I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!

Started 5 months ago | Discussions
Anders W
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Re: Not so slow
In reply to tt321, 5 months ago

tt321 wrote:

Anders W wrote:

tt321 wrote:

Anders W wrote:

G1Houston wrote:

Anders W wrote:

G1Houston wrote:

As some said, you do not want to use it the same way as other lenses. For this, when used indoors, do not use AF-C as it will hunt.

On Pany bodies (the OP has a G3), the lens is not even allowed to enter AF-C as far as I know. My G1 doesn't allow it and I think later Pany bodies behave similarly.

I used it first on a GH1. I do not recall if it can be used in the AF-C mode for still, but in video mode, it will do AF-C by default.

Yes, I was referring to stills only when I said the body wouldn't allow it.

Just had a look. On the G3 AFC is greyed out.

Yes, that's what I thought.

Video AF is somewhat painful indeed.

IIRC, it's not just the noise. It's also slow in video (IIRC, I only tried once), perhaps because they are afraid that the mechanism might overheat if it's running fast and continuously. That may also be part of the reason why Pany bodies won't allow it to use AF-C for stills.

Is this lens unique in this? I will check all my other lenses...

As I recall (but I am not sure), it is unusually slow in video compared to other lenses. It is surely unique in that it Pany bodies do not allow it use AF-C for stills.

So should use MF in video. I almost exclusively MF in video anyway but the video targeted lenses (such as the power zooms) do AF quite well in video if someone wants to use that feature. So it's a minus for the 20 in that respect.

I hardly shoot any video. But if I did, I'd probably try to MF too. The back-and-forth search that CDAF has to perform looks pretty bad (disturbing) to me in video. PDAF (which should be useable with video if it's on the sensor) should be able to do better in that regard but I have no idea whether it is at all used for video on the only MFT cam that has it (E-M1).

The problem if you try to MF during video with native MFT lenses is that they are no good for pulling focus with precision due to their focus-by-wire design (except possibly those Oly lenses that have the special MF focus clutch). Even with focus by wire, a given distance on the focus ring should correspond to a given change in focus. But that's not the case. It depends not only on how far but also how fast you turn the ring. Completely idiotic in my not so humble opinion.

A bit like flicking on an iPad, do you want precision movements or some kind of interpretation of your speed/acceleration added in to enhance your gestures? They chose to enhance it with the derivatives which is not unreasonable as if you focus slowly you are into precision and if you move fast you want to travel a long distance. They of course should have added the capability of distance only without any derivatives for video, but in the absence of that, they did provide shooting without a lens

I am afraid no excuses are good enough in this case.

However I quickly learned not to do that so even in video, I use only AF-S. I also use the lens on E-PL5 but I never bother to find out whether it works in AF-C, which is to be avoided with this lens.

Right. No point moving to AF-C even when the body allows it (as does my E-M5).

Agree. Probably has changed with the E-M1's PD?

I'll believe it when/if I see it. My E-M1 should arrive any day now. But it does not seem all that clear if/how the E-M1 uses PDAF for AF-C with native MFT (as opposed to FT) lenses. And to the extent that it does, it remains to be seen if that helps any with the 20. I am not holding breath and honestly don't care much. The lens is already doing perfectly well for what I want to use it for.

The last sentence sounds like famous last words. When you discover a new capability and start using it, you will look back and find it hard to image how you could have tolerated life without it. I used to think that standard issue sliced white bread was all I needed for bread. Now I can only vaguely recall those dark ages

As you know, I am hardly among those who speak against the blessings of technical innovation. It's just that I have so far never found any reason to use this lens with AF-C or in ways where its AF-S behavior is really bothersome.

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abe4652
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to Wesley Byrne, 5 months ago

To steal a line from a kid's cartoon:

Yes. Yes it is. Painfully slow on an em5. Tolerable on an em1

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Anders W
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to micksh6, 5 months ago

micksh6 wrote:

Why do you feel mislead? Of course it's slow and it has been shown here long time ago. You just needed to look at the right tests:
http://www.dpreview.com/forums/post/52045407
http://www.dpreview.com/forums/post/52049352

A "controlled" test can also show that 20mm focuses much slower than other lenses and hunts more often too. It's not needed to refocus from close-up to infinity in order to see that. These tests show refocusing between about 5 and 7-8 feet.

Those tests are not controlled. They are biased in ways and for reasons spelled out in the thread to which you link. That's why they are not the right tests.

