Setting up Image Size for professional printer

[nudibranches]

Hi,

I have hunted around for an awnser to this for a while but can't find anything conclusive.

I am sending a TIF to a professional printer, and I am after a 12x18 inch colour print.

What image sizing do I select? The printer isn't familiar with Lightroom and said not to touch it other than selecting 3''dpi.

So does that mean I should unclick "Resize to Fit" and just put in 3''dpi? Or do I specify 12x18 inches?

Many thanks.

 

[Denis Pagé]

What you want to send him is a picture having 12 x 3'' by 18 x 3'' pixels or 36'' x 54'' pixels. You can optionaly declace 3'' ppi but it is just a declaration written in the header of the file and depending on format, his software can force it to be seen as 72 ppi for example. This is his job then to declare it to be 3'' ppi as the only thing he does really need, is enough pixels to cover 12" x 18" at 3'' ppi.

 

[nudibranches]

Aha!!!! Denis!!!! You little ripper!!

Light finally goes off in head.

So if I wanted a 4x5 at 3''dpi I'd be setting up 12'' x 15'', and if I wanted a 8x1' I'd be doing 24'' x 3''' etc etc?

 

[Denis Pagé]

:idea:room!

This is it. The one making the print can set the other parameter or have to.

 

[Replytoken]

Why not just crop the image to the ratio required and send him a file with as much resolution as possible? It seems kind of odd that we strive to take the highest resolution images possible with our cameras, yet we show few regrets when we reduce the resolution for printing. While 3'' DPI/PPI usually produces a nice image, it seems that you would only stand to gain with a higher resolution image, with the exception of a larger file size, or problems with printer software that cannot properly re-size the file. While the latter is possible, it would seems quite odd in this day and age for a printer to only be able to work with one set resolution. I would ask if the printer needs the file cropped to the printing ratio, or if they need the resolution set EXACTLY to 3''DPI/PPI for the given print size. This of course assumes that you have a file that can yield more then 3''DPI/PPI for your desired print size.

--Ken

 

[Denis Pagé]

This of course assumes that you have a file that can yield more then 3''DPI/PPI for your desired print size.

Here it is just 7.2 megapixels... We can go far with assumptions and I won't assume he will have to upsample. The point is just that he was asked for 36'' 54'' pixels whatever the reasons of the print shop or his source file. :|

 

[Replytoken]

Here it is just 7.2 megapixels... We can go far with assumptions and I won't assume he will have to upsample. The point is just that he was asked for 36'' 54'' pixels whatever the reasons of the print shop or his source file. :|

While I agree that we can, and should not, go far with assumptions, I am still concerned that for some reason (which I shall not make any assumptions as to what they are although I have several), it seems that we are too often giving up potential quality for convenience without question. Perhaps this issues needs a post of its own, but I thought it might be useful to readers who view the topic beyond the OP.

--Ken

 

[Denis Pagé]

Thanks Ken. This may also depend if one prefer to use Lightroom's resampling & print sharpening methods or let the printer (not the device) do that. It was also much discussed here that many times, those asking for given specs to print a file often don't know what they are asking for or talking about. And we didn't even talked about the format of the exported file!

 

[Replytoken]

Thanks Ken. This may also depend if one prefer to use Lightroom's resampling & print sharpening methods or let the printer (not the device) do that. It was also much discussed here that many times, those asking for given specs to print a file often don't know what they are asking for or talking about. And we didn't even talked about the format of the exported file!

Well stated, Denis! And, you raise a good question which we often discuss in a related fashion - are there reasons to prefer LR's resampling and sharpening to that of a printer or a printer's software?

Years ago, Qimage was a very popular printing program, and I believe that it still is. I considered buying the program for printing, but I realized that Picture Window Pro, my image editor, provided me with really great prints because, IMHO, it had great resampling abilities. I always tried to feed it the highest resolution file, cropped to the print ratio I wanted, and let it do its "magic". I would like to believe that printing and editing software has improved with respect to resampling since then, but I may be mistaken.

Take care,

--Ken

 

[Denis Pagé]

As Mark Sirota pointed out last december "LR 2.2 uses an adaptive bicubic algorithm acting in linear (zero gamma) space". Give a look at these results from our very own forums...

 

[Mark Sirota]

Right, and if there's a reason to resize in LR before sending to the printer, this is it. If you want the advantage of LR's excellent resizing and output sharpening algorithms, you need to know the final size and PPI that the printer will use.

To determine whether that's worthwhile for you, send them an unsharpened full-res file and one sized and sharpened in Lightroom, and see whether you can tell the difference (and if so, which you prefer).