Is there a really good 70-300mm out there?!

<p>I'm in the process of rationalizing my equipment, selling off a bunch of stuff, buying a few things, and hopefully in the end having a smaller quantity of gear that nevertheless is on the whole more useful. One of the things that I'd like to acquire is a good 70-300mm zoom lens. In my particular case this is for the Sony Alpha / Minolta Maxxum mount, but the problem I'm finding does not seem to depend on mount / brand--or even cost!</p>

<p>Basically, all of the zoom lenses of roughly 70 or 75mm to 300mm are unsharp / low resolution at the long end. Even the Canon L-series version (Canon 70-300mm f/4-5.6L IS USM) and the Sony G-series (<a>Sony 70-300mm F4.5-5.6 G SSM</a>) apparently suffer from this. Neither of those high-end lenses is in my intended budget, but options like the otherwise-attractive Tamron SP 70-300mm f/4-5.6 DIVC USD AF and the Sigma 70–300mm f/4–5.6 DG OS AF (to say nothing of the old / reissued Sony (ex-Minolta) 75-300mm f/4.5-5.6, see http://www.popphoto.com/gear/2008/12/lens-test-sony-75-300mm-f45-56-zoom?page=full) have the same issues. (I am judging this from the test reports from places like <em>Popular Photography</em>--see http://www.popphoto.com/gear/2010/11/lens-test-tamron-sp-70-300mm-f4-56-divc-usd-af, http://www.popphoto.com/gear/2010/03/lens-test-sigma-70-300mm-f4-56-dg-os-af, and http://www.popphoto.com/gear/2011/03/lens-test-canon-70-300mm-f4-56l-usm--and ephotozine, http://www.ephotozine.com/article/sony-70-300mm-f4-5-5-6-g-ssm-interchangeable-lens-review-13922.)</p>

<p>I suppose I could keep my old Minolta AF 70-210mm f/4, which had excellent optical properties for its day (and constant f/4), but also at the long end seems a tad soft, and won't reach past 210mm. But for kids' sports, something longer and hopefully faster-focusing would be nice.</p>

<p>So any ideas, suggestions, test reports you think I should read? Thanks!</p>

 

<p>You're looking at mostly lenses in the consumer area here. That said, the newest Tamron version is actually pretty good.</p>

Buy a lens which has focal length past 300 mm (e.g. Sony 70-400 mm f/4.5-5.6 (out of budget per OP), Sigma 50-500mm, etc.)?.

<p>I have looked at these tests myself and I agree that there is no 70-300 lens which bucks the trend of the 200-300 drop in performance. It is however a matter of degree. When I looked a few months ago now, the Canon 70-300 4-5.6 IS and the Tamron 70-300 4-5.6 SP VC looked to be the best of the mid-price lenses and the Canon 70-300 f4-5.6 L IS in the top price bracket. I have been reasonably happy with the Canon 70-300 f4-5.6 IS. It is pretty sharp with some drop-off at the 300 end especially at the edges. The centre remains quite good. The issue which might make me go for the Canon 70-300 L lens in preference is contrast. (Price as well!) The mid price lenses appear to have lower contrast at the long end than the L lens.<br>

I came to the conclusion that what was inportant for me was a compact lens with the best available preformance. I don't want to carry around anything much bigger than the 70-300 zoom and either the Canon (non-L) or the Tamron SP would have been the right compromise between weight and performance for me. So my advice is to look for the best option available given the requirements of your photography. </p>

 

<p>It would be extremely expensive to have a zoom with as wide a range as 70-300 be "perfect" all the way through the focal length range. So, yes, they all have an IQ fall-off as the focal length gets to the long end.</p>

<p>As Colin said, though, it is a matter of how much they degrade. The Canon 70-300 f/4-5.6L exhibits this, but to a far lesser degree than the Canon 70-300 f/4-5.6 (non-"L") nor the Tamron SP 70-300 f/4-5.6 Di VC USD. Of course, that is comparing a $1,600 lens to two $500 lenses, so one would hope that the lens costing 3x the price should have better IQ!</p>

<p>The simple answer is, if you want or need the best image quality at 300mm, then get a prime. No zoom that covers 230mm of range is going to be both perfect throughout the zoom range AND inexpensive. Or, find a lens that goes past 300 (to, say 400), in the hopes that the "bad" end is past your desired 300mm... But even finding a 300mm prime may not be easy. I'm sure there are varying qualities of those, as well!</p>

<p>Few of us can afford all the great lenses, and even if we could, we couldn't carry them all! So we all make sacrifices and trade-offs in lens selection. </p>

 

<p>Better get a lens with a shorter zoom ratio, or a prime. The shorter the zoom ratio, the easier it is for lens designers to achieve optimum image quality.<br /><br />Back in the 70s the 100-200mm f5.6 Canon FD zoom was very simple optically and good performing.<br>

One of the first Canon EOS zooms whas the Canon EF 100-300mm f5.6, it is pretty usable optically, and i'm told the "L" version of the same lens is just superb (despite being old).<br>

70-300 is stretching it too much, and besides, if you want to work at 70-100mm, it is far lighter to use a 80mm or 100mm prime.</p>

 

<p>Thanks for your thoughts. I guess I'll wait and see whether any very promising new lenses come out at the second trade show toward the end of the month; and if not, tap B&H for a Tamron SP 70-300mm f/4-5.6 Di USD before the rebate ends at the end of the month, or <em>maybe</em> (if I can find a really favorable and reliable test report) a Sony DT 55-300mm f/4.5-5.6 SAM; test it against the old Minolta AF 70-210mm f/4; and then sell on eBay the one I find overall less useful to me.</p>

<p>But the situation continues to surprise me. Interestingly, if you accept (for what they tell you) the <em>Popular Photography</em> tests, at 300mm, the Canon L is not appreciably better the top Tamron except wide open (f/5.6), and the Tamron actually beats the Canon at f/11 (at the other practical apertures, f/8 and f/16, the Canon tests out very slightly better). As to the idea that a 4.3x zoom range is too much, I don't buy that any more. Nikon of all companies sells a 17x zoom for DSLR's (18-300mm), and its user reviews at B&H are averaging 4.8 out of 5.0 (as of today, with 92 reviews--and yes, I realize these reviews are relative to expectations for the lens). Even the top pro lenses are around 3x and slightly handicapped by needing faster maximum apertures (constant f/2.8's of 16-50mm, 17-55mm, 24-70mm, and 70-200mmm).</p>

<p>Yes, that's consistent with my experience - the Tamron is a really sharp lens. Now there may be other reasons to choose a more expensive lens. For example, some are better built, or have faster or more reliable AF, or better VR (which doesn't matter in your case).</p>

<p><em>Basically, all of the zoom lenses of roughly 70 or 75mm to 300mm are unsharp / low resolution at the long end</em></p>

<p>If you look at photozone full frame tests, the 70-300 L at 300mm clearly edges out the Tamron in CA and MTF50 is also better in the Canon lens at f/5.6 and f/8. The Canon lens also has less vignetting. At 300mm, f/5.6 the MTF of the 70-300L is very close to that of the Canon 300/4L IS prime lens at f/5.6! Hardly "unsharp / low resolution", if a long zoom at its longest focal length is approximately equal to a faster prime lens stopped down, now is that.</p>

<p> Popular photography doesn't exactly do the most credible lens tests. I have often found their resutls to be at odds with my real-world experience on those lenses that I own. By contrast, photozone is very tractable.</p>