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ATPM 17.06
June 2011




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Wonders Never Cease

My mom is now 83. She actively fought me over why she needed a new computer; after all, her PC worked just fine. I bought her a refurbished iMac with the beautiful screen for Christmas three years ago and set it up for her with a wireless connection so the children and grands could hop on, too.

The next Christmas, she got an iPod, then last year, she got an iPad because she would be able to see the screen on the iPad easier than the iPod. She told me on the phone just yesterday that she didn’t know how badly she needed this technology until she had it and used it. She exclaims constantly how easy the iMac is to use, how beautiful the screen is to look at, and how easy it is to see. And, it’s faster than that old PC, so she did need the new computer after all!

She’s had no trouble with actually using either the iPod or iPad, and little trouble with the iMac. She has always been a reader, but had gotten to the point that books were too hard to read and she didn’t like the books on tape. First the iPod and now the iPad have been lifesavers in ease of use for reading. We use the Kindle app, which allows us to share one account. She loves listening to her music, too. Truly, Apple employees and Mr. Jobs have created products which surpass mere fanboi enthusiasm and enter into the realm of perfect engineering.

—Zanne Baker

Thank you for sharing your story. The iPad is an extraordinary device for reading content in a wide variety of formats. I find new uses for my iPad every day.

—Robert Paul Leitao

Two iPhones and a Rice Bowl

You can go a step better and get silica gel from a craft shop like Michael’s for drying things like wet iPhones. You could also help by warming this slightly. Maybe put the box with phone and powder in the sun. If you have this in a cold area like a back room in the winter the drying process could take a long time.


That’s another creative approach. I prefer the rice bowl because rice is readily available in most kitchens or pantries and available for quick purchase at any local supermarket.

I don’t suggest anyone with a wet iPhone or iPod touch delay taking action. I’m not an expert in this area, but I suspect prolonged water exposure does the most damage to the device.

—Robert Paul Leitao

A Tutorial on Resolution

OK, so what I’m wondering is…

Is it possible to take a 72ppi, 14.222″×10.667″, 1024×768 pixels image and resample to 300ppi, and then resize to be able to print a 48″×36″ photo suitable for hanging on the wall?

Thank you!


1024×768 is simply too small for the huge dimensions you’re looking for. Yes, technically you could resize it up to 48″×36″, but it would come out looking as bad, or worse, than the blurry bulls-eye target example seen in this article.

Photoshop would allow you to set those numbers and it would simply “invent” the pixels to fill in the missing data, making a guess as to what should be there. The bigger the enlargement/resize, the more guessing “and blurry errors” Photoshop will make.

I usually work on 200ppi for photo lab reproductions. The extra resolution of 300ppi is usually only needed for commercial offset printing. If you don’t look too closely, you can probably get away with just 150ppi, considering it’s a wall item that people usually look at from a bit of a distance.

Let’s do the math. Just multiply the desired dimensions by the ppi to find out how many pixels an image must have to get the dimensions without enlarging and possibly causing blurriness:

  • 46″ multiplied by 150 (ppi) is 6900, and 36″ multiplied by 150 (ppi) is 5400. So you’d have to have at least 6900×5400 pixels for 46″×36″ @ 150ppi if you don’t want to enlarge/blur the original. At this resolution, 1024×768 pixels is only enough resolution for 6.8266″×5.12″.

  • 46″×36″ @ 200ppi would need 9200×7200 pixels. This is probably the resolution you’d want to target for a typical photo.

  • 46″×36″ @ 300ppi would need a whopping 13800×10800 pixels! That’s 149 megapixels!

Does this make sense, or is it still complicated? Let me try it this way: I have a 12.2 megapixel Nikon D90 camera. The largest pixel dimension it produces is 4288×2848. Here’s the inch size at the three ppi resolutions I’ve discussed:

  • 150ppi—28.586″×18.986″

  • 200ppi—21.44″×14.24″

  • 300ppi—14.293″×9.493″

So at 150ppi, even my high-resolution Digital SLR camera doesn’t quite reach 46″×36″.

Having said all this, large photo prints are made from DSLR resolution all the time. There’s a process photo labs do (I’m not well versed on it) that make the image still look OK. But I’m afraid a 1024×768 image just ain’t gonna cut it.

—Lee Bennett

Thank you so much for answering my question! I’m still a little confused however! All those numbers, and ppi’s and pixels etc. And I swear I was good in math!

Anyway, from your reasoning, if I can get away with 150ppi for a wall item and I go as big as 18″×18″, then I would need 2700×2700. Correct? The camera I’m working with does goes as high as 7M 3072×2304 pixels. I guess I’d have to crop it for the square image that I’m looking for, but 2304 is still not enough right? Will this camera just not work? It’s a Panasonic Lumix DMC-FZ8. I can’t tell you how much I appreciate your help. I’m really trying to wrap my head around this.

Thank you,


Correct: 2700×2700 at 150ppi is 18″.

Your 7MP camera at 3072×2304 at 150ppi is 20.48″×15.36″.

Talk to the photo lab, though. I couldn’t say whether they’d tell you 150ppi is too low of resolution, or if they have technology that would make a larger print look nice even though the resolution would technically be less than 150ppi.

There’s probably some way to do it. After all, people print enormous banners and billboards that would technically be too big for even 15MP of resolution. The right photo lab could probably get the job done.

But coming full circle, a 1024×768 image, I can promise you, is simply light years beyond too small.

—Lee Bennett

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