Although I do not consider myself a "dedicated' landscape photographer, I have spent time and effort (and money*) on kitting myself for landscapes. I am not sure if I am waiting for some long lost bug to re-bite me, or I subconsciously want to force the issue because I live in landscape central (Tasmania, Australia, where you can see sandy beaches and snow in the same hour). Either way, I consider myself always semi prepared. I just need to get my head right.
The 12-40 lens was originally purchased to do landscape and has since proven it's worth as a work lens, giving me rarely used, but necessary, wide angle capability. I don't love using it normally as I find zooms less satisfying generally and this specific lens too bulky for close quarters use (plus I still have trouble trusting it for some things). My reasoning, apart from the sheer convenience of a zoom when working from a tripod and weather proofing, is that I did not feel the 17mm and by extension the 12/14mm options were as good across the frame when stopped down. An important consideration in landscape work.
Travelling light in Japan (2 bodies, 2 primes), I shot what I saw, how I could. Low and behold, the 17mm lens, strictly a street lens in my mind up to now, has turned out some lovely images. I always felt the 12mm had the potential to be the stronger one of the two here, but once again, the little 17mm has punched above it's weight.
I consider this lens the equal of the 75mm in that it produces the right look for the lens it is. Straight tests of resolution and distortion give the field to the 75mm hands down, but the bigger story is, the 75mm does what a medium telephoto should do and the 17mm does what a wide standard should do best, so they cannot be measured equally (apples/oranges). Olympus decided to make the 17mm out of metal like the 75mm and not plastic like the supposedly optically better 45 and 25mm lenses. I am starting to see why.
I almost grabbed the 15mm Panasonic a couple of years back. It is a slightly better lens in some areas, but I found it looked brighter (nicer?), but thinner which is not always a good thing. I think I like what the 17mm brings in highlight control and warmth.
The perceived sharpness of all of the landscape shots is very good. I though I was looking at 45mm lens images at first because telephoto lenses usually show more natural snap (distances can be hard to judge after the fact).
EM5 17mm
The detail in the image below is fairly high at leaf level, but the contrast of the full sized image looks very snappy. I think the zoom is probably sharper looking with close screen viewing, but I don't think the images would look very different in print.
17mm at f5.6 crop. Not a lot of sharpening applied.
Remember, this is hand held, unpolarised at ISO 400, using f5.6, not f8/ISO 100 on a tripod. there were almost no unusable images out of 50 or so, in trying weather (it was quite dark and I was usually holding an umbrella).
EM5 17mm
This image has a dreamy quality, even though it is sharp front to back. I have often not responded to OMD EM5 landscape shots as I would like, but these came effortlessly. It might just be the light and the subject, but it felt different.
I (we) should not judge our landscapes/gear with purely technical specs. The look of the image is as important to landscapes as any other form of artistic endeavour, not just technical perfection.
This makes me wonder if I should look at getting the 12mm and selling the zoom. I could travel lighter and use smaller filters and also get back to the one bag kit. I would also have a wider angle for street work.
*Filters, lens coverage range, tripods, specific bags, weather proofing, camera releases and macro capability are all landscape photography considerations. If I could rule it out completely, life would be much simpler.