Need comments: What I understand about inkjet printer resolution...


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Originally posted by tsdh

No. That's different kind of acts.
I don't disturb people for my own benefits, nor for fun.

Then? So what's your purpose of antagonising one of the moderators, if not for fun and laughter? There's really no sense in doing what you did, so please refrain from such acts in future.

Regards
CK
 

Originally posted by Darren

Not quite true - for ClubSNAP, we try to emphasize more on face-to-face meetings with the forums acting as a catalyst for those meetings. Witness the many threads and posts on regular outings and SEEDs. And we plan for more formally organised meets in the future. You should try to attend (if you are in Singapore that is) and get to know the members (and occasionally mods/Founding Members) personally. Of course, at the meetings, we also talk mainly about photography but at least the chance for a real friendship to grow is there.
That's good. I would like to clarify my points:
- CS centered on the internet forum, then grow into face-to-face meetings. The foundation was laid on the inter-member communications.
- Formal organisation centered on meetings, then (some) grow into internet forum. The foundation was laid on the inter-member meetings.

Those are two different approach giving different result.

Just to clarify - no single 'super-power' controls (I really hate the word control - we have never tried to, and will never control things in ClubSNAP) the forums in ClubSNAP. Decisions are made collectively (behind the scenes) by mods and Founding Members.
Sorry for using the word 'control', probably it is more appropriate to use the word 'manage'. Surely I know there is no single 'super-power' here, it is just a superlative to describe people who manage the forum.

Every one (members, mods and Founding Members) is individually responsible for their words and actions in ClubSNAP. Just as if a mod or Founding Member posts a comment on a thread, that post is a statement of the individual's experience and opinion, and not necessarily as a collective norm. We are not the Borg, you know ... ;)
Thanks for your explanation. That's the beauty of internet forums as compared to a formal conventional organisation.
by the way, may I know who bear the cost to keep this forum up and running?
 

eh hem...eh hem...

With all due respect, this is NOT the right subforum or thread to discuss about what proper forum behaviour should be.

tsdh, if you have a technical question of your own, please start your own thread.

OK, after some email correspondence with Jed and putting some more thoughts on the issue, here's how I understand the resolution of inkjet printers:

1. My analysis in my original post is basically correct, but as I have mentioned, it has over-simplified the issue.

2. The Canon S9000 has a resolution of 1200X2400 dpi. So it can lay a total of 4 X 8 = 32 ink dots per colour in a pixel when printing at 300 ppi.

3. The Canon S9000 has Photo Cyan and Photo Magenta inks. This help to increase the intensity levels that the printer can deliver for Cyan and Magenta. A reasonable guess would be double of what could be achieved with only the regular Cyan and Magenta inks.

4. Points 2 and 3 means that the printer can actually deliver a much higher colour resolution than What I have initially thought possible when printing at 300 ppi. I would not even attempt to calculate the possible combinations here, as I will only over-simplify the calculations again.

5. The human eye may not be able to differentiate 256 shades of a single printed colour, and may also not be able to differentiate 16 million different colours (256X256X256). I am pretty sure my eyes can't do that.

In conclusion, I am now pretty convinced that I can safely print at 300 ppi on my Canon S9000 without any perceivable loss in colour resolution. In fact I have read a post in dpreview suggesting that 600 ppi should be the optimum print resolution for Canon S900/9000 printers, even though the human eye may not be able to resolve anything higher than 200~300 ppi.

I am stating my own understanding here, and you are welcomed to correct me or add more details to this discussion.
 

Originally posted by tsdh

That's good. I would like to clarify my points:
- CS centered on the internet forum, then grow into face-to-face meetings. The foundation was laid on the inter-member communications.

Time for some history lesson.

This community started off with a single thread in DC&P. The purpose was to get those who interested in photography in meet in person. Without this, I suppose there's no way or it even take a longer time for us to evolve into what we are today.

The name clubsnap is birthed 5 months later and shortly after that, 14 founding members decided it's high time to create an identity for this community and to build on the spirit of the first meeting, i.e. you can do a check on Clubsnap calender and thus, Clubsnap forums are born.

