If you have a M4/3 camera like the Olympus OMD EM5, or Panasonic G6, and are wondering what lenses to buy for expeditions, adventure or travel, you might find this post useful. In general, I'll carry the following three lenses for expeditions and adventure. They are light, versatile, and high quality.
Wide Angle Lens
What I Use - Panasonic 7-14mm f/4.0
The lens that's mostly on my camera is the Panasonic 7-14mm f/4. It's an ultra-wide zoom lens and I probably shoot 70-80% of my photos and video with it. Wide angles are a staple for adventure photography because they allow you to get very close to the action and still capture background. They also have great depth of field, which can be useful in outdoor situations where you may want to capture as much foreground and background detail as possible.
Option 1 - Olympus 9-18mm f/4.0-5.6
Sometimes I wish I'd gotten this lens instead. It's lighter, more compact and cheaper. It doesn't go out as wide, but has a bit more reach on the long end. Personally, I prefer this focal length range of this lens over the Panasonic, but from what I've read, the Panasonic is a little sharper with a little faster aperture. I don't think you can go wrong with the Olympus 9-18mm if you should choose this.
Option 2 - Rokinon 7.5mm f/3.5 Fisheye
If your main lens is the 12-50mm or a superzoom, then you may feel that either of the above wide-angle options have too much overlap. A fisheye is a great option, but one that you have to be careful not to overuse. The Rokinon (aka Samyang, aka Bower) fisheye is a cheap option (about half the price compared to the Panasonic version) that you can throw in your bag and pull out for special shots. It's very sharp, but the downside of this lens is that the aperture needs to be set mechanically on the lens (old style) and you need to focus the lens manually (which is no big deal on a fisheye because the depth of focus is so big you can just set the focus at 1.5 or 2m and forget it).
Superzoom Lens
What I Use - Olympus 14-150mm f/4.0-5.6
The 14-150mm f/4-5.6 lens from Olympus is probably the sharpest superzoom I've used. It's probably the lens I like least, but one that is quite frequently on my camera. I would say 10-15% of my shots are made with it. Superzooms are very useful in expedition or adventure situations when your mobility is limited (like if you're on a fixed rope or belay when climbing, or on a kayak, or when you are just plain too tired to make a lens change!) or when you need big changes in focal length in rapidly changing situation (eg. you are at a crowded market place, capturing the scene with the wide end of the superzoom and, in a fleeting moment, need to zoom in to capture a face in the crowd). If you are climbing El Cap, a possible two lens combination could be to use this lens in combination with a fisheye.
Option 1 - Panasonic 14-140mm f/3.5-5.6
Panasonic's 14-140mm f/3.5-5.6 lens is new on the market. For Panasonic camera owners, its a no-brainer: Buy this version for the image stabilization which is built into the lens. Olympus owners can use either superzoom because image stabilization is built into the body of the camera. Take note that Olympus lenses zoom the opposite direction from Panasonic. For me, the zooms on Panasonic lenses are more natural, and if this lens had been out when I bought my superzoom, this would have been my pick. It's even lighter than the Olympus version, and has faster apertures across the range. It's in short supply at the time of writing, and few reviews as to how it performs.
Option 2 - Olympus 12-50mm f/3.5-6.3
This is one lens I haven't used, but by it's reputation, it should be even sharper than the two superzooms above. Technically, it's not a superzoom. The focal length range starts from a very useful 24mm (in full-frame equivalent) wide angle. That's wider than the above superzooms, which only start out at 28mm. But the long end stops at 50mm (100mm in full-frame equivalent), which would appear to be useful for portraits, but the maximum aperture at this focal length is only f/6.3, which would give the same amount of background blur on a full-frame 100mm lens at f/12.6.
Prime Lens for Sharpness, Portraits and Low Light
What I Use - Panasonic 20mm f/1.7
The 20mm f/1.7 is great because being a pancake lens, it is very small and light. Primes are very sharp and have fast apertures. I use primes whenever I can in preference to zooms. Because they are so sharp, they are great for capturing detail. Their fast apertures also help to blur away the background, making them good for isolating subjects. The 20mm f/1.7 is my default night lens, as the big aperture and focal length are useful in low light conditions. On Panasonic cameras, there is a special teleconverter ETC Mode which extends the usefulness of this lens for video. Essentially, ETC Mode multiplies the focal length by 2.7 times with no image degradation in video mode. This means that if you are shooting video with this lens on a Panasonic body like the GH3, you can have a 'wide-ish to normal' 20mm lens that converts to a 54mm f/1.7 'portrait-ish' lens! In a pinch, I'll use the digital teleconverter on my OMD EM5 to get a similar effect, although it doesn't work as well on Olympus bodies as there is some image degradation. Take note that although the autofocus speed of this lens was ok on my GH2 body, it crawls on my OMD EM5. There is a new version of this lens that is being released soon that should bring about autofocus speed improvements.
Option 1 - Olympus 45mm f/1.8
I really like this lens and use it every chance I can. It's lightning fast to focus on my OMD EM5, super sharp and has a nice out of focus, blur highlights (bokeh), making it a great portrait lens. When I can only carry two lenses due to weight considerations, I'll carry the 45mm lens together with my 7-14mm, and skip the 14-150mm. As a three lens kit, I'll occasionally carry the 45mm instead of the 20mm in my travel kit, if I'm expecting to shoot some portrait stuff. In general though, the 20mm is a more versatile focal length and makes it into my bag most of the time.
Other Prime Lens Options
In reality, there are a huge assortment of prime lens options that will do the job, including all sorts of legacy lenses that you can fit on M4/3 bodies using an adapter. You'll need to manually focus and set aperture on the lens, but any of these could work depending on your budget, style and interests.
