Canon XSi with a EF-S 17-85mm f/4-5.6 Image Stabilized USM SLR Lens for taking pictures of a cruising/crawling 9 mo old?

[catherine_grant]

<p>I am considering buying a used Canon XSi with a EF-S 17-85mm f/4-5.6 Image Stabilized USM SLR Lens that I found for a great price. Is this lens going to be "fast enough" or faster than a standard kit lens for taking pictures of my fast moving 9 mo old? Does the f/ # being lower mean faster, or higher mean faster? This will be my first DSLR and I want a great all around lens for taking pictures of her both inside and outside as she grows. Thanks!</p>

[jean_yves_mead]

It's slow. It may not necessarily be too slow for your needs, especially outdoors, but you would be doing yourself a great favour if you also bought a speedlight (or learned to get the best out of your pop-up flash). Bear in mind that image stabilisation won't help you with a moving subject.

[Matt Laur]

<p>The higher the f-number, the slower the lens. A lens that shoots at f/5.6 when at its widest aperture at 85mm is going to require you to use either a high ISO, or be in very good light to freeze motion. Or, of course, you can add flash to the mix. But if you to want to shoot in available light, in perhaps less-than-ideal indoor light - you may want to consider adding a faster lens to the mix.</p>

[JAPster]

<p><em>Does the f/ # being lower mean faster, or higher mean faster?</em><br>

<em> </em><br>

The f/# is a relative number that tells you the diameter of the diaphragm opening (ie, the aperture) in relation to the lens focal length. So an f/8 aperture will be a setting that will open the aperture to a diameter 1/8th the focal length. An f/11 aperture will be an opening whose diameter is 1/11th the focal length. And an f/4 aperture will be an opening whose diameter is 1/4rth the focal length. So you see, as you move to a lower # on the Aperture Scale, you are selecting an aperture that is LARGER, and whose diameter is a larger fraction relative to focal length. A large aperture is something like f/1.4 , and a small aperture is something like f/22. When talking about a camera lens, they use the term 'fast' for lens that can open to f/2 or lower. And by 'fast' they mean that you can open to f2 or lower to let in a lot of available light, which may enable you to get a good exposure in marginal light.</p>

[976photo]

<p>Don't confuse "fast lens" with "fast shutter speed"</p>

<p>A fast lens opens to a wider aperture (lower f-stop number) which lets in more light, useful in low-light situations.</p>

<p>Fast shutter speed will enable to to "freeze" the action, which is useful for a moving baby if you want to avoid motion blur.</p>

<p> </p>

[JDMvW]

<p>Speaking from my own experience some years ago, I was all prepared to shoot the then new kid (now in college) with my full SLR outfit, but fortunately the wife went out and bought a automatic focus Point-and-Shoot with flash. Stuffed it full of fairly high speed color negative film, and I can't remember ever digging out the SLR for the next several years. Nowadays you can get digital ones that are water (=urine, feces, and barf) proof. Just throw the darned thing into the diaper bag and Bob's your uncle.<br>

You're going to have other things on your mind than swapping lenses, etc. Once they start moving, there's a definite tendency to go free-range.</p>

<p>Mind you I have the older 17-85mm lens and like it a lot, It's the handiest lens of all for an APS-C body. But not for toddler pics.</p>

[catherine_grant]

<p>Which lens do you recommend for toddler pictures that is fast enough and is not a huge amount of cash? Any in particular? Based on these posts the kit lens' will be too slow as well? I will be taking some pictures outside but I am sure a lot will be inside as well. Thanks!</p>

[jaydesi]

<p>Honestly, the lens is fine, if you're willing to use a flash. It's probably cheaper than another lens...consider the 430 EX used, pick up a diffuser (very inexpensive) and you'll be thrilled with the results. Much better than the on-camera flash of both the DSLR and a P&S.</p>

[phule]

<p>You're probably over-thinking this, Catherine. A DSLR camera is like a tool box. You have to start somewhere. Buy what you can afford and, when you find yourself running into limitations, figure out what tool will allow you to overcome those limitations.</p>

<p>You could save yourself a bunch of money by going with the XSi and just the Canon 18-55 IS kit lens. Keep it simple and don't get into this loop where you spend so much time obsessing over making the "right" choice that you never make any choice.</p>

[mike_hitchen]

<p>Getting a wide-aperture zoom in that focal range will cost you a whole heap more ($1000 for the 17-55 or $700 for the Tamron 17-50). You could get the 17-85 IS or the 18-55 IS and supplement it with the 50mm f1.8 (real cheap at $100 and great quality) - the wide aperture will be good for indoor shots.<br>

When the toddler starts running around a bit more you can then think about a longer range zoom.</p>

[976photo]

<p>I think you're still getting the term "fast lens" confused with actual speed of shots taken. A Fast lens means it opens to a wider aperture so it lets in more light quickly, or faster, than a lens that does not open as wide. It has nothing to do with<strong> shutter speed</strong>, or taking pictures quickly.</p>

<p>What you will need a "fast lens" for is <em>indoor shots with low lighting conditions and <strong>no flash</strong></em>. By being able to open the aperture wider, you allow more light into the camera for proper exposure and you can use a slightly faster shutter speed. However, it will still probably be too slow of a shutter speed to capture a moving toddler without motion blur.</p>

<p>To freeze the action and prevent blur, you need a fast <strong>shutter speed</strong>, and you can get that easily if you decide to use flash. The flash will pop up and provide enough light for you to set a quicker shutter speed and capture that moment of the toddler running across the room with a big smile on his/her face, with no motion blur. <strong>If you're going to be using flash</strong>, honestly the lens you use won't matter.</p>

<p>Fast lens does not mean fast picture taking. It's a confusing term.</p>

[976photo]

<p>You could probably save money by getting the camera you mentioned with the kit lens, and buying a <strong>speedlight flash</strong>, that is an external flash unit that mounts on top of your camera via the hot-shoe mount. Get one that swivels so you can use bounce flash and it'll give you better quality results than your camera's built-in flash AND you can avoid that annoying red-eye effect.</p>