20 f/2.8 AF-D Sharpness Quality Issue?? Advice needed.

<p>Note: I've posted this as a response on an <a href="../equipment/nikon/20-2.8.adp">old thread</a>, but was hoping to get some quick response in case I need to return this lens soon.<br>

I just picked up a used (Excellent Condition) 20 f/2.8 AF-D from Adorama and am considering returning it. I'm concerned it isn't as sharp as it should be.<br>

<br />I would appreciate it if someone could take a look at the comparison photos to a 17-55 posted on my Flickr site and provide an opinion? <br>

<a rel="nofollow" href="http://www.flickr.com/photos/jazzandlee/sets/72157624216807191/" target="_blank">http://www.flickr.com/photos/jazzandlee/sets/72157624216807191/</a><br>

Below are two examples. I can post more if necessary. 1st is roughly the center of the image and focus point at 5.6. 2nd is at f/9 in the bottom right corner. It really helps to view the rest of the shots at the various apertures. In general it does not meet my expectations from reviews online, and at worst it seems blurry.<br>

<a title="f5.6 A by Lee von Gynz-Guethle, on Flickr" href="http://www.flickr.com/photos/jazzandlee/4727594899/"><img src="http://farm2.static.flickr.com/1244/4727594899_f6ca54393a.jpg" alt="f5.6 A" width="500" height="342" /></a><br>

<a title="f9 A Corner by Lee von Gynz-Guethle, on Flickr" href="http://www.flickr.com/photos/jazzandlee/4727595153/"><img src="http://farm2.static.flickr.com/1085/4727595153_cd155b5f69.jpg" alt="f9 A Corner" width="500" height="342" /></a><br>

I've compared the 20 to the 17-55 at 20 and included each shot's full resolution file as well as print-screens of the comparison in LR3 Beta 2. They were all taken hand-held, available light, overcast skies, with no processing in LR3 Beta 2. All shot at ISO 400, same speeds at various apertures with a D300s. B&W MRC UV filter on the 17-55, nothing on the 20. All auto focused. The first set (labeled A) focus at the bottom left corner of the back windshield. Second set (labeled B) focus on the middle of the back, red edge of the seat.<br>

I noticed that the 20 seems to have out-performed the 17-55 for the close-up shot of the bike in the corners at f/9 (see f9 B Corner 1 and 2). Strange, because it absolutely failed when focusing on the car at all apertures. Maybe I shook the 17-55 a bit at 1/80th, not sure.<br>

Could this be a bad lens? Or is this the expected performance? I wouldn't mind the corner sharpness or having to stop down for full sharpness, but I want to use this for quality landscapes while traveling and if the center isn't super sharp at f/9 or f/11, it's really a deal breaker.<br>

Thoughts are much appreciated. Thanks.<br>

Lee</p>

<p>The AF 20mm lens was designed for film camera use. If you want a DX lens that is sharp to your requirements, you may not want to keep the AF 20mm lens. Nikon has spent some time engineering lens for the DX format....</p>

<p> </p>

<p>I understand there may be sharper lenses than the 20 mm, and the 17-55 is for sure one of them. However, I'm more interested in knowing whether this is what I should expect from the lens on a DX body (which should actually improve performance compared to FX). Many people appear to be using this on DX and FX digitals with great success in terms of sharpness.</p>

<p>It seems like the center sharpness at f/9 isn't great. If it's what I should expect, then so be it, but it isn't then I'm going to return it and wait for another chance to purchase the lens.</p>

<p>I would think any prime on any body should meet my requirements of "super sharp" in the center at f/9 or f/11. If not, what's the point? </p>

<p>Nikon designs a DX lens to have crisp center area sharpness. If you get a FX body and take a image with a DX lens, you can see that the area of focus is not covering the whole sensor.</p>

<p>The AF 20mm lens you have (used?) may have had a rough life and it may not behave as a new lens would. Only the clerk at Adorama knows who had the lens before....</p>

<p> </p>

<p>Jerry,</p>

<p>Thanks for taking the time to respond, but I understand that it is a used lens and may have issues. My exact question is very specific - whether someone who has experience with the 20 mm can tell me whether the sharpness shown in these photos is typical of the lens or whether it is under-performing. </p>

 

<p>" B&W MRC UV filter on the 17-55, nothing on the 20." - not fair comparison, - take off the filter of the multi group multi element zoom lens since is not needed there - except for protection, and put if on the old less coated lens that would benefit more from the UV filter, and try again.</p>

