Tips for setting up dpi for printing please.

[MRfanny]

Hi again,

quick question as i dont know much about this but is there a rule of thumb in regards to dpi when exporting for printing? how do i down size the original 2752 x 4128 image to print on say 500 x 750 to fit onto A4 for optimum printing at home on an epson or to a printshop. 300dpi at the correct pixel size?

I am looking at sending some images for a models portfolio and looking at limiting her printing size to A4. Don't really know how it generally works between photogs and models in this regards as its my first shoot. Anyone in this field feel free to chime in =)

I am used to using illustrator to set multi page layouts for printing, this involves importing an image onto a 300ppi layout. I'm not too sure what illustrator does in terms of resizing the image after that. What is a good workflow for setting up and printing a booklet or portfolio, photoshop one image at a time?

thanks in advance

 

[Bob]

First as to print resolution:
Adobe default is 300 ppi for print and is usually acceptable to most commercial offset printing services. Depending on the actual printer you are using, there is thought that marginally better results are obtained in the print file is prepared at native printer resolution. In the case of Epson inkjet printers, this is 360 ppi. Do not be confused with the printer's resolution since multiple inkjet drops are used to approximate the color and density of each pixel printed.
A4 borderless is 210 x 297 mm which works out (at 360 ppi) to 2988 x 4212 pixels at optimum quality.

Be sure that you sharpen to compensate for the slight blur that comes with printing although the recent Epson 7900 series drivers seem to be pretty good at holding sharpness.

For Model portfolios, there are two general approaches.
1) many portfolios today are digital and on-line portfolios are generally in the range of 700-800 pixels maximum dimension. Almost all of the portfolio images I provide are this size, sharpened for screen viewing and converted to the sRGB color space.

2) Images for print portfolios (in the U.S.) are generally 9 x 12 inches although there is some movement to 8.5 x 11 inches. They are printed borderless and are intended to fit in a binder that uses clear plastic sleeves to protect the images. I do not know what size is favored elsewhere. An image that has been re-sized for optimal quality at 360 ppi of course can be printed at twice the size (and half the resolution) and many are satisfied with the quality although I am not unless the print is much larger.

There is no way to prevent your model from taking a 360 ppi file and having it printed at 180 dpi at twice the size. Printers do not support digital rights management (which is a PITA anyway). My recommendation is to deliver the web resolution images and make the prints for her. I have seen the sorts of drug-store prints that some models obtain from files and I recommend that if your name follows the prints as it should, you are best the one in control of the final image quality. Should you deliver portfolio images to your models I suggest including a limited usage rights clause in the model release that limits the model's usage of the images provided to self promotion purposes. That is not a guarantee, but at least it sets the understanding.

As for workflow, I use photoshop pretty much all of the time except for casual images. Import each one, re-size appropriately, make your adjustments, sharpen and then convert to the desired output color space.

thanks
-bob

 

[MRfanny]

thank you very much bob.

ill take your advice and supply her with web sized files. I think at 72ppi, 800px works out to be a tad under A4 size which i think is a nice decent size for her to use.

For printing, is jpeg fine or is there a preferred format like tiff? and colourspace?

The limited usage rights clause is something to think about, i think i need to read up more on model releases, I didn't get her to sign anything for this shoot. Are they typically generic , or do different countries have different standards, ie Australia.

Thanks again.
Muc

 

[Bob]

For printing, the format and color space depends on the printer you use.
I have used some who wanted tiffs and AdobeRGB 1998, lower-end printers often prefer jpeg and sRGB.
I retain all images in layered tiffs or psd/psb format. When required, I adjust them for a particular use and save a version appropriatly named so I know what it is.

Model releases vary a bit from country to country as local law varies, but an explicit model release that defines your terms is usually pretty good everywhere. I needed one in French once while shooting in France though, they are fairly particular about what language a contract must be in.
The variation in local law usually pertains to what rights are retained by model and photographer (mostly photographer) when there is no contract present. I suggest that you look at web based resources or perhaps something down-unda for local guidance, perhaps a local photo club might be a source. For legal advise, contact a local attorney skilled in the art of copyright and performance law. I am NOT a lawyer so anything I say is my opinion alone and subject to error, omission, or downright stupidity (disclaimer added for the lawyers amongst us)
-bob

 

[MRfanny]

thanks bob....much appreciated.

 

[ralleydesew]

If you use bitmap images with low resolution first, then extend them significantly, they produce very little and in most cases will be unrecognizable. Plan your first layout to determine the required print size and resolution of your images.

 

[jessieshelled]

If you use bitmap images with low resolution to begin with and then scale it in totality they make very poorly in most cases did not identify. Plan your layout first to determine the required print size and resolution for your images.