chuck

Maybe you should try again with a 24 or 36 Mpixel camera. Without the provision to feed the actual focal distance of the lens back to the camera, the AF system has to operate on a open loop to prevent excessive hunting. This means phase detection AF system has little or no ability to compensate for the slop in the focus mechanism. Feeding the actual focal distance back to the camera allows the AF system to operate in a closed loop. This allows the camera to compensate for mechanical slop. Canon started using closed loop AF system sometimes after EOS-5D Mk-2. Nikon probably started roughly around the same time. This would put the start of the closed loop AF system in Nikons at some point between D700 and D600.

I will guess autofocus performance with any non-D screwdriver AF lenses, like this 70-200f4 AF, would be poor on a high pixel count DSLR. The reason is without distance encoder, the lens would not feed back to the camera any data about its actual focal position. So the autofocus becomes an open loop system, and any slop in the screw driver AF system would become uncorrected focusing error. I wonder if anyone has done any systematic studies of the focusing precision of different generations of Nikon AF lenses on cameras like the D750 and D810. My guess is pre-D Screw driver lenses would have the worst focus precision. AF-D screw driver lenses would do significantly better. AFS lenses would do even better still, because it would be closed loop, and it would have minimal slop.

The size of the lens hood actually shrank dramatically between 70-200 /2.8 VR-1 and VR-2, which doesn't help the problem. Also the new smaller hood for the VR-2 also has curved, rather than straight, front edge. This makes it very dangerous to stand the lens on its hood, unlike with every other Nikon lens hood. A totally idiotic design change.

<p>The point Rodeo seems to be making is smoothness of out of focus highlights is independent of the lens' resolving power. So 58/1.4 could have achieved resolving power at least matching those of any lens at its price or lower without sacrificing the nominal objective of better out of focus transition.<br> The fact that it didn't achieve that level of resolving power suggest resolving power was deliberately reduced.<br> So the question is for what real reason was it reduced, if the real reason could not have been to improve out of focus highlight.</p> <p> </p>

<p>Why design a lens for less than optimal resolving power, unless through it one gains some other attribute? If less than optimal resolving power is really desired, why not use firmware or manual focus to achieve it so that optimal resolving power can be recovered if desired?</p>

<p>The difference in weight between the 80-400 and 200-500 is equal to the weight of a D810 body. I certainly noticed the difference.</p>

<p>Ah, yes, thank you, Ilkka. Operator error always trumps engineering.</p>

<p>Another advantage of not pursuing focal plane sharpness as the overriding objective is that based on recent history, reasonable degree of focal plane sharpness would be overtaken in just a few years. Lens considered outstandingly sharp in 2008 is now considered below average compare to their peers.<br> However, there seems to be less pressure to ratchet up the general standard of performance in other areas.<br> So a lens considered outstanding because of its focal plane sharpness is not likely to last long in its tenure. However, a lens considered outstanding in other areas would last longer in its tenure as being an outstanding lens.</p>

<p>I just updated the firmware. The LV not reflecting exposure compensation is not fixed. At least not in the way I think of as being "fixed".<br> I thought the image being displayed in LV should reflect the current setting of the exposure compensation. But that is still not done. The image looks the same regardless of what compensation is dialed in.<br> Also, if would be nice if the LV shows what part of the image would be blown out under the current exposure setting. That is not done either.<br> I am not sure what they mean by fixing how compensation is displayed in LV.</p>

<p>It was clearly a prestige project, but it seems to reveal a poor grasp of what attributes would confer prestige. <br> Also, why not do this with the 50f/1.4? Why the goofy 58mm focal length? 58mm only invites comparison with the 58mm f/1.2, and highlights the fact that F mount is too small to handle both electronic contact and f/1.2?</p>

<p>Good, they fixed the fault which cause the LV to not reflect exposure compensation.</p>

<p>I ordered mine from B&H on Oct 7 and got it on Oct 12. It likely depend on when they get a shipment.<br> BTW, at 500 f/5.6, this lens appear to handily out resolve the 80-400 at 400 f/5.6 at the pixel level. The VR also work clearly better than those on the 70-200. It probably also work better than those on the 80-400, although that might be more subjective. You will love it.</p> <p> </p>

