Tuesday, May 27, 2014

Nikon Zooms: 70-300mm VR versus 70-200 f/4 versus 70-200 f/2.8 II

Left to Right: Nikkor 70-300mm, 70-200mm f/4 and 70-200mm f/2.8 II

There's a long(ish) zoom lens for every budget in the Canon and Nikon lineups. Nikon's catalog is perhaps a bit simpler and more straightforward; you pay more, you get more. Naturally, when users upgrade to full frame, they feel compelled to go with the "pay more option" because they feel that they need to "get more" from their FX body. There's a certain logic to this as it makes little sense to spend a lot of money on a FX body only to try to save money on an inferior lens. Note: "inferior" not "cheaper." While everybody wants the 70-200mm f/2.8 VR lens, few can justify it. Surely, the consumer grade 70-300mm VR can't be spoken with in the same breathe... can it?

Different Lenses for Different Applications


The three lenses in question are:

  • Nikkor AF-S 70-300mm f/4.5-5.6 G IF-ED VR
  • Nikkor AF-S 70-200mm f/4 G ED VR
  • Nikkor AF-S 70-200mm f/2.8 G ED VR II

Each serves a different purpose in the Nikon lineup. The 70-300mm VR is the least expensive lens, and the one that is the most likely to be a carryover from DX usage to FX usage. It's often owned by shooters drawn to the D7000/D7100 type cameras. Even though it has the slowest maximum aperture of the three, the image quality from 70-200mm is more than acceptable, with 300mm being a "nice to have." It's easily faster focusing and optically better than the two DX zooms that sit below it in the modern Nikon catalog. Even though it has the longest reach of the three lenses here, it is both the shortest and the lightest when the zoom barrel is retracted.

The 70-200mm f/4 VR could be slighted as being the poor man's 70-200mm f/2.8., but that is unfair considering that it is remarkably optically consistent throughout its aperture and focal length range. Like it's Canon counterpart, the the Nikon 70-200mm f/4 brings up the old adage of "you'll remember the quality after you've forgotten the price." Though there is no reason why you could not make a living with this lens, the lack of an included tripod collar is a one of these (annoying) little things that reminds you that Nikon doesn't want you to think of this as a professional lens. This lens fits well with the non-professional nature of the Nikon D610, and packs and travels relatively easily.

The 70-200mm f/2.8 is the lens that everybody lusts after, but which few an afford. The second version of this lens is optically superior to the venerable first version, but there is one significant trade-off as we will see. When people ask if this lens is worth it, what they really mean is that they want it but can't find a way to afford it. What they don't realize is that merely owning the lens is only the first step in a series of increasing costs. Not just the lens: filters will cost more because of the increased front element diameter (77mm vs 67mm for the f/4), tripods will cost more because of the added weight, and bags will cost more because of the increased size.

Just a reminder: Only the 70-200mm lenses (f/4 and f/2.8) are compatible with the Nikon teleconverters. The 70-300mm will not work with any of the lens multipliers because the rear element does not provide enough clearance for the additional attachment.

Bokeh at Maximum Aperture


All of the following images were shot with a Nikon D800 at 200mm, subject distance was approximately 10 feet. Differences in size reflect the different amounts of "focus breathing" that each lens produces. The first example of is the difference in bokeh for each lens at maximum aperture at 200mm.  Bokeh at long focal lengths is a luxury that is only afforded by faster aperture lenses, but it is a useful photographic composition tool for all photographers, as long distance shooting very often means action and moving subjects. During times like these, the photographer doesn't always have the option to position the subject against a non-busy background, so well developed bokeh is useful for isolating the subject against everything else that is going on.

There are no surprises, here, the 70-200mm f/2.8 wins hands down in terms of bokeh and subject isolation. However, do  note that the magnification of the 70-200 f/2.8 is noticeably less than the other two lenses when not focused on an object at infinity. This is the phenomenon known colloquially as "focus breathing" and it is something that the version two of the 70-200mm f/2.8 suffers from more so than the first version. Though problematic, this affects shooters to varying degrees. As usual, how much this is a problem depends on your shooting style and habits. One of the things to adapt to in moving from DX to FX is in using the 70-200mm lenses; on crop frame, these lenses are all about distance and getting closer to the subject. However, on full frame, the reach is reduced and the focal length isn't completely about getting closer to the subject per say, but rather about controlling perspective compression at mid/medium far distances.

For a taste of how the bokeh develops through the aperture range of each lens, click each image for the expanded view in all of the following samples.

Nikon zooms at 200mm, maximum aperture.


