Questions regarding printing

[george013]

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.

I'm just asking an explanation of a statement Manfred made. I just don't get it.

May I say that I do agree with his reaction in the other thread Camera megapixels and print size. Starting with "Good explanation Bill".

I'm not the one making it more difficult as it is.

I'll stop. I'm sure Bo knows what she asked for.

George

[Manfred M]

I'm just asking an explanation of a statement Manfred made. I just don't get it.

I'm sorry that you don't get it George.

I don't know if this is related to the way I explain things or if something else is going on. I do a fair bit of printing and have printed well over 100 images so far this year; primarily on my own photo printer (Epson 3880); but have also done some on the Epson P600 and P800 printers. I'm not sure how much you understand about the photo printing process.

[george013]

I'm sorry that you don't get it George.

I don't know if this is related to the way I explain things or if something else is going on. I do a fair bit of printing and have printed well over 100 images so far this year; primarily on my own photo printer (Epson 3880); but have also done some on the Epson P600 and P800 printers. I'm not sure how much you understand about the photo printing process.

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

You're suggesting here that the advice is not valid for non-inkjet printers. All I'm asking is to be more specific.

George

[Manfred M]

You're suggesting here that the advice is not valid for non-inkjet printers. All I'm asking is to be more specific.

George

Now that is clear:

The advice was based on knowing the native resolution of the printers, as measured in dots per inch (DPI). I would have thought that this was clear from the example calculation in #2.

I have had work printed on lower resolution printers (150 DPI), so my preparation work centred around that resolution. Unless we know the native resolution of the printer we are going to have the image printed on, it is impossible to scale the image properly. To do this, we need to know what printer is being used.

[dem]

A slightly different perspective. 6 Mpx is enough to make a print of any size that is going to be viewed from a distance similar to the print's diagonal. Whether it is an A4 print viewed from a normal reading distance or a 3 meter bilboard viewed from 3 meters away, a human eye can only resolve about 6 Mpx worth of detail within this angle of view.

If you have a 24 Mpx image, you can make A2 prints that will look perfect from a normal reading distance, or examine your 3 meter poster from 1.5 meter away and be still amazed by the picture quality.

If one is using a 300 dpi printer to make an A4 print from a 24 Mpx image, the printer will downsample the image to its native resolution which works out at only about 7 Mpx. Lots of image detail will be lost during printing but then you would not be able to see them anyway without a magnifying glass. So to show all 24 Mpx on a 300 dpi printer you need to make A2-sized prints. Do not be afraid to print bigger than that though.