<p>Your choice of subject for the comparison, the shiny glass and shiny car, is not the best to compare for the sharpness. Also compare sharpness in the flat surface, to eliminate any out of focus influence, and use a tripod, to eliminate incidental motion blur.</p>

<p>You know better, but seems that the pictures are much different from both lenses.</p>

<p>Try something less relfective with more defined details, and you could see better the difference. Typically, they compare using large newsppaper on a flat suface like a wall or a barn doors.</p>

<p>Do your test also from a longer distance.</p>

<p>The 20/2.8 new Nikkor I have is sharp all over the field, definitely af 5.6, 8, etc. but is more prone to reflections, and does not reduce the haze as well as your zoom.</p>

<p>For one 17-55/2.8 perhaps you can get 2 or 3 older used 20/2.8 lenses?. The size and weight of the 20 mm makes it more suitable for walking around the city or in wilderness.</p>

<p>Frank,</p>

<p>Thanks for the helpful comment. I don't have a B&W for the size of the 20 mm, otherwise I would've used it. And I didn't think about the 17-55 w/ B&W until after the fact. I wouldn't think the 20 mm "needs" a haze filter. </p>

<p>You make a good point that the scene has a lot of reflections. I thought this would be a good test for sharpness... I'll try another scene or two.</p>

<p>Tripod - yeah, didn't have it with me. Tried to keep speeds above 1/80. Will take some with the tripod.</p>

<p>Your last comment really makes me consider sending this guy back. I just wish there were new copies available....</p>

<p>Lee sharpness is a visual illusion and harder to test for than resolution and contrast.<br>

So to test for sharpness is better done using a resolution test target.</p>

<p>Luckily the difference between the newer zoom and the 20mm lens is so obvious that a test under ideal conditions is not really needed.<br>

Yes the zoom is better in sharpness than the zoom in the near distance where the zoom is at best. I rarely used both lenses stopped down a lot so it is a bit surprising (but not totally off) that the difference is so large at f9. But you may want to test if this is symmetrical. Some of the 20mm AFD lenses I saw were not perfectly centered.<br>

I would only prefer this prime for size and price over the excellent zoom (for DX).<br>

If you are after better performance shooting against the light the older AIS 20mm f3.5 is better.<br>

Hope this helps.</p>

<p>Lee,<br>

I do not own these lenses, but looking at the charts/verdicts on Photozone.de I would expect noticable differences between the two of them.<br>

Whereas the 17-55 center resolution is judged as "Stellar", the 20mm reaches only "good",<br>

Also the 20 gets comments like : "The Nikkor AF 20mm f/2.8 D had a very good reputation during the film era but the D200 didn't really like the lens"<br>

This does not say that the 20 is a bad lens, but it would imply to me that it isn't the best wide lens available either. ..</p>

<p>I try to remember that time ago I compared my primes to the 17-55 on a D200... It was a <em>fast dirty test </em>where I found that the only prime that outperformed the zoom was a 55 Micro (I had the whole range in different versions, but sadly not the AFD20/2.8). The 20/2.8AiS was clearly the worst.</p>

<p>Then I`d not be surprised if the 17-55 outperforms any prime... as it was my experience.</p>

<p>Another issue could be the right focus;</p>

<ul>

<li>Are your pics 100% in focus? You need to know this to compare sharpness.</li>

<li>Are you 100% confident in your camera&lens AF ability? If so, nothing to say.</li>

</ul>

<p>If you have Live View, you should use it to achieve an <em>almost</em> perfect focus.</p>

<p>FWIW, I recently did a quick & dirty comparison of my 20/2.8 AFD to my new 16-35/f4 VR on a d700. The results were similar to yours: The 20 prime was clearly not as good as the newer zoom under any conditions, eg, center, corners, stopped down, etc., but, by no stretch could it be called "bad". </p>

<p>For many applications, it's far more than "adequate" and I still use it for walking around or other situations when I don't want to look like I have a grenade launcher attached to the front of my camera. :-)</p>

<p>Attached is an image taken a couple of years ago with my 20/2.8 AFD on a d200 body, handheld. This version is obviously processed, but as you can see, one can certainly get a good sharp, contrasty image out of it, pixel peeping criticisms not withstanding. From your comments, I suspect your lens is probably in ok shape.</p>

<p>Tom M.</p>

<p>PS - If you haven't already done so, shoot a brick wall and compare the sharpness in all 4 corners. If they are the same, the lens probably hasn't taken a hit, was assembled well, etc.</p><div></div>

