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When we talk about optimizing a PDF, what we actually mean is that what we are trying to do is reduce the file size of the PDF while maintaining the quality of the text and graphics. And the reason that you'd want to do that is because you need this digital file to be downloaded quickly from a web site, for example. So maybe a lot of your customers don't have the fastest DSL or fiber optic connections to the Internet, but you want them to be able to download say this catalog as a PDF and not have it take three hours to download. So you want to reduce the file size but you still want all the followers to look really nice.
Now, if you're just trying to transfer a large PDF to somebody else and you are trying to avoid long times in transferring something as an attachment to an e-mail, there is a different solution, so that you don't need to actually have to worry about optimizing. If you are just trying to send one thing to one person you can always use Adobe's new Send Now online service and I'll be talking about that in a different video. The Send Now online service lets you send very large PDFs to one or more recipients without having to go through somebody's mail server. But we are talking about a situation where you want to send out a PDF to many people or you want to make it available to be downloaded from a web site, so you want to reduce the file size while maintaining the quality of the file.
So first of all, when we're going to do this in Acrobat, we need to figure out how big is the file on the first place. We could always jump over to the Finder or Windows Explorer and select the file and figure out how large it is there, but that's too much work for me. I like to find out right in Acrobat and all you need to do is go to the File menu and choose Properties or press Cmd or Ctrl+D. In the first tab in Document Properties, look down here and you'll see File Size, right? So that's a fast way to find out. There are a few other places too where you get a report of file size but, I use this all the time.
So its 11.2 megabytes, which is a pretty hefty file size. So let's take a look at this file and see, you know, I wonder why it's so large and I would guess, I am sure that you're right there with me, is that it's because it's got so many images and images take up a lot of space because of their resolution and all the colors they use. So what we want to do though, the images are very important to this document. We want to reduce the file size, but keep the image quality pretty high. Now there are two ways to go about optimizing a PDF in Acrobat, one is what I call the quick and dirty way and the other one is the more scientific way. And I am going to show you both ways right here.
Now, the quick and dirty way, you go to the File menu and choose Save As and choose Reduced Size PDF, right? What could be simpler than that? There is only one decision to make and that is which version do you want to make this new PDF compatible with? It's going to assume you want to make it compatible with the current version or later which is Acrobat X in this case, but it could be earlier. Now this really just depends like if I create a PDF that's compatible to Acrobat X and later, and I give it to somebody say with Reader 7, or 8 or 9, in most cases they're still going to be able to open it.
They might get a little peep of complaint from Reader saying this was created in a later version and there maybe elements that you can't see, but we know that there are no elements like crazy Flash video or anything in this PDF, so that's not that much of a concern. What is a concern is that if you save it in an early version, like say Acrobat 4 and later, Acrobat can't do that good of a job of making the file size smaller. Only because in early versions of Acrobat it doesn't support some of the features that are supported in later versions and it has to convert that to something simple, which usually means the file size gets larger, all right? So I know it sounds kind of backwards that the later the version, the smaller the file size, but that's what it's like.
So you should choose a file size that's pretty late in the game, definitely version 6 or later if possible. So, but, well I am just going to leave this at version 10 and later and we'll just say OK. Now, one other little side is that this Apply to Multiple button, if you need to reduce the file size of, say, 10 years' worth of PDF archives of your newsletter because you're going to upload them to the web site, you might as well click Apply to Multiple. That will give you a dialog box that lets you add a whole bunch of PDFs that you can apply this to all of them at once. But we are going to skip the Apply to Multiple button right now, we have seen that before in some of the videos like on Watermarks and Background, so.
All right, instead let's just go right to OK and now it does not actually compress this file, it makes a copy and compresses the copy, which is nice, so you always have the original not going to get harmed and we'll call this final reduced, so we can keep track of it. So it's processing the images and what it's actually doing it's going through a whole bunch of different steps to make this a smaller file and I have not been able to find it documented anywhere exactly what it's doing.
