Setting aperture on the OM Zuiko using the 4/3 adapter

srinivasanj · 18th June 2008

Hi, does anybody know how to control the aperture when using the 4/3 adapter and an OM Zuiko? I currently have a 510 and a 50mm f/1.8 with the adapter. The diaphragm is controlled via two buttons at the rear end of the lens. Set the aperture 'size' using the aperture ring and press the two buttons together, we can see the diaphragm closing in. But am not able to 'lock' it into place using the adapter.

Is there a specific way of doing this?

Thanks!

Mikefellh · 18th June 2008

Yup, buy a better adapter. A few of the cheaper OM adapter brands don't engage the aperture (which should be engaged as soon as you lock the lens on to the adapter, whether or not it is on the camera).

Make sure you have locked the lens properly onto the adapter though (the red dot should sit at the top when locked, just like the 4/3 lenses), and DON'T press the lens release button as you have been to engage the aperture (unless you want to remove the lens from the adaptor)...for the DOF preview feature you only have to press the ONE button.

srinivasanj · 18th June 2008

I think I am getting something wrong.

1. Can I say that there are no moving parts in the adapter, third party or original?
2. The aperture control is using the aperture ring at the front of the lens?

Say the smallest f number is 1.8 and I set the aperture ring to point to 5.6, how does the lens get set to this value? The lever at the rear of the lens is suppose to move into the position and get locked in right? How is that achieved?

Mikefellh · 18th June 2008

In the following images you'll see in the middle of the adaptor a little "finger" that sticks out:
In this image you can see it on the top right:
http://www.enjoyyourcamera.com/image.../1977639_0.jpg
and in this image it's visible on the top left:
http://www.enjoyyourcamera.com/image.../1977639_1.jpg

(if you can't see the images when you click on the links, go to http://www.enjoyyourcamera.com/Objek...ml?language=en and click on the pictures there).

When you attach the adaptor to the lens (whether or not the adaptor is mounted on the camera) this finger will move the lever that engages the aperture...if you turn the aperture ring from f/1.8 to f/5.6 with the adaptor properly attached to the lens, you should see the aperture closing even if it's not on the camera. If this is not happening, either your adaptor is defective (or made too cheaply that they forgot the finger or made it too small), or there's an issue with the lens (the lever is too small or damaged/bent). Unlike the OM camera where the lever moves when you click the shutter, when using it on a 4/3 camera there's no signal to engage the aperture so the adaptor has to engage it at all times.

When shooting with an OM lens on the camera you have to use what's called "stopped down metering"...the idea is when you focus on the subject you'd have the lens at f/1.8 so you can see what you are focusing on...then when it is time to take the picture only then do you close down the lens to f/5.6 and meter (half-press) and take the picture. Remember your camera has to be on either A or M, P or S modes won't work because the camera has no way of controlling the aperture on the OM lens.

srinivasanj · 19th June 2008

I figured it out. I had not attached the lens to the adapter properly and locked it in. Earlier the lens was 'locked' to the adapter at the lowest f number. This was wrong since I should have actually turned the lens a little bit more so that the locking can happen at the highest aperture. I was basically being overly careful with the lens and didnt want to force it through. The adapter does feel a bit too tight on the lens..wondering if MF-1 would feel smoother...

Mikefellh · 19th June 2008

I have the original MF-1 (the one that was given away to E-1 & E-300 users), and it IS tight on some lenses, and one lens it won't lock (the opening for the aperture lever isn't long enough so that the lever stops before the ring can fully lock). Anyway, I wouldn't worry about it being too tight, or being able to rotate the lens a bit when it is locked...tollerances on some lenses aren't very good.

By the way you should be able to attach the adaptor at ANY f/stop...the f/stop lever isn't used when using an adaptor (because the camera of course uses electronics to control f/stop); I don't even look what setting the f/stop is when I attach an OM lens.

