AE lock ignored when adjusting ISO in manual mode

drougge · 10-24-2011, 10:40 AM

I use manual mode a lot. When I want to change the aperture but not the exposure I can use AE lock. The same is sort of true with shutter speed, except the camera adjusts aperture instead of ISO which is what I'd prefer. Or with a manual lens it just doesn't work.

But this is not the main problem, the main problem is that if I adjust the ISO nothing is else follows along, thus changing my exposure. I have not been able to find any setting that changes this, but it may well be there anyway, anyone know where?

Or it could work with newer firmware versions, even though the release notes didn't say anything about it. I'm using 1.03.

Wheatfield · 10-24-2011, 03:22 PM

The concept of manual mode is just that. You are controlling every aspect of the camera's operation with no input from the camera itself.
If you adjust one parameter and the camera adjusts another to compensate, you are no longer controlling everything, and are no longer shooting in manual mode.
Your camera is working exactly as it is designed to work, and is working exactly as you should be expecting it to work.

bobmaxja · 10-24-2011, 05:11 PM

IT's time to read the Book Exposure to understand how to adjust the aperture , speed and ISO. I use the manual mode and use the EV to get the proper exposure.

drougge · 10-24-2011, 05:51 PM

I though I was being clear, but apparently not.

I understand exposure just fine, but AE lock is supposed to lock the exposure in manual mode as well, despite the A in the name.

To be extra clear:
When I use AE lock in manual mode, shutter and aperture can be adjusted without changing the exposure, but changing the ISO will change the exposure. If I wanted to change the exposure, I would not activate AE lock.

pentup · 10-24-2011, 07:18 PM

This seemed odd to me too, at first: In manual mode, with a correct exposure indicated, if you set AE lock, then press the ISO button, the exposure indicator disappears (which I find bizarre; what purpose is served by that??) and if you, for example, raise the ISO, then hit the button again to make the meter reappear, the shutter speed and aperture will be the same as before, but you will of course have an over-exposure. And AE lock is still set, but now locked to a different exposure than what you set it at. Which at first seems to violate the whole point of AE lock, and I assume that's why the OP finds it wrong -- but ...

I think the reason may simply be that the camera, in manual mode, has no way of knowing whether you would prefer the shutter speed to change, or the aperture, in order to preserve the exposure when you change ISO. I don't see any way around it -- but I think it would have been better if Pentax had the camera cancel AE lock when the ISO button is pressed. It seems to me you simply have to choose among Av, Tv or Sv to get the behavior you want. In Av mode changing ISO will change shutter speed, in Tv it will change the aperture, and in Sv -- well, I never use it, and I don't understand how it works. Sometimes it changes shutter speed, sometimes aperture.

Incidentally, the AE lock and ISO behavior is the same in the other modes -- if you change ISO when AE is locked you'll freeze the aperture and shutter speed, and change the exposure.

By the way, you probably know this already, but in manual mode you can quickly return to centered exposure (which of course may differ from what you originally locked anyway) by hitting the green button, and you'll still have AE lock on, and you can adjust from there.

drougge · 10-24-2011, 08:27 PM

It would be perfectly possible to have an option for what I wanted changed. Or follow my setting for the green button. It's an interface bug, but I'm still hoping there's some way to set the options so I don't suffer from it.

Choosing a non-M mode isn't really a solution, since the reason I'm using M in the first place is so the meter doesn't mess with me.

(Also, AE lock tracks ISO fine in Av and Tv modes for me, so either there's an option for this somewhere, or it differs between firmware versions.)

pentup · 10-24-2011, 08:40 PM

But what is it exactly that you want to change when you change ISO? If you want the shutter speed to change, then you can use aperture priority. If you want aperture to change, then use shutter priority. With either one, you can set ISO where you want, and one other (non-priority) setting will change to compensate. But really -- in manual mode, how is the camera supposed to know which setting you want to change (shutter speed or aperture, or some combination of both?) when you change ISO? The only way it can is if you use the green button, and you have to decide in advance whether you want the shutter speed or the aperture shifting.