I know for sure that one of the things that it does is it reduces the resolution of the images. We have got an alert that says, there are some things in this PDF that it couldn't do much with, some things that contain image masks that were not downsampled, you will get that alert every once in a while. That just means if you did something fancy in the originating program, sometimes it can't give out that image data and it has to skip over those images. That's fine. All right! So we're looking at this. It looks pretty good to me, I don't know about you. The images still look pretty sharp. Let's see the file size.
We'll go back to File, Properties, check that out; 2.18 megabytes, that's pretty good from 11-something, right? I can sort of see that this little thing got a little fuzzy over here but I mean look at these pansies over here on the left, they look pretty great and I am zooming in a little bit, they look good and I think this is perfectly fine for downloading. So that was 2.8 or 2.18 megabytes, let's see if we can get it even smaller. For that, we're going to take a look at the more scientific way of optimizing a PDF that I mentioned at the get go.
It's in the same menu if you remember, go to File > Save As, and instead of Reduced Size PDF we want to choose Optimized PDF. I think that's a dumb name, it should say Reduced Size, Optimize, or make it smaller, better or something, but Optimized PDF opens up a dialog box that basically gives you complete control over every aspect of a PDF, many more than you ever thought existed, and what it should keep, what it should retain and what it should change when you click the OK button.
In other words it's going to create another PDF that's optimized and it's going to use these settings. One is this button up here, Audit space usage. If you click this, it will just take a second and it'll go through your PDF and tell you hey! What's causing all this space? So it will say your total size is 2.28 megs and 92% of that is because of the images. There is some document overhead that's 3%, that's the next largest thing. Now, you might get some documents that maybe the largest amount of size isn't coming from images but from document overhead, or from forms, or because of all the embedded fonts.
This will give you an idea of the area over here that you need to pay attention to. So if most of our problem children are the images, we need to spend a lot of time in the Images pane and trying to reduce that, okay? So we'll say OK. So here in Images, now I've already been playing with this for a while, but normally when you open it, you're going to see that this first field says 150 and this field says something like 225. Well, what its saying is that if I click OK, it's going to look at all these images and any image that is currently above 225 pixels per inch of resolution, it's going to reduce those to 150 pixels per inch, and it will do the same thing for grayscale images and monochrome images.
Well, I know in this case that it's mainly color images, so I am not even going to pay attention to this. And I might say you know, I don't need 150 pixels per inch, 72 will be fine, 72 pixels per inch is the resolution for most web graphics and people will be downloading this from the web, so they won't be expecting anything really high. I'll leave this for 72, and I don't want this applied to only images that are above 225. I swiped over here and it automatically changed it to 108; some sort of math is happening in the background, but I want every single image to be 72, so I am going to say, if it's over 72, make it 72.
Then you just click OK and you do that a few times and check the different file sizes to see which one worked the best, which one made the optimal PDF? And when you find the magic combination, you should definitely save it. So we can save, we'll call this Low-res catalog for web, because I am going to bring everything to 72, so that's low res. Let's just leave that as is and then we'll go ahead and make a new one. So we'll say this is reduced, I'll say optimized, just o-p-t there.
See if we can get it even smaller. It's going through the images, all right, yes, we had a problem. All right, so it opened it up, you can see up here in the title, it's final-reduced-optimized. Let's take a look. I always want to wish we had a drumroll kind of sound effect. Look at that, it's under a meg, 788k. I think it's as small as we're going to be able to make this thing and still be able to see the images. So these are now 72. They don't look that bad, do they? And it did other optimizations too, those other things that were checked on, all right? So it made a nice, look at how nice this looks, and it's less than a meg, we started out with 11.5.
All right, so now I think you have a really good idea of how to reduce your file sizes while keeping the image and text quality as high as possible whenever you want to optimize a PDF in Acrobat.
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