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DSLR Guide News - A Summer Tip For Preventing Blur
July 27, 2009
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I can now breathe a giant sigh of relief.
That Nikon D5000 Guide that I've been hinting about for months now has finally been published.
It took me awhile to add the finishing touches - every time I went back to the guide to finish it up I found a few more things that I wanted to write about.
The sum and substance of the D5000 is this: Nikon managed to pack a ton of features into a small lightweight camera that retails for hundreds of dollars less than the (almost) comparable D90.
If you're just making the move from compact point-and-shoot to digital SLR, then the D5000 should definitely be one of the cameras on your list of options.
Focal Length and Shutter SpeedThis month's section on photo technique will be suited for both beginning photographers as well as those who are more advanced.
The question we're hopefully going to have answered by the time you get done reading this is: what is the relationship between the focal length of the lens on my camera and the shutter speed that I use?
And - more importantly - why should I care?
Let's kick things off by talking about focal length.
The focal length of your lens determines how your digital SLR "sees" the world - and therefore what you are able to take pictures of. Focal lengths are measured in millimeters and can range from 10mm all the way up to 800mm.
Most lenses these days are zooms, which means that they have a variable focal length. For example, the most common kit lens is an 18-55mm zoom (from wide angle to standard).
Put into compact camera terms, this is a 3x zoom (just divide the large number by the small number). There are other more powerful zooms that you can get your hands on, like Tamron's 18-270mm lens, which is equivalent to a 15x zoom.
This quick introduction to focal length brings us to our first key point:
The longer the focal length of the lens, the greater the amount of visible camera shake.
Here's what this means: you're holding your camera in your hands and have the lens set to an 18mm focal length. When you look through the viewfinder, the image looks nice and steady (provided you're not jumping up and down).
The minute you use a 400mm lens with your camera, you'll see the image in the viewfinder moving ALL OVER the place, even when you do your best to hold the camera rock solid.
This is why sports photographers and wildlife photographers all use some kind of support for their cameras: either a tripod or a monopod (a one-legged tripod). These types of photographers all use super telephoto lenses, and there's just NO WAY you can keep a huge lens steady when holding the camera in your hands.
On to key point number two:
Camera shake can make your entire photo appear blurry.
The reason why you want to completely eliminate camera shake when you're taking pictures is because it has the potential to make your entire picture look blurry.
However, the photo will only appear blurry at certain slow shutter speeds (aha! I finally got around to shutter speed).
If your shutter speed is fast enough - say, 1/1000th of a second - then you can take pictures from the window of a truck driving over a bumpy road and your images will still look nice and sharp (also often called "tack sharp" in photo lingo).
However, the minute your shutter speed slips below 1/30th of a second, you're running the risk that your great photo opportunity won't turn out as clear as you expect it to.
There is (as you might have guessed from the title of this section) a direct relationship between the focal length of your lens (which can magnify the effect of camera shake) and the shutter speed (where slow shutter speeds and a shaky camera can lead to blurry photos).
Here it is:
You can avoid camera shake blur by using a shutter speed that is faster than 1/(focal length) of your lens.
Let's look at some specific examples where we match the focal length of the lens with the shutter speed required to avoid motion blur:
The first thing that you'll notice is that the shutter speeds listed above aren't exactly 1/(focal length) of the lens. This is because there are only a limited number of shutter speeds you can use - you can't set your shutter speed to 1/18th of a second.
Since certain shutter speeds don't exist, you just have to pick the next closest shutter speed - just make sure that the one you pick is almost the same as 1/(focal length) of the lens. For example, with a 50mm lens, 1/60th of a second is just fine, while 1/30th of a second is risking a blurry photo thanks to camera shake.
Before we wrap up this discussion of focal length and shutter speed, there are a couple of important points to make:
Example 1 - Focal Length:18mm | Shutter Speed: 1/15
Example 2 - Focal Length:55mm | Shutter Speed: 1/15
New Nikon Digital SLRs
The Nikon rumor mill is in full swing and most cameras that have been "leaked" before all turn out to be real in the end (the Nikon D5000 is one such example).
So what do Nikon enthusiasts have to look forward to toward the end of 2009?
This camera probably won't have the articulated LCD that's available on the D5000, and it may also not have a movie mode. Essentially, it's a minor upgrade to the D60, while the D5000 represents a more significant jump in terms of features (and therefore price).
The next camera falls into the pro-sumer or advanced amateur category and it's expected to be called the Nikon D300s.
The D300s will build upon the impressive features of its predecessor, the D300. Expect the D300s to include a new HD video mode (higher quality than what you can get with the D90 and D5000) along with an impressive ability to shoot very high ISO with very little noise.
Advanced amateurs with enough disposable income and professional photographers should be treated with the Nikon D700x - a full-frame digital SLR with a video capture mode (much like the existing Canon EOS 5D Mark II).
Remember that these cameras are merely rumors right now...but a lot of rumors about Nikon have been 100% right in the past.
Other Photography Sites
Great Photo Blogs
Recommended Digital SLR Retailers(These are the three online stores that I use to purchase all of my digital SLR photography gear)
In ConclusionThis month I changed my contact form around a bit.
I realized that I was answering a lot of personal e-mail but that there were probably more than a few people (besides the person asking the question) who would like to know the answer.
The new contact form addresses this issue - now when visitors to the site have a question, my response will be visible to everyone who visits the site later on.
Think of it like a giant Q&A for digital SLR cameras: small details or analysis that I don't yet have on the site may be addressed in this new section of the site. The site search feature at the top of the page will let you find the answer to ALL of your questions.
And - of course - if you can't find the answer, then you're perfectly welcome to use the new contact form to ask.
Happy picture taking!
--Chris Roberts, Your Digital SLR Guide
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