I am making this assertion because I feel that I know the basic building blocks of Clubsnap better than you.

If you have other queries about the formation of this community; ask.
 

Originally posted by AdamGoi
This community started off with a single thread in DC&P. The purpose was to get those who interested in photography in meet in person. Without this, I suppose there's no way or it even take a longer time for us to evolve into what we are today.

The name clubsnap is birthed 5 months later and shortly after that, 14 founding members decided it's high time to create an identity for this community and to build on the spirit of the first meeting, i.e. you can do a check on Clubsnap calender and thus, Clubsnap forums are born.

I am making this assertion because I feel that I know the basic building blocks of Clubsnap better than you.

If you have other queries about the formation of this community; ask.
Thank you for your info on the history of CS.
That history actually doesn't change the nature of CS which focused its mainstay in inter-member communication. I will explain further:
This web forum is the identity of CS. If it is eliminated, then there will be no more CS (in the view of public).
Unlike other conventional formal organisation, they may also have web forum, but it is not the identity of the organisation. The forum may or may not be there.

As you said, the goal is to get members to meet in person, but in fact, it is the forum which contribute more than the meetings. Members probably almost everyday visit the forum, while they may not every week come to the meeting. (Ian who based in Perth, will miss lot of meetings .. :) ) Thus the forum become the "binding factor" at CS, altough I do agree with YSLee (or Darren?) who said that the real friendship grow from face-to-face meeting.
 

Hi tsdh.

Let me put it this way. My purpose of going through all these is just to point out to you that you got the sequence wrong, i.e. internet centred 'then' to face to face meeting; please refer to the part which I quoted you.

Let's make this plain and simple; I just want to set the record straight, for the benefit of making the community aware how it came about. The first meeting was the turning point; it was then after, the post counts @ DC&P began to increase which propelled and encouraged us to organise more activities like photoshoots, SEEDs and such.

The forums do play an important role and that's why we decided to start our very own forums.

Enough said; if you still want to interpret otherwise, by all means. I have said my piece...now back to our regular programmes ;)
 

Originally posted by AdamGoi
Hi tsdh.

Let me put it this way. My purpose of going through all these is just to point out to you that you got the sequence wrong, i.e. internet centred 'then' to face to face meeting; please refer to the part which I quoted you.

Let's make this plain and simple; I just want to set the record straight, for the benefit of making the community aware how it came about. The first meeting was the turning point; it was then after, the post counts @ DC&P began to increase which propelled and encouraged us to organise more activities like photoshoots, SEEDs and such.

The forums do play an important role and that's why we decided to start our very own forums.

Enough said; if you still want to interpret otherwise, by all means. I have said my piece...now back to our regular programmes ;)

Thank you. Case closed.
 

Hi Roy Goh,

In inkjet printing, does the dot size in picolitre play a part in your theory?

When we print both 2MB and 6MB into same size, say 3R, thus yield a 300+ppi and ~600ppi photo, isn't there a significant difference in sharpness and details under normal visual inspection?

Please enlighten.
 

Originally posted by KamWeng
Hi Roy Goh,

In inkjet printing, does the dot size in picolitre play a part in your theory?

When we print both 2MB and 6MB into same size, say 3R, thus yield a 300+ppi and ~600ppi photo, isn't there a significant difference in sharpness and details under normal visual inspection?

Please enlighten.

Hi KamWeng,

In my "theory", I assumed the dot size to be exactly equal to the area calculated from the printer's DPI rating. This is not the case in real life. Please bear in mind that I am not an expert in this area, so I am partly guessing in what I am going to tell you here.

The actual size a droplet of ink creates on the paper is dependent both on the amount of ink and the characteristics of the paper. I read about a term "dot gain" in the colour correction book that I am reading now, and I believe it is something like a ratio between the actual dot size media and the amount of ink in a droplet that created the dot.

Having a high dot gain will defiitely affect the sharpness and also the colour accuracy, and I believe Photoshop actually has a setting to compensate for dot gain. Unfortunately, I am only using the limited edition, so this feature is not available for me to experiment on. I am hoping that this has been taken care of in the ICC profile that I am using for the printer and the paper type I am using.

