Force wide open on M bodies with DA lenses

mer · 12-09-2009, 08:37 AM

Hi

is there a way to force DA lenses ( without aperture ring ) to shoot wide open ? I use a ME Super and I want to use the 18-55mm wide open. Is there any way to do that ? ( like tape aperture lever etc )

keyser · 12-09-2009, 05:57 PM

Originally posted by mer

Hi

is there a way to force DA lenses ( without aperture ring ) to shoot wide open ? I use a ME Super and I want to use the 18-55mm wide open. Is there any way to do that ? ( like tape aperture lever etc )

You may find a way to keep the aperture lever open, but there is a notch on the aperture ring of the lens which tells the camera what aperture was pre-selected. I suspect on the DA series this would tell the camera that when the shutter is fired, the light will be substantially lower than the TTL reading (i.e. the minimum aperture of the lens).

Your pics would be substantially over exposed unless you manually set the shutter speed.

I do stand to be corrected as I don't have any DA lenses.

Stratman · 12-13-2009, 02:17 AM

They WILL shoot wide open on a manual body. You can not stop them down since they have no aperture ring.

stevebrot · 12-13-2009, 02:41 AM

Originally posted by Stratman

They WILL shoot wide open on a manual body. You can not stop them down since they have no aperture ring.

Sorry, but not the case. On M and K series bodies, a DA lens will be wide open to compose and stops down to its minimum aperture at taking time. The reason is that those older bodies are not forward compatible to the DA lenses. They give the aperture lever its full travel while A mount and newer bodies move the lever only as far as is needed for the aperture set by the body.

Ditto for A and FA lenses when the aperture ring is on the "A" setting.

Steve

(Have several pre-A film bodies...)

Last edited by stevebrot; 12-13-2009 at 02:54 AM.

stevebrot · 12-13-2009, 02:54 AM

Originally posted by keyser

...Your pics would be substantially over exposed unless you manually set the shutter speed...

Metering (ironically) is correct for the taking aperture (fully stopped down). The DA lens that I own (18-55) has the appropriate "stop" on the mount that communicates the appropriate minimum aperture offset for the lens. The camera uses that offset to bias the meter for the taking aperture.

Steve

stevebrot · 12-13-2009, 02:58 AM

Originally posted by mer

Hi

is there a way to force DA lenses ( without aperture ring ) to shoot wide open ? I use a ME Super and I want to use the 18-55mm wide open. Is there any way to do that ? ( like tape aperture lever etc )

I would not tape the aperture lever. Doing so may jam the shutter mechanism on the camera...perhaps permanently. Your best option might be to pick up a cheap A or P series body and shoot in P or Sv mode.

Steve

12-09-2009, 08:37 AM	#1
mer Senior Member Join Date: Nov 2007 Location: Greece Posts: 237	Force wide open on M bodies with DA lenses Hi is there a way to force DA lenses ( without aperture ring ) to shoot wide open ? I use a ME Super and I want to use the 18-55mm wide open. Is there any way to do that ? ( like tape aperture lever etc )

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12-09-2009, 05:57 PM	#2
keyser Veteran Member Join Date: Aug 2009 Location: Tsawwassen, BC Posts: 376	Originally posted by mer Hi is there a way to force DA lenses ( without aperture ring ) to shoot wide open ? I use a ME Super and I want to use the 18-55mm wide open. Is there any way to do that ? ( like tape aperture lever etc ) You may find a way to keep the aperture lever open, but there is a notch on the aperture ring of the lens which tells the camera what aperture was pre-selected. I suspect on the DA series this would tell the camera that when the shutter is fired, the light will be substantially lower than the TTL reading (i.e. the minimum aperture of the lens). Your pics would be substantially over exposed unless you manually set the shutter speed. I do stand to be corrected as I don't have any DA lenses.

12-13-2009, 02:17 AM	#3
Stratman Veteran Member Join Date: Mar 2007 Location: St Louis, Missouri U S A Photos: Gallery \| Albums Posts: 2,464	They WILL shoot wide open on a manual body. You can not stop them down since they have no aperture ring.

12-13-2009, 02:41 AM	#4
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Stratman They WILL shoot wide open on a manual body. You can not stop them down since they have no aperture ring. Sorry, but not the case. On M and K series bodies, a DA lens will be wide open to compose and stops down to its minimum aperture at taking time. The reason is that those older bodies are not forward compatible to the DA lenses. They give the aperture lever its full travel while A mount and newer bodies move the lever only as far as is needed for the aperture set by the body. Ditto for A and FA lenses when the aperture ring is on the "A" setting. Steve (Have several pre-A film bodies...) Last edited by stevebrot; 12-13-2009 at 02:54 AM.

12-13-2009, 02:54 AM	#5
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by keyser ...Your pics would be substantially over exposed unless you manually set the shutter speed... Metering (ironically) is correct for the taking aperture (fully stopped down). The DA lens that I own (18-55) has the appropriate "stop" on the mount that communicates the appropriate minimum aperture offset for the lens. The camera uses that offset to bias the meter for the taking aperture. Steve

12-13-2009, 02:58 AM	#6
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by mer Hi is there a way to force DA lenses ( without aperture ring ) to shoot wide open ? I use a ME Super and I want to use the 18-55mm wide open. Is there any way to do that ? ( like tape aperture lever etc ) I would not tape the aperture lever. Doing so may jam the shutter mechanism on the camera...perhaps permanently. Your best option might be to pick up a cheap A or P series body and shoot in P or Sv mode. Steve