Questions regarding printing

Just admiring your B&W- in particular the stones on the beach- but perhaps I can hijack this post to ask a question

Could you please explain the rules for printing sizes

For example , with an image of say 6000 x 4000 pxls what would be the maximum size I could print onto good paper without losing quality ?

Are there any other factors pertaining to the original image that come into the equation?

Many thanks

Bo

Barbara - this post should really go into a new thread on its own, so I have moved it.

In terms of discussing this topic, it is a very complex one and one can get into all kinds of issues and sub-topics on how to prepare images for printing, papers, profiles, etc.

Sticking to the easiest part of your question; the answer, in part, depends on the printer that you are planning to use. Canon and HP inkjet printers have a native resolution of 300 DPI (Dots Per Inch) while Epson ink jet printers have a resolution of 360 DPI. Other types of printers will all have different native resolutions.

The quick and easy answer is that for HP and Canon printers; 6000/300 = 20" (50.4 cm) and 4000 / 300 = 13.333" (33.9 cm). For Epson printers 6000/360 = 16.7" (42/333 cm) by 4000/360 = 11.1 inches (28.2 cm).

If we want to get into even more detail, we would have to discuss recommended minimum viewing distances and a number of different factors including sharpening, paper finish, etc.

Bo

I think this maybe refers to one of my images and led you to the question.

For my part, I have no wish or intent to confuse you about what Manfred says is a complex topic. I would, therefore, merely wish to say that I endorse what he says 100%.

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Originally Posted by lunarbo

Just admiring your B&W- in particular the stones on the beach- but perhaps I can hijack this post to ask a question

Could you please explain the rules for printing sizes

For example , with an image of say 6000 x 4000 pxls what would be the maximum size I could print onto good paper without losing quality ?

Are there any other factors pertaining to the original image that come into the equation?

Many thanks

Bo

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William mentioned some some items concerning this question not so long ago.

https://www.cambridgeincolour.com/fo...htm#post709035

George

Donald, Manfred,George and William -

Thank you all so much. I don't know how I missed the earlier thread on this forum but the answers there are as clear as it seems we can make of a complex situation !

As a starting point an absolute given is a tack sharp image processed with due consideration - I'm OK with that and now that I'm using FF Canon with usually an L lens & tripod, any slip ups will be with the operator not the kit.

I'll use the 300ppi as a guide only but it is a starting point when considering what I want to print- generally for around the home.

I hadn't thought of the desired distance of the viewer from the image. Clearly this is a consideration with certain images where bringing the viewer in close adds some intimacy. On the other hand a small image in an exhibition or competition hall can get lost amongst other giant "look at me!" pictures.

Thanks again guys. You've answered my question and made me think onwards

Hi Barbara,
Further to your comment

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I'll use the 300ppi as a guide only but it is a starting point when considering what I want to print- generally for around the home.

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I would add a suggestion to consider if you are using an Epson printer (I can't talk for other vendors).

It is worth keeping in mind that for the bigger format Epson printers, that the native resolution of the Epson driver is 360 ppi. If the Epson driver doesn't receive an image at 360 ppi, it will re-sample the image to 360 ppi in the background.
In some cases, it's fine,but, in some other cases, due to the nature by which the Epson driver performs the re-sampling, detail can be lost, and there may be noticeable edge artifacts.
To be honest I have never noticed this occurring on any of my prints, but I do re-sample my images (I use Photoshop) to 360 ppi as the final stage of final image preparation before I print. :)

OK James, many thanks for the information.

If I want to print over A4 size I'll need to find a commercial outlet to do the printing and on this little island my options are limited so all knowledge could be useful!

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Originally Posted by lunarbo

OK James, many thanks for the information.

If I want to print over A4 size I'll need to find a commercial outlet to do the printing and on this little island my options are limited so all knowledge could be useful!

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Many commercial photo printers do not use an inkjet process, so the advice we have given is not necessarily relevant. You would have to ask the technicians about the equipment that they are using, if you want to get to that level. Another thing to be aware of, most of these printers use the sRGB colour space, so you need to convert your image first, if you are using something else like AdobeRGB (or wider).

Another common issue is that most computer screens are set much to bright, so printed images come out looking too dark. I would suggest that if you are looking at large prints to do a smaller and inexpensive test print before you go to something larger. What you see on your screen is a transmitted light, additive, RGB image whereas printed output is reflected light, subtractive, CMYK.

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Originally Posted by Manfred M

Many commercial photo printers do not use an inkjet process, so the advice we have given is not necessarily relevant. You would have to ask the technicians about the equipment that they are using, if you want to get to that level. Another thing to be aware of, most of these printers use the sRGB colour space, so you need to convert your image first, if you are using something else like AdobeRGB (or wider).

Another common issue is that most computer screens are set much to bright, so printed images come out looking too dark. I would suggest that if you are looking at large prints to do a smaller and inexpensive test print before you go to something larger. What you see on your screen is a transmitted light, additive, RGB image whereas printed output is reflected light, subtractive, CMYK.

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Can you be more specific?

