Tuesday, 20 September 2011

Lens buyer's guide

So, you have a Micro Four Thirds camera? Now, what lenses should you buy?

Before trying to answer this question, let's take a step back and ask: Why would you need more lenses?

Compact cameras and interchangeable lens cameras

A user coming from the compact camera world may be confused by the apparent need for more lenses. Even fairly inexpensive compact cameras comprise a feature packed lens: A zoom range of 12x or more, starting at a very wide angle, macro functionality, and even pretty decent maximum aperture (a low f-value). All this in a small package.

When "upgrading" to a Micro Four Thirds camera with the kit lens, they may easily be disappointed. They now have a larger, more expensive camera, which only features a 3x zoom lens, starting at 28mm equivalent wide angle, and no macro functionality. How is this an upgrade at all?

The answer to this lies in the size of the imaging sensor. Compact cameras generally have a very small sensor, which allows the manufacturer to design very small lenses that have all the functionality most people would want. With a larger sensor, it is physically impossible to design a lens which does the same, at least within reasonable economical constraints.

So why don't all cameras have small sensors, so that the built-in lens can solve all the photographic needs of the user?

It turns out that a camera with a larger sensor has other advantages. The main four advantages for a larger sensor camera, as I see them, are:

1. Ergonomics. A larger sensor camera needs to be larger, and hence the camera itself has more space for buttons, wheels and levers. This gives the user a better grip to hold, and easier access to functions through the user interface. Compact cameras only have room for a small handful of buttons, and require the user to use menus to access the camera functions.

2. Sensitivity. With a larger sensor, each photosite has a larger physical area, meaning that you can theoretically get a better image quality with in a low light situation (high ISO). This can also give a better dynamic range, and overall better image quality.

3. Selective focus and bokeh. With a small lens camera, the depth of focus is very wide, meaning that a lot of the image will be in focus. While this is good for a lot of applications, larger sensor cameras allow for selective focus, making the background of the image go out of focus.

4. Diffraction. A physical concept called diffraction dictates that there is a limit to how high the pixel density on the sensor can be. Hence, to get more megapixels, the sensor needs to be physically larger.

Here I have compared the image quality of the GH2 with the basic kit lens with a small sensor compact camera. The GH2 has significantly better image quality, due to the larger sensor size.

However, the disadvantage with a large sensor camera is that not one single lens will cover all the photographic needs. Hence, the camera is often designed to have interchangeable lenses, so you can change lens depending on what kind of image you intend to take.

Micro Four Thirds Lenses

The main players in the Micro Four Thirds camera system are Olympus and Panasonic. Since all cameras and lenses are from the same system, they can be combined. So you can put an Olympus lens on a Panasonic camera, and vice versa. In some cases, however, it makes sense to match the manufacturer when buying lenses. I will comment this later in the article.

In this article, I have split the content into a number of lens categories. Before going into the details, here is a brief description of each category:

Pancake Lenses: This is not a common lens category. For example, for the Nikon lens system, existing for more than fifty years, there is only one single lens which is generally regarded as a pancake lens. Pentax has a handful of pancake lenses. But for the Micro Four Thirds lens system, size is important, which may be why pancake lenses are more common here.

Low Light Lenses: For use in low light environment, for example when you want to photography people indoor without using a flash, for concert photography, and so on.

Kit Zoom Lenses: When you buy a camera, you often have the option to buy a basic zoom lens in a kit together with the camera. This lens is generally small, light, cheap, and often has a zoom range of around 3x. It is not too common to buy this type of lens standalone.

Tele Lenses: Long focal length tele lenses are used to photograph things that are far away.

Wide Angle Lenses: Covering a very wide field of view, these lenses allow you to pack a lot of features into one single image. However, the wide perspective can give unexpected perspective distortions.

Superzoom Lenses: These lenses are designed for covering a wide range of focal lengths, from wide angle to tele. Hence, having one of these lenses on your camera should remove the need to change lens often. The zoom range of these lenses is usually 10x or more.

