Olympus Focusing Discrepancy.

[Hugh Paterson]

[No message]

 

[pocoloco]

Forum posting discrepancy?

 

[Hugh Paterson]

Gee thanks! Now I've got to type the whole damned thing again, as the system won't accept alterations after someone has replied (even in jest), and you replied while I was in the process of retyping it!

 

[JDLaing50]

Gee thanks! Now I've got to type the whole damned thing again, as the system won't accept alterations after someone has replied (even in jest), and you replied while I was in the process of retyping it!

You gotta be quicker.

 

[Hugh Paterson]

OK, I'll start again!

I've discovered that my Olympus 75mm F1.8 lens sometimes hunts back and forward over its full travel before finding focus when used with my OM-D E-M1 Mk 2 camera body. It happens about 50% of the time, specifically with interior/ambient lighting. This does not happen when used with my other Olympus and Panasonic lenses, nor does it occur when I use this same lens on my Olympus PEN-F.

Its a shame for what should be a great camera/lens combination, particularly since the E-M1 MK2 is acclaimed for it's super-fast focusing.

Any ideas why this should happen?

 

[JDLaing50]

OK, I'll start again!

I've discovered that my Olympus 75mm F1.8 lens sometimes hunts back and forward over its full travel before finding focus when used with my OM-D E-M1 Mk 2 camera body. It happens about 50% of the time, specifically with interior/ambient lighting. This does not happen when used with my other Olympus and Panasonic lenses, nor does it occur when I use this same lens on my Olympus PEN-F.

Its a shame for what should be a great camera/lens combination, particularly since the E-M1 MK2 is acclaimed for it's super-fast focusing.

Any ideas why this should happen?

In poor lighting the contrast sometimes is not great enough to make it catch focus.

Takes a little getting used to.

 

[stateit]

Fluorescent lighting (compact fluorescent/regular fluorescent) or tungsten filament/halogen lighting?

 

[greg 123]

OK, I'll start again!

I've discovered that my Olympus 75mm F1.8 lens sometimes hunts back and forward over its full travel before finding focus when used with my OM-D E-M1 Mk 2 camera body. It happens about 50% of the time, specifically with interior/ambient lighting. This does not happen when used with my other Olympus and Panasonic lenses, nor does it occur when I use this same lens on my Olympus PEN-F.

Its a shame for what should be a great camera/lens combination, particularly since the E-M1 MK2 is acclaimed for it's super-fast focusing.

Any ideas why this should happen?

I used the EM1ii with 75 1.8 combination indoors in low light recently and didn't find focus to be a problem. The focus hunting didn't strike me as excessive. Results from that combination are striking. Maybe my lighting wasn't as challenging as what you were dealing with. A typical shot was f1.8 1/125s at ISO 3200. DXO prime kept noise from being a noticeable distraction. Shutter speed was necessary to handle movement of the subject. There was no fluorescent lighting in my use if that is a suspect.

 

[drj3]

Do you have the EVF Frame Rate set to High? One DPR post indicated that may cause a problem with some artificial lighting.

 

[Skeeterbytes]

Agree that type of light could be a factor. If you're in S-AF, maybe try C-AF to see whether PDAF helps rein it in. Otherwise, could be a time to switch to MF. Lacking the snap manual focus or focus limit switch, the 75 is a little trickier to wrangle than some other lenses.

There's also the mkii built-in focus limit option to explore.

I have used the 75 for stage performances and sports with stadium lighting and haven't noticed it to wander excessively on the E-M1. Don't have a mkii yet so can't compare direct results.

Happy sleuthing,

Rick

 

[Danielvr]

In poor lighting the contrast sometimes is not great enough to make it catch focus.

When that's the case, the 'AF Scanner' setting can alter the behaviour of the lens.

From the English manual (p.111):

AF SCANNER (Custom menu Gear A1)

Sets the AF scan function* for when the camera cannot focus on the subject or the contrast is not clear.
* Scans whole range from minimum range to infinity for focus point when the camera cannot focus on the subject or the contrast is not clear.

[mode1]: AF Scanner is not activated.
[mode2]: AF Scanner is activated once only.
[mode3]: AF Scanner is activated.

 

[Hugh Paterson]

Do you have the EVF Frame Rate set to High? One DPR post indicated that may cause a problem with some artificial lighting.

 

[s_grins]

Gee thanks! Now I've got to type the whole damned thing again, as the system won't accept alterations after someone has replied (even in jest), and you replied while I was in the process of retyping it!

All lenses do the same under certain conditions. When you switch your camera ON, lens by default is focusing into infinity, and when and if, under poor light, you ask lens to focus on close up subject, lens has difficulties.

All lenses behave the same way.

 

[Hugh Paterson]

Agree that type of light could be a factor. If you're in S-AF, maybe try C-AF to see whether PDAF helps rein it in. Otherwise, could be a time to switch to MF. Lacking the snap manual focus or focus limit switch, the 75 is a little trickier to wrangle than some other lenses.

There's also the mkii built-in focus limit option to explore.

I have used the 75 for stage performances and sports with stadium lighting and haven't noticed it to wander excessively on the E-M1. Don't have a mkii yet so can't compare direct results.

Happy sleuthing,

Rick

 

[Hugh Paterson]

Gee thanks! Now I've got to type the whole damned thing again, as the system won't accept alterations after someone has replied (even in jest), and you replied while I was in the process of retyping it!

All lenses do the same under certain conditions. When you switch your camera ON, lens by default is focusing into infinity, and when and if, under poor light, you ask lens to focus on close up subject, lens has difficulties.

All lenses behave the same way.

 

[bgalb]

It is also probably true that the camera firmware is a little immature. Olympus seems to push the envelope a little in getting their cameras out and the firmware is the last piece of the puzzle to be finished.

Look at the E-M1 and the number of firmware updates it received (which I appreciate). I expect there will be noticeable improvements in performance in several areas with the next update (and hopefully no regressions like the E-M1 4.2 update)

 

[453C]

It is also probably true that the camera firmware is a little immature. Olympus seems to push the envelope a little in getting their cameras out and the firmware is the last piece of the puzzle to be finished.

Look at the E-M1 and the number of firmware updates it received (which I appreciate). I expect there will be noticeable improvements in performance in several areas with the next update (and hopefully no regressions like the E-M1 4.2 update)

Once the GH5 gets wide release, I expect we'll see a bump in MkII AF performance. I doubt Olympus sandbagged Panasonic, but once the GH5 is released, they'll have a good idea of where the MkII sits, and how much they need to crank up performance against all of the competition.

 

[Danielvr]

All lenses do the same under certain conditions. When you switch your camera ON, lens by default is focusing into infinity, and when and if, under poor light, you ask lens to focus on close up subject, lens has difficulties.

Just to add that you can change this behaviour using the 'Lens Reset' setting (on E-M1.2: Gear A3 in the menu). When you turn this off, then lens won't reset to infinity when you power-up the camera.