I think a curved focus target attributes to slow AF with this lens.

Any lens will have greater difficulty focusing on a curved than a non-curved surface since for the former there is no single point where the entire surface contained within the focus box can be in perfect focus. But on what grounds would the 20 have greater difficulty focusing on a curved surface than other lenses of similar FL?

Slow AF wouldn't be that noticeable on flat target such as brick wall.

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micksh6
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to Anders W, 5 months ago

Anders W wrote:

micksh6 wrote:

Why do you feel mislead? Of course it's slow and it has been shown here long time ago. You just needed to look at the right tests:
http://www.dpreview.com/forums/post/52045407
http://www.dpreview.com/forums/post/52049352

A "controlled" test can also show that 20mm focuses much slower than other lenses and hunts more often too. It's not needed to refocus from close-up to infinity in order to see that. These tests show refocusing between about 5 and 7-8 feet.

Those tests are not controlled. They are biased in ways and for reasons spelled out in the thread to which you link. That's why they are not the right tests.

I didn't start this thread stating that 20mm is slow, so you might as well tell OP that he is biased and the lens is actually fast.

Whether you like my tests or not they showed exactly what OP is seing now. Your tests, on the other hand, showed that 20mm is as fast as other lenses.

BTW, a year ago I replied to your post with test results which you linked today: "the claim that 20mm focuses as fast as other fast primes is just plain wrong and it can mislead people". http://www.dpreview.com/forums/post/51100467

Perhaps, this is why OP feels misled now.

I think a curved focus target attributes to slow AF with this lens.

Any lens will have greater difficulty focusing on a curved than a non-curved surface since for the former there is no single point where the entire surface contained within the focus box can be in perfect focus. But on what grounds would the 20 have greater difficulty focusing on a curved surface than other lenses of similar FL?

This is what tests show. Explanation of test results can be a different topic.

Some time ago I suggested that it might be because of noisy focus motor. Noise is caused by vibration. Vibration also leads to blurred images, and it's much harder for camera to find peak contrast on blurred images. Peak contrast of curved surface is already is harder to determine than of flat surface. And if some contrast samples are impaired by blur this can make AF fail, or it can lead to slow AF.

Because of that 20mm lens may require more AF iterations, and it's more likely to start hunting than other lenses in the same conditions.

This isn't happening in good light, but in low light exposure time during autofocus becomes longer and if it's around 1/125-1/250s the quality of AF samples is very likely to be affected by low-frequency vibration (around 200Hz or so).

You know very well about shutter shock. You can think of this as focus motor shock. You can feel vibration when 20mm is focusing, and camera is taking images when doing it.

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MrGubrz
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to Wesley Byrne, 5 months ago

the one downfall, but for how fast the cameras could potentially focus, its a serious let down.  i gave my orig away

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GeorgianBay1939
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Re: Well duuh, Panasonic 20mm f1.7 II AF is SLOW
In reply to FrankS009, 5 months ago

FrankS009 wrote:

I have never been able to understand the complaints on this forum and in this thread about slow AF with the 20mm. I have had mine for several years, and it has always been fine.

F.

-- hide signature --

"We shoot the things that move us in ways that will move others." David duChemin

That is probably because you know how to use the 20/1.7 pancake.  Apparently others also know how to use it.  Some of them have contributed to this thread.

OTOH, some folks blame their equipment, or worse, other contributors, for their inability to maximize the strengths and minimize the weaknesses of a particular piece of gear.

I use that lens a lot at indoor social functions, with no problems, but I don't go from very close subjects to distant ones in one jump, or vice versa.  Nice lens, (in spite of its noisiness).

Tom

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tt321
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to Anders W, 5 months ago

Anders W wrote:

jhinkey wrote:

Anders W wrote:

jhinkey wrote:

The OP has a G3 listed in his gear list - this is a quite "old" model at 3+ years - could the G3 focusing be contributing to the slowness of the 20/1.7?

While the G3 is perhaps not quite as fast as the most recent models, it is surely no slouch either. Middle-generation as far as MFT AF speed is concerned. Besides, to the extent that the G3 is slow with the 20, it is slow with other lenses too. Body processing time is what it is no matter what lens is used.

I've never used my 20/1.7 on my G5 or GH2 so I have no idea how much slower it could be. I was just suggesting that perhaps the AF speed of the 20/1.7 is slowed down enough on a not-so-current body (like a G3) that it passed the threshold of minimum nimbleness for the OP.