Pro zoom lenses: High end zoom lenses, usually with a large, constant maximum aperture, quick autofocus, and commonly with weather protection. There are two so far from Panasonic: The Lumix X 12-35mm f/2.8 and the Lumix X 35-100mm f/2.8. Also, Olympus has launched the 12-40mm f/2.8 pro standard zoom lens, and a 40-150mm f/2.8 high end tele zoom lens is expected to be available in 2014.

Portrait Lenses: For taking portrait pictures, meaning a headshot, or a head-and-shoulders picture, usually at about 1-2 meters distance.

Specialty Lenses: Other lenses that don't belong in other categories.

Here are my opinions about the lenses in these categories:

Pancake Lenses

The lenses in this category are prime lenses, meaning that they are not zooms. They have a constant focal length, and hence, a constant field of view.

There are three choices: Panasonic Lumix G 14mm f/2.5, Olympus M.Zuiko 17mm f/2.8, and Panasonic Lumix G 20mm f/1.7 (from left to right below, not to scale).



These lenses are somewhat different. The Lumix 14mm lens is the widest, obviously, and also the smallest and lightest.

The Lumix 20mm lens is the fastest, it has the largest maximum aperture. This makes it the most useful for low light photography. Also, with the longest focal length, it is more useful for photographing a person, but not so good for a group of persons. On the other hand, it has a fairly slow and noisy autofocus.

In the summer 2013, this lens was discontinued, and a new version of the lens, Lumix G 20mm f/1.7 II (H-HS020A) was released. The new version has the same basic specifications, and appears to have the same optical design. The exterior design is new, though, with a black or silver metal finish.

As the new lens has the same optical design, it still has the old style focus assembly which moves all the lenses back and forth. Panasonic may have improved the focus mechanism, so that it operates quicker and less audibly, but as long as it does not feature internal focusing, it just cannot be as quick as the other Panasonic Micro Four Thirds lenses. Internal focusing would have required a totally new optical design.

The new designs of the Panasonic Lumix G 20mm f/1.7 II:


Here is my article which compares the 14mm and 20mm lenses from Panasonic.

The Olympus 17mm lens doesn't stand out too much. It is not the smallest, nor the widest or fastest of the pancakes. On the other hand, it is the cheapest. The field of view lies between the two Panasonic pancake lenses.

Do you need to match the manufacturer when buying the pancake lenses? Not really. If you put a Panasonic lens on an Olympus camera, you don't get automatic software correction of some chromatic aberration artifacts. But the lenses don't exhibit too much of these artifacts anyway, so this is no big problem.

So what lens should you buy? If autofocus (AF) during video is important, don't choose the Lumix G 20mm f/1.7 lens. It has too slow AF, and can easily lose the focus for several seconds during video recording, especially in low light.

If low light performance is important, of course you should choose the one with the largest maximum aperture, which is the Panasonic Lumix G 20mm f/1.7.

None of these lenses can be considered a portrait lens: They are too short for that. However, they can all be used for environmental portraits, in which you include more of the person than just the head and shoulders. For pictures of a group of people, one would normally choose the widest, the Panasonic Lumix G 14mm f/2.5.

All these lenses are considered to be good optically, however, people often say that the Olympus 17mm f/2.8 is slightly inferior to the Panasonic Lumix pancake lenses.




Low Light Lenses

A low light lens is a lens designed for being used in situation where the available light is low, and you don't want to use a flash. This could be indoor, at a concert, outdoor at night, and so on.

The lenses in this category have a large maximum aperture, and hence, a low f-number. The Panasonic Lumix G 20mm f/1.7 from the pancake category is also a low light lens. With an aperture of f/1.7, it is among the fastest Micro Four Thirds lenses available.

At the moment, the ultimate low light lens is the Panasonic Leica DG Summilux 25mm f/1.4. Corresponding to a classic normal lens for a film based SLR system, 50mm f/1.4, this lens is good for photographing in low light environments, and when you want a high degree of selective focus and bokeh. Sporting a Leica logo, it is a rather expensive lens:



25mm is perhaps not the optimal focal length for a low light lens. It is too short for a portrait lens, and too long for photographing a group of people indoor. But, it remains a classic focal length for bright lenses, and I am sure many people like this lens a lot.

