Best DSLR lenses: how to buy camera lenses
Hopefully I convinced you to buy a DSLR camera in the article on choosing a digital camera to buy, and helped to choose the right one for your purposes. But don’t rush to a shop just yet!.. There is another very important decision to make. In fact, a more important one than the camera body itself! You need to choose your first DSLR lenses. This article gives some advices to help you with this difficult choice.
Nikon AF 85mm F1.8, Nikon AF-D 50mm F1.8,
and Nikon AF-S 18-200mm F3.5-5.6 G DX VR
Why are DSLR lenses so important?
Given that all DSLR sensors are sufficiently good (and quite similar, unless you step from a cropped to full-frame), the optics have more impact on the image quality than the camera itself. The lens defines what the sensor sees: how much light reaches the sensor, how nice the colors are, how sharp the image is, etc. The lens quality defines if there is an optical distortion, chromatic aberration, vignetting, and other artifacts, and how strong they are.
In addition, a lens is a much longer-term investment than a camera body. The earliest Nikon lenses manufactured somewhere in the middle of the 20th century still work fine on new DSLRs (except some problems with the cheapest entry-level cameras). Newer lenses have, of course, some advantages over the old ones: for example, the presence of auto focus, its speed, vibration reduction, etc. Nevertheless, the image quality does not improve that much, because optics do not evolve with the speed of computer technologies. A DSLR camera body, however, becomes outdated in several years, due to the constant technology evolution. Thus, it makes more sense to invest into better lenses from the beginning, as chances are you will use them for the rest of your life!
Finally, lenses can be significantly more expensive than camera bodies. This might not be obvious now, when you look at cheap kit lenses, but if you ever decide to go for a top quality professional telephoto lens...
DSLR lens characteristics
Camera lenses are mainly characterized by their focal length and the maximum aperture. Without going into details, the focal length defines the angle of view of the lens, and the aperture defines how much light passes through the lens.
The focal length is measured in millimeters. The higher the number is, the smaller the angle of view is, and the stronger the magnification of the visible objects is. And vice versa, the lower the focal length is, the wider the lens’ angle of view is. For example, a 18mm lens is a wide-angle one, you would choose it when shooting architecture which is close to you. 600mm is a strong telephoto lens, you would like it to shoot an animal running several hundred meters away from you. As can be expected, it is easier to manufacture middle-range lenses than very wide or very long-focus ones, and this defines the lens price. It is also much easier to manufacture good-quality fixed focal length lenses than zoom lenses (with variable focal length, which you change to zoom in or out). This is the reason why fixed lenses provide the best image quality for low prices.
Nikon AF 85mm F1.8: my favorite lens.
The aperture is a number which is actually the focal length divided by the entrance pupil (the diameter of the lens opening). The higher the number is, the smaller the opening is, and the smaller amount of light passes through the lens. For example, you want to use F1.8 in low light conditions (there is not enough light, so you want to pass as much as possible to the sensor), and F16 when there is too much light (to limit the amount of light reaching the sensor - otherwise you will get a white rectangle). Again, it is difficult to manufacture high quality lens with extreme aperture characteristics. It is especially difficult to create wide-open telephoto lens. Many lenses achieve F4, for example, but only a few go to F1.8 and even fewer - to F1.4.
DSLR lenses classification
Let’s try to classify DSLR lenses:
- Cheap low-quality zooms (kit lenses)
- Professional zoom lenses
- Fixed focal length lenses
- Macro lenses (special-purpose, not covered here)
- Extremely wide-angle lenses (special-purpose, not covered here)
- Extreme telephoto lenses (special-purpose, not covered here)
Cheap low-quality zoom lenses are most probably those you looked at up to now :-). They are also called kit lenses, because they are often offered together with entry-level DSLRs. Semi-professional and professional DSLRs are rarely sold together with these lenses, because those who buy these cameras are not likely to be satisfied by the kit lens quality.
Professional zoom lenses start at around 1000-1500 Euro. They are supposed to be significantly better than the kit lenses.
The best image quality is usually offered by the fixed focal length lenses (let’s call them fixed lenses). At the same time, because they are much simpler than zooms, they are often many times cheaper. My Nikon AF 50mm F1.8 fixed lens was only around 130 Euro (new)! Compared to a professional zoom lens for about 1500 Euro, it can easily be more light-sensitive and produce a better image quality! And this all comes at the price of not being able to zoom in and out, you have to run around to compose your shot... I would say, a great price! Can even save a lot of money on your fitness if you shoot often enough :-) ! For me there is no question: these are the best DSLR lenses.
How to buy camera lenses
Nikon AF-S 18-200mm F3.5-5.6 G DX VR:
a legendary universal zoom lens.
Having introduced the topic, let’s look at how to buy camera lenses, which DSLR lenses to choose first. Again, I assume that you are a photography enthusiast, who is willing to take the hobby seriously.
There are two basic approaches:
- Buy a single universal lens for all purposes.
- Buy a set of fixed lenses and choose the appropriate one every time.
