Does AF Assist engage on the EM5 with the MMF-3 and Standard 4/3 lens?

welcha13 said:

welcha13 wrote:




If that is true then will the OM-D E-M5 work flawlessly with the MMF-3? I assume you can turn off live view and only use the viewfinder. But does the viewfinder behave as sort of a mini live view?

I'm returning the PL-5 in hopes of getting the E-M5 to resolve this issue. I would love to have some light on this specific issue though. I haven't been able to find any solid answers.

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The viewfinder is electronic not optical, I would expect focussing speed (or lack of it) to be exactly the same as using the LCD screen.

But, as I don't have the OM-D E-M5 or any 4/3 lenses, I'll let others give you a definitive reply.

welcha13 said:

welcha13 wrote:

I'll do a brief summary of my current situation

Own e510 and four zuiko 4/3 lenses.

Recently upgraded to E-PL5 with oly MMF-3 (4/3 to m4/3 adapter)

Problem! Focus is incredibly slow (~2 sec) at every press of the shutter. Even if the subject is already in focus. The AF Assist engages and the lens go through a quick nearly full hunt and then a second shorter hunt. In low light the focus sometimes fails entirely.

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I'm not a user of any FT products, but following hili forum since a few years I have heard about it often enough to know a few things :

1) DSLRs are focused mainly using PDAF (phase detect AF) as explained here . This is only possible for DSLRs having a mirror. The body using PDAF will know in which direction it has to move the lens to get focus. The lenses ar bigger and heavier to move into focus.

2) Mirrorless cameras like MFT cameras gain focus by CDAF (contrast detection AF) by analyzing the contrast level of the pictures provided by live view. They proceed by successive measures, ignorant of the directions where they will be more infocus, so they hunt untill find the best infocus (most contrasty) picture. For this native MFT lenses are lighter and better adapted to achieve very small incremental steps forward and back, untill they find the best infocus point.

3) There are two kinds of FT lenses. Some are better compatible with CDAF than others. There was a compatibility table lsting all thevFT lenses and how they were performing in Contrast detect mode, but I haven't been able to find that link.

4) there will be absolutely no difference between the E-M5 and the E-Pl5.

5) Olympus say that it is better to use SAF plus MF when using FT lenses, that one should hold the lens barrel of the SH lenses when shooting or use a tripod collar when shooting with a tripod. They also say that with the MMF3 all functions won't be available (I think that they don't work with CAF ?)

6) There ar rumors that Olympus will eithe dude a new FT body this year, or produce a hybrid camera able to use both FT lenses in PDAF mode and MFT lenses.. Not sure how far this is true. May be ask on the Olympus SLR talk forum ?

welcha13 said:

I thought I had a bad adapter or camera body. I can't imagine a good rating coming from anybody with this performance. I then noticed Olympus and some other mentioning this. It has to do with "non-CDAF" lenses and the live view mode.

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welcha13 said:

So in theory... if you aren't using Live View mode then the MMF-3 will work great with all 4/3 lenses. Is that correct?

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There is only only a live view mode on the MFT cameras, no optical VF. The E-VF is just a smaller live view display. It won't make any difference whether you are using the E-VF or the LCD.

welcha13 said:

If that is true then will the OM-D E-M5 work flawlessly with the MMF-3? I assume you can turn off live view and only use the viewfinder. But does the viewfinder behave as sort of a mini live view?

Click to expand...

No difference between the E-Pl5 and E-M5 or the E-VF and LCD.

welcha13 said:

I'm returning the PL-5 in hopes of getting the E-M5 to resolve this issue. I would love to have some light on this specific issue though. I haven't been able to find any solid answers.

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Sorty to disappoint you. Did you try using all your lenses ? Are none of them allowing a faster AF ? Look whether some are CDAF/ Live view compatible. I think that some ave a version II tht is faster on MFT.

welcha13 said:

NOTE: I'm aware overall focus may be slower with the adapted 4/3 lenses compared to m4/3. That's fine, I just don't want to go through a 2 second focus hunt on each shutter press even if the subject is already in focus. I tested the E-PL5 with the 20mm Panasonic F1.7 lens and the focus is extremely fast and accurate even in low light. That is what finally pointed me to the MMF adapter.

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I fear that this is the harsh reality with some of the FT lenses. Many prefer to shoot in manual focus mode. Or try using SAF+MF as advised by Olympus. I will try to look for that link describing the level of compatibility between FT lenses and MFT bodies.

Here is the link I was looking for; it is a table listing which lenses are compatible with the Panasonic G3 and how far they are compatible (AF, AF speed, CAF etc.. ) with MFT bodies.

The first Panasonic cameras (G1 for instance) were less compatible than Olympus Pens with FT lenses, but what they say for the G3 should be pretty much exactly what is true for all Olympus bodies. The table list all MFT and FT lenses you can use on MFT bodies. Or may be look at the newer models, like the G5 : there should be little difference when it comes to FT lenses, since I don't think that here were any new FT lenses issued since the G3.