http://photobyrichard.com/reviewbyrichard/panasonic-lumix-g-42-5mm-f1-7-review/

http://www.imaging-resource.com/news/2015/06/19/panasonic-42.5mm-f-1.7-lens-review-a-top-notch-ultra-portable-and-affordabl

http://dc.watch.impress.co.jp/docs/review/special/20150902_718283.html

In theory i think this range of focal length with OIS would compliment an slr magic rangefinder and anamorphic adapter really well.

I like the idea of ois on anamorphic since wide options are usually not possible.

Is there a way to set these auto lenses to infinity electronically without touching the lens?

I like the price of this lens.

At every significant aperture value (and by saying ‘significant’ we mean those apertures which aren’t limited by diffraction very much) the Panasonic is slightly better than the Olympus 45mm F1.8, no matter whether you look at the center or at the edge of the frame.

http://www.lenstip.com/440.1-Lens_review-Panasonic_G_42.5_mm_f_1.7_ASPH._POWER_O.I.S._Introduction.html

http://photodanielm.blogspot.ca/2015/11/panasonic-lumix-g-425mm-f17-ois.html

Love the lens - very convenient.

A tale of two lenses: mini review of the Panasonic 42.5/1.7 and the Olympus 45mm

M4/3 owners are lucky. There's some very good portrait lenses available. There's some disagreement amongst professionals about exactly what is a good portrait lens in terms of focal length, and part of this has to do with the crop factor. There's even some disagreements about what a good lens is in terms of color, sharpness and bokeh. In case you get bored easily, I will state my conclusions first:

The Olympus 45mm is a better portrait lens, and the Panasonic 42.5/1.7 is a better lens period.
This conclusion is based on more than 40 years of making photos, films and videos. But it comes down to how you define a good lens. If all you care about is sharpness, get the Panny. If you want your portraits to have a special look, a look that is very subtle and engaging, get the Olly. If you want your color and bokeh to just melt together, get the Olly.

Having said that, the differences are slight. True, the Olly does have better color and bokeh, true also, the Panny has better edge to edge sharpness and it has Image Stabilization (IS). If you are looking for an all-round video lens for your Panasonic camera, especially one with built in IS, the Panasonic is the way to go. '

I own both of these lenses. It's seemingly redundant, but the fact is I want, I need a fabulous portrait lens. A portrait lens that will not exacerbate every wrinkle, and is not too sharp on the edges. The fact is, edge to edge sharpness is a difficult technical feat to achieve, and very few lenses do this well. When we see reviews, we see corner comparisons. "Aha," we say, "the cheap lens isn't sharp in the corners." Generally true. But not good for portraits. You see, in a portrait there is nothing in the corners. We don't even want to be aware that there is a corner.

For portrait lens, you don't want sharp edges--sharp edges makes for sharp, busy bokeh. Not good.

Lastly, the transition area in a portrait lens is key. The viewer should not be aware that the lens is showing two areas, the foreground (the subject) and the background. There should be a seamless transition. No one tests this, few people talk about it, but it is essential for a portrait lens The Olly has this.

OTOH, you can take a fine portrait with the Panny 42.5. You can also add some nice filters to get a more dreamy look. If you are walking out and about, shooting some landscapes, architecture, street scenes--if you are filming events from a medium distance, if you need the IS, the Panny is great.

Let me emphasize that these are both great lenses. Anyone would be fine with just one, and you don't need two. But, in a way, they are quite different and give different looks.

In terms of focal length, these are really ideal for portraits unless you really want razor thin depth of field. If you want that DOF, step up to the Olly 75mm. Another option is to pick up a nice old prime MF lens and add a speed booster.

In terms of handling or travel, both lenses are small, light and compact. However, the Olly is smaller and lighter and fits the smaller mounts like the GM1 or the GM5 better. The Panny has the IS mechanism, so it needs to be a bit bigger. Both lenses focus well. The Olly is silent, the Panasonic occasionally makes some noise. On a later model Panasonic body the 42.5 lens will focus amazingly fast.

When purchasing one of these lenses, keep in mind that both have tremendous optics. You can't go wrong with either one.

If you have unlimited cash, you might consider the Panasonic/Leica 42.5/F1.2. It is super fast and super sharp. However, it is big, heavy, and for portraits the Olly is almost as good, unless you really want that ultra thin DOF. The 42.5 1/7 is sharper at the edges at 1.7 than the much more expensive 1.2 (if that's what you want), and the 1.7 has better macro capabilities.

Measurements

https://www.lensrentals.com/blog/2018/03/finally-some-more-m43-mtf-testing-are-the-40s-fabulous/