I'm not sure what you mean by "follow your setting for the green button," but you can set the green button to give you Program Line, Tv Shift or Av Shift.

How does the meter "mess with you" in the other modes? I'm just curious.

Last edited by pentup; 10-24-2011 at 08:48 PM.

derekkite · 10-24-2011, 09:12 PM

I understand what he is asking for. If you are in M mode, hit ae-l, and shift the aperture, the shutter speed shifts as well. Hyper manual I think it is called, and pretty slick. If you hit ae-l, change the iso, nothing changes with it, ie. the exposure isn't adjusted as you change.

The program line selections are either shutter speed or aperture. The option of adjusting the sensitivity would be nice.

With my adaptall lenses with a pk adapter, no aperture feedback, if I want to increase the shutter speed I have to set the iso manually to what I figure might be close, hit the green button and adjust the iso until I get a shutter speed close to what I want. This in M mode. Being able to shift the shutter and iso in tandem to maintain an exposure would be very nice.

drougge · 10-24-2011, 09:14 PM

I want ISO changes with AE lock to also change the shutter speed. Just like I want the green button to change the shutter speed. In the latter case I have set this option, and it works. In the former, there is no option, and it doesn't work. But even without a separate option, it could assume I want the same thing changed as with the green button, except obviously not based on what the meter sees.

If I use some automatic mode the camera will change my exposure based on how much light it sees. Or as I put it, mess with me. That's the point of those modes. When I want it to not do that, I use manual mode. (Sure, I can use AE lock to stop it, for a little while, but then it will go right back to tracking the light.)

Wheatfield · 10-25-2011, 06:35 AM

It looks like you've hit on a combination that the programmers didn't think of.

Mychael · 10-26-2011, 02:02 PM

Forgive me if this is a dumb question. I've not yet got a DSLR but have had 35mm so understand manual settings.
Just clear things up for me.
Is everyone saying that even in full manual mode (with older manual lenses) you still don't have full control over setting your own aperture/shutter speed and I.S.O ? Accepting of course that any over/under exposure is all of my making.

drougge · 10-26-2011, 04:22 PM

You have full control, of course you do. Both with old and new lenses. I'm just trying to get all the convenience a modern camera could trivially give me.

sterretje · 10-26-2011, 11:08 PM

If I understand your problem correctly, you can use P mode. It does exactly what you're asking for

In my setup
rear dial changes aperture
front dial changes shutterspeed
changing iso either changes aperture (if the last thing you changed was shutterspeed) or shutterspeed (if the last thing you changed was aperture); if you did not change any yet after you locked the exposure, it will alternate between aperture and shutterspeed adjustment

drougge · 10-29-2011, 06:19 AM

Unfortunately, you do not understand my problem correctly. I can and do use the automatic modes. They are fine, but they are not a replacement for manual. In an auto mode, pressing AE lock is a temporary thing, they go back to tracking the light if I leave the camera a short while.

It seems pretty clear there is no solution to my actual problem short of a fixed firmware. So, anyone have an opinion on where I should send my bug report to have at least some chance of having it acted upon?

HawaiianOnline · 10-29-2011, 05:08 PM

So, you're basically making a creative choice in overriding the metering system and going fully manual? This in and of itself is more flexible in terms of creative choice over going with another mode (Av, or TAv) and using exposure compensation. This allows selective overexposure or underexposure depending on what exactly you're trying to achieve.

10-24-2011, 10:40 AM	#1
drougge Veteran Member Join Date: Jan 2010 Location: Malmö Photos: Gallery Posts: 787	AE lock ignored when adjusting ISO in manual mode I use manual mode a lot. When I want to change the aperture but not the exposure I can use AE lock. The same is sort of true with shutter speed, except the camera adjusts aperture instead of ISO which is what I'd prefer. Or with a manual lens it just doesn't work. But this is not the main problem, the main problem is that if I adjust the ISO nothing is else follows along, thus changing my exposure. I have not been able to find any setting that changes this, but it may well be there anyway, anyone know where? Or it could work with newer firmware versions, even though the release notes didn't say anything about it. I'm using 1.03.