From Olympus, there is the Olympus M.Zuiko Digital 17mm f/1.8. It has the premium metal finish, just like the Olympus M.Zuiko Digital 12mm f/2 and the Olympus M.Zuiko Digital 75mm f/1.8, and is a somewhat expensive lens. It corresponds to the classic wide angle field of view, at 34mm equivalent. At this field of view, the maximum aperture of f/1.8 is quite impressive for a relatively compact size of the lens:



Olympus have made their interpretation of the classic normal lens, the Olympus 25mm f/1.8:



It is available in silver or black finish, and does not have the same high end finish as the Olympus M.Zuiko Digital 17mm f/1.8 or Olympus M.Zuiko Digital 75mm f/1.8. Still, the lens performs well, and is popular, despite a somewhat steep price.

There is also another low light lens available at a rather reasonable cost: The Olympus M.Zuiko Digital 45mm f/1.8. (See the Portrait Lens section below for more discussion.) On a Panasonic body, you will have no image stabilization, which may be a problem with this fairly long focal length. You cannot expect to video record stably without some support.




Kit Zoom Lenses

Kit zoom lenses are usually bought together with the camera. So to include them in this guide might seem a bit superfluous. However, for the sake of completeness, here are my opinions on them.

In this category, it is wise to pair lens and camera according to the brand. This is because Panasonic and Olympus have chosen different philosophies when it comes to Image Stabilization.

Panasonic

Four lenses are available with the Panasonic brand: Lumix G 14-45mm f/3.5-5.6, Lumix G 14-42mm f/3.5-5.6, Lumix X PZ 14-42mm f/3.5-5.6, and Lumix G 14-42mm f/3.5-5.6 II all with OIS built in. Shown below, from left to right:





The lenses above are also sorted according to date of launch: the 14-45mm lens was the very first kit zoom lens, sold with the Panasonic Lumix G1 camera. It was later replaced with the newer kit zoom, the 14-42mm. In 2011, the pancake kit zoom with powerzoom, Lumix X PZ 14-42mm was launched.

The third kit lens announced, the Lumix X PZ 14-42mm f/3.5-5.6, is completely different. It is made to achieve two extra goals: To be very compact, and to feature a power zoom. It extends using an internal motor before being usable upon powerup. Zooming can only be done with the zoom lever on the lens side, which engages a dedicated internal zoom motor.

Motorized zoom is largely a nuisance when photographing. You have much better control using a zoom ring. However, if you intend to zoom during video recording, a power zoom is needed. It is virtually impossible to zoom smoothly using your hand. Many would say that zooming during video should be avoided, as it seldom looks good anyway. But with a motor zoom, you have a much better chance of pulling it off.

It doesn't even have a focus ring. To focus, you must use a focus lever on the side. This, combined with the lack of a zoom ring, makes the lens somewhat awkward for still image photography. So if you're only interested in still images, this lens is not ideal for you. Unless, of course, you also value compactness.

Personally, I have found the Lumix X PZ 14-42mm f/3.5-5.6 compact zoom lens to have an image quality not up to the standards of the cheaper Lumix G 14-42mm f/3.5-5.6. However, I still use it, due to its compactness.

Finally, the Lumix G 14-42mm f/3.5-5.6 II was launched in 2013, for use as a kit lens with the Panasonic GF6 and Panasonic G6 cameras. It is more compact than the first version of the lens, although not as compact as Lumix X PZ 14-42mm f/3.5-5.6 compact zoom lens. So far, reports indicate that the Lumix G 14-42mm f/3.5-5.6 II is a good lens, with good sharpness, and a good quality construction, including a steel mount.

Lumix LensG 14-45mmG 14-42mmX PZ 14-42mmG 14-42 II
Year released2008201020112013
Diameter60mm61mm61mm56mm
Length60mm64mm27mm49mm
Weight195g165g95g110g
Filter thread52mm52mm37mm46mm
Front lens diameter*45mm30mm21mm25mm

So what lens should you choose? The first kit zoom, the 14-45mm, is probably the better than the second, the first 14-42mm version. The first version of the 14-42mm lens was made mostly to cut costs, and features a 25% smaller front lens element. It is also lighter, partially due to the plastic lens mount. The second version of the 14-42mm kit zoom lens is probably better than the first version.

