privatebydesign said:jrista said:Until you show me full size versions of those images you shared, which appear to be quite sharp to me, that prove they are soft and needed IS (vs. say better focus), I'm sorry but I have to disagree tat it is "completely, patently, and demonstrably ridiculous." I've shot enough with a 50/1.4 to know that my shutter speed is most often well above the 1/focalLength and even above the 1/focalLength*2 baselines to produce shake-free shots except in more extreme circumstances (such as your second photo, however that would usually be where you jack up the ISO to compensate.)
If we were talking about an 85mm f/4 or even f/2.8 lens, I would completely agree with you...but 85mm lenses are f/1.8 or faster, 50mm lenses are usually f/1.4, and most frequently used at their faster apertures. Additionally, with wider fields, it takes more camera movement to result in meaningful motion of image detail at the pixel level, so blur from camera shake becomes less and less likely the shorter the lens.
And what's with the hostility? Wrong side of the bed day today or something?
First off, no hostility at all, just a very strong disagreement with your untenable point of view. Calling something sh!t that is sh!t is not hostile. I'm just doing an Arthur Morris on you.
Very clever. Although even Arther Morris has more tact than you do.
privatebydesign said:Second, you are now putting limits on aperture and iso for focal lengths, you can't do that. What if I want/need f8 and 1/4 at iso 400? Then IS would be good to have. Just because a prime lens might be between f1.2 and f2.8 doesn't mean that aperture is appropriate for the image to be taken, as per my second image example. Same with iso, I used 800 for the second image and ETTR'd because I didn't want to lose DR between the candle flame and the very dark wall detail, if I'd had IS I could have got more DR, and shadow detail, by going to 100iso.
Third, the size of the pixel and the arc of blur are completely unrelated, assuming you have enough resolution to resolve the arc of blur, as my two images with 2003 sized pixels clearly do, having more resolution would not make the blur better or worse, only reproduction size would. Same as diffraction limits and airy discs, more resolution is not worse, but it doesn't increase or decrease the diffraction.
Fourth, do you honestly think I would post an illustrative example that doesn't illustrate my point? I have posted hundreds of them!
Anyway, here are the 100% crops with zero sharpening or noise reduction on the best point of focus. They are both focused within this 700 x 700px square, the sharpness falls off as you go further away. They both show camera movement as can be evidenced by the shadow/ghost around the front of the monks face in image one, and the fact that the second image crop is the sharpest section of the frame, the point of focus and I were completely static (I was braced against a wall) and my camera is set to not take a picture without achieving focus.
Well, not going to get into a deep debate with you. We have our opinions. They still differ.
Fair point about aperture, don't disagree with you there. However from the manufacturer's standpoint, I think THEY see it differently. I do believe that faster apertures are used more frequently with the fast primes (especially the fast portrait primes), and I believe that gives manufacturers less reason to invest in designing IS systems for those lenses. I'm not saying the reason is good, as I already pointed out before, the reasoning for why 85mm and shorter focal lengths is INVALID (that's what I've been saying the whole time...you seem to think I'm saying the opposite).
Your third point is exactly what I'm talking about. Today we definitely have enough resolution to resolve the blur from camera shake at 85mm. Probably at 50mm if your talking about stopping down to f/8 (personally, I've never had a problem with my 50mm f/1.4 up through around f/2.8 or so...I've used it to photograph a good number of nighttime car shows in years past. I don't generally use it at f/8, and I certainly don't try to use my camera at ISO 100 in the dark, personally I think that's a little unreasonable...but to each his own, I guess). If the 7D II comes out with a 24mp APS-C, that will only be even more true that IS on lenses with focal lengths shorter than 85mm will be increasingly necessary. That is exactly what I was saying...hence the reason I'm confused about your responses.
Regarding your first image...the kind of softening there looks like a small amount of camera shake blur and a lot of missfocus blur. I think the softness would have been significantly less if the guys head was fully in focus. I think camera holding technique can help there as well...that looks like a pretty well-lit scene to me for a fast prime, and it certainly appears as though you were using a wider aperture.
As for the second image, it might be possible that IS would let you do what you describe, however your burning up three stops of hand-holdability just to reduce your ISO. That doesn't leave much room to reduce shutter speed any more to compensate for camera shake, and IS gets sketchy in that last stop (even the IS of the much-vaunted EF 600 gets borderline when you try to push it to a full four stops of hand-holdability unless you have wicked-stable hands.)
Anyway, if you want to pull an Artie, don't come off like a jerk, and maybe actually teach something...your current approach is rather wanting.
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