I see what you mean. But as Pekka Potka showed in a test that no longer seems to be available on line, regrettably, the increase/decrease in AF speed when you move from a body with slower AF to one with faster (he compared the E-P3 with an earlier Oly) is about the same no matter which lens we are talking about (including the 20/1.7 which was among the lenses in his test). He also showed that the 20 was about as fast as other lenses included in his comparison under the test conditions he chose (AF-S, switching between focus targets at one and five meters if I recall correctly, no hunting).

Generally with my 20/1.7 on my GX7 I have no real complaints - only when racking from near to far or back does it show it's lack of speed. Short hops between distances are usually quick enough not to be an issue. Tracking of a fast moving object is not something I've generally tried to do with my m43 gear.

Yep.

I may swap it out for the new 15/1.7, but not because of AF speed . . . .

Personally, I am unlikely to swap. Possibly supplement, although I am far from sure I really need another prime between the 12/2 and the 20/1.7.

Since when does need come into gear buying?

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Adrian Van
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to Chris R-UK, 5 months ago

My copy of the Panasonic 20mm f1.7 was not slow at all. Never noticed any slowness. Of course I think it was the original version 1. Great lens, too bad I sold it to get another lens with different focal range.

However, if you say version 2 is slow....

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krugman
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Re: Relativity
In reply to Jacques Cornell, 5 months ago

Jacques Cornell wrote:

tgutgu wrote:

Since there are now alternatives to the 1.7/20mm, which are equal or better in IQ (1.8/25mm, 1.4/25mm) and which have a fast AF, there isn't any point left to buy this lens

...

Unless it's exactly what you need.

The 20 may not be the best at any one thing, but it still offers a unique combination of characteristics not replicated by any other lens. I didn't expect to love it - being used to 35mm on FF - but it makes a great walkabout because of its combination of brightness, minimal size & weight, high optical quality, and a really useful perspective that nicely spans the range between "normal" and "wide". Oly's 17 f1.8 focuses faster but reportedly lags a bit in IQ and is big enough to make a GX1 less pocketable. 25mm is a very different perspective than 20mm and isn't a substitute. And, the other pancake (14 f2.8) is much wider and dimmer.

Also, "slow" is relative. The 20 still focuses faster and quieter than my old Canon 35mm f2 on a 1-series.

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jacquescornell.photography

This thread is discordant to my ear. In the mu4/3 forum you will find many people who say this lens is why they chose M4/3, or who will say that this lens never comes off their camera. The image threads there show excellent photos of lots of moving subjects, including people.

In my experience using an Oly EM10, the 20mm Panasonic focuses quite fast, definitely fast enough for street shooting.

it seems to me that terming this lens an absolute dog, and something Olympus should be ashamed to have released, is needlessly provocative,.

Krugman

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Anders W
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to micksh6, 5 months ago

micksh6 wrote:

Anders W wrote:

micksh6 wrote:

Why do you feel mislead? Of course it's slow and it has been shown here long time ago. You just needed to look at the right tests:
http://www.dpreview.com/forums/post/52045407
http://www.dpreview.com/forums/post/52049352

A "controlled" test can also show that 20mm focuses much slower than other lenses and hunts more often too. It's not needed to refocus from close-up to infinity in order to see that. These tests show refocusing between about 5 and 7-8 feet.

Those tests are not controlled. They are biased in ways and for reasons spelled out in the thread to which you link. That's why they are not the right tests.

I didn't start this thread stating that 20mm is slow, so you might as well tell OP that he is biased and the lens is actually fast.

Don't worry. I already told him what the facts are a couple of times, latest here:

http://www.dpreview.com/forums/post/53583615

Whether you like my tests or not they showed exactly what OP is seing now. Your tests, on the other hand, showed that 20mm is as fast as other lenses.

My tests show exactly that yes, but only under the specific conditions I spelled out in the post where I originally reported my test results as well as in posts where I refer to them, latest in the post I link to above. As you you should be well aware by now, I have no trouble recognizing that the AF of the 20 is slower than that of other lenses under several other conditions. As you can see, this too is clearly pointed out in the post I link to.

The problem with your tests is that they don't show much at all due to unrobust test conditions that make the outcome very sensitive to minor variations along with a failure to control these variations sufficiently well.

BTW, a year ago I replied to your post with test results which you linked today: "the claim that 20mm focuses as fast as other fast primes is just plain wrong and it can mislead people". http://www.dpreview.com/forums/post/51100467

Perhaps, this is why OP feels misled now.