18th June 2008	#1
srinivasanj Member Join Date: Apr 2008 Posts: 275	Setting aperture on the OM Zuiko using the 4/3 adapter Hi, does anybody know how to control the aperture when using the 4/3 adapter and an OM Zuiko? I currently have a 510 and a 50mm f/1.8 with the adapter. The diaphragm is controlled via two buttons at the rear end of the lens. Set the aperture 'size' using the aperture ring and press the two buttons together, we can see the diaphragm closing in. But am not able to 'lock' it into place using the adapter. Is there a specific way of doing this? Thanks!

18th June 2008	#2
Mikefellh Member Join Date: Oct 2005 Location: Toronto, Canada Posts: 1,460	Re: Setting aperture on the OM Zuiko using the 4/3 adapter Yup, buy a better adapter. A few of the cheaper OM adapter brands don't engage the aperture (which should be engaged as soon as you lock the lens on to the adapter, whether or not it is on the camera). Make sure you have locked the lens properly onto the adapter though (the red dot should sit at the top when locked, just like the 4/3 lenses), and DON'T press the lens release button as you have been to engage the aperture (unless you want to remove the lens from the adaptor)...for the DOF preview feature you only have to press the ONE button.

18th June 2008	#3
srinivasanj Member Join Date: Apr 2008 Posts: 275	Re: Setting aperture on the OM Zuiko using the 4/3 adapter I think I am getting something wrong. 1. Can I say that there are no moving parts in the adapter, third party or original? 2. The aperture control is using the aperture ring at the front of the lens? Say the smallest f number is 1.8 and I set the aperture ring to point to 5.6, how does the lens get set to this value? The lever at the rear of the lens is suppose to move into the position and get locked in right? How is that achieved?

18th June 2008	#4
Mikefellh Member Join Date: Oct 2005 Location: Toronto, Canada Posts: 1,460	Re: Setting aperture on the OM Zuiko using the 4/3 adapter In the following images you'll see in the middle of the adaptor a little "finger" that sticks out: In this image you can see it on the top right: http://www.enjoyyourcamera.com/image.../1977639_0.jpg and in this image it's visible on the top left: http://www.enjoyyourcamera.com/image.../1977639_1.jpg (if you can't see the images when you click on the links, go to http://www.enjoyyourcamera.com/Objek...ml?language=en and click on the pictures there). When you attach the adaptor to the lens (whether or not the adaptor is mounted on the camera) this finger will move the lever that engages the aperture...if you turn the aperture ring from f/1.8 to f/5.6 with the adaptor properly attached to the lens, you should see the aperture closing even if it's not on the camera. If this is not happening, either your adaptor is defective (or made too cheaply that they forgot the finger or made it too small), or there's an issue with the lens (the lever is too small or damaged/bent). Unlike the OM camera where the lever moves when you click the shutter, when using it on a 4/3 camera there's no signal to engage the aperture so the adaptor has to engage it at all times. When shooting with an OM lens on the camera you have to use what's called "stopped down metering"...the idea is when you focus on the subject you'd have the lens at f/1.8 so you can see what you are focusing on...then when it is time to take the picture only then do you close down the lens to f/5.6 and meter (half-press) and take the picture. Remember your camera has to be on either A or M, P or S modes won't work because the camera has no way of controlling the aperture on the OM lens. Last edited by Mikefellh; 18th June 2008 at 10:11 PM.

19th June 2008	#5
srinivasanj Member Join Date: Apr 2008 Posts: 275	Re: Setting aperture on the OM Zuiko using the 4/3 adapter I figured it out. I had not attached the lens to the adapter properly and locked it in. Earlier the lens was 'locked' to the adapter at the lowest f number. This was wrong since I should have actually turned the lens a little bit more so that the locking can happen at the highest aperture. I was basically being overly careful with the lens and didnt want to force it through. The adapter does feel a bit too tight on the lens..wondering if MF-1 would feel smoother...