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manual focus question for 17mm and 20mm owners

pellicle

New member
Hi

I was just thinking, I have read that the micro 4/3 cameras essentially 're calibrate' focus on power up, combined with the fact that they have 'focus by wire' I wonder if the focus point set during manual focus remains exactly where it is between powerup cycles?

if someone can test this I think it is important for people who may be wanting to "zone focus" and use an optical finder
 

PeterB666

Member
Not sure what you mean by focus point. Focus by wire means that there is no direct relationship between the focus ring and the focusing of the lens. If you turn the focus ring quickly, there are bigger changes in focus. If you turn the focus ring slowly, there are small changes focus. In other words, the relationship is variable.

Theoretically this could be quite good but there are some downsides. There is no infinityh focus stop possible. There is no focus sale on the lens. Basically, if you cannot see the image in the viewfinder or EVF, you cannot focus with a MFT lens.

The E-P1 can turn the RESET LENS setting to ON to reset the focus to infinity each time the camera is turned on, otherwise it stays were it was when turned off. (I assume the Panasonic cameras can do something similar).

If RESET LENS is OFF, moving the focus ring when the camera is NOT turned on and NOT in MF mode has no effect as you are not controlling the focus motor in those situations.

Zone focus isn't possible with MFT lenses as you don't have a focus scale but some of the Scene settings will change the focus (I think).

You can make use of depth of field and there is a depth of field preview option in the E-P1 but it must be assigned to the Fn button to use it.

Manual focus lenses work quite well. I use a collection of old Olympus OM and other lenses via adapters. Naturally, you can use zone focusing on these lenses.

P.S. The 20mm lens works quite nicely in MF mode and the focus by wire focuing ring has a nice feel to it even if it is nothing like good old machanical focusing.
 
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greggebhardt

Guest
I have tested my 20mm and it does not "wake up" in the same focus position and has got to be refocused from what I can tell
 

laptoprob

New member
This is exactly why in some circumstances a good old manual lens works best. Or it is what we dinosaurs are used to...
 
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Vivek

Guest
I have tested my 20mm and it does not "wake up" in the same focus position and has got to be refocused from what I can tell
This is the case with the Oly-D 17mm as well. A real shame. 78g lens doing the back and forth all the time.

Manual focus lenses with real apertures and with focus that does not go haywire on its own are my most used lenses as a result.
 

pellicle

New member
dratt ... its what I expected

sigh

well at least I am gathering more information on this system and what its limits and issues are.

laptorob ... are we really dinosaurs?
 

pellicle

New member
This is the case with the Oly-D 17mm as well. A real shame. 78g lens doing the back and forth all the time.

Manual focus lenses with real apertures and with focus that does not go haywire on its own are my most used lenses as a result.
say, if ever you get the urge to sell it, let me know ... even if you ebay list it let me know the auction number and I'll see about acquiring it ....
 

PeterB666

Member
I have tested my 20mm and it does not "wake up" in the same focus position and has got to be refocused from what I can tell
I just did a test of the 20mm on the E-P1 with RESET LENS set to OFF (in the menu - Gear Symbol, A - AF/MF, RESET LENS)

When turned off and on again from either S-AF or MF, the lens was focused at the same point as when it was turned off.

When RESET LENS is set to ON, the lens is focused at infinity when the camera is turned on (a handy trick to remember next time I try and to some astrophotography). I tested that too and that appears to be the case.

I didn't bother testing C-AF as I don't use it.

I have no idea how the Panasonic cameras behave but that is what the Pansonic 20mm lens does on my Olypmus E-P1.
 

PeterB666

Member
This is the case with the Oly-D 17mm as well. A real shame. 78g lens doing the back and forth all the time.

Manual focus lenses with real apertures and with focus that does not go haywire on its own are my most used lenses as a result.
Seems like you have your camera on C-AF. Mine doesn't do that on S-AF or MF.

C-AF is absoulutely crap. I have set my C-AF so that it only works when the AEL/AFL button is pressed but I have found that when letting go of the button that it tends to go off focus just a bit most of the time so it is still useless.

Stick to S-AF and set RESET LENS to OFF.
 
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Vivek

Guest
There is no lens reset off in G1, is there?

Lens is almost always used in MF mode (which isn't really manual focus in these cams), rarely in AFS and never in AFC (camera blinks with a warning to change).

Some system.
 

PeterB666

Member
Looks like Olympus cameras have got something right in its focusing system. AF may be slow, but it can be turned off and you can have it set to turn the camera back on with the lens focused as it was (unchanged) or at infinity.
 

pellicle

New member
Folks

I'll test my G1 when I get home tonight ... normally I use the camera in AF-S or Manual focus on the dial ...

pete: the bit you mentioned:
(in the menu - Gear Symbol, A - AF/MF, RESET LENS)
I'm guessing that's a Oly menu setting I don't have ... I'll look for an equivalent

thanks
 

PeterB666

Member
Yes, that's the E-P1 menu. I didn't know what camera you had.

I would have thought that the Panasonic had something similar but some of the terminology in the Olympus menus is weird so it doesn't help much. Took ages to find too, but once I rediscovered it, it sort of makes sense.
 

PeterB666

Member
Thinking about it, I have heard that Panasonic cameras don't really focus that much quicker than Olympus cameras but cheat by having the focus always on so when you go to take a shot, the lens is often already focused when you point it.

I am not sure what they call it, maybe something like Predictive AF?
 

pellicle

New member
Thinking about it, I have heard that Panasonic cameras don't really focus that much quicker than Olympus cameras but cheat by having the focus always on so when you go to take a shot, the lens is often already focused when you point it.

I am not sure what they call it, maybe something like Predictive AF?
I can confirm that on AF-S one shot the image stays blury untill I half press the shutter ... winding the focus manually to the closest it will go then pointing it at infinity detail it focuses as fast as the USM 28-105 Canon lens I had (until I bought my G1)
 

pellicle

New member
Ok Pete

according to the manual Pre-AF may be what you have heard of:

Depending on the setting, camera will adjust the focus
automatically before pressing the shutter button halfway.
I have mine set to off ...

the choices are:

About [Q-AF ] and [C-AF]
[Q-AF] will adjust the focus automatically when the jitter of the camera gets small. [C-AF] will adjust the focus at all times (continuous AF operation). The camera will adjust the focus automatically, and the focus adjustment when the shutter button is pressed becomes faster. It is effective when you do not want to miss a photo
opportunity.

p106-107 are interesting

lastly I can confirm that the camera looses focus with the kit lens between power cycles
 

PeterB666

Member
Ok Pete
lastly I can confirm that the camera looses focus with the kit lens between power cycles
Problem solved by getting the E-P1. Had to rub it that there are some advantages to the E-P1 (I won't mention 20mm IS lens for the E-P1 that looks just like the one you have).

I would be quite happy to have the Pre-AF thingie instead of the lens not resetting focus each time it is powered on.

What we need is a composite Panapus G-P2 camera.
 

laptoprob

New member
are we really dinosaurs?
Well, in this more and more automated world, I guess so. But when using the Panny AF lenses I am in constant doubt. Focus is fast and accurate, but changing focal point, hyperfocal use and other things that are so easy on strictly manual equipment make me use manual stuff quite a lot.

But dinosaurs are fascinating, don't you think? Other animals that survived since (almost) that long maybe even more. Crocodiles, sharks, Komodo lizards etc. Fantastic designs!
 
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Vivek

Guest
What we need is a composite Panapus G-P2 camera.
I would opt for an Olympana EG-1.

I like the size of the Olympus battery plus it isn't blocked by firmwares- in addition, there will no LUMIX logos..:D
 
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