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The purpose of this thread is to answer this long debated topic and to help people choose their lens 50mm lens better. I am by no means an advance amateur so all the information I've consolidated comes from reviews I had found up, as well as some informative concepts on a digital vs film lens by Franglais. Therefore if you have any questions, please contact the respective people.
If you want a concise answer, look at the attached image.
http://www.luminescentphoto.com/arti...mm_Nikkor.html
http://www.naturfotograf.com/lens_norm.html
50mm f/1.4 AF-D 50mm f/1.4 AFS
MTF Charts (from nikon.com)
Build
Both of these two lenses are built very well. The new 50mm lens has a much larger barrel and doesn't feel as "solid" as the AF-D model, but I think this is due to the way the outer barrel is constructed on the AF-S version. Because the AFS lens is a "G" design, it has no aperture ring. The AF-S version has a black finish that matches the finish on the D3, D300, and D700. The new AFS version has the rubber gasket on the F-mount for weather sealing benefits. Both lenses have an enclosed distance scale that goes from 0.45m to infinity. The new 50mm has the traditional MA/M switch on the side of the barrel allowing users to go between autofocus (with manual override) to manual focus without having to engage a switch on the camera body. The AFS version of this lens has a new optical formula, but note that it is not an internal focusing design. This means that the lens elements will extend in and out as you focus. One thing I found pleasant with the 50mm AFS is that the barrel is quite recessed, similar to my old 50mm f/1.8 Nikkor. This designwill surely help shade the front element even if you are not using the supplied bayonnet hood.
Handling
The focus ring on the new Nikkor appears to be geared differently than the one on the AF-D model. To go between 0.45m and infinity requires approximately a 180° turn of the ring. Moreover, the AFS focus ring appears to be "geared down," in that there is not a 1:1 relationship between the rotation of the focus ring and the rotation of the lens barrel. The greater travel of the lens barrel and "geared down" focusing ring should be a benefit to manual focus operation. Because the focus ring does not rotate when autofocus is engaged, the 50mm AFS is a little easier to handle during AF operation. The larger diameter body of the AFS lens also makes it easier to handle on today's larger DSLR bodies, such as the D3 and D700.
Autofocus performance
As with all AFS lenses, autofocusing is smooth and quiet. However, due to the longer rotational distance that the focus barrel must travel, the 50mm AFS takes longer to go from minimum focus to infinity than its predecessor. I timed AF performance on my D700 body. The 50mm AFS required 0.8 seconds to travel from minimum focus to infinity. The 50mm AFD only required 0.5s. While some may find this disappointing, it is not entirely suprising-- the 50mm AFS is not an internal focus design as most of the other AFS Nikkor lenses are. That means the entire lens barrel must be moved by the focus motor. Additionally, Nikon has clearly engineered this lens to be manual-focus friendly; the geared-down focus ring and greater travel means that manual focusing operation is far easier than on earlier AF designs. In subjective testing, I found little practical difference in AF tracking speed between the AFS and AFD versions of this lens. Both proved adept in focusing on my dog running straight at me. In theory, the AFS lens should perform better than the AFD version on lower-end Nikon bodies because the AF motor is independent of the camera. The AF motor in cameras like the D3 and D2 series is known to be more powerful than those in other Nikon bodies; further testing would be required to see if there are differences in performance between the D3 and say, the D80.
Image Quality
I produced a series of test shots with a Nikon D700 using matrix metering. I captured all images in NEF format and then converted them to JPEG using their camera default settings in Capture NX 2.1.1. The 50mm AFS Nikkor shows improved image quality over the AFD version of this lens, especially when shot wide-open. While both lenses have reduced contrast at f/1.4, the AFS version seems to do a little bit better in terms of overall sharpness. By f/2.0, nearly all CA is gone on the AFS lens, while the AFD version still shows purple fringing until at least f/2.8. (Note: because Capture NX applies CA removal automatically, results from in-camera JPEGs may vary. I chose to leave CA removal ON in Capture NX because that is how I process my NEFs) In my limited time with the 50mm AFS, I've noticed that bokeh seems slightly better than the AFD version. Background lines are slightly less harsh in the AFS lens, but the difference is very small. The AFS version of this lens has overall better sharpness and contrast, especially at the edges of the frame, than the AFD version. In my tests, the AFS produced results at f/4.0 that were nearly as good as those at f/8 with the AFD version.
Conclusions
Both versions of the Nikkor 50mm f/1.4 lens are excellent. Depending on the features you require, you may not find it necessary to spend the extra $155 to get the AFS version. Despite the fact that the differences between these two lenses seem small, these small differences cannot be ignored. Having AFS focusing means full-time manual override. If you like the 50mm focal length, and don't currently own the AFD version, I think the 50mm f/1.4 AFS G is a strong contender-- especially when you consider that you actually get a lens hood and rear lens cap when you purchase it (which would add another $30 to the price). I will need to do some more testing of the AFS autofocus performance in active situations. I was a bit surprised that the AFS lens didn't seem to focus faster than the AFD. Of course, some of this is psychological perception. The quiet focusing and longer focusing rotation on the AFS lens makes it feel slow, but my AF tests lead me to conclude that it tracks just as fast as the AFD lens. If you are using a newer Nikon DSLR, especially one of the larger bodies, I think the larger diameter of the 50mm AFS lens is a plus. The 58mm filter thread was an odd twist; most Nikkor primes in this range have a 52mm filter thread. If you have filters for an older 50mm Nikkor, you won't be able to use them on the new one.
