is this correct from original to final to enlarge a TIFF?

GL
Posted By
glenn_losack
Dec 5, 2008
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417
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< http://www.pixentral.com/show.php?picture=1H2h5g9T8l4fJcb3tM BfU4QqvqY4hi0>

first time i am enlarging images using a custom lab who will charge me 1/3 less if i send them ready images, i.e size, color space, sharpened sized correctly TIFFS .

I have sold many images sending files but never did this myself!

is this the accurate way to enlarge the image (up ressing) using image size and bicubic smooth?

am i missing something here doing something wrong?

thanks
Ramon Anne !!!!!!!

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– in 4 materials (clay versions included)

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AS
Ann_Shelbourne
Dec 5, 2008
As you are starting from a Tiff, you might try using ACR to do the rezzing-up. ACR apparently uses a superior and different method from Photoshop’s to do this.

If you use Photoshop to up-rez you are on the right track with Bicubic Smoother but you are enlarging by 200% and I wonder if you actually need 300 ppi for the printed output.

Check with your printer as to how much resolution he actually needs.
R
Ram
Dec 5, 2008
Glen,

It’s not clear to me what the original dimensions (in so many pixels wide by so many pixels high) of your original image are.

In general, I don’t bother upsampling (or downsampling) if the pixel per inch resolution of the final image falls anywhere from about 180 ppi to 400 or 480 ppi. Remember that the printer does its own upsampling. In this regard, it’s very important to know what the printing lab is doing.

As Ann suggests, input from the lab is essential in this respect.

Here’s an old post of mine in a thread you might find pertinent:

Ramón G Castañeda, "Your opinion on this method of resizing" #7, 30 Dec 2007 5:11 pm </webx?14/6>

Even more relevant are Jeff Schewe’s comments on that same thread:

Jeff Schewe, "Your opinion on this method of resizing" #14, 30 Dec 2007 11:24 pm </webx?14/13>
GL
glenn_losack
Dec 5, 2008
Ramon/Ann i use MPIX. They are fantastic, but have set fixed crop areas when you upload your images to buy prints and some of my Gallery images are being cropped with MPix’s crop areas . I cannot use them since i cannot sacrifice detail in my images.
so i went to local lab in Manhattan and they have 2 different prices. One is called PREFLIGHT and the other is CUSTOM.
Preflight means i go in there with my TIFFS color space, dimensions everything …… and they just press a button i guess.
CUSTOM ( 3 times the price) they will do it all.
Im quite able to deal with the Image Size area in Pshop. MPIX tells me it doesnt matter what size you dial in IMAGE SIZE like 24 x 37 inches. As long as the pixels number 2400 x 3600 and the resolution is 200 upward, you say 180 OK.
is this the truth and only details i need
thats good enough for a 2 feet by 3 feet image?
as long as the IMAGE size shows over 2400x 3600 ill get a 2 by 3 feet bleed? WHat the print lab is doing is not part of the deal. Im not being asked anything and im just supposed to prepare the TIFFS, so i dont follow you here.

what if i wanted a 4 feet long and 15 inches high print? how would i know how many pixels would suffice?

here is a sample enlargement
will this suffice for a 2 x 3 3 x 4 or in fact 4x 5 feet image

< http://www.pixentral.com/show.php?picture=15g1o0b65TiLZfoMp5 5RfWlq7njaYQ0>
AS
Ann_Shelbourne
Dec 5, 2008
Try this for yourself in either Photoshop/Image Size or in a New document dialog and you will see that a file that is 2400 x 3600 pixels would only produce a print of 13′ x 20" at 180 ppi.

Why does this lab restrict you to such small file sizes?

For a print measuring 4 x 5 FEET you would need 10800 pixels x 8640 pixels at 180 ppi!
R
Ram
Dec 5, 2008
Glenn,

I’m not sure exactly what you’re asking. Your screen shots add to the confusion rather than clarify things.

I don’t have any idea what kind of printer your labs uses, and each image is different, depending on its content.

You are not pinning down the exact original dimensions or the target print dimensions.

will this suffice for a 2 x 3 3 x 4 or in fact 4x 5 feet image

Well, which one is it? 2×3 or 3×4 or 3×5? What kind of image? From what distance will it be viewed?

The screen shot is adding to the confusion. The one you show at 200 ppi has already been enlarged (if it stems from the one labeled "original"), and so has the one labeled "final tif".
GL
glenn_losack
Dec 5, 2008
my last chance here, i apologize for any misunderstanding of my thread but i cant explain it better.
will try!

lets say i start with a file that is pixel dimensions 70.8M width6666 length 3710
document size W 22.22 HEIGHT 12.367 reso 300 p/inch
all checked bicubic smoother.

want this image to be enlarged to 36 inches x 24 inches ( lets say ). How would i do this? my techniques:
can I lower the resolution to 200 and with all boxes checked raise the Width as close to 36 as possible and have the length change accordingly or whatever comes closest to 36 x 24.
using bicubic smooother?

is this all i need to do?

I do not know what the lab uses!!!!!!! I am not privy to this information.

now if i wished to go from the original file to 3feet by 4 feet adding another foot to each side. what amount of pixels would i need? ann gave me the answer she did mathematically.

is it just a matter of checking the resample image
and dial in your choice of width and height?
with resolution at 180-300 dpi

please dont make this more complicated than it is
im not writing a book on printing just want to make sure i give the lab the proper file the price is one third what it would cost if i let them do it all.
R
Ram
Dec 5, 2008
lets say i start with a file that is pixel dimensions 70.8M

Totally irrelevant. :/

width 6666 length 3710

OK, now we’re talking.

document size W 22.22 HEIGHT 12.367 reso 300 p/inch

Yes, but WITH resampling OFF!

all checked bicubic smoother.

