Calibrating for Epson 7880

[ethansun]

I will be calibrating my 7880 using ink republic's irk4-nano v2 (with more saturated red), I've ordered their set cartridge and and ink but experienced some delays due to quality checks.
I'll be posting results using base linearization and profile using IT8 targets and will be comparing Delta E and H measurements against original inks.

Ethansun

 

[ethansun]

kindly give some suggestion for other test that you would like to do if this was your printer. i'll do my best to accomodate your requests...

 

[nertog]

kindly give some suggestion for other test that you would like to do if this was your printer. i'll do my best to accomodate your requests...

Aha, very interesting. I'm looking forward to see the results. I recently measured quite a lot of different inks and I huge differences in density of the different inks. The chroma of each of the C,M and Y inks was quite similar so I'm wondering if the huge differences in light magenta and light cyan have any impact on the gamut? Do you have any way of measuring the LAB values of each of the inks in your R7880?

Wim

 

[ethansun]

Hi nertog, i'm also looking forward to seeing the overall gamut of irk4-nano ink, as for the LAB values we can check using color verifier. The Epson 7880 has 9 inks C M Y K LC VM VLM LK LLK, I believe Vivid Light Magenta and Light Cyan will have some effect on the gamut i'm not sure as to the extent, I have no comparison though on the gamut of printers without these inks, maybe someone can post their results...

about the ink density this is based on the paper we print the inks on, i'll be using Semi-gloss Inkjet paper from a local supplier, I believe its from China.

I'm not so familiar with chroma could you explain further...

 

[nertog]

Chroma is very similar to the saturation of a color. The higher the chroma of your inks, the wider the total colour gamut will be.

With density I don't mean the amount of ink on paper here, I rather mean the pigment concentration of the inks. The light cyan and light magenta of the IRK4 inkset are much darker than the inkset I am using. I profiled and Epson R3000 using the same inkset although the light Magenta and Light cyan inks had a lower density. I'm curious if this has any effect on the gamut. I can imagine the darker the light cyan and light magenta, the less ink from these colours has to be used but...the more visible the individual ink dots will be in light gradients.

 

[pharmacist]

Hi Wim,

actually I do not see any graininess in the very light skies with the IRK4-nano inks. I checked this with both the original Epson K3 vivid ink in my Epson R3000 and the same print produced with the larger droplet Epson Pro 3800 with IRK4-nano ink and to my eyes I cannot observe individual droplets even on very light tones of blue skies. Note: the Pro 3800 produces 3.5 pl droplets, the R3000 just 2 pl.

 

[ethansun]

Hi Wim,

thanks for explaning Chroma, so the light cyan and light magenta of your irk4-nano are much darker compared to i suppose oem ink? I'll look into it once inkrepublic delivers.

with regards to ink density having effects on the gamut, i think if you have a profile that has a properly balanced grey then images will not be far from your target profile say iso, swop etc.. but will be visible when colors are trapped meaning when LC & LM inks mixed they will produced a much darker color than your average oem ink. then again you still have your standard cyan and magenta to compensate for that. I think if we were to make our CYAN to True Blue and Magenta to True Red maybe we can achieve a much wider gamut, but since this is Light Cyan and Light Magenta i believe this has a more subtle effect on the gamut.

if you wanted to save ink you can modify your Total Ink Limit.

this is just my theory and I could be wrong...


Hi Pharmacist, i'm a fan of your calibrations and test on 3800, i also ordered the irk4-nano v2 with more saturated red. hope you'll do some more test... have you tried G&G inks (Everbrite)?


regards

 

[nertog]

Hi Wim,

actually I do not see any graininess in the very light skies with the IRK4-nano inks. I checked this with both the original Epson K3 vivid ink in my Epson R3000 and the same print produced with the larger droplet Epson Pro 3800 with IRK4-nano ink and to my eyes I cannot observe individual droplets even on very light tones of blue skies. Note: the Pro 3800 produces 3.5 pl droplets, the R3000 just 2 pl.

Then it remains a questionmark why inkrepublic did this. Maybe to correct the greybalance?

Hi Wim,

thanks for explaning Chroma, so the light cyan and light magenta of your irk4-nano are much darker compared to i suppose oem ink? I'll look into it once inkrepublic delivers.

with regards to ink density having effects on the gamut, i think if you have a profile that has a properly balanced grey then images will not be far from your target profile say iso, swop etc.. but will be visible when colors are trapped meaning when LC & LM inks mixed they will produced a much darker color than your average oem ink. then again you still have your standard cyan and magenta to compensate for that. I think if we were to make our CYAN to True Blue and Magenta to True Red maybe we can achieve a much wider gamut, but since this is Light Cyan and Light Magenta i believe this has a more subtle effect on the gamut.

if you wanted to save ink you can modify your Total Ink Limit.

this is just my theory and I could be wrong...


Hi Pharmacist, i'm a fan of your calibrations and test on 3800, i also ordered the irk4-nano v2 with more saturated red. hope you'll do some more test... have you tried G&G inks (Everbrite)?


regards

Well, SWOP and ISO gamuts are very small compared to what these printers so it's not a challenge for them. I was just thinking that it might make a difference in light, saturated red, green and blue. These primary colours are very difficult to produce with a standard CMY inkset.

Blue and Red ink will really limit your available colour gamut. Ink on paper is a subtractive colour process and needs pure cyan, magenta and yellow to optimize the gamut. You can of course use CMY + any other spot colour to optimize the gamut.

Let's see with the profile says

 

[ethansun]

Hi Wim,

I did not know you were aiming for a much wider target... I agree about the light, saturated red, green and blue being difficult to produce with a standard CMY inkset maybe this is why Epson opted to put more inks... with 7900 we have green and orange inks, they are claiming that this inkset can match colors using hexachrome.

About the Blue and Red ink i was thinking along the line of RGB Blue and RGB Red + Yellow, with the right greybalance and profile i believe this could produce colors that are wider in gamut than your standard CMY inkset, please take note I used standard as there are inks that have been developed like soy kaleido which claims that their CMY can duplicate almost 98% of RGB gamut.

best regards