As you have probably guessed already, in general, I vote for the second approach, because universal lenses are by definition not nearly so good as fixed ones. But even myself, I have a couple of universal lenses for the case when the convenience and the operation speed are more important than the image quality. I can also imagine that when buying your first camera, you do not have a budget for many lenses. Thus, I recommend the following: buy one universal lens, and one or more fixed lenses. Use fixed lenses whenever possible, and the universal one - only when there is no other choice.
The most universal Nikon DSLR lens I know is the Nikon AF-S 18-200mm F3.5-5.6 G DX VR II. 18-200mm is a huge range, this lens was a pioneer a few years ago. One lens for nearly any need (except for some very special-purpose needs), from wide angle to telephoto! A miracle! It is, however, quite pricey, I see it offered for 680 Euro. There exist significantly cheaper counterparts from Sigma and Tamron. But their quality is very poor in comparison with Nikon, according to multiple reviews I have seen. Thus, you choose between an expensive poor universal lens and cheap much worse ones :-). Probably a cheaper Nikon lens, with a smaller range, is preferable if you cannot afford the 18-200mm.
For the fixed lens, I recommend to start with a 50mm lens, which can be considered the most widely used focal length. All manufacturers offer 50mm lenses, as far as I know. For Nikon, choose between the Nikon AF-S 50mm F1.4, Nikon AF-D 50mm F1.4, and Nikon AF-D 50mm F1.8, depending on your budget (ordered by price, which drops about 3 times). See a good comparison here. The cheapest of these 50mm lenses, Nikon AF-D 50mm F1.8 (only about 130 Euro new), is about 5 times cheaper than the Nikon 18-200mm, 4 to 8 times more light-sensitive (which means you can get a good photo when 4 to 8 times less light is available!), and produces a much better image quality!
Then, probably after some time to spread the budget damage, consider also a 85mm lens. My Nikon AF 85mm F1.8, which I bought second-hand for about 150 Euro, is my absolute favorite lens! No expensive brand new lenses compare to it, except hopefully our new Nikon AF-S 50mm F1.4 which we did not compare to it yet!
Image quality discussion
Nikon AF-S 50mm F1.4 G and Nikon AF-D 50mm F1.8: great fixed lenses.
Please be warned: when speaking about the image quality here, I compare rather subtle differences. Working with microstocks (more information on the DOPhoto site), I am used to inspect every photograph completely at the 100% zoom, when every image pixel is represented by a single monitor pixel, also called "actual size". I am used to throw away any photo which is not absolutely sharp where it should be when seen at the actual size. This is very different from what most photographers shooting for themselves do.
The lens sharpness difference is usually only visible when a photo is shown at the actual size. A lens must be a way too bad to show a visible sharpness difference when an entire 10 megapixel photo is shown on a 20 inch monitor... Some lenses also have better colors, which is visible without zooming. There are also other technical characteristics distinguishing the lens quality, such as the amount of distortion, vignetting, image artifacts (e.g. chromatic aberration), etc.
Let me try to illustrate the zoom vs. fixed lens quality difference. The images below show the same scene photographed with Nikon D200. Two different lenses mentioned above, the super universal zoom Nikon AF-S 18-200mm F3.5-5.6 G DX VR and the fixed Nikon AF-S 50mm F1.4 G, are used. I did my best to make sure that all the conditions, such as the exposure and other settings, are the same. To make sure that my hands to not contribute to the sharpness, the camera is fixed on a solid tripod, and a remote shutter release is used. In addition, I use the mirror lock-up, a camera setting which raises the DSLR mirror in advance to guarantee that it does not shake the camera. The vibration reduction is switched off on the 18-200mm lens, as it is recommended when shooting with a tripod, because it can actually degrade the sharpness in this case. The 18-200mm lens is set to 50mm (well, I missed a bit and it actually is 48mm - that's why the composition is a bit different). This is far from both the minimum and the maximum (where zoom lenses perform the worst), thus I do not challenge the lens here. Also, the used aperture of F/8 is approximately in the middle of the supported range for both lenses, thus they are at their best also from this point of view. The RAW photographs produced by the camera are converted with Adobe Lightroom, without any image adjustments except for cropping. Click the previews to see the full corresponding photograph. Your browser will most probably fit it in the browser window, try to click on the image to show it at the actual size.
Nikon AF-S 18-200mm F3.5-5.6 G DX VR
photo (click to see the full image)
Nikon AF-S 50mm F1.4 G photo
(click to see the full image)
The following two images show an actual size crop from these photographs to make them easier to compare:
Nikon AF-S 18-200mm F3.5-5.6 G DX VR photo: actual size crop
Nikon AF-S 50mm F1.4 G photo: actual size crop
I see the difference very clearly. The 50mm lens produced a sharper image. It also seems to have a bit more vivid colors, and a better contrast. This, however, might not be properly judged from these photographs, because the lighting conditions were changing rapidly (the clouds moved rather quickly) while I was changing the lens. Nevertheless, my experience suggests that this is so. Moreover, if you look at the edge of the roof on the 18-200mm photo, you can notice a slight chromatic aberration (a thin yellow halo along the roof), while at the 50mm photo all the edges are nearly perfect.
