Quick Poll Nikkor 24-70 f2.8 (Good/Defective)

[hawkman]

<p>Shun,<br />Thanks for you comment but I don't believe in bad luck I am just more picky and careful than an average PN user when inspect gear, the reason I exchanged D700 bodies was because they had hot pixels, I believe the majority of D700s do have hot pixels but most owners are not able to notice/find them for various reasons. The same is true about lenses, based on elementary statistics it is impossible that all the 5 random samples that I got were from a "bad" pool unless there was a conspiracy by B&H!<br />Did you ever test the 4 samples on tripod side by side at all focal lengths and apertures?<br />And yes, the first 5DMKII I bought was defective too, the second one was good. Here is a photo showing the defective MKII if you have any doubts. <a href="http://www.stanford.edu/~ahazeghi/Photos/photonet/IMG00009.jpg">http://www.stanford.edu/~ahazeghi/Photos/photonet/IMG00009.jpg</a></p><div></div>

[ShunCheung]

<p>I never had more than two 24-70mm/f2.8 AF-S in my possession at the same time. I found very serious vignetting at 24mm/f2.8 from the first sample photo.net received from Nikon USA, and I thought it was defective. They shipped us a second sample, on which I found the same type of vignetting.</p>

<p>We got the 3rd sample months after that and the 4th sample was purchased by a European friend. He mail orderd it in the US before the price increase earlier this year became effective (but had been announced). He had it shipped to my house, and I tested it for him. When he came to the US a few months later, he picked that up from me.</p>

<p>I should have two samples of the 35mm/f1.8 AF-S DX soon, and I'll see whether there is any variation or not.</p>

[hawkman]

<p>Mine has vignetting at 24mm and f/2.8 too, but it is not that bad, it is at the the very extreme corner. For me the uneven sharpness at 70mm and f/8 was much more of an issue than the vignetting.</p><div></div>

[ilkka_nissila]

<p>I'm not sure if this kind of a query could yield any useful answer since people with problems are more likely to respond than those without. My 24-70 is fine, easily the best zoom I've used.</p>

[dan_south]

<p>Mine works fine. I've tested it for sharpness against every other lens I own, and it surpasses all of them. AF works perfectly. I did the whole slanted ruler test along with just about every other test I could think of - no issues whatsoever. It's built like a tank.</p>

<p>The only issue I have with the 24-70 is that it exhibits mild pin-cushion distortion at the wide end. Most of the time I let it go, but for photos of buildings and interiors it sometimes requires correction in post-processing.</p>

<p>BTW, the "vignetting" in the photo of the trail above is not vignetting. It's light fall-off, a trait that all wide-angle lenses exhibit. Try shooting large format with a wide-angle lens sometime. You'll see plenty of fall-off in every frame unless you opt to use a center filter and drop a couple of stops of shutter speed on each exposure. Frankly, I think that photo would look BETTER with MORE fall-off. Look at an Adams print. He usually darken his edges. On purpose.</p>

<p>I'll return you now to your regularly-scheduled hair-splitting session. This thread has inspired me to invest in FedEx stock. ;-)</p>

 

[hawkman]

<p>Dan,<br />Vignetting is the same as "fall off"<br>

<br /><a href="http://en.wikipedia.org/wiki/Vignetting">http://en.wikipedia.org/wiki/Vignetting</a><br /><a href="http://www.the-digital-picture.com/Canon-Lenses/Canon-Lens-Vignetting.aspx">http://www.the-digital-picture.com/Canon-Lenses/Canon-Lens-Vignetting.aspx</a></p>

<p>Maybe you are trying to point out the difference between optial vignetting and natural vignetting, the example above is optical vignetting beacuse it goes away by stopping down the lens.</p>

<p> </p>

[hawkman]

<p><em>I'm not sure if this kind of a query could yield any useful answer since people with problems are more likely to respond than those without. My 24-70 is fine, easily the best zoom I've used.</em><br>

The point of a thread like this was to show sample variation does exist for this particular lens, if you have direct comparison between two 24-70 lenses that show no variation at all, it would be nice to post it here.</p>

<p> </p>

[dan_south]

<blockquote>

<p><br />Vignetting is the same as "fall off"</p>

</blockquote>

<p>Hmm, sorry, but you can't believe everything that you read on wikipedia.</p>

<p>Vignetting is caused by physical obstruction. The lens barrel or attachments like modular filter holders prevent light from reaching the far edges of the lens' angle of coverage.</p>

