doesn't change (I didn't say that it did). However, if you are trying to create a certain apparent density using a halftone (dithered) process, you will use more colored dots (and fewer white ones) if the colored dots are lighter (light ink), than if they are darker. By using lighter ink and therefore more colored dots, the image looks less grainy.

As far as printers and DPI they all work to a maximum of 300. A print with more dpi will be reduced by the printer software.
--
Richard Hunt
UK

R C Hunt said:

As far as printers and DPI they all work to a maximum of 300. A
print with more dpi will be reduced by the printer software.

Click to expand...

btw in the case of Epson printers, it's 360 not 300 - ppi (pixels per inch).

One needs to look beyond such simplistic figures, when working out how large a photo can be printed in practice. Different image types, printers, papers and intended usage will set different limits of acceptability. Source image detail above 300ppi will make a difference in some circumstances, and 240ppi is fully adequate for some other circumstances.

RP

... to make more money on consumables
--
Zone8

The photograph isolates and perpetuates a moment of time: an important and revealing moment, or an unimportant and meaningless one, depending upon the photographer's understanding of his subject and mastery of his process. -Edward Weston

I have a 4-color Canon iP4300 and I cannot see any dots or dithering when printing my 6MP D-SLR pictures.

I also have a 6-color Epson PictureMate and the prints from my 4-color iP4300 look about equal to the 6-color PictureMate (both are excellent BTW). The PictureMate is very cheap to operate so I used that for all of my 4x6 prints.

zzzzzzzzzzzzzzzzzzzzzzzzzz,

Canon is indeed a special case, they have droplets of 1pl only and therefore much room to comensate the need of more colors...in most cases enough room for the human eye.
--
Peter

Bob Collette said:

You are correct, the DPI doesn't change (I didn't say that it did).
However, if you are trying to create a certain apparent density
using a halftone (dithered) process, you will use more colored dots
(and fewer white ones) if the colored dots are lighter (light ink),
than if they are darker. By using lighter ink and therefore more
colored dots, the image looks less grainy.

Click to expand...

So you are saying that because "Photo Cyan" and "Photo Magenta" are darker colors, then there would be less lighter dots on the print and thus the print would look less grainy?

Well then why do they make these light dots that we then have to get rid off? Obviously a 4 color printer can make both dark and light dots, so why do we have to buy another 2 colors just to make some of those light dots go away?

mobyline said:

zzzzzzzzzzzzzzzzzzzzzzzzzz,
Canon is indeed a special case, they have droplets of 1pl only and
therefore much room to comensate the need of more colors...in most
cases enough room for the human eye.
--
Peter

Click to expand...

So you are saying that because Canon has this revolutionary 1pl drop size, they dont need more than 4 colors in order to achieve "lab quality" prints?

zzzzzzzzzzz said:

I have a 4-color Canon iP4300 and I cannot see any dots or
dithering when printing my 6MP D-SLR pictures.

I also have a 6-color Epson PictureMate and the prints from my
4-color iP4300 look about equal to the 6-color PictureMate (both
are excellent BTW). The PictureMate is very cheap to operate so I
used that for all of my 4x6 prints.

Click to expand...

The PictureMate has 6 colours, but the two extra colours are blue and red, which are used to increase the gamut, unlike the light cyan and light photo that are used to minimize the visibility of the dots.

Track said:

So you are saying that because "Photo Cyan" and "Photo Magenta" are
darker colors, then there would be less lighter dots on the print
and thus the print would look less grainy?

Click to expand...

It's the opposite. Photo Cyan and Photo Magenta are lighter colours.

Track said:

So you are saying that because "Photo Cyan" and "Photo Magenta" are
darker colors, then there would be less lighter dots on the print
and thus the print would look less grainy?

Click to expand...

No, he said they are lighter inks and since they are lighter you
can use more of them in the halftomning process giving a
smoother image at some tonal range (he called it less grainy).

Track said:

Well then why do they make these light dots that we then have to
get rid off? Obviously a 4 color printer can make both dark and
light dots, so why do we have to buy another 2 colors just to make
some of those light dots go away.

Click to expand...

A 4 color printer can make one color for each color of ink.
It can't print a light or dark cyan dot unless it has separate light
and dark cyan inks. Halftoning is how the printer generates
a range of color tones to overcome the limitations of a set number
of inks it has to work with.

Halftoning is used by the printer so the human eye sees it
as a range of light to dark. This is done by controlling the number
of ink dots in any given area of the paper (but the ink dots from
the same ink source are always the same color).

Bob is saying the different inks allow some improvements in the
halftoning process and that, in turn, improves the perceived image
quality. The improvement seems to be perceived (subjectively) as less
grainy images. To understand how it works might require a
stronger understanding of halftoning.

Track,

yes in the special case of the Canon ip4200, ip5200, ip4300, ip5300 I can see no visible (at least for me) flaws compared to a Canon Printer with more inks. Additionally there is an economic advantage...these light inks ran out very, very fast! And my personal observation, Canon prints without light inks do last longer! The reason therefore could be that the dark inks have much more room for fading.
http://www.steves-digicams.com/2005_reviews/canon_ip5200.html

In his conclusion Steve makes following statement: "The iP5200 is another of Canon's 5-color printers that leaves me wondering why I own and use the 8-color i9900. When I see just how good the photo prints look when using only the three primary colors (cyan, magenta and yellow), I don't know why I need those other ink colors, or the added expense. With the 1-picoliter size ink droplets the prints are virtually grainless."
--
Peter

Ok, so the iP6700D is less grainy but has less sharp text.. I really cant figure out wich one to buy - 6700D vs. 4300.

Hmm.. on hand the iP6700D's text quality isnt THAT bad.
On the other hand the iP4300's photo quality isnt THAT bad.

...get the ip4300, cheap to run and outstanding image quality...full duplex, less carts to buy.
--
Peter

Yeh, but the iP6700D is only a little bit more costly and has better print quality.

I can't really see any dots with either of my printers (4300 and PictureMate Deluxe). As far as I am concerned they are both "Photo Quality".

The 4300 also does text very well.

Dominic.Chan said:

zzzzzzzzzzz said:

I have a 4-color Canon iP4300 and I cannot see any dots or
dithering when printing my 6MP D-SLR pictures.

I also have a 6-color Epson PictureMate and the prints from my
4-color iP4300 look about equal to the 6-color PictureMate (both
are excellent BTW). The PictureMate is very cheap to operate so I
used that for all of my 4x6 prints.

Click to expand...

The PictureMate has 6 colours, but the two extra colours are blue
and red, which are used to increase the gamut, unlike the light
cyan and light photo that are used to minimize the visibility of
the dots.

Click to expand...