July 2008 Helpline
Bang For The Buck
Q) About a year ago, you helped me decide on an SLR camera, and I love it. I've taken a short camera class only to learn there's so much more to learn. Now I want a versatile lens, so I can carry just one lens with me. I'll need a zoom (150mm to 300mm?) as I'm sure to be far away when I want to take pictures of tennis players and capture action shots. I know from friends that the lens can't be too long or you can't take it into sporting events, and I need a lens with stabilization. Also, I teach first-grade speakers of other languages, and I enjoy taking their pictures, too.
Via the Internet
A) Choosing an all-around lens is a matter of compromises. There are two main considerations: focal length and aperture. I bring this up because you mention quite a range of lenses. At the far end, you refer to focal lengths of 150mm to 300mm. You really have to ask yourself how much you need. Unfortunately, as you get into telephotos, the light-gathering ability of the lens drops-we call them "slower" lenses. In general, the longer the telephoto, the slower the lens. Yet you mentioned you want to shoot tennis games. Obviously, a faster lens is needed to capture the fast action.
Back to compromises. Do you shoot mostly outdoors with a lot of light or do you shoot under lower light levels? The answer decides more about what lens to get than simple focal length.
Light levels and lens speeds might seem like obvious considerations, but it's the thought process I go through when I select lenses. I try to get the fastest lens I can afford while still getting close to the focal length I really need (not the focal length I want).
As you've mentioned, stabilization is another factor. I generally encourage people to get a stabilized lens if they don't use a tripod. In your case, you wouldn't be able to use a tripod at a pro sporting event anyway.
One other thing to consider (and I'm not helping much by bringing this up) is the other end of the focal length. Having a wider-angle lens gives you a lot of opportunities to capture some interesting shots—other than a "backhand down the line."
Lastly, I know budget is a concern, but if your goal is to carry just one lens, you may need more than one lens. You might not carry them all at the same time, but you'll have more options if you decide to purchase one lens that meets the needs of photographing tennis and sports action, and another lens better suited to photographing your first-graders.
Windows On A Mac
Q) I bought an Epson PowerLite 1715c multimedia projector because it can be used computer-free with just a flash drive if a slideshow is created with the Windows-based Epson Easy Slide Maker program. I've switched from Windows to Mac. Epson states the 1715c can be used computer-free only with its Windows-based proprietary program.
That leads to my question-is there a difference between JPEG images created with Windows- or Mac-based Photoshop? At what point does the Windows or Mac platform make a difference? It seems to me that I can read CDs with Mac-created Photoshop images with a Windows machine, and PowerPoint presentations are interchangeable between a Mac and a Windows PC. Is there a program that can be installed on a Mac that allows me to use the Epson program on the Mac? As a worst-case scenario, can I create my slideshow or PowerPoint presentation with Photoshop on my Mac, copy it to a backup hard drive and bring it into a Windows machine where I could place it in the Epson slide program and save it to a flash drive?
Via the Internet
|Epson PowerLite 1700 Series Profile|
Now on to your larger question: whether there's a difference between JPEGs created on a Windows computer and those created on a Mac machine. While there are some things that Windows does differently than Mac and vice versa, there's really no difference between the JPEGs created on a Windows or Mac machine. Sometimes there may be problems reading hard drives and even CDs between the two platforms, but that's not file-related. JPEGs, like TIFFs, are platform-independent.
You also asked about PowerPoint presentations. A PowerPoint presentation that was created on a Windows machine usually can be opened on a Mac and vice versa. Of course, you'll need to have PowerPoint installed in both machines, and sometimes embedded movie files or fancy animations or effects may not play properly.
Your Epson projector doesn't play PowerPoint files (or any presentation files) directly, however. Files first must be converted to a specific file format (a "scenario" file) that the projector can use. This conversion is done by the Windows application that Epson includes with the projector. (In the case of PowerPoint, an alternate solution is to use PowerPoint to export the presentation to a series of stills that then can be displayed in sequence without PowerPoint transitions.)
You mention a worst-case scenario, where you create a PowerPoint presentation on your Mac, copy it to your Windows machine and use the Epson software to convert it. That procedure should work fine. The only problem might be slight differences in available effects or transitions in the Mac and Windows versions of PowerPoint. Also, you'll have to make sure that the font you use to create the show is available on both machines, otherwise PowerPoint will use a substitute font. Substituting fonts can cause type to shift position and appear to change in size.
Your worst-case scenario involves using two computers. There's another option. If you used to use Windows and have switched to a Mac, but miss that one application that only runs under Windows, you could consider running Windows on your Mac. When the Mac platform changed to the same type of Intel CPU that's used in Windows machines (prior to that, Macs used the PowerPC chip), it opened up the option of running Windows on a Mac. Surprisingly, Apple has embraced this concept by creating Bootcamp.
Bootcamp allows you to install a copy of Windows (XP or Vista) on your Mac. The reason it's called Bootcamp is that you have to reboot your computer to switch operating systems. Bootcamp is built into the Leopard version of the OS X operating system and requires an Intel-based Mac computer. Bootcamp doesn't come with Windows, so you have to purchase it or use the copy from your old Windows machine, following licensing issues, etc. The look and feel of using Windows through Bootcamp is identical to running a regular Windows computer.
If you don't want to reboot your computer each time you switch between operating systems, you might like third-party programs such as Parallels Desktop (www.parallels.com) and VMware Fusion (www.vmware.com). These create a "virtual" Windows machine on your Mac computer that loads like any other program on your Mac. In my experience, the performance is a little slower than with Bootcamp, and not every Windows application runs correctly. You'll have to decide if you're willing to trade faster performance for the ability to run both operating systems at the same time.