Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Pentax / Samsung dSLR, K Mount Mirrorless

Reply
 
Thread Tools Search this Thread
Old Oct 2, 2006, 10:02 PM   #1
Senior Member
 
NonEntity1's Avatar
 
Join Date: Jul 2006
Location: Lake Placid Florida USA
Posts: 2,689
Default

I now have a couple of manual focus lenses without the A setting on the aperture ring. I have read several posts about how you need to use the AE-L button with these lenses. The funny thing is that it appears that I don't. Thus far, I have been slapping the lenses on, setting my aperture on the ring, choosing the focal length when the camera asks (for the shake reduction), and snapping away. I never touch the AE-L button and I can see the camera changing the shutter settings as I change the aperture. Now, thus far I have only used them in Av, so maybe that makes the difference? If so, this is good news for me because I seem to do about 90% of my picture taking in Av. Or am I missing something here?

Thanks,

Tim
NonEntity1 is offline   Reply With Quote
Sponsored Links
Old Oct 2, 2006, 10:19 PM   #2
Senior Member
 
philneast's Avatar
 
Join Date: Apr 2005
Location: Hobart Tasmania
Posts: 489
Default

No that is right if you are working in AV mode.


You use AE-L button in fully manual mode.

With lenses that have automatic diagphrams you compose and focus with teh diagphram at fully wide open ignoring the actual apeture setting. For eth meter to take a realistic reading the lens needs to reduce the apeture down to the you have made.

Using the AE-Lbutton does this for a short period of time and enables the metering function. It also seems to alter the shutter speed setting to match the apeture selected.

Then you can decide if this combination is right before you take the photo, and of course this combination of Apeture and Shutter speed stays tha way in the manual mode until you change it.

There is also a Depth of Field preview function (on my DS anyhow) that shuts the lens down and permits manual metering, but this does not change shutter speed automatically, you get an indication in the viewfinder of how many stops under or over the camera thinks your settings are.
philneast is offline   Reply With Quote
Old Oct 3, 2006, 10:51 AM   #3
Member
 
Join Date: Jul 2006
Posts: 52
Default

Wow! I didn't realize this. I bought a few older lenses with an aperture ring and to be able to use them with the Pentax in a real "aperture-priority" mode by altering the aperture ring directly rather than having to use the little dial on the camera body is much more intuitive (and just like I used to do it on my old film cameras!).

Woo-Hoo!
themacguy is offline   Reply With Quote
Old Oct 4, 2006, 5:23 PM   #4
Senior Member
 
NonEntity1's Avatar
 
Join Date: Jul 2006
Location: Lake Placid Florida USA
Posts: 2,689
Default

OK, further experimentation and reading have led to a greater understanding. My method does seem to work on my one lens without any mechanical automatic diagaphram control. On my manual lenses with the mechanical diagaphram control but no A setting I have to use manual mode to actually have the camera set at the correct aperture. Otherwise, in Av mode, the camera leaves the diagaphram wide open no matter what setting I have chosen on the aperture ring. Apparently what I thought was the camera adjusting shutter speed to match aperture in Av mode was simply the camera adjusting as I pointed it in a different direction so that I could see the aperture ring.

I now understand why everyone uses these lenses in manual mode and I now understand what Phil was trying to tell me. Sorry themacguy, but it does not work the way I thought it did.

Tim
NonEntity1 is offline   Reply With Quote
Old Oct 4, 2006, 7:13 PM   #5
Senior Member
 
bper's Avatar
 
Join Date: Jan 2006
Location: Washington State
Posts: 454
Default

Just to try and clarify further. Any of the screw mount (M42) lenses, even though they say Manual / Auto will not work other then in the M setting on the camera. The M42 lenses use a pin that goes in and out and the K mount uses a lever that goes up and down to operate the aperture. So the M42's have no way of connecting the aperture mechanically as do the K mount lenses. They take pictures just fine, but you need to use the M setting on the camera and the AE-L button to set the shutter speed to the correct light meter setting. Be sure to set everything in manual including the switch on the lens or the diaphram will not operate- Bruce
bper is offline   Reply With Quote
Old Oct 5, 2006, 12:07 AM   #6
Senior Member
 
philneast's Avatar
 
Join Date: Apr 2005
Location: Hobart Tasmania
Posts: 489
Default

Yes you can use screw mount (m42) lenses in Av or aperture priority mode, at least on my DS.

If the lens has a manual diagphram operation then you set the apeture, and the diagphram shuts down to that apeture setting, in Av mode the camera will set the shutter speed automatically when you take the picture.

The only down side is that with th aperture shut down focusing may be a bit more difficult. I usually focus with the lens wide open then stop it down for the actual shot.

As Bruce points out there is no mechanical connection between the M42 lens and the camera to automatically alter the aperture.

Phil




philneast is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 7:46 AM.