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Old Jan 10, 2010, 8:31 PM   #41
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Well it was the A550 review rather than a full comparison of the 4 options. The results are a bit of a mixed bag. I'm sure you can guess where to find it but PM me if you don't.
Since we're talking about it, we might as well say it's the review at http://www.dpreview.com ;-)

Actually, I thought the comments in some areas (particularly in the performance section) were way off base, or the reviewers just didn't bother to look at the numbers from the cameras they were comparing it against. For example, if you note the comments about sluggish read/write speeds to memory cards, where it mentioned things like pedestrian performance to a fast SD card (and using stronger terms about the Memory Stick Duo card they tried), it really doesn't make any sense at all to me. IOW, I'm wondering if they even bothered to look at their own tests for the T1i before making those statements in their A550 review (since the T1i was one of the cameras they were using in the comparison portions and I didn't see those types of comments in it's review.

If you look at the numbers for both cameras, the Sony is actually faster in that regard. For example, the Sony clocked in at 4.8fps shooting JPEG fine (with no limit to the number of frames). Also note that the Sony defaults with Dynamic Range Optimization turned on, which can impact performance.

When you go to the Raw section, it was able to take 14 photos before the camera slowed down at 5fps, with a 1.2fps buffer full rate, taking 10.8 seconds to flush a full buffer. Now, if you look at the T1i, it's only able to take JPEG fine images at 3.4fps. Ditto for raw files.

The T1i only gets 11 frames shooting raw before it's buffer is full (versus 14 for the Sony), with a slower 1fps buffer full rate (versus a slightly faster 1.2fps with the Sony). IOW, the Sony's write speeds to media are pretty decent (not what you'd gather from their comments if you didn't look at the T1i's test results there).

Buffer flush time was 9.1 seconds with the Canon (versus 10.8 seconds for the Sony). But, the Sony has a larger buffer (so, of course it's going to take longer to flush it). USB Transfer times were also slightly faster with the Sony.

What really got my attention was all of the comments about the Memory Stick Duo being used. They didn't even bother to test the faster Pro HG cards in it (yet didn't mind knocking how slow the card they used in it was). If you go to newegg.com (my favorite vendor for memory cards and computer related accessories), you can buy a Sandisk 30MB/Second 16GB HG Pro Duo card for around $90 with free shipping. A Sandisk 16GB SDHC card with 30MB/Second rating will cost you around $115 there with free shipping.

I haven't seen the A550 tested with one yet, but I've seen the A700 able to write to one at 25MB/Second (which is faster than I've ever seen any camera write to any SDHC card, 30MB/second rating or not).

So, I thought it was pretty unfair the way they worded that whole performance section, especially since the A550 can write just as fast or faster to a 30MB/Second Sandisk SDHC card compared to the T1i from what I can see from their own tests using one in both cameras, and they knocked the A550's performance to Memory Stick media without even testing a faster Memory Stick HG Pro model.

Ditto for their wording of the AF area. In some areas they talk about how the Sony's AF Performance is fast and accurate (if not class leading in one part of the earlier comments in the performance section), and yet in another area, they say they weren't impressed with the speed of it's AF tracking because it couldn't keep up with the 5fps drive speed and felt sluggish compared to a newer Nikon model.

Well... yes, I don't have any doubt the AF speed is very good, as tests I've seen show that even a lower priced Sony like the A330 is faster in most lighting compared to the T1i, although the T1i starts to pull ahead slightly in very low light once you get down to around EV 2 (which is much lower lighting than a typical home would be at night via Tungsten lighting). Sometimes another camera model can seem faster because it focuses quieter compared to the Sony models (so you don't notice the speed as much with a quieter lens, unless you're carefully watching the viewfinder).

The only site I'm aware of that tests models in various lighting levels in controlled conditions is popphoto. You can see what they said about the lower priced A330 model on this page, with comments on how it compared to the T1i. They haven't clocked the newer A550 yet (but, it's very unlikely to be slower than the A330).

http://www.popphoto.com/Reviews/Came...Sony-Alpha-330

As far as the A550's Continuous AF not keeping up with 5fps, that's probably true. I spent some time yesterday analyzing some of the videos demonstrating it's tracking of moving subjects and it looks like it's slowing down to around 3fps when switching focus points much, and that switching can cause a slightly uneven frame rate, making it appear to be slightly sluggish. But, i suspect DRO is stealing some processing time. Also, the T1i has a maximum frame rate of 3.4fps. ;-)

As for the Nikon, they specifically mentioned that use of D-Lighting would slow down it's frame rate in it's tests. Yet, they didn't test it that way (or publish the numbers if they did).

The Sony defaults with DRO on (and both Nikon and Sony license technology used for those features from the same vendor (Apical Imaging), which is pretty common knowledge in the industry as Apical has made press releases in the past about that kind of thing.

http://www.apical-imaging.com/

IOW, if I were Sony, I think I'd change the camera defaults to leave it off (or point out that the reviewers should at least test the Nikon with D-Lighting turned on to make it a fair comparison if they're going to make comments comparing them in that area).