<p>Light fall-off occurs in absense of physical obstruction due to physical properties of the lens' optics. Light fall-off on wide-angle lenses is intensified by polarizing filters. You can mount a UV filter that's the same thickness as a polarizer on a wide-angle lens. If the edges don't become darker with the UV filter mounted but DO become darker with the polarizer mounted and activated, that's an example of fall-off rather than vignetting.</p>

<p><a href="http://www.largeformatphotography.info/filters.html">http://www.largeformatphotography.info/filters.html</a></p>

 

[hawkman]

<p>Dan<br />I am sorry but Wikipedia is much more reliable than an unknown website like <a href="http://www.largeformat">www.largeformat</a>..., it has valid academic refrences not just some average Joe's comments. There are references to optics text books.<br /><br />BTW I learned this several years ago in an engineering optics class, as I indicated above the example is optial vignetting because it goes away by stopping down the lens as it should.</p>

[ken_i_h]

<p>So sorry for late came back. Mine works fine. No problem zooming back and forth. Had to adjust AF a bit, but okay. S/N is US298xxx purchased last March at Adorama walk-in. Pretty happy with this. Hope this thread help you take a plunge.</p>

[lex_jenkins]

<p>The term "light falloff" was generally preferred in technical discussions for many years by most texts and periodicals. "Vignetting" usually referred to physical blocking of the light. Up until the past decade on the internet I never saw the term "vignetting" routinely applied as a substitute for "light falloff", but now the terms are used so interchangeably that some printed publications are copying the same terminology. It seems imprecise and tends to lead to confusion since it's often necessary to differentiate between physical/mechanical vignetting and optical vignetting (light falloff). This can be seen on Canon's website in an effort to distinguish between the two. Makes better sense just to use the older terms. Many of the more credible websites and patent applications still seem to prefer light falloff to describe this phenomenon.</p>

[hawkman]

<p>Hi Lex,<br />Thanks for the clarification, I am familiar with the terminologies that are used in engineering optics which might be different from what was used in the past or in other communities. The type of vignetting that is called <em>optical vignetting</em>, refers to shading of off-axis rays incident upon rear elements by the front elements in a multiple-element lens such as the 24-70. It reduces the effective aperture opening for off-axis incident light causing gradual loss of intensity towards the periphery of the image. It can be fully eliminated by stopping down the lens, the example above is clearly this effect because as I mentioned it goes away when I stop down.<br /><br />The other type of vignetting which Dan referred to is what is called "<em>natural vignetting"</em> in most text books that are in publication today. It is not due to blocking of light rays, it is due the angle of incidence (hence it is more of a problem for wide angle vs telephoto) and it is proportional to Cos^4(teta) where teta is the incidence angle (for example if teta=90deg i.e. ray parallel to sensor the incident intensity flux is zero). This type of Vignetting or fall off if you like, is completely independent of aperture and cannot be mitigated by stopping down<br /><br />There is also another type of vignetting specific to digital cameras and it is called <em>pixel vignetting</em>, it has to do with the dependency of absorption coefficient in the semiconductor material on the angle of momentum vector for the incident photon. Microlenses are used to correct this effect.<br /><br />Any ways, I am sorry if the terminologies were different, I am not old enough to know all the terms that were used in the past, thanks for your clarification.</p>

[mizuho_saito]

<p>Thank you everybody for all of your quick responses. Now I just have to wait until the 24-70 is back in stock. =( Then I can decide where to buy from.</p>

[scott_pogorelc]

<p>I've owned the 24-70 for a little over a year now. It is a terrifc lens that is sharp and focuses wickedly fast. The fact that it is frequently out of stock may provide a some indication of what people think about the lens. Take the techo-babble in this thread with a grain of salt. If you are not happy with the lens once you get it, you can always return it.</p>

[paul_b.1]

<p>I also Had to adjust AF : +15 on my D3. Otherwise works fine. Vigneting at 24 is not that bad, but linear distorsions are. The AF is fast and quiet. Somehow I have the feeling that the lens it's much better in the real life, vs. the test lab !?.</p>

[peter_kervarec]

<p>Hi Mizuho<br>

Go straight ahead and buy one. I have one and its razor sharp, beautiful contrast and what one would expect of a lens that price. I have had mine for 6 months and use it a lot. One of the posters cropped an area and then enlarged it and complained. I think any lens would have failed that test.</p>