Bokeh at Equivalent Aperture


Most lenses when stopped down to f/8 produce similar looking results. However, there is one surprising consequence to the 70-200mm f/2.8's focus breathing:


Surprisingly, the f/2.8 lens does not produce the best bokeh in this shooting situation. (Look at the display on the back wall, not on the display rack in the middle distance.) So what's going on here? The rule of thumb for depth of field (DOF) is that at equivalent subject magnification, the DOF is the same regardless of the focal length.... the key concept is equivalent subject magnification. Even though these are all shot at the same focal length, the f/2.8 lens does not produce the equivalent magnification; that only happens when lenses are focused at infinity. So in essence, because the the subject is larger relative to the background in the first two shots, the background blur is also magnified. To produce the same bokeh with the f/2.8 lens, you would have to set closer until the subject fills the same area within the picture frame.

Nikkor AF-S 70-300mm f/4.5-5.6 G IF-ED VR


Compared to its more expensive siblings, there the 70-300mm VR is limited by its slow maximum aperture. Even at this short focus distance, the background is blurred when wide-open, but it can look busy. However, if shot against a simpler background, the results would be more pleasing. One thing to watch out for with this lens is when shooting against a busy background with the VR turned on. The combination of slower aperture and the lens correcting for handshake during shooting can make for strange/busy looking backgrounds.

f.5.3
f/8
f/11
f14

Nikkor AF-S 70-200mm f/4 G ED VR


Consistent is the word with the 70-200mm f/4. Sharpness is good to excellent throughout the whole aperture and focal length ranges; there aren't many flaws that will jump out at you for all except for the most critical use.

f/4
f/5.6
f/8
f/11
f/14

Nikkor AF-S 70-200mm f/2.8 G ED VR II


Save for the aforementioned focus breathing, the 70-200mm f/2.8 version II offers the most of the three lenses. Not to mention the extra reduction in depth of field that the f/2.8 aperture offers, but also that the shutter speed can be double what the f/4 would afford in similar shooting conditions.

f/2.8
f/4
f/5.6
f/8
f/11
f/14

One final word about focus breathing: The 70-200mm f/2.8 version II, could arguably be poorly suited for DX use. Since most DX users are looking for reach with these lenses, the problem of reduced magnification at near and middle distances works at cross purposes. These users would actually be better off with a good-condition first version of this lens; it's not optically as good but that is mitigated by the smaller DX image circle.

Concluding Thoughts


The problem with having "the best" lens is that it takes work to extract "the best" image quality from it all of the time. Part of that is because photography is by nature a craft, and those who spend more time honing their craft will be the ones who will benefit the most. However, the real problem is falling into the trap of looking at good/better/best as merely a linear progression. Though it is mostly true that these lenses get better as the price increases, they are not necessarily the best for all situations. The 70-200mm f/2.8 produces gorgeous looking images with outstanding subject isolation, but the shrinkage in magnification at closer/middle range subject distances adds an extra degree of complication to its usage.

 The ostensibly lesser two lenses are also excellent performers for their intended shooting roles. Yes, it is worth saving for the f/2.8 lens, but if outright lens speed isn't an absolute must, the cheaper lenses have their benefits as well.




With thanks to Broadway Camera:




5 comments:

  1. I have a Nikkor 70-300 AF-S G ED VR 4.5-5.6 that I purchase quite a few years ago. All reviews I have seen on it are not good in comparison to the above lens, can you explain why that is? The quality of photos seems acceptable, it's just a 'cover all bases type lens' or 'Jack of all trades master of none.." :) It seems to work well enough for limited use. Thank you for some interesting and informative articles. I was put onto your site recently by Broadway Camera.

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    Replies
    1. I think it's an underrated lens; for its price it does what it does very well. It's overshadowed by the 70-200 f/4 and f/2.8 lenses, but those are different tools. The variable aperture is a downside to the 70-300; usually, if you are shooting at something far away the chances are that it is also moving quickly (sports, animals, etc.) If that is the case, a fast maximum aperture helps with capturing action, but the price goes up significantly. The key to the 70-300 is to keep it under 200mm for the best results; there is a decline in quality when used all the way at 300mm, but not so much so that you can't claw back some of the contrast in post processing.

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  2. Hi, I like the comparison, the simplicity of the language used the posted images very well. I had made up my mind for the 2.8-vr2, but seems that I am leaning towards f/4.
    However, I could not understand when talking about 2.8 VR2 you say, "but also that the shutter speed can be double of what the F/4 would offer in similar shooting conditions". Can you please elaborate on this one.
    Thanks

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    Replies
    1. an aperture size of f/2.8 theoretically lets in twice as much light as an aperture size of f/4. when you can gather twice as much light, you then can shoot with half as long a shutter speed (ie. twice as fast) to get an equivalent exposure. The 70-200 2.8 would actually allow a little more than twice as fast a shutter speed as the 70-200 f/4 has about a 25% slower t-stop rating.

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    2. an aperture size of f/2.8 theoretically lets in twice as much light as an aperture size of f/4. when you can gather twice as much light, you then can shoot with half as long a shutter speed (ie. twice as fast) to get an equivalent exposure. The 70-200 2.8 would actually allow a little more than twice as fast a shutter speed as the 70-200 f/4 has about a 25% slower t-stop rating.

      Delete