Personally, I think you shouldn't spend the extra effort to get the now discontinued, older, 14-45mm lens. While it is probably better than the second, the 14-42mm is perfectly fine, in my opinion. You should rather spend the effort to take pictures, and save the money for future lens purchases. If you value compactness, get the Lumix X PZ 14-42mm f/3.5-5.6 compact zoom lens. Otherwise, get the newest 14-42mm zoom lens.

Olympus

Olympus also offers three kit lenses: Olympus M.Zuiko Digital ED 14-42mm f/3.5-5.6, Olympus M.Zuiko Digital ED 14-42mm f/3.5-5.6 II, and Olympus M.Zuiko Digital ED 14-42mm F3.5-5.6 II R (left to right below):



With the Olympus kit lens, the choice is simple: Get the newest one. The II-version is better optically than the original kit lens. And the II R-version is largely the same lens, but focuses better, especially during video.

Tele Lenses

Tele lenses are designed to photograph items that are further away. The zoom range generally starts at the portrait lens focal length, corresponding to around 40-45mm for the Four Thirds format. Since they usually feature an aperture of f/4 at this focal length, better than the kit zooms, they can be used as portrait lenses if you mind the background a bit.

Other uses for tele lenses are spectator sports, wildlife, and other situations where you cannot get closer to what you are photographing.

With the narrow field of view of tele lenses, image stabilization is important, and it makes sense to match the manufacturer of the camera and lens.

Panasonic

The Lumix G 45-200mm f/4-5.6 is the most reasonably priced tele lens for Panasonic cameras, and in my opinion, it gives a good value for money. It features quick and silent AF, and good sharpness. In the longer end, around 150-200mm, the sharpness is not as good, but still usable.



In 2012, a new, more compact tele zoom lens was announced. It is the Lumix G 45-150mm f/4-5.6. It is 27% shorter than the 45-200mm lens, and carries an inexpensive price tag:



For Panasonic camera users who want a tele lens, I would recommend the Lumix G 45-200mm f/4-5.6 lens, or the Lumix G 45-150mm f/4-5.6, depending on how you value the compactness.

The only exception is if you know that you need a very long lens, in which case it may make more sense to buy the bigger brother, the Lumix G 100-300mm f/4-5.6:



While the smaller lens starts at the typical portrait lens focal length, 45mm, the larger starts at 100mm. 100mm is already a very long lens for the Four Thirds format. So as the 45-200mm lens can be used as a "walk around lens", the 100-300mm lens remains a specialized long tele lens at all zoom configurations, with a more limited area of use.

Just like in the kit zoom category, Panasonic has a power zoom lens, the Lumix X PZ 45-175mm f/4-5.6:



It is more compact and lighter than the Lumix G 45-200mm tele zoom lens. Also, it does not extend when zooming, meaning that it is a more solid construction. There is no wobbling front segment. It's main feature is the power zoom, which works very well. It can be operated by a lever, or by a "zoom by wire" electronically coupled zoom ring.

In my test, it has better optical properties than the older Lumix G 45-200mm lens.






Olympus

Olympus have got two tele lenses, with one covering longer focal lengths. Again, get the shorter lens, the Olympus M.Zuiko Digital ED 40-150mm f/4-5.6 for most tele needs. There is also a newer version with better autofocus performance, the Olympus M.Zuiko Digital ED 40-150mm f/4-5.6 R. As the optical formula is similar, get the newest version (right, below), if you have the possibility:



The longer lens, the Olympus M.Zuiko Digital ED 75-300mm f/4.8-6.7, is built to be compact, and for that reason features a smaller maximum aperture than the similar lens from Panasonic. This makes it somewhat less suitable for applications where you need to capture movement with a fast shutter speed, e.g., sports, or where the light is limited.



This is a lens for those who value compactness of their system, and are willing to pay for it. In 2013, a new version of this lens was launched. It has a new design, and the zoom ring is a bit stiffer. Optically, it is the same, but comes at a lower price!




