RAW V Jpeg for enlargement

Irishman

Irishman

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I have a shop looking to use one of my photos for a large 5mx3m display.

I have already sent them the Jpeg version at 24 mp but they say it is not good enough quality when enlarged to the size they want, now they are asking for the unprocessed RAW version thinking this will improve the quality.

My question is, will it make any difference to the quality by much?

Also, what sort of size file would be required to print to 5m x 3m?

Thanks
 
I would not give them the raw file. The raw file is still only 24mp and nothing you or they do will change that.

The only thing that you can do is use a program to enlarge the image to the required size. 5m is 197 inches so the first thing you need to do is find out at what PPI they want to print the image, this will vary depending on the viewing distance. Multiply that PPI by 197 and that will give you the pixel count of the width you are aiming for.

There are various programs that can enlarge an image. The latest version of LR, Photoshop, On1 Resize, Gigapixel AI to name a few.
 
It would be useful to know a bit more information. The intended viewing distance and the material they are intending to print on. E.g canvas or photo paper. Your RAW file is not going to contain your edits so ask if there is an alternative file like TIFF as an example (but TIFF may not be suitable due to the size.)
 
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Thanks folks, that's what I thought, no difference between the two
 
They have probably read that they need 300ppi for a quality print (which is completely untrue)... with how prolific that information is on the web, it can be impossible to convince someone that it is not true; especially since it is espoused by many print shops.

The PPI is not a limitation unless you are seeing pixelation in the print; in that case you can resample to a higher resolution for a higher PPI print in order to eliminate the pixelation, but it doesn't help otherwise (sharpness/etc).

Your best bet is probably to upsize to 300ppi/60,000px long edge using an Ai program; of course that's going to be a huge file (~2,160MP and probably 2+GB)... it's ridiculous, but it will probably make them happy.
 
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As a rule of thumb the general viewing distance of an image is 1.5 times the diagonal.
The diagonal of a 5m x 3m image is 7.071m, Multiply that by 1.5 and that gives you a viewing distance of 10.6m

The recommended minimum ppi for 10m is 18ppi

So, we know that 5m is 197 inches which means that you need a file size with the longest edge being 197 x 18 = 3546pixels. If your image has a higher pixel count then they can print at a higher ppi. A 24mp image should have a long edge pixel count of around 6000px which means they can print the image at 30ppi which would be suitable for a viewing distance of around 5m.

the Artists Print Room

www.theartistsprintroom.co.uk www.theartistsprintroom.co.uk

If you walk up to a large bill board and view it from a few inches away. All you are going to see are dots.
 
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ecoleman said:
As a rule of thumb the general viewing distance of an image is 1.5 times the diagonal.
The diagonal of a 5m x 3m image is 7.071m, Multiply that by 1.5 and that gives you a viewing distance of 10.6m

The recommended minimum ppi for 10m is 18ppi

So, we know that 5m is 197 inches which means that you need a file size with the longest edge being 197 x 18 = 3546pixels. If your image has a higher pixel count then they can print at a higher ppi. A 24mp image should have a long edge pixel count of around 6000px which means they can print the image at 30ppi which would be suitable for a viewing distance of around 5m.

the Artists Print Room

www.theartistsprintroom.co.uk www.theartistsprintroom.co.uk

If you walk up to a large bill board and view it from a few inches away. All you are going to see are dots.
Click to expand...

Fantastic, thank you very much
 
ecoleman said:
As a rule of thumb the general viewing distance of an image is 1.5 times the diagonal.
Click to expand...
The standard viewing distance is equal to the diagonal measurement (DoF calculators/DoF scales/CoC diffraction sharpness).

20/20 vision is 1 arcmin of resolution; which is 170dpi at 20", and 20dpi at 20ft (just short of the 7m diagonal).
ecoleman said:
The recommended minimum ppi for 10m is 18ppi
Click to expand...
That chart is reasonable at longer distances, but at short distances it falls back to the same stuff...
300ppi is really only applicable for critical viewing of a print with a loup... but he's recommending 360ppi.

What resolution (ppi) is your monitor set to? I'll bet it's not much more than 100-120ppi; and if it is set higher you probably have to zoom in on things (beyond 100%) to make them even visible. So why would you ever need 360ppi for a printed image (especially an inkjet/dye sub print)?
 
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I'm a big fan of getting big images out of little files, but I do think that upscale may be pushing it. One problem is that it's not actually a billboard, customers will be walking right up to it. Gigapixel is very very good, but I find the results can look a bit plasticky, try it.

Is it worth taking a crop to fit A3 at that enlargement factor and printing it to show them what it would look like?

Sounds fun, what's the image of?
 
I produced something similar for a friend of mine recently. He needed a 6x2m image of an aircraft coming into land for an exhibition stand backdrop. I edited one of my old photos to give the 6x2 ratio with the long side at 6000px (1px = 1mm) and asked the printer to do the rest as they know what dpi is needed for any particular viewing distance. It turned out really well :)
 
Might the quality problem be that the JPEG artefacts are visible at that size? Converting from the raw file to a TIFF rather than a JPEG might solve the problem.
 
Nod said:
Might the quality problem be that the JPEG artefacts are visible at that size? Converting from the raw file to a TIFF rather than a JPEG might solve the problem.
Click to expand...
Will try that
 
Nod said:
Might the quality problem be that the JPEG artefacts are visible at that size? Converting from the raw file to a TIFF rather than a JPEG might solve the problem.
Click to expand...
Unless the jpeg was output at reduced quality (or edited/saved MANY times), there shouldn't be any jpeg artifacts.
 
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