I also read in that book that most people would not be able to detect any improvement in sharpness (under normal viewing conditions) when the print resolution exceeds 300 ppi. I have yet to conduct any such comparisons myself, but so far I am happy with the 300ppi prints that I have made.

I am still looking forward to some input from other members here.
 

Originally posted by roygoh


I also read in that book that most people would not be able to detect any improvement in sharpness (under normal viewing conditions) when the print resolution exceeds 300 ppi. I have yet to conduct any such comparisons myself, but so far I am happy with the 300ppi prints that I have made.


Well I've done some comparisons and there IS not little difference when go beyond 400ppi and further. I personally find that 300ppi is a bit soft. That's for inkjet printing of course. I'm trying to find out whether it's the same for photo lab's continuous tone printing.

And also I think we don't really need c and m when the droplet size go real small i.e. 2pl (and below if possible) where CMYK is sufficient.
 

i seriously doubt that 300dpi is 'soft', we are talking about normal 'consumer' inkjet printers right? Of course, my printer is from the previous generation...

Originally posted by KamWeng


Well I've done some comparisons and there IS not little difference when go beyond 400ppi and further. I personally find that 300ppi is a bit soft. That's for inkjet printing of course. I'm trying to find out whether it's the same for photo lab's continuous tone printing.

And also I think we don't really need c and m when the droplet size go real small i.e. 2pl (and below if possible) where CMYK is sufficient.
 

Originally posted by KamWeng


Well I've done some comparisons and there IS not little difference when go beyond 400ppi and further. I personally find that 300ppi is a bit soft. That's for inkjet printing of course. I'm trying to find out whether it's the same for photo lab's continuous tone printing.

"300DPI softness" is more likely due to insufficient sharpening.....
 

I did sharpening - 9 (maximum) in Camedia software. In fact the photos look over sharpened on screen before print.

I'm comparing the printout to those desktop calendars' scenery photo. :embrass: Maybe I'm asking too much.

My printer is also from the previous generation - 1440dpi@4pl. But is sufficient to produce very sharp 6MB images at ~600ppi (not dpi). That kind of sharpness is what I'm satisfied with.
 

From my layman perspective, I would say that there is definitely a perceptible difference (in human terms) between 300dpi and 600dpi (or higher). While I have not seen photos printed at 600dpi, I know that I can definitely see the difference in quality between two pages of identical text printed at 300dpi and at 600dpi, having done a test once on an office laser printer.

However, I think the question in most people's minds is whether 300dpi is "good enough". IMHO, it certainly is more than acceptable, but this is obviously a very subjective issue. In any case, there are a lot of other factors at play, eg. the viewing distance we use (close scrutiny of a print vs. at arms length) and the fact that different people's eyes will have differences in resolving power, perhaps due to age or eyesight(?).
 

We are talking about inkjet photoprinting.

Originally posted by Midnight
From my layman perspective, I would say that there is definitely a perceptible difference (in human terms) between 300dpi and 600dpi (or higher). While I have not seen photos printed at 600dpi, I know that I can definitely see the difference in quality between two pages of identical text printed at 300dpi and at 600dpi, having done a test once on an office laser printer.

 

Originally posted by erwinx
We are talking about inkjet photoprinting.
You are right in pointing out that there will be differences due to the printing technology itself. However, my point is that supplying sufficient image data to create a 600ppi print (sorry, I mistyped it as "dpi" in my earlier post) will generally result in a perceptible difference compared to only giving enough to create a 300ppi print. I cited the laser printer example only because that was the one test I have performed myself on this issue, but I would presume that similar results would be observed with a comparable test using an inkjet printer.
 

Originally posted by Midnight

You are right in pointing out that there will be differences due to the printing technology itself. However, my point is that supplying sufficient image data to create a 600ppi print (sorry, I mistyped it as "dpi" in my earlier post) will generally result in a perceptible difference compared to only giving enough to create a 300ppi print. I cited the laser printer example only because that was the one test I have performed myself on this issue, but I would presume that similar results would be observed with a comparable test using an inkjet printer.

