alexdi

<p>I wrote an extended review of this lens here:<br>

<a href="http://www.amazon.com/review/RWBEPO8NZOTNK">http://www.amazon.com/review/RWBEPO8NZOTNK</a></p>

<p>Boths 16s are sharper in the corners at equivalent aperture. If you're on full-frame, the 17-40 at 17mm isn't that great until f/8 or f/11, where you'd be fine with the 16 series at f/5.6. Unless you're on a super-strict weight budget, I don't see any reason to prefer the 17-40.</p>

<p>I have Canon's 50/1.4 and 28-135. I don't have a 24-105/4 or Sigma's 50/1.4. <br /><br /> The 50/1.4 is my go-to portrait lens. It's a complement to the 28-135, not a replacement. You can't get a creamy background at 50mm with the zoom and you can't get range out of the prime. The prime is so small that there's little reason not to take it along. If you have the light and space to rack the zooms out to 100mm or more, however, they're fine for portraits in a pinch.<br /> <br /> The 28-135 has better focus. The 50/1.4's focus is just on the border of adequate. It's fast enough for slow subjects, but not consistent. There's too much play in the focus mechanism. You can correct for the average shift with the 7D and 1D bodies, but not the inherent variance between shots at wide apertures. The 50/1.8 is even worse. If it's important that I get the shot with my 40D, I stop down to f/2.8. I never use automatic focus point selection.<br /> <br /> Sigma's focus is said to accurate in the range between 5 and 15 feet. Outside of that, it may have a front or back-focusing tendency.<br /> <br /> Sharpness of the 50/1.4 is without peer from f/2.8 onwards. The Digital Picture shows a marginal advantage over the 24-105/4. Photozone, a significant one. My copy is the sharpest lens I've owned, 200/2.8L inclusive. But the 24-105/4 is also a cracker of a lens, so I don't consider this a significant factor. Distortion, CA, vignetting, and other problems can be corrected in ACR, DxO, and similar software. It'll add an extra processing stage to panoramas, but the results will be the same.<br /> <br /> If you must only use one lens, bring the 24-105/4.</p>

<p>It's a matter of priorities. Sigma has a nontrivial width advantage. Tokina has a fast fixed aperture ideal for video. And Canon's lens sits in the middle, with a zoom range that's capable of a more general-purpose role. What's your preference? Mine mirrors that of Jeff Owen. <br /> <br /> Be aware that Sigma has had major lapses in quality control. I once settled on the original Sigma 10-20. All three had decentering problems significantly worse than either of the two Canon 10-22s I tested. The Digital Picture reported similar issues (e.g., front-focusing with the 70-200/2.8) and Tokina isn't necessarily in the clear either. If you opt for either of the third parties, choose a retailer with liberal exchange policies.</p>

<p>To reinforce an earlier post, you might consider the Tamron 70-300 VC instead. Better AF, better contrast, better edge performance, and at least where I am, about 30% cheaper.</p>

<p>http://forum.photozone.de/index.php?/topic/355-tamron-70-300-vc-exposure-issues/<br /><br />You're not the first.</p>

<p>The Canon lens isn't a one-trick pony; that additional zoom range isn't trivial. It's better on the long end than Sigma's original 10-20 and equal on the wide. The aperture has never been a limiting factor for me. All three lenses have excellent sharpness, though I did encounter multiple Sigma copies with decentering.</p>

<p>Impressive. That, and the GH2's enormous detail advantage suggest that Canon hasn't quite tapped what their sensors can do. High-ISO stills continue to favor the 60D/7D.</p>

<p>If you're into portrait lighting, I'd recommend:</p>

<ul>

<li>A high-quality studio strobe with a modeling light. While you can start with small hot-shoe flashes, they're less powerful and more limited. Batteries, chargers, and accessories to approximate a bare-bulb effect can get expensive quickly, and lighting is very trial-and-error without a modeling light. </li>