Wide Angle Lenses

To capture a wide cityscape, or a group of people at a short distance, you need a wide lens. There are some quite wide lenses available for the system. As image stabilization is not as needed for short focal lengths, I'd say you can put these lenses on both Panasonic and Olympus bodies. Don't worry about the lack of image stabilization on Panasonic bodies, is my opinion.

The (relatively) low cost alternative at the moment is the Olympus M.Zuiko Digital 9-18mm f/4-5.6:



It has a reasonably small size, low weight, and performs well. The focal length range is useful: Going from a pretty extreme wide angle to a "normal" field of view in the long end.

For the person who wants even more extreme wide angle performance, the Panasonic Lumix G 7-14mm f/4 is the right choice. It will set you back more in terms of cost, but offers a staggering wide angle view in the short end. It performs very well optically, and is built to a high quality.



The Olympus M.Zuiko Digital 12mm f/2 is a prime wide angle lens. At 12mm, it is not extremely wide, but should be wide enough for many applications. It has a construction involving a lot of nicely polished metal, and is quite unusual for having a focus scale, and a depth of field scale:



It is a pricey lens, and you probably pay some premium for the retro metal construction.





Superzoom Lenses

Superzoom lenses mimic the "compact camera feeling", in that they enable a very large zoom range. Starting at 28mm film equivalent wide angle, and with a zoom ratio of 10x or more, they cover the focal length people tend to use most. The downside is that the lenses are large, expensive, and don't have very impressive maximum aperture.

As image stabilization is important in the longer focal length range of these lenses, it is recommended that you buy the Panasonic lens for use on a Panasonic camera, and the Olympus lens for an Olympus camera.

From Panasonic, a new lens was launched in April 2013. The Lumix G HD 14-140mm f/3.5-5.6 improves upon the the predecessor by having a smaller size (58mm front lens thread rather than 67mm for the older lens), comes with a better aperture range (f/3.5-5.6, rather than f/4-5.8), and even comes at a lower list price.



I would recommend getting the newer lens. I have tested it, and found that it improves on the predecessor in almost any conceivable way.

Should you buy a superzoom lens, rather than the Lumix G 14-42mm f/3.5-5.6 and the Lumix G 45-200mm f/4-5.6, which when combined cover a larger focal length range at a smaller price? That depends. Combining two lenses may mean that you miss the occasional shot: Changing between the lenses takes some time, while just rotating the zoom ring of the superzoom lens is very quick.

In my experience, the new Panasonic 14-140mm superzoom lens is as good as the separate lenses through most of the zoom range, and hence, for versatility it is often better to get the superzoom lens.

The Olympus M.Zuiko Digital ED 14-150mm f/4-5.6 features a slightly longer zoom range. However, that is just barely significant. What is more significant, is the relatively smaller size and weight. The Olympus superzoom lens is much more portable:



According to what I have read, the Olympus superzoom lens has adequate image quality.

We are also waiting for a competing lens from Tamron, the Tamron 14-150mm F/3.5-5.8 VC. Featuring Optical Image Stabilization (O.I.S.), I'm guessing this lens is intended as an alternative to the Lumix G HD 14-140mm, and hence, we can expect it to sell at a somewhat lower price when it becomes available. However, almost a year after being announced, it has still not materialized. So this lens is so far vaporware.





Pro zoom lenses

Again, one would normally match brands when buying these pro zoom lenses. From Panasonic, we have two lenses: The Lumix X 12-35mm f/2.8 and the Lumix X 35-100mm f/2.8. The first is a standard zoom lens, while the latter is a tele zoom lens.

Both of these lenses are generally considered very good, and relatively compact compared with similar lenses for other systems. The are rather expensive, though. In my bokeh test, I saw that the Lumix X 12-35mm lens has quite nice bokeh, while the Lumix X 35-100mm lens has non-round out of focus highlights off the image centre, quite normal for Panasonic lenses. This is probably no issue in low contrast situations, e.g., daylight, but can be distracting for night photos.

From Olympus, similar lenses were announced in 2013. The Olympus 12-40mm f/2.8 pro standard zoom has a slightly longer zoom range than the corresponding lens from Panasonic, making it more useful for, e.g., portraits.