[ShunCheung]

<p>Here is a test shot from the first 24-70mm/f2.8 photo.net received, at 24mm, f8 on an D3 (FX) body. Obviously it was hand held, but the shutter speed was 1/640 sec. By f8, all light fall off problems are gone. There is a hint of chromatic aberration on the rim of the hat and on the light pole. I focused on the tennis court, but at f8, I got good depth of field coverage from fairly close to infinity.</p>

<p>The vignetting issue was thoroughly discussed in this thread last year: <a href="../nikon-camera-forum/00OF78">http://www.photo.net/nikon-camera-forum/00OF78</a><br>

The image samples I posted to that other thread were captured with the exact same lens used for this image. Vignetting is only an issue at 24mm, f2.8 and f4.</p><div></div>

[michael_oxford]

<p>I'm just throwing this out there, but concerning light falloff and vignetting, isn't it probable that is also sample specific due to errors in calibration & ect? .... although I figure if you stop down far enough regardless then you should get enough projection, but you'll hit a wall with diffraction...</p>

<p>To the OP, I would buy from a local shop if given the chance. Much more convenient to test samples in store than having to ship everything back and forth to B&H.</p>

[mizuho_saito]

<p>I have decided that this will be my next lens, I just have to wait for them to come back in stock. And yes Michael, I will most likely buy from a local retailer since it only costs a little extra, but they may price match to B&H, but then there's also tax if I buy at the store =(, and tax on a 1700 lens adds up. But the upsides would be that I would be able to handle the lens and try it out before I purchase. I hear B&H customer support is exceptional, I have bought an SB-900 from them recently, but I haven't had to return anything to them yet. It would just be more convienent to be able to drive 15-20 minutes to the local shop though if I wasn't satisfied.</p>

[ShunCheung]

<blockquote>

<p>but concerning light falloff and vignetting, isn't it probable that is also sample specific due to errors in calibration & ect?</p>

</blockquote>

<p>As I pointed out before, I have tested 5 different samples for vignetting/light fall off and all of them show the same type of serious vignetting at 24mm, f2.8. I even sent a RAW file to Nikon USA for verification. They replied that was normal and actually pointed out that Nikon Capture NX would fix that automatically for the D3. (At the time I talked to Nikon, the D700, D3X and NX2 had not been introduced yet.)</p>

<p>Of course, unless you shoot a uniform blue sky or white wall at 24mm, f2.8, the vignetting becomes much harder to detect. I don't think that is a major concern in real-life shooting. Personally, I wouldn't worry about the so called "sample variation" for this lens.</p>

[liljuddakalilknyttphotogra]

<p>I've had one for probably about 15 months - no problems. I love the lens.<br /> Lil :-)</p>

[bjørn rørslett]

<p>For what it's worth I've used seven samples of the 24-70 that all behaved in the same fashion. The results are excellent. Even a prototype I tested (not in that tally) by and large performed similar to the others except for having less efficient coating.<br>

My personal 24-70 sees a lot of use. Like the other recent "pro" lenses it is designed to break at the bayonet mount if getting a severe blow so as not to damage the camera. Replace the mount and the signal cable within and you're good to go - a Nikon repair shop does this in 15 minutes (I have timed the operation).</p>

[dan_south]

<p>Now that I think about it, the dark area in the corner of Arash's trail photo probably IS vignetting (caused by the dimensions of the lens barrel). Light falloff would have faded from light to dark more gradually.</p>

<p>The 24-70 f/2.8 G has a very bright and even image circle across the frame. This tiny patch of shadow in the corner would be impossible to see in the viewfinder of any Nikon camera, even the ones that claim to have 100-percent coverage (which is typically slightly smaller than 100 percent of the frame). The shadow can be neutralized via software, removed by the gentlest of crops, or avoided altogether by shooting at f/8.</p>

<p>Upshot: This small amout of vignetting (or fall off - I've lost track) doesn't seem like much of a problem. Just frame a tad wider if you absolutely can't live with microscopic shadows in the corners of your images. As mentioned, large format shooters would love to have this much evenness of brightness across the frame when shooting at wide angles. Enjoy!</p>

 

[torben.palm]

<p>My example also works perfect (on D300) - sharp and fast. I love it!</p>

[paul_duncan2]

<p>My copy, serial 223... I've had since release and very happy with it</p>