Nikon 50mm 1.4G vs 1.8G Bokeh

<p>I am trying to decide between these two lenses for my D7000. The 1.8 is lighter (by 100g), cheaper (by 120GBP) and, according to MTF and initial tests, sharper. I also hear that, due to the manual focus ring being less sensitive/precise than the 1.4, the focus is a bit faster? Anyway, I may be splitting hairs with the last one but, all in all, the 1.8 seems more appealing on many fronts. However, the 1.4 has 9 aperture blades. Does this have a significant advantage over the 1.8 or are they pretty much indistinguishable? Has anyone purchased the 1.4 just for this reason? I have seen images from the two taken wide open of lights against a dark background to record the exact shapes of the aperture opening but is it an issue? If the two lenses both shot a portrait against neutral tones of foilage without any highlights would the bokeh tell one from the other? I also heard somewhere that, stopped down to the same aperture, the 1.4 bokeh would be more detailed. Can any one explain why? Many thanks for your time. Oh... come on Nikon, release a new AF-S 85mm 1.8G (or even better, an AF-S 100mm f2G) this August pleeeeeeease!!!</p>

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<p>If the two lenses both shot a portrait against neutral tones of foilage without any highlights would the bokeh tell one from the other?</p>

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<p>Yes, but if you truly don't have any highlights, reflections, or obvious crisp shapes/lines/objects in the background, the difference will be subtle. The moment that contrasty objects/shapes come into play, the differences start to become more obvious. The newer 1.8 G seems a bit less fussy this way than the 1.8 D. The problem is that you don't always have the luxury of controlling backgrounds to that degree. But remember that if you're considering shooting wide open or close to it, the intermediate/distant background isn't the only thing you have to consider. At portrait-ish distances (say, a head-and-shoulders shot with a 50mm lens on DX from a few feet away), you're going to have things like the subject's trailing shoulder out of focus. What happens if that person is wearing clothing with a distinct pattern on it? (that's a rhetorical question: what happens can be truly ghastly with some lenses!)</p>

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<p>Has anyone purchased the 1.4 just for this reason?</p>

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<p>Well, I bought <em>Sigma's</em> 50/1.4 for just this reason. It's all about shooting at wide apertures, and focuses very quickly. Roughly the same price as Nikon's newer 50/1.4. Those two lenses are built around different priorities. Nikon's seems to be aimed at more general use, while Sigma's is aimed at being used fast, at middle distances. I'd probably grab the Nikon if it was for landscapes, but I'd always grab the Sigma for people. We are splitting hairs here, though.</p>

<p>Wide open, diaphragm blades use to be hidden behind an "aperture" ring; they should not be obvious, if so, they are probably damaged (I actually don`t recall to have checked it on a Nikkor, but it is quite common on Leica and Mamiya lenses, "damage" issue included).</p>

<p>Where you have read that the f1.8 version is sharper? According to photozone.de both lens`performance is on pair (D3X), being the f1.8 a negligible hair behind at all apertures, <em>excep</em>t for center resolution (only center) at f8-11 (only f8-11) which is another negligible hair above the f1.4 version. The difference is such minimal that I`d think the only difference is to have or not f1.4.</p>

<p>Jose makes a very good point. If you're buying a fast lens for use wide open, then the number of iris blades is completely irrelevent, since the aperture will be as round as the lenses themselves.<br /> Once you start to stop down, then things begin to get iris dependent. However the shape of the individual blades may be more important than how many of them there are. Also Bokeh is far more affected by the degree and "sign" of the spherical aberration correction of the lens, and whether you're looking at out-of-focus highlights in front of, or behind the subject. Bottom line is that you should check your backgrounds and foregrounds for compositional distractions anyway.</p>

<p>Another thing to consider is that f/1.4 is often <em>too wide</em> to use with today's sensitive cameras because there's simply too much light to use even the fastest shutter speed of 1/8000th. That's without taking into account the non-existent depth-of-field at that aperture.</p>