This lens is still quite new, but reviewers generally say that the image quality is very good. You could very well use it on Panasonic cameras, but be aware that since it does not feature OIS, you will get no image stabilization available for video recording, for example.

Olympus also have a longer pro zoom lens in the pipeline, with the impressive specifications 40-150mm f/2.8. This will be a large, heavy, and very expensive lens. It will probably perform very well. It is expeced to be available in 2014.





Portrait Lenses

According to the traditional understanding of the word, a portrait lens is a lens with a focal length of around 42-52mm (on a Four Thirds size sensor), with a fast maximum aperture. At the moment, there is only one single lens in the Micro Four Thirds lineup which satisfies this, the Olympus M.Zuiko Digital 45mm f/1.8:



This lens is priced at a fairly reasonable level, which makes it a must have for Micro Four Thirds users who are serious about portrait photography.

With no Optical Image Stabilization built in, it is not too good for handheld video recording, neither with an Olympus camera, nor with a Panasonic camera.

Some would say that a portrait lens must have a very fast aperture, preferably f/1.4 or better. They might be dissatisfied with the f/1.8 maximum aperture of the 45mm Olympus lens. I would personally say that f/1.8 is large enough to get a sufficiently thin depth of focus (DOF) for portrait photography.

Olympus also has a higher end portrait lens, the Olympus M.ZD ED 75mm f/1.8:



This is an expensive, well built tele lens with a large maximum aperture. It is generally considered to be one of the best Micro Four Thirds lenses.




The Panasonic Leica 45mm f/2.8 1:1 macro lens could also be used as a portrait lens, in my opinion, even if the maximum aperture is much smaller than the traditional definition of a portrait lens dictates. As long as you make sure the background is not too distracting, you should be fine using this lens as a portrait lens, in my opinion. (See the Specialty Lenses category below.)

For a low cost alternative, you could also consider using the Lumix G 45-200mm f/4-5.6 tele zoom lens in the shorter end as a portrait lens. Or use the Olympus M.Zuiko 40-150mm f/4-5.6 if you have an Olympus camera body. With a maximum aperture of f/4 in the short end, you cannot blur the background as much as you might prefer. But with some planning of the composition, I don't see why you shouldn't be able to pull it off.

Yet another low cost option is to get the Sigma 30mm f/2.8. It is a tad bit short for a portrait lens, but I think it is a good alternative on a low budget.

Sigma lenses

Sigma joined the Micro Four Thirds lineup with two prime lenses in 2012: The Sigma 19mm f/2.8 EX DN and the Sigma 30mm f/2.8 EX DN:



Sigma 19mm f/2.8 and 30mm f/2.8 (not to scale)

These lenses were designed by Sigma to be used on several mirrorless formats, including the Sony NEX series, Sony E-mount. The NEX cameras use an APS-C sized sensor, slightly larger than the Four Thirds sensor, with an 1.6x crop factor.

On this crop factor, the 19mm lens corresponds to a traditional wide angle lens, while on Micro Four Thirds it is not as interesting. It is very close to the Lumix G 20mm f/1.7. As the Lumix G 20mm lens is more compact, and brighter, I don't see the need for the Sigma 19mm lens. On the other hand, the Sigma 19mm lens focuses much quicker and more silently, and is cheaper. If this is important to you, it may be an interesting lens. See my review here, which compares the focus speed and image quality with the Lumix G 20mm f/1.7 lens.

The Sigma 30mm f/2.8 EX DN lens, on the other hand, is more interesting in my opinion. As I see it, it has quite good image quality, and can be used as a portrait lens. If you want good image quality on a budget, this might be a lens to consider.

These lenses are in fact already discontinued. Replacing them in 2013 are new versions, called Sigma 19mm f/2.8 DN and Sigma 30mm f/2.8 DN. They are part of Sigma's "Art" line of lenses. They have the same optical designs, but a different exterior, available in black or silver metal finish. The focus ring is now made out of smooth metal:



Sigma 19mm f/2.8 DN (2013 version, "Art lens")

From an ergonomic point of view, this is a strange choice. It looks like a smooth metal focus ring will be less convenient to use. In practice, the ring rotates quite easily, so this is no real issue, though. It looks like the remake is all about a new styling, while retaining the original optical properties.