Not now. That’s irrelevant. You’ve just set the resolution, you’re NOT re-sampling at all (yet).

That’s where you were introducing confusion.

The rest is OK. 🙂
R
Ram
Dec 5, 2008
I do not know what the lab uses!!!!!!! I am not privy to this information.

Demand it. Period.
R
Ram
Dec 5, 2008
lets say i start with a file that is width 6666 length 3710

want this image to be enlarged to 36 inches x 24 inches ( lets say ).
How would i do this?

Leave Resampling OFF!

Input the new length: 36 inches, and…

…now you know your other dimension is 20.036 inches, so you’re short about 4 inches. You cannot obtain the new dimensions you want without cropping your image to the proper aspect ratio, or distort the hell out of the image.

You HAVE TO crop to the correct aspect ratio. No ifs or buts.
GL
glenn_losack
Dec 5, 2008
Ramon

leaving resampling off will lower the resolution
doesnt this matter if it goes below 180 ????
why not leave it checked and increase the file size?

whats the problem with keeping the same resolution?
AS
Ann_Shelbourne
Dec 6, 2008
If you start with a file that is 70.8 MB
6666 pixels wide by 3710 pixels high and set the resolution to 180 ppi

You will get a print that is approximately 37 inches wide by 20 inches high.

Use the image Size dialog with "Resample Image" UNchecked to see how this works.

Changing to 300 ppi (without Resampling) would produce a print from the SAME file of approximately 22 inches wide by 12 inches high.

If you want this image to be enlarged to 36 inches x 24 inches you would set the height to 24" which would change the width to 43 inches.

(However, you will eventually need to crop the image to fit the width of your 36" paper and will lose some of your image).

If you look in the image Size dialog, you will see that the ppi has now been reduced to 154 ppi.

At this juncture, you select "Bicubic Smoother"; Check the "Resample Image" box;
and enter your required "180 ppi" .

In the top half of the dialog, you will see that your image has now been up-rezzed to: 6762 pixels wide by 4320 pixels high — but that it is still set to print at 24" x 43".

You click OK — and will now have to crop the width of the image back to your required 36".

Just do all of this in the Image menu/Image Size dialog and it will be very easy and straightforward.
R
Ram
Dec 6, 2008
whats the problem with keeping the same resolution?

You re-sample, therefore you lose quality.

leaving resampling off will lower the resolution

Yes, it will. To about 185 ppi, giving you a 36x20inch print. I’d be happy with that.

But you can increase it the resolution if you want, as long as you understand what that means.

You still have to crop.
R
Ram
Dec 6, 2008
Remember this, Glenn:

Resampling means either upsampling, i.e. inventing pixels that aren’t there in order to achieve a larger image, or downsampling, i.e. discarding pixels with real information in them in order to achieve a smaller image.

If you can get to your target print dimensions by leaving resampling OFF (thereby changing the resolution) then you’re retaining all the image information and not making up pixels that aren’t there. Of course, you then have to look at the resulting resolution in order to make sure it still meets your standards. (In my case anything between 180 ppi and 480 ppi will do. Those are my personal standards.)
NK
Neil_Keller
Dec 6, 2008
Glenn,

You have the right to know how your lab is handling your images; if they are just resizing or resizing with resampling; and at what resolution.

If you link horizontal ppi/vertical ppi/resolution together (resampling off), you are doing nothing more than enlarging or reducing the exact same pixels you have in your original — kinda like inflating or deflating a rubber balloon. You are in no way changing the content of the picture.

If you resample your image in any way, the computer has to figure out how to interpret the added or subtracted pixels, and how to substitute other pixels that now represent smaller or larger pieces of the original; and always resulting in some deterioration of the original image — sometimes subtly, sometimes fairly obviously. You never add good content when you resample.

Neil
NK
Neil_Keller
Dec 6, 2008
Glenn,

The other thing to remember is that generally the larger the image, the further away people tend to look at it, and the lower resolution you can get away with. A transit graphic on the side of a bus or truck, or a 24-sheet billboard on a rooftop can have pixels at a resolution so coarse that it would be totally unacceptable from a more usual 18" reading distance.

But the file size for that truck graphic can very well be EXACTLY the same as you would use for a typical magazine page or spread, without any sense that it was "low resolution".

Neil
R
Ram
Dec 7, 2008
Glenn,

If you’re still around, this is highly recommended reading for you.

It’s a PDF by Photoshop Evangelist Julianne Kost titled:

PSCS2 Image Size — Common Questions (PDF) <http://www.jkost.com/pdf/photoshop/cs2/imagesize.pdf>

If you need to know things like the relationship of mega pixels, file size, image size, and print size, as well as determine at what size to scan, what resolution to use for printing, slideshows and the web, then this PDF is for you!

<http://www.jkost.com/pdf/photoshop/cs2/imagesize.pdf>

It applies to CS4 as well, of course.

How to Improve Photoshop Performance

Learn how to optimize Photoshop for maximum speed, troubleshoot common issues, and keep your projects organized so that you can work faster than ever before!

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