I also suspect the Sony is geared more towards accuracy with it's AF tracking, as some of the comments I've seen from A700 users have been very positive, and you also have to look at accuracy of a system, not just if it can sustain it's maximum rate.

The only test I've seen of Continuous AF performance from a group of cameras was using vehicles on a closed course, making multiple passes to see how well cameras performed by looking at total shots captured, percentage of in focus shots, etc. .

In that particular test a Sony A700 had a very high percentage of in focus shots (i.e., it's geared towards higher accuracy). It had less total in focus shots, because it's frame rate was slower than some of the competitors being tested. But, even compared to the higher priced Nikon D300, which has a faster frame rate, the A700 still managed to get more in focus shots.

http://www.pentaxforums.com/forums/p...good-info.html

I seriously doubt that the algorithms Sony is using have not improved with over 2 years gone by since the A700 came out and I suspect that some of those improvements have gone into the A500 from comments I've seen from users of it so far (those that have also used the A700). I have used the D5000 and some of the other Nikon models like the D300 and D3, so I have a feel for them. Apparent speed of operation does not necessarily indicate number of in focus shots, just because camera's frame rate isn't varying using Continuous AF. ;-)

What I think is probably needed is a controlled conditions way to test predictive AF in a more stressful manner with multiple subjects moving at different speeds and/or directions. That way, you're taking a lot of the subjectivity out of the equation.

Now, another area the Sony gets knocked in is Noise Reduction. IMO, Sony's technique is actually pretty decent and I think they've made huge progress in that area with the newer A500 and A550, with less post processing required, because the built in algorithms are doing a really good job in that area for almost any size print you'd use from them, while keeping noise well controlled. Download the images yourself and compare them at various viewing and print sizes.

The Sony A550's Dynamic Range is also best in class. ;-)

IOW, I got the feeling that they were emphasizing the negative (especially in the performance section). Maybe that was just an oversight because they didn't bother to check their own test results from the other cameras before making some of those comments. But, I didn't like their approach or wording, especially considering the T1i's test results there.

Now, I do shoot with a Sony A700, so I probably have some bias in that direction. But, reading that review left a bad taste in my mouth after analyzing what they said in more detail and looking at the numbers they got from the T1i. It's probably one of the few times I've thought their comments were way off base, especially considering their own tests results for the T1i, and their own comments in their D5000 review about how D-Lighting can impact it's performance. But, they didn't test the D5000 performance that way (or at least not publish those numbers), or point that out in the Sony's performance review when making comments on how it compares.
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Old Jan 10, 2010, 8:41 PM   #42
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DPReview is useless. The forums are dominated by members that are ignorant and intolerant, and the reviewers are biased and incompetent.
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Old Jan 10, 2010, 9:00 PM   #43
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Actually, I think the reviews there can be very useful. But, sometimes, they seem to overlook the obvious when making comments about cameras in some areas and how they compare to others (as in the performance section of the A550 review with comments on slow write times to media).
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Old Jan 10, 2010, 9:05 PM   #44
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Their reviews of Canon and Nikon gear are useful.
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Old Jan 10, 2010, 9:16 PM   #45
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As far as the A550's Continuous AF not keeping up with 5fps, that's probably true. I spent some time yesterday analyzing some of the videos demonstrating it's tracking of moving subjects and it looks like it's slowing down to around 3fps when switching focus points much, and that switching can cause a slightly uneven frame rate, making it appear to be slightly sluggish..
Jim - I believe you're misunderstanding the comment in the review. What they're implying is not that the camera doesn't take 5fps but that the shots are out of focus - i.e. the predictive focus can't keep the subject in focus for the 5 fps.
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Old Jan 10, 2010, 9:19 PM   #46
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That's not what I'm seeing from analyzing that camera's behavior via videos demonstrating that feature (the frame rate is what's not keeping up with the camera's AF tracking, not the other way around). IOW, the AF Tracking is not allowing it to sustain 5fps.
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Old Jan 11, 2010, 12:01 AM   #47
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you could get the Sigma 17-70/2.8-4.5 macro lens instead of the kit lens. It's better, faster, it's a 1:2.3 macro lens, and on a Sony body, it will be stabilized..
Would I need an adapter to get this lens to work on the sony? So this lens can do everything the Kit lens can do plus better macro capabilities?
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Old Jan 11, 2010, 12:07 AM   #48
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There is a sony version of this sigma. But if you want to save some money, get the sony body, and skip the kit lens, as this lens will have pretty much all the wide angle of the kit lens with a little more reach, and be macro at 1:2, which is pretty good for handheld macro. It is about a 370 dollar lens. Make no sense in doubling up the range having this lens and the kit lens. And then you can just get the fast 50mm prime to start.
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Old Jan 11, 2010, 1:11 AM   #49
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I can probably get the fast 50mm prime in hong kong for about the same price as this..
sigma AF 70-300mm F4.0-5.6 DG OS
I think this also fits the sony as well. Would you recommend this lens because it would give me even further reach than the 17-70, and perhaps give me some decent close up shots aswell?
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Old Jan 11, 2010, 1:11 AM   #50
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the above lenses would be in addition to the 17-70 sigma lens
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