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Tuesday, April 7, 2009

The Lowdown On Zooms

Digital And Optical Zooms • How Many Clicks Do You Get? • The Color Of sRGB And Adobe RGB (1998) • Film Vs. Digital Vs. Sensor Size...Again

Labels: How-ToColumnTech Tips
How Many Clicks Do You Get?
Q I wonder about the longevity of the shutter mechanisms on recent-model, video-capable D-SLRs. Most shutters are advertised to be capable of 500,000 or so cycles, so if you’re shooting at 24 or 30 fps, you wouldn’t get far before reaching the lifespan of the shutter. Is there something I’m missing?
S. Wolpert
Via the Internet

A Pro cameras such as the Canon EOS-1Ds Mark III and Nikon D3X are rated at approximately 300,000 cycles (shutter clicks). The two D-SLRs that offer video (Canon EOS 5D Mark II and Nikon D90) are actually rated at approximately 150,000 cycles. If we do the math, that would give us less than 1.5 hours of video before the shutter would be worn out. Actually, the shutter doesn’t fire for every frame of video. It simply opens the lens, and each video frame is controlled electronically. Each video segment is only one click (cycle) of the shutter. That’s why it doesn’t sound like a machine gun when the camera is capturing video.

I’d be more concerned about wearing out shutters when frequently using techniques such as time-lapse (one of my personal favorites), where I typically shoot over 1,000 images (and as many as 4,000 or more) for each finished segment. In this case, each frame does represent a cycle of the shutter. With this said, even if you do wear out a shutter mechanism, it’s not a terminal condition for the camera; it’s easily replaced for about $300.

The Color Of sRGB And Adobe RGB (1998)
Q I recently sent some files for printing to a printing house I hadn’t used before and was disappointed with the very unsaturated and washed-out results. I shoot in Adobe RGB (1998) and process in Photoshop CS2. Would you please clarify the debate between sRGB and Adobe RGB (1998), both in capture and the preferred format for image printing?
L. Caine
Golden, Colorado

A Adobe RGB (1998) and sRGB each refers to a defined portion of the range of colors visible to the human eye. The defined spaces are established standards by which cameras, monitors and printers are calibrated. The sRGB space is smaller (shows fewer colors), but it’s more representative of what some applications, particularly the Internet and lower-quality magazines and newspapers, are capable of displaying. Adobe RGB (1998) is more representative of what today’s photo printers can do. It seems pretty obvious to me that you’d want to capture, process and print your photographs with the most extensive color space available. So most of us set our cameras, calibrate our monitors and print our files in Adobe RGB (1998).

It’s possible that your new printing lab took your Adobe RGB (1998) image and printed it with sRGB. In that case, the printed results would tend to be less colorful than those you see on your monitor. Always check the lab’s guidelines for preferred file formats before you send your images. Some labs prefer to print from sRGB even though it has a smaller color space.

Another standard, Pro Photo RGB, has significantly more colors than Adobe RGB (1998). Unfortunately, most devices we photographers use aren’t yet capable of that color space. It may become a standard in the future.


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