<p>Your grand dad seems to have been an interesting person.</p> <p>You can get a better idea of the market prices of these items by visiting KEH.com. They will buy your stuff at close to market prices, but more importantly they will let you enter the particulars of the items, tell you what they will pay, without your committing yourself to sell.</p> <p>You can also visit ebay, search for similar items, and use the watch function to keep track of what the auction for the items cleared at.</p> <p> </p>

<p>The deal seems to be over. I went to a Best Buy at Rockville, MD. They still have the low price labels on their 16-35 and 80-400 display lenses, but their inventory system no longer show the lenses at the labeled prices, and they refuse to honor those prices.</p>

Hi, thanks. Prefocus is a good idea. The night sky is really too dark for manual focusing as well. Mary, yes, merging two shots with different exposures for foreground and background sky is great idea. In some recent attempts at shooting the sky in Yosemite I found exposing properly for the foreground overexposed the sky, and also cause star trails. Merging two shots would solve the problem,.

<p>When I attempted to take photos of the night sky, the scene is too dark for either phase detection AF or for LV to detect anything. Is there any other clever way to obtain sharp focus, except through focusing by distance scale and a large dose of trial and error?<br> Nikon AF lenses do not seem to focus to infinity right where the focus scale says infinity.</p> <p> </p>

<p>It's not available on line. It is in-store purchase only. I believe the deal is only available at those Best Buy stores which normally stock these lenses.</p>

<p>The 16-35 f/4 VR is currently $629.99 at the same Best Buy. That's a 50% discount from the normal list price. Other lenses still have their normal full prices.</p>

<p>Hi, Mary:<br> That's right. It says AF-S. It also says so in the confirmation email from Best Buy.<br> Also, although out of stock for sale, the store still had the lens for display, with the price label of $1,489 under it. The display lens is most definitely the new AF-S N version without the aperture ring. </p>

<p>According to Nikon_rumors, this has been going on for a while, at least since the weekend. </p>

<p>Hi, Mary, it is the new AFS version. I also could scarcely believe it.</p>

<p>I just went to the Best Buy at Fairfax, VA, and saw the 80-400 now listed in-store for $1,489. It does not appear to be a fluke, because the store is out of stock, and associates checked on their system and transferred the lens at this price from a different store without any sort of price override. <br /> This price is not advertised on the Best Buy website, where the lens still list for full price. It also still list for $2,696 at B&H. <br /> I don't know what the story is and why the lens is so heavily discounted in the Best Buy. Perhaps they intend to make room for the 200-500VR. Perhaps they have advance information that Nikon will discontinue or replace this lens soon, although I tend to doubt that.<br /> If you are looking at this lens, or are considering this lens as an alternative to the 200-500, you may wish to call your local Best Buy and see if the lens is available for this quite remarkable price. It is apparently an in-store price only.<br /> I naturally bought the lens from Best Buy at this 45% discount. I bought the 200-500 partially because 8 0-400 was too expensive at the list price. Now I will have the opportunity to test these two lenses agains t each other in detail.</p> <p> </p>

<p>I use EXIF Viewer for IOS. I notice with the same lens, sometimes the information about which lens is used is there, sometimes it is not. The focal length, aperture, shutter speed, VR, AF information are always there.<br> Any idea why the lens ID is spotty?</p>

<p>Are you planning to shoot against the sky or against a terrestrial background?</p>

<p>Again, it is much more important to get a lens with the right coverage than the lens with the best optics.<br> You sacrifice a lot more potential good shots because your lens didn't have the right coverage, then you ever would because your lens had the right coverage, but was optically deficient.<br> For most purposes, the difference in the optical performance between the Nikon and the Tamron is a matter of how many angels can dance on the head of a pin.<br> You can scrutinize the head of the pin under a microscope and publish the results. But it has very little to do with most picture taking situations.</p> <p> </p>