How to ensure I can print LARGE and CLEAR.

[yalegurney]

I'm a photographer.  I shoot with the Canon MarkIV.  I use both Photohsop (2021) and Lightroom.  I shoot in RAW.  The last time I sent my images out to print large, I had clarity issues (large as in 72x60 and up (billboard size).  I'm perxpled and unsure where I am going wrong.

ANY help and suggestions on camera and/or Adobe settings to help would be GREAT.

Thanks!

[thes4755864]

First you would want to ensure you are capturing the highest resolution possible with the camera.  I'm not familiar with the Mark IV but have a 7D Mark II and there's a button "Q" that brings up a screen with all that data.  You can also find it by cycling through the options in Menu.

If you're then processing an image make sure you've set the DPI to very high.  Even if you have a huge file, if your DPI is only 72 then it will be a small image when it's printed.  I've done magazine work and have had that happen at times.  So check the file's DPI in Photoshop before you Save As.  Obviously check the print size too, since if you're printing at 6x4 postcard size and trying to blow it up to a billboard, that will be a problem.  

Good luck!

[D Fosse]

The ppi number is a function of the size. The file is just pixels.

Pixels per inch. It means exactly what it says. More inches = lower ppi number. But the file itself is exactly the same. It's just pixels.

[TheDigitalDog]

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@thes4755864 wrote:

If you're then processing an image make sure you've set the DPI to very high.  Even if you have a huge file, if your DPI is only 72 then it will be a small image when it's printed. 

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As mentioned, that has absolutely no bearing on the quality of the image data or how it can be printed. It is merely a metadata tag. 

1000x1000 @ 72 DPI (or PPI if you prefer for this discussion) is no different than 1000x1000 @ 100 PPI or 1000x1000@ 1000 PPI; they all have 1000 pixels that can be divided up per inch in this case; just a tag. 

An old but still so pertinent article on resolution:

Resolution.pdf

And for inkjet users:

The Right Print Resolution

[D Fosse]

There are no settings. It's just pixels. If the original photograph is of good quality, it will be suitable for reproduction at any size.

I assume you mean the Canon 5D Mark iv. In that case the sensor resolution is 6720 x 4480 pixels. While not the highest resolution on the market, it's plenty good enough for any practical purpose.

Contrary to popular myth, you don't need more pixels/higher ppi for large format printing. That's a misunderstanding. The exact same file will work for a magazine spread or a wall-sized billboard. The bigger it is, the farther away you will stand to see the image, so the effective optical resolution is the same.

There is a formula (that I can never remember) - but here's how I usually illustrate it:

[davescm]

"There is a formula (that I can never remember)"

This one   :  ppi required = 6878/Viewing distance

It comes from the following :

A good human eye can resolve 60 line pairs per degree i.e. pairs of black and white lines.  So in half a degree we would have 60 single lines.

Simple trigonometry means that the width containing those 60 lines can be calculated by:
               Width of 60 lines = Viewing distance x tan(0.5°)

Once we know the width for 60 lines (or pixels) we can calculate how many lines per inch can be seen by using 60/Width of 60 lines.

So putting those together gives us

60/(Viewing distance x tan(0.5°)) = 60/(Viewing distance x 0.0087269)

= 2/(Viewing distance x 0.000291)    

= 1/(Viewing distance x .0001454)

= 6878/Viewing distance

Dave

[JJMack]

If you print and image from single Camera RAW image  72 feet by 60 feet billboard size the image will be soft up close where the human eye can resolve down to 300ppi,  Even if you interpolate the RAW image's pixels up to 56GP and print the 72' x 60' image at 300ppi.   A poor quality large billboard size image will look fine from at a 100 yard distance. You may even see it as sharp.  When you interpolate an image up on down in sized you loose some image quality, However the printed image may look less pixelated interpolated up in size

[NB, colourmanagement]

Hi yalegurney

You're going to need a certain number of pixels per inch or cm across the image width.

As Dave and D.Fosse have explained, the number of pixels required is dependent on viewing distance, this means that a billboard requires pretty much the same number of pixels as a double poage magazine spread.

(Viewing distance is, of course, most often a product of image size, you normally view a massive print from further away than an A4, say. Think of those massive Kodachromes in Grand Central Station).

Lets say print size is 24 inches on the larger dimension and the viewing distance requires 240 PPI. Then your image has to be a minimum of 240 x 24 = 5760 pixels. 

Dont miss out on sharpoening either. Many do. Sharpen at final ouput size and resolution.

 Also its not always "more pixels are better", if you send an A3 image to a designer and they place it at A5 its not going to look sharp, better to downsize then sharpen then send it. 

When downsizing I tend to make a copy and archive the full rez original, repeated resizes and resharpens often play havoc with image quality.

I hope this helps
neil barstow, colourmanagement net :: adobe forum volunteer
google me "neil barstow colourmanagement" for lots of free articles on colour management
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