Well when printing text you are looking at maximum contrast the paper can deliver at the text edge, which rarely happens in photos.
 

Originally posted by KamWeng


Well I've done some comparisons and there IS not little difference when go beyond 400ppi and further. I personally find that 300ppi is a bit soft. That's for inkjet printing of course. I'm trying to find out whether it's the same for photo lab's continuous tone printing.

And also I think we don't really need c and m when the droplet size go real small i.e. 2pl (and below if possible) where CMYK is sufficient.

]Originally posted by KamWeng


I did sharpening - 9 (maximum) in Camedia software. In fact the photos look over sharpened on screen before print.

I'm comparing the printout to those desktop calendars' scenery photo. Maybe I'm asking too much.

My printer is also from the previous generation - 1440dpi@4pl. But is sufficient to produce very sharp 6MB images at ~600ppi (not dpi). That kind of sharpness is what I'm satisfied with.

You got to be very clear on what you are claiming, or else you will generate confusion and posibbly start another heated argument.:D

When you claim that 300ppi is a bit soft, are you comparing it to the same picture printed at 600ppi? Also, even if you are comparing with 600 ppi, did yout print from an image that has that amount of resolution to start with, or did you interpolate to higher resolution for 600ppi print?

Your next post is even more confusing. Now are you saying that you compared a 300 ppi print to desktop calendars and made the deduction that the reason for your print being comparatively soft is due to the ppi?

Please don't take this in a negative way. I am not challenging you, but I would like to know what basis did you put you statement on.

Regarding the PC and PM colours, someone in dpreview posted that he actually prefered the output from Canon S750 (4-colour) better than the S9000 (6-colour).

I wonder if there is a way to switch my S9000 into 4-colour mode so that I can make a comparison myself.
 

4 vs 6 colour

extended colour gamut is always preferable for me. just print some natural scenery pics with a wide range of blues and greens. (natural blues and greens not disney-colour ;) )

(1) How does a 4 colour printer print a significantly lighter shade of a colour thats significantly lighter than the colour of the ink? And how does it deal with the transition from this lighter shade towards darker shades....


I haven't read the dpreview comment, but maybe that guy is just printing Disney-colour pictures where gamut is irrelevant...
 

Originally posted by erwinx
4 vs 6 colour

extended colour gamut is always preferable for me. just print some natural scenery pics with a wide range of blues and greens. (natural blues and greens not disney-colour ;) )

(1) How does a 4 colour printer print a significantly lighter shade of a colour thats significantly lighter than the colour of the ink? And how does it deal with the transition from this lighter shade towards darker shades....


I haven't read the dpreview comment, but maybe that guy is just printing Disney-colour pictures where gamut is irrelevant...

The gentlemen who did the comparison and posted his conclusions is called John Mills. He is the boss of Weink I think. Weink is a supplier of 3rd party inks for inkjet printers. Go to the printers and printing forum in dpreview and do a search for "john mills" and you should be able to find his post.

What he said in his post is of course subjective, and he has already been criticised by many other forum members. By the way, he used a print of his wife, thus comparing skin tones and not just Disney colours.

I am quite interested to find out for myself how much impact there is by adding the 2 photo colours. Is it just a marketing gimick by the printer companies to sell more ink? If the PC and PM colours are half the intensity of the regular C and M ink, then can the same effect be acheived with the regular C and M inks by making the ink drop size even smaller?

I supposed this is related to your question (1). How does a laser printer print shades of grey with only black toner? Half tone. By controlling the density of black dots on the white printing paper, the black dots blend with the background white when viewed at normal viewing distance to appear grey. The smaller the dots can be, the more continuous the apparent tone variation can be achieved.

By the way, by adding the photo colours, does it really extend the colour gamut, or simply increase the colour resolution acheivable within the same gamut? Since the photo colours are a lighter version of the original C and M inks, it cannot really extend the gamut of CMYK printing, am I right?
 

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