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Thursday, 12 March 2015


I wonder when I hear that the old Pan 20mm. 1.7 is slow-focusing, because it does not feel so to me. I've tried it on different cameras, and generally it feels like a .3 to .5 second focus time to me. Not state of the art, but surely faster than I can focus manually.

The 20/1.7 is substantially faster on my GX7 than on the E-Pl1. Also note that it is the only m43 lens that cannot be used in continuous AF mode on Panasonic cameras. Panasonic has some firmware magic that does a better job of understanding where the lens is focused before it begins to hunt. The original Olympus kit lens is also noticeably slow by comparison to the latest MkII R MSC version.

I can't tell you how I know the relative speed difference. The fast lenses seem to have already locked focus on something appropriate on the half press before I even have time to think for an instant about composition or exposure. The slow ones have me thinking "dear Lord, lock on to something before the shot is lost."

Would these still be your favorite lenses if you were shooting a full frame vs a 4/3?

[I've owned a 24-MP Sony A900 full-frame camera since new and still have it, and owned a D800 for about seven months. So, yes. --Mike]

Contrast-detection AF requires a light focusing element which can quickly shift directions, because a small amount of "hunting" is inherent to the algorithm.

What I've heard is that the 20mm lens was an older design without the necessary properties.

I would expect all new lenses to be fast focusing. Have you seen any m4/3 lenses since the 20mm which weren't?

Interestingly enough, I've been buying the Oly lenses for 'professional usage', and filling in odds and ends with the Panasonic and Sigma for knocking around. If Panasonic had developed a professional level prime line right off the bat, I might have waited to do the buying, and bought this lens, as I love an 85.

Panasonic's decision to have a 14 instead of a 17 (which to me is a very unusable 28mm, when what I really want is a 35mm and 24mm), and a 20mm (which regardless of quality is still a 40mm, i.e. not a 35mm, and if I wanted a 'near normal', it'd be on the 58mm-60mm side), seemed to be lens decisions based on....? Oly's decision to go with the accepted range of equivalents 24mm, 35mm, 50mm, and 90mm (acceptable instead of an 85), seems to have made all the sense...

The 45mm Olympus f1.8 is a very fast focusing lens, even on the slower cameras (E-P1, E-PL1, E-P2, etc.)

The slow ones, AFAIK are all early lenses: the 17mm f2.8 Olympus "pancake", the original 14-42mm Olympus zoom, with the rotating front element (Ctien has one), and the 20mm Panasonic f1.7. These are faster on later model cameras, but still slow in comparison to the rest of the lenses that are available, but they be come quite usable on the faster cameras.

I kept my 20mm Pansonic, and now use it in AF mode on an e-p5 or e-m5. I used to use it in "semi-zone" mode on E-P1, E-Pl1 and E-P2 cameras (de-couple AF from the shutter button, pre-focus with AF lock button, shoot away.)

I've thought about moving to the 17mm f1.8 Olympus, but actually like the 40mm e-FOV for all around use (compared to the 35mm e-FOV), even though I have always thought of myself as a 35 guy. (Latest adventure is the 27mm f2.8 Fujinon XF on an X-A1, also 40mm-e.)

The mixed and often lackluster reviews of the 17mm f1.8 Oly have not been encouraging, either. I'll be interested in how your crowd source review of the 17mm turns out!

OMD EM5 mark 1, 17mm/1.8 and 45mm/1.8 Olympus lenses. Perfect little travel kit. Both focus really fast, and the IS is amazing. Handheld 1/8 sec no problem.

...Oh, and a M42 50mm/1.4 Super-Multi-Coated Takumar on an adapter for when I want Bokeh. Seem to remember you liking those ;)

>So is the Oly lens one of the fast-focusing ones, or not?

It is for me. I've used it on a GH2 and now a GX7 and it's very quick. My impression from forum comments over the past 4 years that I've been using m43 (and my own experience with 6 lenses, zooms and primes, from both brands) is that most of the lenses are acceptably quick, with just a few notorious exceptions like the 20/1.7

I must say that this is really tempting for me. The Nocticron is too rich for me. I appreciate IBIS at this focal length so I think for myself and most people with the Panasonic bodies it is ( all else being equal) clearly the one to have over the Olympus. Can't wait!

I may be wrong, but I think the Panasonic 20mm is notable among M43 lenses for its relatively slow focus speed. It certainly feels very leisurely compared to my three other M43 lenses (Panny 14mm and Oly 45 and 40-150 non-Pro). I'd describe the Olympus 45/1.8's focusing as lightning fast, but maybe I just lack comparison.

As for the Panasonic 20mm, my most used lens by a massive margin, the focusing is usually fast enough for what I do, although the lack of speed becomes very noticeable when I use my other lenses. In fact, if you'd ask me what could be improved upon with that lens, I'd place ability to focus in low light far ahead of focus speed. High-ISO banding, when paired with my E-M5, I could also do without.

But that lens is just so right in all other aspects. I happen to be a sucker for compact, fast-ish, slightly-wider-than-normal lenses with great flare resistance.

Yes, the Olympus 45mm f/1.8 lens does indeed focus in a snappy fashion. I've made some great portraits of family and friends with it while just sitting around and chatting with them. The combination of fast AF and tap-to-focus-and-shoot using the rear LCD on my E-M1 allows me to just have a conversation, maintaining eye contact and quickly capture very natural portraits.

Yes, the Oly 45 1.8 is fast to focus. No one complains about that. In fact, hardly anyone complains about that lens, period. It is a relative bargain and great to pair with the similarly small and lightweight 25 1.8.

