Sunday, 2 February 2014

Comparison @ 45mm

Many M4/3 lenses cover the 42-45mm focal length. And there is a good reason for that. This corresponds to 85-90mm in traditional 135 film format, which is the well known portrait focal length.

Here is a collection of M4/3 lenses covering 45mm, both primes and zoom lenses:

From left to right: Lumix X PZ 45-175mm f/4-5.6, Olympus 45mm f/1.8, Lumix X 35-100mm f/2.8, Panasonic-Leica 45mm f/2.8 1:1 macro (custom hood solution)



The lenses


The Lumix X PZ 45-175mm f/4-5.6 is a compact tele zoom lens with power zoom. The zooming can only be operated electronically, which is good when you want to zoom while recording videos. It also works well for stills, as you can use the zoom ring much like a normal mechanical zoom ring. The lens is very good optically, and is a good choice for those who would like a compact tele zoom lens, at a somewhat steeper price. There are also more moderately priced alternatives.

From Olympus, the first dedicated portrait lens for Micro Four Thirds, the Olympus 45mm f/1.8. It is reasonably priced, quite good in terms of sharpness and bokeh.

Launched with the GH3 in 2012, the Lumix X 35-100mm f/2.8 is Panasonic's interpretation of the classic pro tele zoom lens. Sporting a constant f/2.8 max aperture across the focal length, it is generally regarded as a very good lens. It is also one of the most expensive Micro Four Thirds lenses available.

Finally, the Panasonic-Leica 45mm f/2.8 1:1 macro is responsible for a lot of firsts in the Micro Four Thirds lens lineup: The first Leica co-branded lens, the first macro lens, the first prime lens with OIS, the first portrait focal length prime. It is fairly expensive, and Olympus users are probably better off getting the Olympus 60mm f/2.8 for macro capabilities.

The test


In my previous comparison, I tested the lenses at pretty close focus distance. This time, I chose to use a longer distance. The focus distance is about 20m, practically infinity. I had the camera, the GH3 on a tripod, and used the 2s shutter delay to avoid camera shake. I set ISO 200.

Here are the test pictures taken:

Lumix 45-175mm @ 45mm f/4 Olympus 45mm f/1.8
Lumix 35-100mm @ 45mm f/2.8 Leica 45mm f/2.8

Analysis


To better compare the image quality, I have collected 100% crops from the images at different apertures. These are from the centre:



Based on the centre crops, we see that all lenses do very well. The Olympus 45mm f/1.8 is a bit soft wide open at f/1.8, and further improves at f/2.8 and f/4. This is quite normal for a fast prime lens. Even the best lenses cannot be expected to be very sharp wide open. For a reasonably priced fast portrait lens, it is doing very well.

The Lumix 45-175mm is quite sharp at f/4, and improves marginally at f/5.6. When testing lenses at 100mm, I was disappointed with the Lumix X 35-100mm f/2.8. This time, however, I am happy to see that it performs well.

Finally, the Leica 45mm f/2.8 1:1 macro is sharp already wide open, as I think most would have expected.

And from the lower right corner:



The corner performance is usually much more challenging for lenses, and this is where we are more easily able to separate the good from the less good. We can also see which lens has vignetting issues: They will have darker corner crops.

Is is no surprise that the Olympus 45mm f/1.8 needs to stop down to f/4 for the best performance. But considering that it is a fast prime, I don't think the f/1.8 image is that bad. Considering the price, I think it is doing well.

The Lumix 45-175mm vignettes a bit at f/4, but doesn't really get much sharper at f/5.6. For a compact tele zoom, I think the corner performance is quite adequate wide open.

It is a bit disappointing to see the vignetting at f/2.8 from the Lumix X 35-100mm f/2.8. However, the sharpness wide open is very good, even in the corners.

One would perhaps have expected the Leica 45mm f/2.8 1:1 macro to perform the best in this test, given that it is the most expensive of the prime lenses. However, it appears to need to be stopped down to f/4 for the best corner performance. That also takes care of the vignetting issue.

Conclusion


The good thing about this test is that all the lenses perform adequate. The Lumix 45-175mm is a well performing, compact tele zoom. My other test at 140mm indicates that it is also sharp in the longer end.

The Olympus 45mm f/1.8 has some issues wide open, especially in the corners, but I think all fast lenses do. It is still a good quality reasonably priced portrait lens.

When seeing the results at 100mm, I was afraid that the Lumix X 35-100mm f/2.8 was widely hyped, or that I had a bad lens. However, my test at 45mm here shows that the lens is in fact very sharp. There is some vignetting, but all in all, this is hardly a major issue.

Finally, Leica 45mm f/2.8 1:1 macro is good, but not perfect.






Alternative lenses


We are blessed with a large number of Micro Four Thirds lenses. If you are interested in this focal range, then there are some alternatives:

If you have an Olympus camera, and want a compact, light, value tele zoom, you can't go wrong with the Olympus 40-150mm f/4-5.6.

An alternative macro lens, especially for Olympus camera users, is the Olympus 60mm f/2.8 1:1 macro. The longer focal length gives you a larger working distance, good for photographing insects.

For the best performing prime lens at a good price, go for the Sigma 60mm f/2.8 DN. It is not overly fast, but has a very good sharpness, and a nice bokeh.

For the very best portrait lens, wait for the Leica 42.5mm f/1.2 to become available. It is the fastest M4/3 lens, and has built in OIS.

Those who want the most selective focus need a lens with a large aperture. The Nokton 42.5mm f/0.95 will give you the most selective focus available with any M4/3 lens so far. However, it has manual focus only.

If you want one of the best lenses, and a good luxury feeling on top, try the Olympus 75mm f/1.8. Due to the long focal length, and narrow field of view, the lens has a limited scope of use, though. It can be used for portraits at a distance of about 2m or more, and for general tele use.

The number of choices is really remarkable.

2 comments:

  1. Your sample pic don't seem to be an exact plane. Maybe the corner of the image from oly 45mm is just not in the DOF anymore at f/1.8.

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    1. At 45mm f/1.8 and 20m focus distance, the depth of field is 4.2m in the front and 7.2m to the rear. I think it is safe to say that the building wall is inside this by a large margin. So DoF is not an issue here.

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