10-24-2011, 07:18 PM	#5
pentup Veteran Member Join Date: Jul 2010 Location: Flushing NY Photos: Albums Posts: 413	This seemed odd to me too, at first: In manual mode, with a correct exposure indicated, if you set AE lock, then press the ISO button, the exposure indicator disappears (which I find bizarre; what purpose is served by that??) and if you, for example, raise the ISO, then hit the button again to make the meter reappear, the shutter speed and aperture will be the same as before, but you will of course have an over-exposure. And AE lock is still set, but now locked to a different exposure than what you set it at. Which at first seems to violate the whole point of AE lock, and I assume that's why the OP finds it wrong -- but ... I think the reason may simply be that the camera, in manual mode, has no way of knowing whether you would prefer the shutter speed to change, or the aperture, in order to preserve the exposure when you change ISO. I don't see any way around it -- but I think it would have been better if Pentax had the camera cancel AE lock when the ISO button is pressed. It seems to me you simply have to choose among Av, Tv or Sv to get the behavior you want. In Av mode changing ISO will change shutter speed, in Tv it will change the aperture, and in Sv -- well, I never use it, and I don't understand how it works. Sometimes it changes shutter speed, sometimes aperture. Incidentally, the AE lock and ISO behavior is the same in the other modes -- if you change ISO when AE is locked you'll freeze the aperture and shutter speed, and change the exposure. By the way, you probably know this already, but in manual mode you can quickly return to centered exposure (which of course may differ from what you originally locked anyway) by hitting the green button, and you'll still have AE lock on, and you can adjust from there. Last edited by pentup; 10-24-2011 at 07:30 PM.

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10-24-2011, 03:22 PM	#2
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,981	The concept of manual mode is just that. You are controlling every aspect of the camera's operation with no input from the camera itself. If you adjust one parameter and the camera adjusts another to compensate, you are no longer controlling everything, and are no longer shooting in manual mode. Your camera is working exactly as it is designed to work, and is working exactly as you should be expecting it to work.

10-24-2011, 05:11 PM	#3
bobmaxja Veteran Member Join Date: Mar 2010 Location: Laval, Quebec Canada Posts: 2,171	IT's time to read the Book Exposure to understand how to adjust the aperture , speed and ISO. I use the manual mode and use the EV to get the proper exposure.

10-24-2011, 05:51 PM	#4
drougge Veteran Member Join Date: Jan 2010 Location: Malmö Photos: Gallery Posts: 787 Original Poster	I though I was being clear, but apparently not. I understand exposure just fine, but AE lock is supposed to lock the exposure in manual mode as well, despite the A in the name. To be extra clear: When I use AE lock in manual mode, shutter and aperture can be adjusted without changing the exposure, but changing the ISO will change the exposure. If I wanted to change the exposure, I would not activate AE lock.

10-24-2011, 08:27 PM	#6
drougge Veteran Member Join Date: Jan 2010 Location: Malmö Photos: Gallery Posts: 787 Original Poster	It would be perfectly possible to have an option for what I wanted changed. Or follow my setting for the green button. It's an interface bug, but I'm still hoping there's some way to set the options so I don't suffer from it. Choosing a non-M mode isn't really a solution, since the reason I'm using M in the first place is so the meter doesn't mess with me. (Also, AE lock tracks ISO fine in Av and Tv modes for me, so either there's an option for this somewhere, or it differs between firmware versions.)

10-24-2011, 08:40 PM	#7
pentup Veteran Member Join Date: Jul 2010 Location: Flushing NY Photos: Albums Posts: 413	But what is it exactly that you want to change when you change ISO? If you want the shutter speed to change, then you can use aperture priority. If you want aperture to change, then use shutter priority. With either one, you can set ISO where you want, and one other (non-priority) setting will change to compensate. But really -- in manual mode, how is the camera supposed to know which setting you want to change (shutter speed or aperture, or some combination of both?) when you change ISO? The only way it can is if you use the green button, and you have to decide in advance whether you want the shutter speed or the aperture shifting. I'm not sure what you mean by "follow your setting for the green button," but you can set the green button to give you Program Line, Tv Shift or Av Shift. How does the meter "mess with you" in the other modes? I'm just curious. Last edited by pentup; 10-24-2011 at 08:48 PM.

