Photoshop Question

[Helevitia]

Greetings fellow MURCers,

I have, what I hope, is a simple question.

You know how you put down an image and it looks great at a certain size but the bigger you make it, the worse it starts to look. This I understand. Here is my question:

I am making something that I am giving to a print shop to put on a banner. The banner is obviously much bigger than the photoshop page. Will the banner print it as it sees it on the paper or, will it blow it up and make everything thing look horrible?

It seems that it will look p[roper because the printing shop is asking for an image and I assume they just print what it sees but on larger paper? I mean, how do they make banners currently? Do they just make something in photoshop like me and then get it printed out? Maybe they actually tell photoshop to make a huge banner size paper but work with it on smaller, workable dementions? I wasn't worried about it until I started thinking about it some more and now I have no clue. I will call the shop tomorrow to ask but I know there are a bunch of you on here that use photoshop all the time. Your input is greatly appreciated.

Thanks,

Dave

[KeiFront]

You can better ask the print shop about these questions, at which dpi do they want the picture which format do they expect (PSD, TIFF, EPS, PS or PDF), etc.
It's easier for the print shop if you provide a correct file according their standards.

[az]

Since a big banner is usually viewed from a distance, a little blurriness isn't too bad.

You should generally use the <s>biggest</s> highest quality possible image as a source, though. I know that you can get a reasonably good looking 50x75 cm print from a 5 mp (2560x1920) image, with a little retouching (I'll read it up if you want).

AZ

AZ

[Helevitia]

cool, these are the kinds of answers I am looking for! az, read up on what? Not that I will complain if you read up but I don't understand what you mean

Thanks guys!

Dave

[Helevitia]

hmm, now I have another quesiton. If I make it too big, than the images I currently have will look horrible if I blow them up. What do people do when they start out with a small image? Do they painstakingly retouch them? Thanks again!

Dave

[KeiFront]

Helvetia, what will be the size of the banner(s)? And do you need one copy or several copies of it?

[az]

I meant read up on which steps the mag I read this in took to preserve quality

AZ

[Helevitia]

Originally posted by KeiFront
Helvetia, what will be the size of the banner(s)? And do you need one copy or several copies of it?

The banner will be 4' x 6'. Only 1 copy.

Dave

[Helevitia]

Originally posted by az
I meant read up on which steps the mag I read this in took to preserve quality

AZ

If you feel like reading it and passing along the information, I would love to know, but please, don't go out of your way.

thanks!

Dave

[az]

4' x 6' is about 1.2m x 2 m, isn't it? How big is the original image?

AZ

[Helevitia]

Original image is 6" x 9"

[az]

So the banner will be 8x as big as the original file... Well, if it gets rastered, that might work (just look closely at one of those big advertising posters), though the print shop will of course know better than I

If it is a photo or something similar, resampling it to a bigger size (best multiples of 100%), then (this is the trick!) adding noise, and then sharpening will make the image appear sharper than it really is when blown up.

The trick about adding noise is that the brain then interpolates, and that the softness of a resampled image looks boring and undetailed and blurred. Problems with adding noise are that large unicolored surfaces look dirty/grainy, and that adding too much noise is of course bad for th image. You have to decide how much (and which kind of) noise you add and how much (and which kind of) sharpening you use.

AZ

[Helevitia]

Wow! Cool! Thanks for the info. Although I sort of know what you are talking about, it will still be a learning experience

Thanks again!

Dave

[UtwigMU]

Well I teach Photochop:

Firstly the resolution is important:

Print is made of fine dots of Cyan, Magenta, Yellow and Black that are printed at different angles to avoid moires.

Different print jobs are made at different lpi (lines per inch):
- Magazines, adds 150-175
- Newspapers 100-(133)-150 lpi

You need at least same to twice (one generally makes twice dpi sized images) dpi (dots per inch) vs lpi for final output:
Magazines: 300-350
Nespapers 200-266-300

Screen resolution is generally 96dpi for PC and 72dpi for MAC

Now with regard to banners, bilboards have significantly lower dpi, since they're viewed from cars passing by at high speeds.

Generally you don't want to inflate image. You choose image-image size and tick off resample.

Thus when you increase size resolution decreases or vice versa, pixel size stays the same.

Important is how much raw pixels do you have. Generally A4/letter = ~20-25MB, A3/legal = ~40-50MB, etc....

Downsampling is OK (to tick resample and reduce pixel size.

Upsampling is generally not too good, however algorhytms allow 2-3x upsampling with a few filters. Note that such image is not very good (OK for say some product catalouge, not OK for Naomi Campbell).

My advice, call the graphic studio and ask them, how big image (in pixels) do they need. If they need significantly larger image than you have, you can take it somewhere to be scanned (for instance A4/legal 300-350dpi scan is about 10$ here, I imagine any kind of scan won't cost through the roof for one image even in USA.

I prefer to scan stuff at commercial scanners for prepress since it takes me more time to correct image scanned on my 200$ Umax astra, than it costs me to have it scanned on $1000's Heidelberg Topaz and have it colour corrected.

If the source is natural drawing (aquarell, oil...), photo, dias or negative, you can have it scanned.

If the source is printed material (magazine) scan won't yield more information than it's there (300dpi).

If you created image yourself, create it at bigger resolution if you lack pixels significantly and have time.

Generally my service bureau told me that the students who need a poster for party bring postcard size image and making 2x letter (A2 = 594x420mm) sized banner out of it is not a problem.

IMO it's better to give image to graphic studio and let them inflate it since they are better at it (filtering...), if it's sized enough to be inflated.

If you're going to do it yourself: try median filter at 1-3px radius and then unsharp mask with treshold as low as possible, radius 1-2 and amount to your liking.

[UtwigMU]

So your banner is 122x183cm and your image is 15x23cm.

What's the pixel size of image?

I'd say if you don't need banner to be looked at from close (eg roadside billboard), it could be feasible.

One banner is generally made at digital print shop.

Digital print shop employs laser hi quality 4-ink printing: advantages are no films, print directly from file, best price untill arround 1000 copies.

They print out about 70cm (B2, sometimes B1, no such shop here IIRC) rolls of paper that are then made into bilboard.

For external use print/coating adds to costs.

Bilboard (2x3m) costs about $500 per month here, about half print, the other half rental of advertising area.