</ul>

<ul>

</ul>

<ul>

<li>A large softbox, say 3' x 4', keyed to your strobe. Umbrellas hotspot in the center and throw light all over the place. It'll be harder to control the tone of your backdrop with an umbrella. Softboxes have greater versatility and a more even result with close placement. </li>

</ul>

<ul>

<li>Two reflectors: two 4x8 pieces of foam board attached on the long side to create a wedge you can move around, and a round 5-in-1 diffuser in the 30" range. The combination of a single strobe and a reflector for fill is the bread and butter for many photographers. The big diffuser will let you fill a full-body portrait. The small one is for more intimate shots and won't put too much strain on a typical boom arm. </li>

</ul>

<ul>

<li>A hot-shoe flash. They're useful for accent lights when a plug-in strobe is a bit ungainly. Kicker, hair, and background lights are a couple of good uses. </li>

</ul>

<ul>

</ul>

<ul>

<li>A wireless flash trigger set so you won't be tripping over PC-sync cables. YongNuo's RF-602 is popular and much less expensive than a collection of PocketWizards.</li>

 

<li>Remote-shooting software, a USB 2.0 cable, and a laptop. This will let you see your shots almost immediately without having to chimp. EOS Utility is free for Canon cameras. Remote DSLR Pro is more expensive, but much more capable. </li>

</ul>

<ul>

<li>Heavy-duty stands. They're much more stable than the standard sort and don't cost much more.</li>

</ul>

<p><strong>Things not to do:</strong></p>

<p>Hotlighting. This is any light used for an exposure that's always on. To have any flexibility with aperture and ISO, you need a lot of light. If you're shooting people with a hotlight that powerful, they'll end up squinting or melting.</p>

<p>Cheap all-in-one kits. Amazon and EBay have a lot of these. The first thing you do with a cheap kit is start noticing what's missing. Then you replace the kit. The universal maxim of photography is to do it right or do it twice.</p>

<p>Cheap items where quality is important, i.e., any piece you have to mess with. A lackluster backdrop system won't ruin your day. Bad stands, ball mounts, umbrella mounts, tripods, and so on, will.</p>

<p><strong>A starter set:</strong></p>

<p>From AlienBees, I'd opt for a B800 strobe, a FSB3240 softbox, and an MBA offset arm. That's about $470. Pick up two heavy-duty stands from elsewhere (BH, Adorama, Amazon, EBay) for $70. A 32" 5-in-1 is $15. Photoflex makes an excellent boom head for about $50. A radio trigger and receiver are $30, and $20 for each additional receiver. If you want an additional light, Nikon's SB24 and SB25 are around $70, powerful, and well-built.</p>

<p>Or you could start with the hot-shoe flash and an umbrella. It's the difference between $450 and $110. Maybe you'll find them good enough. If not, you'll probably find a use for them in a subservient role when you upgrade.</p>

<p>Amazon covers return shipping for defective products for up to three exchanges. B&H does not, and I once made the mistake of sending my new lens to Canon for a warranty alignment that negated my ability to return it to B&H. Amazon would have been more lenient and is, to my mind, the best place to buy a lens.</p>

<p>Sigma's hit-rate with lens alignment in primes is better than that for zooms. AF is a separate issue, but I'd be surprised if you encountered uneven performance with the 85/1.4.</p>

<p>The 50/1.4 doesn't actually like f/1.4. It gives a lot of fuzzy halation that doesn't clear until f/1.8. Fine for portraits, not so fine for anything with detail at a distance. AF is about five tiers down from the 135/2 in terms of accuracy and consistency, and perhaps three in speed. Fast enough for people 20 feet away, I'd wager, but you'll start to miss if they run any closer. It wouldn't surprise me if that Tamron macro was just as quick.</p>

<p>Sigma's 50/1.4 is definitely a better optic, but only within a particular subject range. The AF is likely to miss if you're too close or too far. The 85/1.8 handles a lot like the 135/2 except that it's about a stop behind in sharpness.</p>