So you erected a straw-man. The unconditional claim made in the passage of yours that you quote is not and was not my claim. What I am, and have been, claiming is summarized in the post I link to above.

I think a curved focus target attributes to slow AF with this lens.

Any lens will have greater difficulty focusing on a curved than a non-curved surface since for the former there is no single point where the entire surface contained within the focus box can be in perfect focus. But on what grounds would the 20 have greater difficulty focusing on a curved surface than other lenses of similar FL?

This is what tests show.

No. For reasons already spelled out above, your tests do not show that and I don't know of any other ones that do either.

Explanation of test results can be a different topic.

One way of putting test results into question is to ask questions about them.

Some time ago I suggested that it might be because of noisy focus motor. Noise is caused by vibration. Vibration also leads to blurred images, and it's much harder for camera to find peak contrast on blurred images. Peak contrast of curved surface is already is harder to determine than of flat surface. And if some contrast samples are impaired by blur this can make AF fail, or it can lead to slow AF.

Have you ever tried focusing the 20 in 14x zoom AF using a remote and watching the screen as you focus? Did you compare with another lens? If so, what did that tell you?

Further, have you examined the impact of hand-shake in the same situation (14x zoom AF) and how that impact compares in magnitude to any vibration from the focus motor (with the 20 or any other lens)? If so, what did that tell you?

Because of that 20mm lens may require more AF iterations, and it's more likely to start hunting than other lenses in the same conditions.

This isn't happening in good light, but in low light exposure time during autofocus becomes longer and if it's around 1/125-1/250s the quality of AF samples is very likely to be affected by low-frequency vibration (around 200Hz or so).

You know very well about shutter shock. You can think of this as focus motor shock. You can feel vibration when 20mm is focusing, and camera is taking images when doing it.

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jimkohn
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Works absolutely fine for me
In reply to Anders W, 5 months ago

Here's another subjective two cents: on my brand new OMD-EM1 with a brand new copy of the lens, it works just as fast as any other fast prime I've owned.

I'd been watching this thread and wondering, because I had the lens before and never had any complaint regarding AF speed or anything else. But I wanted to wait until my new copy arrived with my new camera. Works great. Love it.

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Anders W
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Re: Works absolutely fine for me
In reply to jimkohn, 5 months ago

jimkohn wrote:

Here's another subjective two cents: on my brand new OMD-EM1 with a brand new copy of the lens, it works just as fast as any other fast prime I've owned.

I'd been watching this thread and wondering, because I had the lens before and never had any complaint regarding AF speed or anything else. But I wanted to wait until my new copy arrived with my new camera. Works great. Love it.

Sounds good! I hope to take delivery of my E-M1 in a few days so what you say sounds reassuring. Not that I really expected its AF to cause any more trouble on the E-M1 than on the E-M5, but anyway.

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mls149
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to Wesley Byrne, 5 months ago

I cannot speak to version 2 of the 20mm, but I have version 1, and use it with my GX7, and I just tested it again. It's focusing is nearly instantaneous, even in my house at night with just some room lights on. Is the difference in your older G3 and the GX7 that great? I don't know, but I do know that I sought out version 1 as it was reputedly better optically. Glad I did now. It's a great lens. BTW, I use 1 area focusing all the time, what are you using for a focusing area selection?

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Mark Chan
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to Wesley Byrne, 5 months ago

Wesley Byrne wrote:

UPS just delivered my Panasonic 20mm f1.7 II. I had read the reviews and knew the Panasonic 20mm f1.7 autofocus wasn't fast, but I wasn't expecting it to be so unbearably slow. Some here have said that the 20mm f1.7 isn't that slow, and that it autofocuses about as fast as other m43 lenses when large focus adjustments are not needed, but they are wrong. This lens is useless for even slow moving subjects. I am definitely returning this lens.

I know the 20mm f1.7 has many fans, presumably folks who photograph static scenes. In my opinion, compared to the 17mm f1.8 and the 25mm f1.8, the 20mm f1.7 is a dog. Panasonic should be embarrassed for releasing this lens with barely-functional AF.

</end rant>

You know, I made the view that the PANA 20mm f1.7 was slow to AF and should be avoided by those that need to take pics of kids and fast moving items / people.  This was quite a few threads back.

There are a few that adamantly state my (and many other's experience) is flawed and that the PAN 20mm - both versions are perfectly capable of 'catching' that moment.

Its plain not.

Choose 17mm or 25mm OLY for that.

