Well, the "opponent" of the "portraiture" 85/1.2 would be the FA* or A* 85/1.4. The 77 is close in technical specs, but a different animal...
Well I actually do not agree here. Smaller sensor works as a crop and from the point of shake sensitivity it is not important whether the size of sensor is 24 or 36mm or 48mm or whatever. The physical size of subject on recording media is the same and also the same is it movement during camera shake, no matter what the size of the media is.
Same FoV on film and crop sensor mean different physical subject size on film and sensor, so it is not the same, if I understood correctly what you meant.
I disagree with your disagreement
. If you put a full frame camera on a tripod, take a picture, and then swap with a crop camera, but use the same lens, what will you get? The crop photo will just show the center portion of the full-frame photo. So when you print both photos at the same size, the crop factor acts just like a magnification. That means any camera shake is magnified by exactly the same factor.
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Well, the physical size of the recording medium is not the same between 35mm film and APS-C sensor. But the image recorded and presented on any given size print, say 8x12", will be the same size for both, assuming no cropping. Now lets assume a fixed shaking magnitude for the camera body, say 1mm for arguments sake, which stays constant for either type camera. For film, the shaking would amount to 1mm/24mm*100% = 4.2% of the height of the image . For APS-C sized sensor, the shaking would amount to 1mm/16mm*100% = 6.3% of the image height. So you can clearly see that the sensor size plays a DIRECT role in the impact of camera shake on the sharpness of the picture. For any given lens focal length, the ratio of shake percentage is 1.5x for APSC vs film. So logically it follows that the minimum shutter speed would also be a factor of 1.5x from film to APSC. Logic does not lie.
Yes I agree with you here. However, for any given print size (say 8x12"), the magtidue of the blurring will remain the same. The difference would be much more noticeable when comparing the same pixel density, say 300 dpi. Here the 10MP would show more shake than a 6MP, due to more of the smaller pixels being blurred by the shaking.
I also agree that good high ISO performance and SR will make a dramatic improvement on the usefullness of something like a 70-300/5.6 or 6.3 lens. I really look forward to getting the K10, so I can get more use out of my Sigma 70-300 and my Tokina 80-400.
The Canon 50/1.8 is a very unique lens. It's way cheaper than anything else in their lineup (quite a few Canon lens hoods are more expensive), and with a build quality to match (though it's quite good optically). It's a big seller simply because it's so very cheap, and it has gotten a (probably deserved) reputation as cheap and cheerful - a lens you can play with to your hearts content without fear of breaking it. It's a "gateway" prime; the first prime lens many people buy, and the lens that convinces quite a few people that primes, not zooms, really are what they're more comfortable with.
Canon offers 70-300 for their 35mm lineup. A 50-200ish lens is the equivalent (and makes better sense) on APS.
Ok, that might work in practice, really
Not really. Depends on what you call "long".
Depends on your definition of decent. In my book, it's easily decent.
You know that 75-300 is exactly 4x? You know that if you take a 75-200 and resize it by 1/1.5 in all dimensions you would get a 50-200?
It has a few shortcomings, but it's nice.
It is an ultrawide zoom. 2x is plenty for an ultrawide to wide zoom.
Then give it to me, I'd like a smaller companion to my Tokina 80-400. Oh wait, it is a 5x zoom, it must be really really bad then! And this must mean I am really really stupid (or just blind?) to like this lens?
...which of course is due to people "pixel peeping" - zooming in to see individual piels, regardless of what resolution/distance the image will actually be viewed on.