George

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Originally Posted by george013

Can you be more specific?

George

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There are a number of different technologies used; some printers use a light sensitive paper that use three coloured lasers (the Durst Lambda used this process), some use a dye sublimation process, others like HP Indigo presses use something along the lines of laser printers, but use a different technology that uses specialty inks. So far as I understand it, Blurb uses Indigo presses. There are different processes out there and all tend to be highly proprietary.

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Originally Posted by Manfred M

There are a number of different technologies used; some printers use a light sensitive paper that use three coloured lasers (the Durst Lambda used this process), some use a dye sublimation process, others like HP Indigo presses use something along the lines of laser printers, but use a different technology that uses specialty inks. So far as I understand it, Blurb uses Indigo presses. There are different processes out there and all tend to be highly proprietary.

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But where shouldn't the calculations not be correct.

George

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Originally Posted by george013

But where shouldn't the calculations not be correct.

George

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If you use a wider gamut colour space and the printer assumes that an sRGB file is being printed, the colours will be incorrect.

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Originally Posted by Manfred M

If you use a wider gamut colour space and the printer assumes that an sRGB file is being printed, the colours will be incorrect.

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That's a total different issue and not asked. The calculations will be correct.

George

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Originally Posted by george013

That's a total different issue and not asked. The calculations will be correct.

George

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In that case I did not understand what you are asking? No the calculations will not be correct as the print software will not convert correctly.

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Originally Posted by lunarbo

OK James, many thanks for the information.

If I want to print over A4 size I'll need to find a commercial outlet to do the printing and on this little island my options are limited so all knowledge could be useful!

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Bo,

It sounds like you may have a home printer, if you do providing us with model might help give you answers to your printing limitations and/or best possible outcomes.

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Originally Posted by Manfred M

In that case I did not understand what you are asking? No the calculations will not be correct as the print software will not convert correctly.

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The question was about sizes. So again, why are the calculations not correct or relevant as you mentioned.

George

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Originally Posted by george013

The question was about sizes. So again, why are the calculations not correct or relevant as you mentioned.

George

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A print head on an inkjet printer has a fixed size and height, so the number of droplets of ink it can deposit are fixed. This means any image that will be printed can only be printed at the native resolution of the printer, which I listed in #2. This means in virtually every case, the image must be resampled to either increase or decrease the size of the image so that it can be printed.

If we do so in the PP software, we can often select the algorithms and workflow that are used to do this. This is of course dependent on the software we use to perform this operation. If not, our printer will use internal printer algorithms to do so, and we will not have any control over the quality of the process. Most experienced printers will do this in post and will also do some sharpening and other tweaks to the image before it is printed.

Does it make any real world difference, as modern printer drivers are quite sophisticated? My own experience is that I can get a better print when I do this myself, but then I tend to be quite picky. I just spent the past 10 weeks learning this craft from a "master printer" and he was able to satisfy me that the work flow he taught me was very solid and creates superior prints. For others, a semi-automated process will work and others will not care an let the printer driver handle this operation.

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Originally Posted by Manfred M

A print head on an inkjet printer has a fixed size and height, so the number of droplets of ink it can deposit are fixed. This means any image that will be printed can only be printed at the native resolution of the printer, which I listed in #2. This means in virtually every case, the image must be resampled to either increase or decrease the size of the image so that it can be printed.

If we do so in the PP software, we can often select the algorithms and workflow that are used to do this. This is of course dependent on the software we use to perform this operation. If not, our printer will use internal printer algorithms to do so, and we will not have any control over the quality of the process. Most experienced printers will do this in post and will also do some sharpening and other tweaks to the image before it is printed.

Does it make any real world difference, as modern printer drivers are quite sophisticated? My own experience is that I can get a better print when I do this myself, but then I tend to be quite picky. I just spent the past 10 weeks learning this craft from a "master printer" and he was able to satisfy me that the work flow he taught me was very solid and creates superior prints. For others, a semi-automated process will work and others will not care an let the printer driver handle this operation.

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Still an answer on another question.
My question in post 9 was if you could be more specific about this statement

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Many commercial photo printers do not use an inkjet process, so the advice we have given is not necessarily relevant.

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George

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Originally Posted by george013

Still an answer on another question.
My question in post 9 was if you could be more specific about this statement

George

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Again, what I was trying to say here is that production printers use specialty equipment that are designed for high volume printing. If one wants to use one of these photo printing companies and get the best prints possible, then one needs to contact them and ask someone knowledgeable about the equipment and paper that they use.

This would include information on the printer / paper that they use (so that the correct profile can be applied to our images), colour spaces that they support and of course the native resolution of their printers. Sometimes there are third party suppliers that have some of all of this information; for instance:

https://www.drycreekphoto.com/


There is information on Fuji Frontier, Noritsu, Agfa D-Lab, LightJet, Durst, and Chromira photo printers.

I suggest, George, if you want to carry this discussion you do so in a new thread. This bears little relation to the questions asked by Bo and feels like you are trying to get the better over Manfred. I suggest that you do this elsewhere.