<p>There isn't really a great answer to this question. I suspect most people just opt for a 24-70/2.8L and deal with the extra noise.</p>

<p>It isn't just about slow. Sometimes the lens won't focus at particular focal lengths or subject distances, like the 50-150/2.8. Or Sigma won't correct a particular type of aberration that ends up throwing off Canon's AF system, as with the 50/1.4 The two most common problems are back-focus for subjects nearer than 5 feet and a focus shift when the lens is stopped down. Neither resolve with AF microadjustment.</p>

<p>I like Sigma because they're often pushing the boundaries of what's possible, but it's a rare Sigma lens that isn't beset by problems with AF or initial quality control. I had no experience with decentering until I encountered it with four copies of the 10-20.</p>

<p>It costs what it does because you'll pay that much. And if you won't, others will.</p>

<p>There are certain features that merit a higher price. It has a fluorite element, weather-sealing, a more sophisticated IS system, and a USM motor. It's also somewhat larger and faster than the 55-250, and a full-frame lens with commensurate superiority in edge performance. In the 70-200 range, it is the least-comprised lens available.</p>

<p>But most of these apply equally to the 70-200/4L. That lens has always been considered something of a bargain, so perhaps the $1200 cost of the IS version is simply adjusting the pricing curve to where Canon believes it should have started.</p>

<p>It's not superfluous if you want a longer portrait lens. I wouldn't expect a lot of indoor use, however. The working distance at a 135mm equivalent is quite long, and keeping hand-shake out of your pictures will be difficult unless you have exceptional indoor lighting. </p>

<p>Wow. Hell of a thread, this. Vijay, your knowledge is tremendous, though it seems as if you and a few of the others have been in a bit of a loop for the last couple days. Nonetheless, I though the engineering perspective was fascinating.</p>

<p>I would be weary about quoting too extensively from Wikipedia. The first line you pulled about exposure latitude, I wrote. It's rather oversimplified relative to the extrapolation you've provided in this thread. In fact, you might consider rewriting it with a reference to the length of the linear portion of a tone curve.</p>

<p>Raw files have no inherent sharpening. How sharp they appear is dictated by the converter settings. More general factors include your particular lens, the aperture and shutter combination, available light, subject movement and distance, focus, noise reduction, and the antialiasing filter on the camera sensor.</p>

<p>Keep in mind that most pictures here are downsized by a factor of 3 or more, and often heavily sharpened with USM. Raw converters were originally designed only to provide "capture" sharpening to counter the inherent softness of bayer interpolation. Most people would then apply USM, Smart Sharpen, or some equivalent as dictated by the output medium for the picture. I can't say if that still holds, but I've never been satisfied solely with the raw sharpening within ACR.</p>

<p>In my experience, the best web sharpening available for downsized images is Photoshop's Smart Sharpen. USM at 0.3 pixels is a fair alternative if you're willing to mask out distracting elements. For files at full resolution, I'd ask the guy responsible for Photozone.de; his raw settings seem to maximize sharpness without introducing a watercolor effect.</p>

<p>If you're into landscapes, the reason to opt for the Tokina is superior edge sharpness. The extra stop is less relevant unless you prefer indoor or street shooting. Even there, both lenses are so wide that it's hardly a bother to hold the camera still for longer exposures. If you're satisfied with the image quality of the 10-22, buy it. The extra range is noticeable and useful.</p>

<p>I'm thoroughly impressed with the 5D II, far more so than I was the 50D. I wouldn't call it a full stop better than the original 5D, but the fact that it's better at all on a per-pixel level is to be applauded. There's essentially no difference between ISO 100 and 800. ISO 1600 introduces some oh-so-subtle softening, which becomes slightly more noticeable at ISO 3200. For small prints with careful noise reduction from RAW, I wouldn't hesitate to wind it all the way to ISO 12800. I'd say the same for Nikon's D3; for the 5D II to nearly match a body with only 60% of its resolution is quite a feat. </p>

Some of you guys are so very optimistic. My response would have been, "give up." The minimum requirements for sports have always been a fast body and an f/2.8 lens, and that's under indoor stadium lights. A Rebel XSi and an f/5.6 zoom at night? Good luck.

