[pdsrms]

Just bought a 645Z. I own two film 645s.
I can't get the AE-L to activate with A series lenses.
I happen to also have a 645D on hand and the same occurs.

The Z came with a 55mm DFA lens and it works fine with AE-L

Please don't tell me the 645Z won't support AE-L with A series lenses?
The A series seems to be compatible in other functions, like metering , and Pentax certainly touts backwards compatibility with the D and Z.

I see nothing in the manual that's helpful to this situation.
But with Digital cameras I don't speak Pentax. Only Olympus and Nikon.
is the problem in the enable / disable controls setting in C5?
Which BTW I don't understand the purpose.

Any other ideas??

[pschlute]

Any other ideas??

Where have you set the aperture ring on the lens ?

[pdsrms]

not on A

not on A

I guess you have to set it to A, otherwise it is recognized as a manual aperture lens, and then AE-L does not work (that is with all Ricoh/Pentax camera's).

[Not a Number]

It should work the same. What mode do you have the camera in? AE-L doesn't work with in Manual mode (M) with the ring off the "A" setting. AE-L doesn't work in X or Bulb mode regardless of the lens type. Any other setting will default to Av and the AE-L should work but the lens will only meter and shoot wide open.

Is the Z new or used? If used perhaps resetting the settings to default or as the same on the D might help.

[stevebrot]

not on A

It should work the same. What mode do you have the camera in? AE-L doesn't work with in Manual mode (M) with the ring off the "A" setting.

There is your most likely answer. M mode on the 645D and 645Z supports a feature set called hyper-manual, one aspect of which is that when AE Lock is engaged, changing the aperture results in a corresponding change to the shutter speed to maintain the same exposure and vice versa. Hyper-manual only works when the body is in control of the lens aperture (ring off the "A" position). When off the "A" position in M mode, AE Lock has no defined function.

BTW...you are correct in that the manual is silent on the M mode behavior and the hyper-manual feature in general. For more information on hyper-manual, see the resource page on the Ricoh Japan Web site:

Ricoh Imaging | Pentax Hyper Control System


Steve

[johnha]

If I may, a correction

There is your most likely answer. M mode on the 645D and 645Z supports a feature set called hyper-manual, one aspect of which is that when AE Lock is engaged, changing the aperture results in a corresponding change to the shutter speed to maintain the same exposure and vice versa. Hyper-manual only works when the body is in control of the lens aperture (ring ON off the "A" position). When off the "A" position in M mode, AE Lock has no defined function.

BTW...you are correct in that the manual is silent on the M mode behavior and the hyper-manual feature in general. For more information on hyper-manual, see the resource page on the Ricoh Japan Web site:

Ricoh Imaging | Pentax Hyper Control System

Steve

That's not the best explanation, they used to have a better diagram:

Put the lens on A, exposure mode to M. Spinning the dials alters your aperture or shutter speed manually. Pressing the green button resets both as per the selected program line (action/depth/MTF etc) which can then be changed separately by spinning the respective dial. Activating AE-L locks the aperture and shutter speed pairing so that either dial shifts both to maintain the equivalent EV value.

In other modes (P, Av, Tv) AE-L should work normally - I'm pretty sure it works in Av even with P6x7 lenses on the Pentax adapter (which are not A lenses).

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Last edited by johnha; 05-17-2020 at 08:54 PM.

[stevebrot]

Please don't tell me the 645Z won't support AE-L with A series lenses?

You may be assured that A-series 645 lenses are supported for AE-L on your 645Z and that the camera is backward compatible for the vast majority of features of your camera. The key is that both A and FA-series lenses are intended to be used with the aperture ring on the "A" position except where such is not possible. For those cases, the metered exposure options are limited to Av and metered M modes. Of those two, only Av provides AE-L, since M is fully manual with no AE to lock.

Page 28 of the user manual has a compatibility matrix for A645 and FA645 lenses. The first two columns concern the lens only and a few exceptions these two series work transparently with your camera. For A645, you are lose AF, automatic lens correction, and auto zoom with flash.


Steve

[stevebrot]

That's not the best explanation, they used to have a better diagram:

Thanks for the concise and accurate description. Hyper-manual and mapping of the AE-L button to allow for fixed EV in M mode are a few of the more neglected and poorly documented features of Pentax cameras.

In other modes (P, Av, Tv) AE-L should work normally - I'm pretty sure it works in Av even with P6x7 lenses on the Pentax adapter (which are not A lenses).

I am confident you are correct on both counts.


Steve

[johnha]

Thanks for the concise and accurate description. Hyper-manual and mapping of the AE-L button to allow for fixed EV in M mode are a few of the more neglected and poorly documented features of Pentax cameras.

I am confident you are correct on both counts.

Steve

Thanks Steve, the diagram I'm looking for combines HyperProgram and HyperManual and probably relates to older cameras where the e-dials couldn't be reconfigured. See the Hyper Program Modes section of this: Feature 3?K-3 | RICOH IMAGING

---------- Post added 05-18-20 at 05:19 AM ----------

Next up: how to use exposure compensation and auto-bracketing to push all your brackets to one side of 'correct' rather than either side, while watching the exposure 'number line' (don't think there's a diagram for that)...

[johnha]

I guess you have to set it to A, otherwise it is recognized as a manual aperture lens, and then AE-L does not work (that is with all Ricoh/Pentax camera's).

Now I've been able to test my D, the above is incorrect (and I suspect similarly for the Z). My A*300 works with AE-L in Av mode when not on 'A' (as Steve mentioned). In addition, AE-L works if you change the f stop on the lens itself, but drops out if you move it into or out of 'A' - this triggers an exposure mode change.

I don't have a Z manual to hand so can't help with menu C5. If it's the same as the D - AE-L with AF lock, I presume this automatically locks exposure when the AF finds focus. I presume C6 - Link AE to AF point - decides whether to use all the metering points or just those related to the selected AF point(s).

[pdsrms]

I was misinterpreting the manual's statement about having the aperture ring on A.
My A lenses now work, Sadly I won't have the pleasure of further adjusting that wonderfully machined ring.
All this and I realized that the my original 645s didn't even offer AE-L

I think I'm going to dust off my handheld spot meter,

Thank You for your comments.

[Not a Number]

All this and I realized that the my original 645s didn't even offer AE-L

Shoot in manual mode. The settings aren't going to change unless you change them.

I have my 645z in Av and my SMC Pentax-A 645 35/3.5 set on 5.6 on the aperture ring. AE-L gives me exposure lock and the ISO changes when I change the aperture ring to f/8 or f/3.5 if in AutoISO. If fixed ISO the shutter speed will change accordingly.

So, AE-L works fine with A-lenses.