In 2013, Sigma also released their third lens for the Micro Four Thirds system, the Sigma 60mm f/2.8 DN. It corresponds to a 120mm tele prime lens in 35mm equivalent terms, and also gets the new metal finish. Based on reviews, people tend to think that it is a good lens, being sharp and having a nice bokeh.





Specialty Lenses

If you are interested in macro photography there are two lenses available at the moment, the Panasonic Leica 45mm f/2.8 1:1 macro lens and the Olympus 60mm f/2.8 1:1 macro lens. With a macro reproduction rate of 1:1, you can photograph items down to a size of 17mm x 13mm:



In my opinion, they can also double as portrait lenses, even though the aperture could have been larger for this application.

The Panasonic 45mm lens focuses somewhat slowly, and for that reason is not ideal for video recording with AF. The optical image stabilization is not so useful for macro applications. It is a pricey lens, but the optical performance is good.

The Olympus lens has the same reproduction rate, so you can use either to photograph equally small objects. The Olympus lens has a somewhat longer working distance, though, the distance from the front lens element to the item you are photographing. This can be useful if you intend to photograph bugs which become shy when you get too close.

Without Optical Image Stabilization (O.I.S.), the Olympus macro lens is not so well suited for general photography on a Panasonic camera. If you use it on a tripod, though, as one would often do with macro photography, this is of course a non-issue.



The lenses with the very widest field of view are the Lumix G 8mm f/3.5 Fisheye lens and the Samyang/Rokinon 7.5mm f/3.5 Fisheye lens.

The Lumix G 8mm focuses very quickly, and has a very short minimum focus distance, which can be used for some interesting effects.



With the fisheye projection, it has a somewhat limited usefulness, and could be viewed as a novelty lens by some. Here is a discussion about how to use a fisheye lens.



Due to its lower cost and good optics, the Samyang/Rokinon 7.5mm f/3.5 fisheye lens can be a good alternative to the Lumix G 8mm f/3.5 fisheye lens.

From Olympus, there is also a cheap and simple 9mm f/8 fisheye body cap lens:



I would not recommend buying this lens. It is rather crudely constructed, and lacks any aperture mechanism at all. Further, it is not a true fisheye lens in the sense that the diagonal covers 180 degrees field of view. The diagonal field of view is only 140 degrees.

Buy Olympus 9mm f/8 fisheye body cap lens only if you want a cheap and compact lens for the occasional fisheye shot. Otherwise, get the Samyang/Rokinon 7.5mm f/3.5 Fisheye lens, which is somewhat more expensive, but a lot more useful.




Panasonic has launched a 3D lens. It features two fixed focus, fixed aperture lenses at 12.5mm f/12:



But don't think that this is a wide angle lens, with the 12.5mm focal length. As the lenses project much smaller image circles, there is an additional crop factor of 2.4, giving a 60mm field of view, relative to a 135 film camera standard. Since the two images projected are small, the resolution of the images are limited.

This lens only works on fairly recent Panasonic camera bodies. And, contrary to what most people would expect, it cannot be used to record 3D videos.

The 3D stereo base is small, only about 10mm. So the 3D effect is only significant for fairly close macro images. Photographing objects that are further away yields a limited stereo effect. So the usefulness of this lens is not very high. Read my review here.

Conclusion

The Micro Four Thirds lens lineup has become quite good. People with a camera and a basic kit lens most likely want to achieve something new with their lens purchase. Here are some common needs, as I see it:

For a more compact lens, look at the pancake lenses. The Panasonic Lumix G 20mm f/1.7 combines a small size with a good low light performance, and for that reason has become an instant classic. The Panasonic Lumix G 14mm f/2.5 has a very impressive small size, and is good for wide angle and fast AF.

For extending the tele effect of the kit zoom, complement it with the Lumix G 45-200mm f/4-5.6 (for Panasonic cameras), or the Olympus M.Zuiko Digital 40-150mm f/4-5.6 (on an Olympus camera, get the newer R-version if possible.) You could also consider the newer powerzoom Panasonic Lumix X PZ 45-175mm f/4-5.6, especially if you are into video, or if compactness and lightness is important for you. For birding or safari use, the Lumix G 100-300mm f/4-5.6 is pretty much the only choice at the moment.

