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Old Aug 14, 2006, 11:10 AM   #11
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I can't wait for Sony to come up with a 18-500mm f/2.8!
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Old Aug 14, 2006, 11:28 AM   #12
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maxxum7d wrote:
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I can't wait for Sony to come up with a 18-500mm f/2.8!
You have a better chance of that homeless person you walk by every day on the streets of the city actuallybeing God.

Besides, I think you should hold out for the 10-500mm F 1.4 Tamron :|


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Old Aug 14, 2006, 12:53 PM   #13
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Maybe a 5-500 f/1.0 ?
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Old Aug 14, 2006, 1:01 PM   #14
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Nah...

A new inexpensive camera model with a perfectly clean ISO 19,200 with a small and light weight 10-500mm f/3.5 in a kit would be OK to me if it's a good quality lens, sharp wide open, no flare or CA, fast AF, etc., as long as I could push it another stop to ISO 28,400 and still get a nice 11x14" print from it without too much post processing (or larger print sizes after noise reduction).

We'll have to better define inexpensive, small and light weight. :-)

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Old Aug 14, 2006, 1:37 PM   #15
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Ok- so though they're both using the widest aperture available, the mechanics of each lens may allow for differing light transmission? In other words, though the aperture is wide open, the lens' capabilities cannot provide the full value of the aperture? hmmm, hard to ask simply. I can understand that if the lens needs to stop down from wide open at a focal length that there is some reason- be that poor glass or mechanical obstruction (from moving elements) or whatever.

It would be hard to determine a fair test for such an instance, but that to me is not important. The relevant point is that at a set aperture value and focal length the Minolta 70-210 is quite a bit faster to focus, especially in marginal light. It is also more sharp though not as 'contrasty'. I find that the Tamron provides more color punch, much like a point and shoot (though not quite as comic book-like) as Canon.

I do find it funny at times how much technical information is desired about photographic equipment and how little is ever asked about technique. I remember learning that the sum of your equipment is about 15% of a photo (some would say more like 5%) and the rest (85%)is composition and technique.

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Old Aug 15, 2006, 1:29 PM   #16
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Maximum aperture is a physical limitation, and is expressed as a ratio of Hole size VS focal length. At 200mm f/2.8 (1:2.8) the aperture opening is 71mm in diameter (grab your calculator and see). Much smaller if your talking 50mm f/2.8. In a zoom such as the 28-300 the aperture is the same physical diameter while the focal length changes, therefore the aperture value changes. Make sense? (In reality lens designers can do funny things like put the aperture blades in a different place than theory would sugest, so the hole may actually be smaller. Theory is much easier to understand than reality!).

Does f/2.8 ever let through a different amount of light than f/2.8 in a different lens? NO! Well, with minor exceptions. Zooms can be about 1/3 stop darker at a given aperture since they have so many more elements than a prime, but the difference is minimal. The transmissive properties of different glass, or different amounts of it, is not enough to have much real world effect on us. You can slap on that 300mm f/5.6 lens and spot meter, then switch to your 50mm f/1.4 and the meter reading will still be acurate. Thats the whole point of using f/stops.

Your lens always operates at its maximum aperture except when the picture is being taken (mirror moves, aperture closes, shutter opens...). Funny thing is that its not HOW MUCH light it passes that allows better AF, but the geometric properties of it all. Very interesting stuff.

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Old Aug 15, 2006, 1:34 PM   #17
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Oh, and regarding the topic at hand, I also have the Tamron 28-300 which I paid a closeout $150 for. The new version with its different coating sells for almost $400 at b&h.

I've only used it outdoors in daylight so far, but its been quite good. Really good, in fact. I also use a tamron 90mm macro, 50/1.7, 24/2.8...etc and it definatly holds its own against these primes in good conditions. It does not have the consistency to do well all the time, and of course when its dim your screwed. I usually set mine to f/6.3 and leave it there. Focus accuracy causes soft images most of the time past 200mm, but I have had enough SHARP pictures here to know that what its capable of.

I've seen a few discussions where it was noted that the tamron 28-300 stands out in relation to the other super-zooms in this range. With the closeout deal its definatly the best deal, but that wont last forever. If it werent for those two factors I would have gotten an 18-200 instead, but for how I use this lens I dont miss the range.
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Old Aug 15, 2006, 4:18 PM   #18
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I have minolta af 24-85 followed JimC advice on this one

and it's crisp and have nice colors but small range.

also the tamron 28-300 a great dealthat i found from a forum here

that i enjoy on a soccer field on a bright day, but have to watch

fstop to get great shots.

i must say that the sigma 24-135 that i've bought lately

fromCameta camera is hard to beat as a walkaround lens.

fast, crisp and goodcolorsthorough the range.All that for$119.00

If i had to keep one lens i would keep the sigma anytime ...

regards

Andy










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Old Aug 19, 2006, 5:26 AM   #19
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I just bought a Sigma 28-300 aspherical lens. It's an older model I think as for one, it's silver, 2 it doesn't have the AF/MF switch on it, and 2 it doesn't look like the ones on the web. I haven't seen any reviews of it so far, but as I have a 75-300, 70-210 beercan, 50 f1.7, and the 18-70 kit lens I can say that it's not bad. It's certainly as good if not better in low light than the kit lens and seems to focus easier than that lens.

Downsides: a bit of a slight yellow colour cast, though I easily removed that in PS. I wish I has the Tamron 28-300 to compare it too. Now all I need is a f2.8 wide angled zoom to make me happy.

Oh why can they make low aperture extreme zoom ranges on non-slr cameras like the A2 and panasonic etc but to get that on an SLR costs you the price of a new car?

need to keep saving.
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Old Aug 22, 2006, 9:13 AM   #20
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I still say the Tamron 28-300mm is the best bargain out there and when used properly provides some decent results.


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