Note that what you see yourself depends very much on the quality of your monitor. My brother is regularly surprised when looking at his photos on my calibrated Apple Cinema display. He often says he could not see some details on his monitor... While there exist very expensive professional monitors for graphics experts (priced at thousands of Euro), many top microstock photographers I know about use the not that expensive Apple Cinema monitors (mostly the 30 inch one) for their work.
This kind of subtle differences we usually speak about when comparing lens quality. If you only look at your photos fitted entirely on the computer screen (do not zoom in to the actual size), ignore minor color differences, and don’t mind some minor artifacts, just buy a single universal lens such as Nikon AF-S 18-200mm F3.5-5.6 G DX VR II and don’t bother with the fixed ones. You can always buy a fixed lens later, if your requirements grow. That is, if you start paying attention to these subtle image quality differences, or if you need to shoot in poor lighting conditions.
A nearly missed important point
Oh no! I nearly missed a very important point! Forget about the Nikon AF-S 18-200mm F3.5-5.6 G DX VR II and other DX lenses if you have a full-frame DSLR! DX means that the light going through the lens does not cover the whole full-frame image sensor. Your full-frame DSLR will automatically switch to the DX operation mode when you put such lens on, and only the center part of your beautiful large sensor will be used! Thus, there is simply no point in buying an expensive full-frame DSLR and using DX lenses with it.
As a universal lens replacement for full-frame, I bought second-hand Nikon AF-D 35-70mm F2.8 and Nikon AF 70-210mm F4-5.6 for a few hundred Euro. These are old professional lenses. They cover the full-frame sensor and are more light-sensitive than the Nikon 18-200mm. As to the image quality, I don't really think they are better than the Nikon 18-200mm, probably even produce a bit more artifacts. New professional lenses of this kind sell at about 1500 Euro each... I decided to avoid those, using the much cheaper and better fixed lenses instead when I need top quality.
Also note that the focal length specification you see on DSLR lenses (such as 18-200mm) is relative to a full-frame camera, even on DX lenses. Non full-frame DSLR cameras usually have a crop factor of around 1.5, which means that the sensor diagonal is 1.5 times smaller than full-frame. The sensor size affects the actual lens focal length. To get the actual focal length, multiply the specified focal length by the sensor crop factor. For example, the 18-200mm lens becomes a 27-300mm lens on a camera with the crop factor of 1.5, such as Nikon D200. This is great when you need a long telephoto lens: my 300mm lens becomes a 450mm lens on Nikon D200 for free (while a 450mm lens would be much more expensive)! On the other hand, this is a pity when you need a wide angle lens, because your 18mm becomes 27mm...
Whatever camera and lens you decide to buy, I advise to use only native lenses from your camera’s manufacturer. If you choose a Nikon camera, buy only Nikon (also called Nikkor for some reason) lenses. I have heard many stories about how bad third-party lenses are, but don’t remember anybody claiming the opposite. Myself, I don’t have any experience with third-party lenses, have only used the Nikon ones.
Unfortunately, our new Nikon 18-200mm broke down after a few years. Not sure I should have mentioned this, because I don't remember any complaints about this lens’ robustness from other people. Thus, my case is hopefully an exception. The problem was in the (auto)focus. It stopped auto-focusing after a bit more than a year. Although the guarantee period had already expired by that time, Nikon repaired our lens for free! Unfortunately, some time later it stopped focusing at long angles at all. Everything works at wide angles, but neither auto- nor manual focus work from around 50mm up to 200mm, thus the lens is quite useless :-(. Instead, we use the old professional 35-70mm F2.8 and 70-210mm F4-5.6 lenses (not DX), bought second-hand for much less than one new 18-200mm. Those old mostly metal lenses feel more robust than the latest plastic ones...
Where to find more information
I have given some general guidelines on how to choose the best DSLR lenses to buy for photography enthusiasts. When considering particular models, I highly recommend to study their reviews at kenrockwell.com and dpreview.com. I often use these resources myself.
Having made some experiments on our joint lens collection with my friend Kwok (his site), I have come to some new conclusions. Most importantly, not all fixed lenses are that good. I thought my poor performer, Nikon 28mm F2.8, was defective, but now it seems just not that good. I definitely prefer the 14-24mm zoom at 24mm, and perhaps even the 18-200mm at around 28mm, to this 28mm fixed lens! Also the 300mm F4.0 fixed lens did not show very impressive results. On the other hand, the old professional 35-70mm zoom is sometimes more comparable to fixed lenses than I expected, it positively impressed me. On Nikon D200 I even confused it with fixes a couple of times, but not on D700. Thus, I am now more careful and instead of claiming that all fixed lenses are better than zooms, claim that 50mm, 85mm, and probably also 35mm are a way better than zooms.
Another observation we made is that there is an obvious difference between the full-frame Nikon D700 and the older crop Nikon D200. On D700 I see difference in lenses that look about identical on D200. It's often about the corner performance (which should be expected when comparing a full frame with a crop camera), but not only. All the lenses we have tested look better on D700 than on D200. I didn't expect the difference would be so obvious... Thus, the body makes more image quality difference than I thought.