[quote name='Yakim' timestamp='1305971634' post='8717']
Klaus, this is an incredibly important review as the lens is very new. Please try to make an effort for an APS-C review.
[/quote]
I believe, if you look at the data resulting from the FF test of the lens,
you can estimate the crop-results quite well. Distortion and vignetting
is already noting to worry about on FF, so this will not cause any
problem on crop. Also, the excellent center-resolution will remain
on crop and (due to the smaller sensorsize) will expand to the borders.
Albeit, borders and corners have not been bad at all in the FF test, they
were just less good as the center) ... so more likely than not, the
120-300/2.8 will prove to be an excellent lens on crop as well.
The only question is ... is it the lens you need for a certain application?
Rainer
We don't measure the focal length. However, taking the rough chart to camera distance as a guidance it was in line with other zoom lenses ... that tend to be a little shorter as well. Prime lenses stay always closer to the truth.
[quote name='Rainer' timestamp='1305978473' post='8725']
I believe, if you look at the data resulting from the FF test of the lens,
you can estimate the crop-results quite well. Distortion and vignetting
is already noting to worry about on FF, so this will not cause any
problem on crop. Also, the excellent center-resolution will remain
on crop and (due to the smaller sensorsize) will expand to the borders.
Albeit, borders and corners have not been bad at all in the FF test, they
were just less good as the center) ... so more likely than not, the
120-300/2.8 will prove to be an excellent lens on crop as well.
The only question is ... is it the lens you need for a certain application?
Rainer
[/quote]
Everything you said can be applied to all systems, so if a certain lens is tested on FF, why test it on APS-C as well? And yet you see the same lens tested on both formats in the same system e.g. Sigma 85/1.4 on 5D2 and 50D, on D3X and D7000.
[quote name='Yakim' timestamp='1307104539' post='9013']
And yet you see the same lens tested on both formats in the same system
[/quote]
Indeed ... but if you look on such tests side by side, you will find, that
my estimation generally holds. I wouldn't go as far to say that crop-testing
is "wasted time" once a FF test is available ... but it digs up less new findings.
I had the chance to try this lens on my 7D and it performs nicely.
Sharpness looks very good but the AF is really not that fast. The Canon 300/2.8 IS is at least twice as fast AND has a focus limiter.
The build quality is good but not without problems. The tripod foot is not exactly rock solid and there are stripes from the mould on the lens barrel.
I think the 5-star rating for price/performance is absolutely appropriate. You can't get any more for just 2500€!
[quote name='simon_k' timestamp='1308042226' post='9200']
I had the chance to try this lens on my 7D and it performs nicely.
Sharpness looks very good but the AF is really not that fast. The Canon 300/2.8 IS is at least twice as fast AND has a focus limiter.
The build quality is good but not without problems. The tripod foot is not exactly rock solid and there are stripes from the mould on the lens barrel.
I think the 5-star rating for price/performance is absolutely appropriate. You can't get any more for just 2500€!
[/quote]
Any idea why? What were the shooting conditions?
[quote name='Yakim' timestamp='1308066356' post='9208']
Any idea why? What were the shooting conditions?
[/quote]
I tested it in the shop and outside where it was quite bright (about 1/500 to 1/1000s at f/2.8 and ISO200).
I guess the size of the lens elements is just too much for the motor. The 70-200 has the same problem. It's not slow but compared to the fastest Canon lenses Sigma should be ashamed of their work.
What I forgot to mention was the OS - it takes a second or so to work but the it is amazingly good. I managed to get shots at 300mm and 1/30s. You have to pixel-peep to see a slight blur.
[quote name='simon_k' timestamp='1308216711' post='9287']
I tested it in the shop and outside where it was quite bright (about 1/500 to 1/1000s at f/2.8 and ISO200).
I guess the size of the lens elements is just too much for the motor. The 70-200 has the same problem. It's not slow but compared to the fastest Canon lenses Sigma should be ashamed of their work.
What I forgot to mention was the OS - it takes a second or so to work but the it is amazingly good. I managed to get shots at 300mm and 1/30s. You have to pixel-peep to see a slight blur.
[/quote]
These lenses have a rear focusing system so the AF unit isn't all that heavy.
However, it is unfair to compare a zoom vs a prime lens here.
That said Ring-USM is still the place to be in Canon land if this is a priority.
[quote name='mst' timestamp='1305843991' post='8654']
Now if they just had replaced the huge front filter thread with a drop-in solution ...
-- Markus
[/quote]
Add a set of wheels too
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