Choose 20mm f1.7 if you don't NEED fast AF under any circumstances or are perfectly happy to live within its limitations.

It is unfortunate you got misinformed. And yes there are many that are misinforming leading to poor purchase decision.

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Mark Chan
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Re: Works absolutely fine for me
In reply to Anders W, 5 months ago

Anders W wrote:

jimkohn wrote:

Here's another subjective two cents: on my brand new OMD-EM1 with a brand new copy of the lens, it works just as fast as any other fast prime I've owned.

I'd been watching this thread and wondering, because I had the lens before and never had any complaint regarding AF speed or anything else. But I wanted to wait until my new copy arrived with my new camera. Works great. Love it.

Sounds good! I hope to take delivery of my E-M1 in a few days so what you say sounds reassuring. Not that I really expected its AF to cause any more trouble on the E-M1 than on the E-M5, but anyway.

Just lol.

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Mark Chan
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to Anders W, 5 months ago

Anders W wrote:

Wesley Byrne wrote:

Wesley Byrne wrote:

UPS just delivered my Panasonic 20mm f1.7 II. I had read the reviews and knew the Panasonic 20mm f1.7 autofocus wasn't fast, but I wasn't expecting it to be so unbearably slow. Some here have said that the 20mm f1.7 isn't that slow, and that it autofocuses about as fast as other m43 lenses when large focus adjustments are not needed, but they are wrong. This lens is useless for even slow moving subjects. I am definitely returning this lens.

I know the 20mm f1.7 has many fans, presumably folks who photograph static scenes. In my opinion, compared to the 17mm f1.8 and the 25mm f1.8, the 20mm f1.7 is a dog. Panasonic should be embarrassed for releasing this lens with barely-functional AF.

</end rant>

Slow AF on the 20/1.7? Absolutely. Except if you use it in ordinary AF-S in the range from 0.75 m to infinity and manage not to send it hunting. Fortunately, that exception accounts for more than 99 percent of my usage.

This is the kind of bad advice I was referring to.

It is neither advice nor bad. It is a correct observation based on controlled testing. See here:

http://www.dpreview.com/forums/post/50877416

What controlled testing did you perform?

Even in these conditions I found the 20mm f1.7 unbearably slow.

Wow Anders, at it again?

When someone 'asks' if 17mm AF is faster than 20mm, what should be the simple and clearest answer?

Yes or NO. Call a spade a spade.

Not 'comparable'; not 'for ordinary use its much the same'; not for 'all practical purposes'.

Just a simple, it is. We can add 'but then I have been able to adapt my photography such that its not an issue.'

This way, you are not misinforming people into thinking that the 20mm lens can do what it cant. A newbie into photography would think that he had a bargain for the 20mm and only later realized the lens was not 'quick enough' for his needs; because somehow, for his 'practical purposes', he would find it slow.

BTW this is from this thread.

http://www.dpreview.com/forums/thread/3636383?page=8

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micksh6
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Re: Works absolutely fine for me
In reply to jimkohn, 5 months ago

jimkohn wrote:

Here's another subjective two cents: on my brand new OMD-EM1 with a brand new copy of the lens, it works just as fast as any other fast prime I've owned.

I'd been watching this thread and wondering, because I had the lens before and never had any complaint regarding AF speed or anything else. But I wanted to wait until my new copy arrived with my new camera. Works great. Love it.

With this lens E-M1 doesn't make much difference comparing to other Olympus cameras. In C-AF mode it sometimes may focus with 20mm faster because of PDAF but the results are not very consistent. S-AF is probably safer to use, then the AF speed is the same as with E-PL5.

The whole debate about 20mm lens AF speed is probably because there are people who try to shoot action and people who only shoot static objects at slow pace.

If you are one of the latter, 20mm lens may have fast enough AF for you, especially in decent light. But then, manual focus lens would probably be good enough for you too. I just don't get why people who don't shoot action and can't provide comparison participate in such debates.

It's all about comparison with other lenses when shooting action. By action I mean moving or running children, for example.

Lenses like 17mm F1.8 and Pana 25mm F1.4 will focus much faster than 20mm F1.7 even in decent light. In low light 20mm will just suck big time not only comparing to these but also to 45mm F1.8 and even Oly 14-42mm IIR kit zoom when it can focus.

But, if you are only shooting semi-static subjects you will never see that. I think this has been stated in this forum in many threads, one just needs to use a search.