For a one lens does it all superzoom, get the Panasonic Lumix G HD 14-140mm f/3.5-5.6 for use on a Panasonic camera, or the Olympus M.Zuiko 14-150mm f/4-5.6 for use on an Olympus camera.

In the wide angle category, the Olympus M.Zuiko Digital 9-18mm f/4-5.6 gives a good value for money.

If you are interested in portraits, the Olympus M.Zuiko Digital 45mm f/1.8 appears to be a good choice, for a reasonable price.

If you want the luxury feel, and let me say that there is nothing wrong with that, consider the Olympus M.Zuiko Digital 12mm f/2 very wide angle lens, the Olympus M.Zuiko Digital 17mm f/1.8 wide lens, or the Olympus M.Zuiko Digital 75mm f/1.8, all with a retro metal construction. Also look at the Panasonic Leica 45mm f/2.8 1:1 macro lens, or the Panasonic Leica 25mm f/1.4. The metal construction of the Olympus lenses, and the premium Leica branding of the Panasonic lenses contribute to a higher price level, but you surely get a good lens in return.

(The images in this article have been picked from four-thirds.org.)

Thursday, 8 September 2011

Noise comparison, aperture change

I have previously compared the focus noise of various lenses. The conclusions from my analysis were hardly surprising, for example, the Lumix G 20mm f/1.7 pancake lens had a rather loud focus noise, due to the traditional focus assembly which moves all the lens groups back and forth.

The lenses with an internal focus mechanism generally featured lower noise, with the Panasonic Leica Lumix DG Macro-Elmarit 45mm f/2.8 1:1 Macro and Lumix G HD 14-140mm f/4-5.8 as exceptions. In the latter case, I believe the microphone was too close to the lens, giving biased results.

You could ask why worry about the aperture change noise. After all, the aperture is generally stopped down just before the shutter is released. And for all Micro Four Thirds cameras, the shutter noise is rather high. So the aperture noise is simply drowned by the shutter noise anyway.

However, there are times when you don't trigger the shutter. This could be when using the new high speed, low resolution mode of the Panasonic GH2. Or, quite simply, when recording videos.

Also, some time in the future, we are going to get cameras without mechanical shutters. When the global shutter technology is mature enough, we will see this in Micro Four Thirds cameras. Then, the only noise we will hear is the focus noise and aperture noise.

To measure the aperture change noise, I placed a mobile phone near the camera, running the "Decibel Ultra" app, to measure the noise level. While I don't trust the absolute measurement of the phone, I think it is good enough to look at the relative levels of noise.

The GH2, and many other Micro Four Thirds cameras, has the feature of stopping down the aperture to preview the depth of focus (DOF). This is very useful, especially for macro photography. I use this feature to toggle the aperture between maximum and f/7.1.

The test



Results

I have only noted down the peak decibel measurements. The results:

LensMeasurementsAverage

Lumix G 8mm fisheye
77 76 7777 dB
Lumix G 14mm79 7778 dB
Lumix G 20mm76 75 73 7675 dB
Leica Lumix DG 45mm macro80 82 81 8382 dB
Lumix G 45-20083 80 81 84 8382 dB
Lumix G 14-4275 76 75 7575 dB
Lumix G HD 14-14078 78 8179 dB

Conclusions

According to the marketing material, the HD designation of the Lumix G HD 14-140mm f/4-5.8 superzoom lens means that it should have fast autofocus, low noise autofocus, and near stepless low noise aperture.

After my analysis of the AF speed, the AF noise and now, the aperture noise, I cannot see that the lens is that special. It performs pretty much like the basic kit lens. What I haven't looked at, though is the aperture change, which is quoted as "near stepless". Accurate to 1/6 stop, is what I have seen quoted.

That said, the Lumix G HD 14-140mm f/4-5.8 zoom lens does have a softer sound when changing aperture.

In terms of aperture noise, the lenses appear to perform quite similar. And this is not strange: The aperture diaphragm mechanisms are probably rather similar between the lenses.