HELP - LEICA R LENS ON SONY a900

[MikalWGrass]

I have a Leica R 50/1.4 on an a900. The R is adapted with the Leitax adapter and the Lao chip. Most of the time I shoot on manual, however, regardless of what mode I shoot in, the fstop never registers properly. Whenever I shoot on shutter priority, the aperture never adjusts properly. Likewise, when I shoot on aperture priority, the shutter never adjusts properly. I am really better off shooting on fully manual and hoping that I remember the fstop.

I was under the impression, perhaps the mistaken impression, that with the Lao chip, all of the functions work except, of course, auto focus.

Can someone please tell what is going on. Please remember that I am not mechanically inclined.

Thank you.

[pegelli]

Since there is no connection between the aperture of the lens and the LAO chip there is no way the actual aperture setting of the lens can be sent to the camera and the camera cannot set the aperture on the lens.

There exists a work around to get the correct aperture in the exif in A-mode if you remember to set the aperture on the camera the same as on the lens and then use a complicated combination of switch/button operations to get the right exposure. I've never really bothered with it though, but if you're really interested I can go and find it. Shooting fully manual is easier, after you determined exposure set the camera aperture setting the same as on your lens and it will show correctly in the exif.

Last remark, for your camera exposure meter to work correctly set the aperture on the camera at the max f-stop of the LAO chip and put your the aperture on the lens at the setting you want to take the exposure at. This is needed because the exposure meter thinks the lens is wide open and it will be closed down to the camera aperture setting when taking the shot, but due to the fact the camera cannot control the lens aperture the shot will be overexposed.

[philip_pj]

Interesting, pegelli. I use A mode on the A900 (with f'ware upgrade) and find it very convenient and often accurate enough. Focus and compose wide open, shut down to taking aperture, press shutter button to get meter reading of s/s, use exposure comp if needed, shoot. This is unchipped.

I was wearing out my index finger in M mode.

I would, however, love a better histo, why do they hide the tiny thing and not provide end points? So may people must just trust their meters, like AF for focus I guess. I put a small piece of grey duct tape on the display so I can see the highlight clip point in bright sunlight.

Speed the A99, with focus peaking, EVF histo and LCD zooming, it will be like heaven for manual focus lens users.

[pegelli]

Originally Posted by philip_pj

Interesting, pegelli. I use A mode on the A900 (with f'ware upgrade) and find it very convenient and often accurate enough. Focus and compose wide open, shut down to taking aperture, press shutter button to get meter reading of s/s, use exposure comp if needed, shoot. This is unchipped.

Indeed, if you shoot "unchipped" the camera aperture will always be "f 1" and as long as you meter light with the lens at shooting aperture (with appropriate + or - EV) you'll be OK.

Good tip on the duct tape, I'll try that. Only on every picture you're chimping at full size will have a small grey bar in the frame.