16 Replies Latest reply: Dec 7, 2008 4:22 AM by Ramón G Castañeda RSS

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

    Community Member
      http://www.pixentral.com/show.php?picture=1H2h5g9T8l4fJcb3tMBfU4QqvqY4hi0

      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 !!!!!!!
        • 1. Re: is this correct from original to final to enlarge a TIFF?
          Ann Shelbourne Community Member
          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.
          • 2. Re: is this correct from original to final to enlarge a TIFF?
            Ramón G Castañeda Community Member
            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 driver 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

            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
            • 3. Re: is this correct from original to final to enlarge a TIFF?
              Community Member
              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=15g1o0b65TiLZfoMp55RfWlq7njaYQ0
              • 4. Re: is this correct from original to final to enlarge a TIFF?
                Ann Shelbourne Community Member
                As you can see for yourself in your examples (or in either Photoshop/Image Size or in a New document dialog) 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!
                • 5. Re: is this correct from original to final to enlarge a TIFF?
                  Ramón G Castañeda Community Member
                  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? 2x3 or 3x4 or 3x5? 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".
                  • 6. Re: is this correct from original to final to enlarge a TIFF?
                    Community Member
                    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.

                    i 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
                    i 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.
                    • 7. Re: is this correct from original to final to enlarge a TIFF?
                      Ramón G Castañeda Community Member
                      > 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. :) The rest needs further clarification on my part.
                      • 8. Re: is this correct from original to final to enlarge a TIFF?
                        Ramón G Castañeda Community Member
                        >I do not know what the lab uses!!!!!!! I am not privy to this information.

                        Demand it. Period.
                        • 9. Re: is this correct from original to final to enlarge a TIFF?
                          Ramón G Castañeda Community Member
                          >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.
                          • 10. Re: is this correct from original to final to enlarge a TIFF?
                            Community Member
                            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?
                            • 11. Re: is this correct from original to final to enlarge a TIFF?
                              Ann Shelbourne Community Member
                              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.
                              • 12. Re: is this correct from original to final to enlarge a TIFF?
                                Ramón G Castañeda Community Member
                                >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.
                                • 13. Re: is this correct from original to final to enlarge a TIFF?
                                  Ramón G Castañeda Community Member
                                  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.)
                                  • 14. Re: is this correct from original to final to enlarge a TIFF?
                                    Neil_Keller Community Member
                                    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
                                    • 15. Re: is this correct from original to final to enlarge a TIFF?
                                      Neil_Keller Community Member
                                      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
                                      • 16. Re: is this correct from original to final to enlarge a TIFF?
                                        Ramón G Castañeda Community Member
                                        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)
                                        >
                                        >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.