Wide Angle Lens
What I Use - Panasonic 7-14mm f/4.0
The lens that's mostly on my camera is the Panasonic 7-14mm f/4. It's an ultra-wide zoom lens and I probably shoot 70-80% of my photos and video with it. Wide angles are a staple for adventure photography because they allow you to get very close to the action and still capture background. They also have great depth of field, which can be useful in outdoor situations where you may want to capture as much foreground and background detail as possible.
Option 1 - Olympus 9-18mm f/4.0-5.6
Sometimes I wish I'd gotten this lens instead. It's lighter, more compact and cheaper. It doesn't go out as wide, but has a bit more reach on the long end. Personally, I prefer this focal length range of this lens over the Panasonic, but from what I've read, the Panasonic is a little sharper with a little faster aperture. I don't think you can go wrong with the Olympus 9-18mm if you should choose this.
Option 2 - Rokinon 7.5mm f/3.5 Fisheye
If your main lens is the 12-50mm or a superzoom, then you may feel that either of the above wide-angle options have too much overlap. A fisheye is a great option, but one that you have to be careful not to overuse. The Rokinon (aka Samyang, aka Bower) fisheye is a cheap option (about half the price compared to the Panasonic version) that you can throw in your bag and pull out for special shots. It's very sharp, but the downside of this lens is that the aperture needs to be set mechanically on the lens (old style) and you need to focus the lens manually (which is no big deal on a fisheye because the depth of focus is so big you can just set the focus at 1.5 or 2m and forget it).
Superzoom Lens
What I Use - Olympus 14-150mm f/4.0-5.6
The 14-150mm f/4-5.6 lens from Olympus is probably the sharpest superzoom I've used. It's probably the lens I like least, but one that is quite frequently on my camera. I would say 10-15% of my shots are made with it. Superzooms are very useful in expedition or adventure situations when your mobility is limited (like if you're on a fixed rope or belay when climbing, or on a kayak, or when you are just plain too tired to make a lens change!) or when you need big changes in focal length in rapidly changing situation (eg. you are at a crowded market place, capturing the scene with the wide end of the superzoom and, in a fleeting moment, need to zoom in to capture a face in the crowd). If you are climbing El Cap, a possible two lens combination could be to use this lens in combination with a fisheye.
Option 1 - Panasonic 14-140mm f/3.5-5.6
Panasonic's 14-140mm f/3.5-5.6 lens is new on the market. For Panasonic camera owners, its a no-brainer: Buy this version for the image stabilization which is built into the lens. Olympus owners can use either superzoom because image stabilization is built into the body of the camera. Take note that Olympus lenses zoom the opposite direction from Panasonic. For me, the zooms on Panasonic lenses are more natural, and if this lens had been out when I bought my superzoom, this would have been my pick. It's even lighter than the Olympus version, and has faster apertures across the range. It's in short supply at the time of writing, and few reviews as to how it performs.
Option 2 - Olympus 12-50mm f/3.5-6.3
This is one lens I haven't used, but by it's reputation, it should be even sharper than the two superzooms above. Technically, it's not a superzoom. The focal length range starts from a very useful 24mm (in full-frame equivalent) wide angle. That's wider than the above superzooms, which only start out at 28mm. But the long end stops at 50mm (100mm in full-frame equivalent), which would appear to be useful for portraits, but the maximum aperture at this focal length is only f/6.3, which would give the same amount of background blur on a full-frame 100mm lens at f/12.6.
Prime Lens for Sharpness, Portraits and Low Light
What I Use - Panasonic 20mm f/1.7
The 20mm f/1.7 is great because being a pancake lens, it is very small and light. Primes are very sharp and have fast apertures. I use primes whenever I can in preference to zooms. Because they are so sharp, they are great for capturing detail. Their fast apertures also help to blur away the background, making them good for isolating subjects. The 20mm f/1.7 is my default night lens, as the big aperture and focal length are useful in low light conditions. On Panasonic cameras, there is a special teleconverter ETC Mode which extends the usefulness of this lens for video. Essentially, ETC Mode multiplies the focal length by 2.7 times with no image degradation in video mode. This means that if you are shooting video with this lens on a Panasonic body like the GH3, you can have a 'wide-ish to normal' 20mm lens that converts to a 54mm f/1.7 'portrait-ish' lens! In a pinch, I'll use the digital teleconverter on my OMD EM5 to get a similar effect, although it doesn't work as well on Olympus bodies as there is some image degradation. Take note that although the autofocus speed of this lens was ok on my GH2 body, it crawls on my OMD EM5. There is a new version of this lens that is being released soon that should bring about autofocus speed improvements.
Option 1 - Olympus 45mm f/1.8
I really like this lens and use it every chance I can. It's lightning fast to focus on my OMD EM5, super sharp and has a nice out of focus, blur highlights (bokeh), making it a great portrait lens. When I can only carry two lenses due to weight considerations, I'll carry the 45mm lens together with my 7-14mm, and skip the 14-150mm. As a three lens kit, I'll occasionally carry the 45mm instead of the 20mm in my travel kit, if I'm expecting to shoot some portrait stuff. In general though, the 20mm is a more versatile focal length and makes it into my bag most of the time.
Other Prime Lens Options
In reality, there are a huge assortment of prime lens options that will do the job, including all sorts of legacy lenses that you can fit on M4/3 bodies using an adapter. You'll need to manually focus and set aperture on the lens, but any of these could work depending on your budget, style and interests.