<blockquote>

<p>Could this be a bad lens? Or is this the expected performance?</p>

</blockquote>

<p>I tried three different 20 2.8 on DX when moving to digital, and none was up to even the 18-70 AFS DX that came kit with the D200. It was a big disappointment since I loved it on film, but I would say yes, it is the expected performance. That lens is just not good on digital.</p>

<p>L.</p>

<p>For what it's worth (playing today out back)...<br>

20mm 2.8 AFD versus 35mm 1.4 AiS.<br>

Both at f9 (supposedly beyond the 35mm's sweet spot) to keep it balanced.<br>

Nikon D200, fine, large jpg. Tripod. I tried to keep the same field of view, not distance.<br>

The 35 and a couple of others are my sharpest (I lack any modern zooms except the 18-35).<br>

The 35mm @ about F4/5.6 has produced some stunning larger prints when my aged eyes correctly focus the darn beastie.<br>

Good luck.<br>

Jim</p><div></div>

<p>To beleaguer the topic, the 35 1.4 at F4 ... note the street sign. Amazing to me.<br>

(D200, same sort of conditions)<br>

Jim</p><div></div>

<p>Before returning it you should test it again, this time focus <strong>manually</strong> instead of autofocus. If your camera has live view use it with the magnification to manual focus. Also test it shooting a flat surface parallel to the sensor plane like a brick wall, on a tripod. <br>

It's entirely possible you have a lens that is front-focusing. If you have a D300/D700/D3 you can fine tune the AF for that particular lens, problem solved. If not then you may need to swap it for another lens that hopefully will AF better on your camera. I know the 17-55 is a great lens but I doubt it would produce significantly better (if any better) sharpness than the prime. </p>

<p>I think your focus is off. Could be user error or bad lens. In the first photo the street (behind the car) is in focus and looks sharp compared to the zoom. I have the 20mm and love it; sharp with little distortion. Try a few more controlled tests then contact Adorama. Their support is excellent.</p>

<p> </p>

<p>Thanks everyone for the comments.</p>

<p>I mainly want this lens for traveling and will send back the 17-55 if it does well enough. I'll try a few more unbiased shots and re-post. </p>

<p>May also try fine tuning it to the D300s...</p>

<p>I bought a 20/2.8 and was very disappointed. I eventually sold it. </p>

<p>I've had two copies of this lens and was hugely disappointed on my film cameras. One of the worst Nikon lenses I've ever used, it wasn't even sharp dead center and I know my focusing wasn't the problem. The 17-55mm is outstanding and the 12-24mm is right behind it. I'd say return the 20/2.8 and try something else, maybe a Zeiss ZF 21.</p>

<p>I sent back a 17-55 DX because sharpness was very mediocre for such an expensive lens, and because it had a high level of barrell distortion.</p>

<p>I also had a Nikon 20mm and sold it since I had very disappointing sharpness on digital camera's. In my opinion you will never be satisfied with it.</p>

<p>Count me in as another former owner of a 20mm 2.8 AF who thought its resolution was below par on a DX, and sold it.</p>

<p>I hate to be the guy that points out the elephant in the room, but has it occured to you that you're not comparing apples to apples? The fact that one lens is DX and one is not is not important only because of how much of the sensor they cover, but also the level of distortion. Your 20mm lens distorts (and has softness issues) like a 20mm lens. Your 17-55 is equivalent to around 28mm, and distorts more like a 28mm lens. If anything, the 28mm 2.8D is much more of a fair comparison, as both lenses SHOULD distort more similarly.</p>

<p>If you really wanted a fair comparison, you'd need to test it against the 12-24 DX, as 13-14 in DX works out to about 20mm on camera.</p>

<p>Personally I've never used the 20 2.8 enough to make a judgement call, but a friend is very fond of it, and I've had excellent results from the 24 and 28 2.8s. At the very least, the D lenses work on almost every Nikon ever built, while the DX lenses do not.</p>

<p>My conclusions were reached on an FX camera-- the D700. </p>

<p><a href="http://www.naturfotograf.com/lens_wide.html">http://www.naturfotograf.com/lens_wide.html</a><br>

I owned both the the MF and AF 20mm 2.8 and like the review from the link I found the 20mm AF was not as sharp as the MF. shooting a D2X I ended up shooting with a 28mm f2 MF as my wide lens. It's not as wide as the 20 but it is a sharp lens even wide open</p>