While no one has played with the new Pany 42.5 yet, the biggest criticism that I've seen is that it fixes a problem that doesn't exist. The only people who need it are those who really want an 85mm equiv., don't want to pay four digits for the Nocticron, and don't have IBIS (either Oly or Pany G7 owners). It looks good for what it is, though.

Question for Mike: have you tried the Nocticron? If not, don't. You might like it too much! It is an amazing piece of glass on the EM-1. If Oly would enable the on-lens aperture ring it would be just about perfect. Between the PL 25, PL 42.5, and Oly 75, you have an absolutely amazing setup that feel amazing on a body the size of the EM-1.

Eek! Suddenly my lovely 20/1.7 is a "slow focuser", a fate worse than ...

Well, OK, if I pay attention, it's not instant on the E-M5, quicker on an E-M5 II, and pretty instant on a GX7 (Seems the same with Quick AF on or off.) But with a GM1, we're back to about E-M5 speed, but Quick AF speeds it up.

DPReview says " It's not as fast as the Panasonic 14-45mm or 14-140mm zooms, but it's not terribly slow either (obviously this depends to some extent on the specific body used, with the E-P1 feeling just a little bit slower than the G1 or GF1)."

Whereby may hang a tale? If you want fast focus, perhaps the choice may come down to both brand and model of camera. Your idea of a "... faster-focusing type ..." may not be useful.

Back to ~85 mm eq. lenses, the Oly 45.1.8 focuses more quickly on my cameras than does the 20/1.7. And, in support of the above provisional thesis, focuses faster on the E-M5 II than the GX7.

As to actual usability, I offer these casual portraits, taken in a rather dimly lit restaurant last weekend.

Taken with the "lowly" E-PM2 I've touted here before as a great pocket camera. In that kind of light, where it uses its focus assist light, first focus from infinity to close in is slowish. Subsequent focus in the same range is quite quick.

Quick enough to get the expressions I wanted. The lens was wide open, so DOF relatively shallow and focus was accurate enough to catch the eyes even at f1.8. I don't think any other lens would have done better.* The 45/1.8's rep as a great portrait lens seems justified.

The above comments on focus speed are obviously not terribly scientific, being based on mounting the lenses on various cameras, focusing on a few near things in moderate to dim light and a far thing in bright light. Failings of personal accuracy and sample variations in equipment all play a role, too.

If I were in your situation, and planning to use the lens on an Oly camera, I'd go with the odds and buy the Oly lens.

* The 2 axis IBIS of the E-PM2 has done very well at 1/50 sec. with 90 mm eq. BTW, my initial experience with the E-M5 II IBIS shows it to be a big improvement at long FLs.

The only slow focusing lenses are the old 17mm f/2.8 and maybe the early Olympus kit lenses. The 45mm was one of the first of the fast focusing lenses. I used it with pleasure on my Panasonic G2 and now on my E-M5.

As you say, the Panny 42.5/1.7 has OIS. It's faster sibling was the first Panny prime with IS.

I imagine this may be in part a response to a competitive disadvantage vs. Oly. Until these two new lenses, Panny's primes have been much more useful in dim light on Oly bodies.

Kinda silly, really, what the speed adds, the lack of IS gives away. I love my GM1 for go everywhere, casual use, but in dim light situations, I can't effectively use their 20/1.7 and Oly's 45/1.8 or 75/1.8.

The E-PM2 is larger and heavier than the GM1, but gives much better results in the dim.

As 42.5 mm is Panny's longest prime FL, it would be the one where IS would be most useful. But experience has shown me that at least the 20-25 mm primes need it, too.

A GM5 with 20/1.7 III OIS and 42.5/1.7 OIS would be sweet.

I've owned the Oly 45 and still have the 42.5 Pana/Leica. I bit the bullet for the sheer fact that it is perfectly useable at maximum aperture, and it delivers the goods all the time, every time and beautifully to boot! I justified the price as this is how I make my living, and dammit, it's just a tool, but a good tool. Right?

Oh, and the 42.5 Pana/Leica focusses very fast, and very accurately.

The Oly 45 focussed fast enough, but wasn't really tack sharp until 2.5 or 2.8. I really wanted to love the Oly, and not have to pay the price for the 42.5, but alas, the difference was noticeable. Where I use a fast prime, is usually wide open, and truly there was no contest.

I do hope the new plain Jane 42.5 Pana (no L brand here) will be stellar at 1.7. The size is more in keeping with the whole M4/3 mind set, small, light, and punches well above it's weight. I'd prefer to carry the smaller lens when I don't have the need for the ultimate in speed. And for me, using the Panasonic cameras, the built in IS is helpful when composing.

I can say with some confidence that no other micro 4/3 lens focuses as slowly as the 20mm (I make do because I love how it renders, but I'm constantly eyeing the 25mm & 17mm alternatives). The older lenses focus less quickly than the new ones, but I am unaware of anything in the published specs of the lenses that would let you know if it focuses quickly or not. Google is your friend.

Well, I don't know how to spot the difference without using a lens, but the Oly 45 1.8 seems quite fast to me. If it is slow, I do not notice it and I do very much notice that sort of thing. It's been said the Panasonic 25mm 1.4 is slightly slow, but it seems fine to me, especially since my first m43 lens other than the kit thing was the Panasonic 20mm. That thing was noticeably slow. Horribly slow. At first I thought it was the camera that was a dog, but no, with other lens it was the magical "fastest focusing camera in the world" like all modern m43s are. The lens was so slow, when I got the Fuji x100, I didn't think it focused especially slow.

You could do the turtle experiment. Take a dead, 3-legged turtle, put it in molasses in the middle of January and leave it outside overnight. Then compare the speed of the turtle with your lens. If the lens is slower than the dead, frozen 3-legged turtle, your lens is slow. Perhaps not as slow as the Panasonic 20mm, but slow.

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