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micksh6
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to Anders W, 5 months ago

Anders W wrote:

micksh6 wrote:

Anders W wrote:

micksh6 wrote:

Why do you feel mislead? Of course it's slow and it has been shown here long time ago. You just needed to look at the right tests:
http://www.dpreview.com/forums/post/52045407
http://www.dpreview.com/forums/post/52049352

A "controlled" test can also show that 20mm focuses much slower than other lenses and hunts more often too. It's not needed to refocus from close-up to infinity in order to see that. These tests show refocusing between about 5 and 7-8 feet.

Those tests are not controlled. They are biased in ways and for reasons spelled out in the thread to which you link. That's why they are not the right tests.

I didn't start this thread stating that 20mm is slow, so you might as well tell OP that he is biased and the lens is actually fast.

Don't worry. I already told him what the facts are a couple of times, latest here:

http://www.dpreview.com/forums/post/53583615

Whether you like my tests or not they showed exactly what OP is seing now. Your tests, on the other hand, showed that 20mm is as fast as other lenses.

My tests show exactly that yes, but only under the specific conditions I spelled out in the post where I originally reported my test results as well as in posts where I refer to them, latest in the post I link to above. As you you should be well aware by now, I have no trouble recognizing that the AF of the 20 is slower than that of other lenses under several other conditions. As you can see, this too is clearly pointed out in the post I link to.

The problem with your tests is that they don't show much at all due to unrobust test conditions that make the outcome very sensitive to minor variations along with a failure to control these variations sufficiently well.

BTW, a year ago I replied to your post with test results which you linked today: "the claim that 20mm focuses as fast as other fast primes is just plain wrong and it can mislead people". http://www.dpreview.com/forums/post/51100467

Perhaps, this is why OP feels misled now.

So you erected a straw-man. The unconditional claim made in the passage of yours that you quote is not and was not my claim. What I am, and have been, claiming is summarized in the post I link to above.

What I said is exactly what you have been saying for a long time

"The practically relevant test data are here and show the 20/1.7 to be just as fast as other, more recent lenses, in ordinary AF-S, even when refocusing within as extreme a span as infinity to 75 cm."

Other your explanations just make your point more clear

"Reason: In virtually all cases, the bottle-neck is body processing time, not the lens AF mechanism."

Taken from here: http://www.dpreview.com/forums/post/52375461

This is just one example, I could find dozens of such examples from the last couple of years where you claim that 20mm AF is as fast as other lenses AF.

There was never a disclaimer about shooting conditions. You made dozens of such unconditional claims in almost every thread related to 20mm lens AF.

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sproketholes
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Re: I feel misled: Panasonic 20mm f1.7 II AF is SO SLOW!
In reply to Wesley Byrne, 5 months ago

Wesley Byrne wrote:

UPS just delivered my Panasonic 20mm f1.7 II. I had read the reviews and knew the Panasonic 20mm f1.7 autofocus wasn't fast, but I wasn't expecting it to be so unbearably slow. Some here have said that the 20mm f1.7 isn't that slow, and that it autofocuses about as fast as other m43 lenses when large focus adjustments are not needed, but they are wrong. This lens is useless for even slow moving subjects. I am definitely returning this lens.

I know the 20mm f1.7 has many fans, presumably folks who photograph static scenes. In my opinion, compared to the 17mm f1.8 and the 25mm f1.8, the 20mm f1.7 is a dog. Panasonic should be embarrassed for releasing this lens with barely-functional AF.

</end rant>

The original 20/1.7 was definitely better for focus speed. I had it on a GF1 and yesterday I tried the mkII on a GH4 and was shocked at how terrible it is.

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NZ Scott
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45 isn't THAT quick
In reply to RickPick, 5 months ago

RickPick wrote:

You shouldn't expect A/F miracles from a 5 year old design pancake lens. I did an informal test once between this lens and the Olympus 45mm, which is acknowledged to be quite fast. I tried this with a range of light levels. The difference in AFS, provided no hunting was induced, was barely noticeable. It does however take a long time to move focus from close to far away or vice versa.

The 45/1.8 is relatively quick to focus for a telephoto lens, but it is significantly slower than a lot of shorter lenses - particularly the 12/2.0 and 17/1.8 - and it does rack a little bit when moving between close and distant subjects.

S

If you read the little manual you will see that it is not intended for AFC and in fact does not work in that mode. Hence it is unsuitable for video work using auto focus.

If you use it as intended it is a very sharp and versatile lens.

Regards,

Rick

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