10-24-2011, 09:12 PM	#8
derekkite Pentaxian Join Date: Sep 2011 Location: Nelson B.C. Posts: 3,782	I understand what he is asking for. If you are in M mode, hit ae-l, and shift the aperture, the shutter speed shifts as well. Hyper manual I think it is called, and pretty slick. If you hit ae-l, change the iso, nothing changes with it, ie. the exposure isn't adjusted as you change. The program line selections are either shutter speed or aperture. The option of adjusting the sensitivity would be nice. With my adaptall lenses with a pk adapter, no aperture feedback, if I want to increase the shutter speed I have to set the iso manually to what I figure might be close, hit the green button and adjust the iso until I get a shutter speed close to what I want. This in M mode. Being able to shift the shutter and iso in tandem to maintain an exposure would be very nice.

10-24-2011, 09:14 PM	#9
drougge Veteran Member Join Date: Jan 2010 Location: Malmö Photos: Gallery Posts: 787 Original Poster	I want ISO changes with AE lock to also change the shutter speed. Just like I want the green button to change the shutter speed. In the latter case I have set this option, and it works. In the former, there is no option, and it doesn't work. But even without a separate option, it could assume I want the same thing changed as with the green button, except obviously not based on what the meter sees. If I use some automatic mode the camera will change my exposure based on how much light it sees. Or as I put it, mess with me. That's the point of those modes. When I want it to not do that, I use manual mode. (Sure, I can use AE lock to stop it, for a little while, but then it will go right back to tracking the light.)

10-25-2011, 06:35 AM	#10
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,981	It looks like you've hit on a combination that the programmers didn't think of.

10-26-2011, 02:02 PM	#11
Mychael Site Supporter Join Date: Oct 2011 Location: Melbourne,Victoria,Australia Photos: Albums Posts: 215	Forgive me if this is a dumb question. I've not yet got a DSLR but have had 35mm so understand manual settings. Just clear things up for me. Is everyone saying that even in full manual mode (with older manual lenses) you still don't have full control over setting your own aperture/shutter speed and I.S.O ? Accepting of course that any over/under exposure is all of my making.

10-26-2011, 04:22 PM	#12
drougge Veteran Member Join Date: Jan 2010 Location: Malmö Photos: Gallery Posts: 787 Original Poster	You have full control, of course you do. Both with old and new lenses. I'm just trying to get all the convenience a modern camera could trivially give me.

10-26-2011, 11:08 PM	#13
sterretje Veteran Member Join Date: Dec 2008 Location: Roodepoort, South Africa Photos: Gallery \| Albums Posts: 3,561	If I understand your problem correctly, you can use P mode. It does exactly what you're asking for In my setup rear dial changes aperture front dial changes shutterspeed changing iso either changes aperture (if the last thing you changed was shutterspeed) or shutterspeed (if the last thing you changed was aperture); if you did not change any yet after you locked the exposure, it will alternate between aperture and shutterspeed adjustment

10-29-2011, 06:19 AM	#14
drougge Veteran Member Join Date: Jan 2010 Location: Malmö Photos: Gallery Posts: 787 Original Poster	Unfortunately, you do not understand my problem correctly. I can and do use the automatic modes. They are fine, but they are not a replacement for manual. In an auto mode, pressing AE lock is a temporary thing, they go back to tracking the light if I leave the camera a short while. It seems pretty clear there is no solution to my actual problem short of a fixed firmware. So, anyone have an opinion on where I should send my bug report to have at least some chance of having it acted upon?

10-29-2011, 05:08 PM	#15
HawaiianOnline Veteran Member Join Date: Jan 2007 Location: Hawaii Posts: 613	So, you're basically making a creative choice in overriding the metering system and going fully manual? This in and of itself is more flexible in terms of creative choice over going with another mode (Av, or TAv) and using exposure compensation. This allows selective overexposure or underexposure depending on what exactly you're trying to achieve.