Nikon D60 - need 50mm lens adviceAn update of the older "screwdriver" 50/1.4 Nikkor was long overdue. The new model, largely finished in lightweight material of an organic nature, sports an improved 8/7 optical design and at last, AFS operation. But unlike other recent new Nikkors, there is no nano-coating and no ED glass inside. While the lens barrel does not extend during focusing, there is no internal focusing (IF) to work its magic (and sometimes, adding colour aberrations) - the inner unit moves back and forth as an entity. Thus, the autofocus operational speed won't set a world record, but for most purposes it suffices well enough. A side effect is that the outer casing needs to be pretty big, thus a 58 mm filter thread is used. This breaks the earlier pattern of normal lenses (by Nikon) being served by 52 mm filters. However, in a predominantly digital era in which filters see much less use than before, this disruption of old habits might be easier to accept. One gets a better fitting lens hood and since it flares just a little, the front element is deeply shaded. Towards the rear there is a rubber gasket to provide weather sealing.
Corner fall-off is visible when the lens is set to the widest apertures, but less annoying than seen with the earlier AF-D model. Fall-off will of course be most visible on the FX cameras. From f/2.8 onwards vignetting is negligible on DX and FX alike. The barrel distortion, typical for this class of lens, is kept under good control. Field flatness also is better than shown by most fast lenses. Image quality is quite good in fact at f/1.4 although some blue fringing can occur at high-contrast transitions, increases to f/2.8 accompanied by a rise in contrast and reduction of fringing, and really gets into its stride in the range f/4 to f/9 or so. The smallest apertures see more softening of the image and a reduction in contrast, so only stop down to f/16 if you desperately need the increased depth of field, or like to shoot into the sun. The aperture opening is nicely rounded and the out-of-focus rendition (bokeh) is softer and less harsh than seen with the older 50/1.4 AFD model (probably due to rounded vs straight, and 7 vs 9 blades). However, the 50 mm lenses are too short to really throw the background way out of focus unless you shoot fairly close and have the lens nearly wide open. So don't expect the image to "pop" like it often does with a telephoto lens.
Colours are rendered vividly saturated and come across crisp and clear. On some subjects, however, one can detect a slight longitudinal colour aberration leading to reddish fringes to the foreground and greenish fringes towards the background. Even in this respect the new lens does better than the predecessor so this behaviour should be interpreted in its proper context, and many shots will not show this problem at all.
Although nano-coating is missing, the new lens handles awkward backlighting and point light sources better than the model it replaces. Ghosting is usually minimal, but when shooting straight into the sun, you tend to be rewarded by a big blur rather weak blue ghost spot. Flare is well controlled, though, and I did not encounter situations in which flare was an issue for my shooting with the AFS 50 G.
The new model is an evolution of the older lens, so you don't need to rush out to purchase it unless you can only work with AFS. Anyone looking for an excellently performing normal lens should consider the "G" carefully. It complements the high resolving power of the D3X in a nice fashion too.
Do tell me if I made a mistake! Thanks!Film and digital have different requirements. The 50mm f1.4D was designed for film. I believe that the 50mm f1.4G design was revised for digital. I don't KNOW what was changed, but here are some things that might have been done:
Firstly things the lens designer seeks to improve:
1. Greater definition across the whole field from maximum aperture onwards. Digital cameras and postprocessing can do wonders to eliminate some lens defects but they can't invent detail that's not recorded
2. Reduce chomatic aberration. This is purple fringing particularly around highlights. On digital sensors this is a disaster because the four light-sensitive elements that make up a single pixel are arranged side-by-side on the sensor. If a thin white line is splurged out into a wide rainbow-couloured one it is not going to be rendered correctly. In film the light-sensitive elements are arranged in a layers and will tend to see the line as white
3. Reduce the reflection of the rear lens element. The sensor is shiny (unlike film). A bright spot on the image will be reflected off the sensor back at the rear of the lens. If this reflects it back at the sensor it will produce ghosting
4. Increase the size of the lens element so that light comes out and hits the sensor head-on, particularly at the edges. On some sensors the light-sensitive element is like a little pit and light hitting it at an agle might not reach the bottom (seems to have been improved with the latest generation of sensors)
Some of the things that the lens designer might let slip because it can be corrected in the camera or by software:
- distortion
- light falloff at the edges of the field
- low contrast
The "D" and "G" lenses are both 50mm f1.4 but there are almost 14 years and a major change in camera technology between the two
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Do note the image differences are very minor and can be neglected for most users!