The 40D is significantly faster in actual use than the 450D. I personally don't even like to hold the 450D, it feels like a toy.

To me, full-frame is preferable for a number of reasons.

<ul>

<li>Depth of field. It's more shallow on full-frame. If you're into portraits, the effect of even an ordinary

85/1.8 wide open is positively dreamy.</li>

<li>More fitting lens range. The 70-200 becomes a proper portrait lens, as do the 85/1.8 and 100/2. All of these

are a touch long on a cropped body, and there's no Canon equivalent to the 70-200/2.8 on the same.</li>

<li>Lower noise. Not a universal truth, but even the ultra-high megapixel full-frame bodies like the 5D II and

the 1D III still have better noise performance than my 40D, which is in turn better than the 50D.</li>

<li>Availability of ultra-ultrawides. Sigma's 12-24 on a cropped body is an interesting, but still rather

ordinary 19mm. On a full-frame body, it's absolutely wild.</li>

</ul>

The counterpoint to all of this is that the 1.6X crop can be a tremendous boon to those who live in the telephoto

range. And cropped bodies cost less, of course.

I haven't tried the 55-250, but I did have a 70-210 for a few years. Light, decent but not spectacular build, and probably the best AF of any lens I've had. I replaced it with a 200/2.8L, but the only fault of the 70-210 was somewhat slower contrast and some softness at the long end. It's not really an indoor lens either. In fact, I never used it indoors. Outdoors, the 55-250 has better center performance, weaker edges, and slower AF. Given how useful the IS unit is, I'd buy the 55-250. Or pick up a 70-300/4-5.6 IS on EBay for $375 by combining Microsoft's "Live.com" discount with any "Buy it Now" purchase.

In the past, wedding photographers made money by charging for prints. No one gave out the original film. If

you've already given him the full-resolution JPEG files, you've forfeited the ability to stop him from making his

own high-quality prints. If that's the case, there's no good reason to deprive him of the RAW files. If he wants

to control the sharpening parameters for larger prints, let him. An amateur is perfectly

capable of adjusting the sliders in ACR, and if he screws it up, that's his business. He could make a JPEG file

look just as bad.

 

By holding back, you look petty, and you'll look even more petty if you try to tack on charges that extend

farther than the cost of burning a disk. Give up the RAW files as an act of good faith. If you want to charge for

them with future clients, add a contract provision to that effect.

I've used my 40D for drum corps, cars, and ice hockey. Something like 80% of these shots are in usable focus. I

attribute the rest to user error, or in the case of hockey, shooting through plexiglass. There is a bit of

weirdness with AI-Servo. It never settles down, even with a stationary object.

 

I've no doubt that any of the 1-series has a superior AF system, but the 40D remains above and beyond any camera

in its price range. I didn't buy it with an expectation of perfection.

The 28-135 doesn't want for image quality if my copy is any indication. It's very sharp between f/5.6 and f/11 at

all focal lengths. Contrast is merely good. I've been using it in tandem with Canon's 10-22 for the last few

months. If you don't mind switching lenses quite a lot, it's not a bad combination outdoors. Indoors, the 28-135

is out of its element, and the lack of a decent wide-angle is problematic for general use.

 

If the Sigma 17-70 isn't lacking in some significant area, there's little reason to replace it. The alternatives

are few. If you do want something else, the 24-70 isn't a bad choice. However, while Sigma's HSM is ~2/3 the

speed of Canon and equivalently silent, it doesn't appear on the 24-70. Certain more recent Sigma lenses have

also had problems with front-focusing.