How do I meter after setting up back button focus?

lindseyd · 04-09-2019, 07:17 PM

I have a Pentax K-70. I've set up back button focus (AF2). How do I meter now? Will I still be able to see the * in the viewfinder?

**DW58** · 04-10-2019, 07:00 AM

By pressing the back button.

pete-tarmigan · 04-10-2019, 11:55 AM

I thought you still had the press the shutter down half-way. Check the user manual.

TerryL · 04-10-2019, 12:49 PM

I would like to know, too. It would be useful when using ND filters.
Terry

**DW58** · 04-10-2019, 01:18 PM

Originally posted by pete-tarmigan

I thought you still had the press the shutter down half-way.

Nope.

StarTroop · 04-10-2019, 02:16 PM

Are you sure you're pressing it down enough? Did you turn off metering by accident? By default on the KP, metering is set to be active for 3 seconds on half-shutter press, even if back button focusing is used. I assume the K70 should be identical.

PDL · 04-10-2019, 07:10 PM

Given my experience with Pentax ( *ist Ds, K10D, K20D and K-3Ii) and back button focus it works as follows.

Pressing the shutter button activates the metering system. That's all.

The use of back button focus does not effect the metering system at all.

**paulh** · 04-10-2019, 07:18 PM

Originally posted by PDL

Given my experience with Pentax ( *ist Ds, K10D, K20D and K-3Ii) and back button focus it works as follows.

Pressing the shutter button activates the metering system. That's all.

The use of back button focus does not effect the metering system at all.

My experience as well.

lindseyd · 04-10-2019, 07:33 PM

Originally posted by PDL

Given my experience with Pentax ( *ist Ds, K10D, K20D and K-3Ii) and back button focus it works as follows.

Pressing the shutter button activates the metering system. That's all.

The use of back button focus does not effect the metering system at all.

So is it still metering even if I don't see the * in the viewfinder?

**monochrome** · 04-10-2019, 07:57 PM

Just happened to have my KP next to me. Either half-pressing the shutter button or pressing the back button turns on the meter for three seconds,

Adam · 04-10-2019, 08:09 PM

Originally posted by lindseyd

So is it still metering even if I don't see the * in the viewfinder?

Yes. The * only denotes AE-L, I believe.

**DW58** · 04-10-2019, 08:14 PM

Am I missing something? I set my K-70 for back button focus on day one. I pick a brightly lit subject and press the back button. Subject comes into focus and I see exposure values in the viewfinder. If I move to a darker subject one of the exposure values in the viewfinder changes. Even without pressing the back button again. Which value changes depends on my setting. T. Av. TaV. Etc. I have not touched the shutter release button since I turned the camera on.

PDL · 04-11-2019, 01:14 PM

Originally posted by DW58

Am I missing something? I set my K-70 for back button focus on day one. I pick a brightly lit subject and press the back button. Subject comes into focus and I see exposure values in the viewfinder. If I move to a darker subject one of the exposure values in the viewfinder changes. Even without pressing the back button again. Which value changes depends on my setting. T. Av. TaV. Etc. I have not touched the shutter release button since I turned the camera on.

No, you are not missing something.

Using the back button for focus starts the process to start the focus process, which is basically the same thing as ""starting the camera". When either the shutter button is pressed to "start the camera" or the back button is pressed to start focus - which is essentially "starting the camera" the meter will be started.

Now I have noticed that pushing the back button focus on my K-3II will be somewhat delayed when the battery has been used for some time. Add into this I have the dust-removal running on each power up so there is a delay punching the button (either one) and having the system respond.

When the camera "goes to sleep" it will come back to the present (rather than the trite term come back to life) by pressing either the Menu button, info button, AF button etc. When you press a either the LV button/switch, AF button or shutter button, the meter starts and the camera is getting ready to take a picture.

As Adam stated above the * in the viewfinder is the AEL lock (exposure lock) and the exposure meter has to be operating for the * to show up.

**mikesbike** · 04-11-2019, 05:31 PM

Originally posted by lindseyd

I have a Pentax K-70. I've set up back button focus (AF2). How do I meter now? Will I still be able to see the * in the viewfinder?

The back AF setup is not for metering. It is for focusing- Auto Focus to be specific. But the button is alternately used as an AE-L button instead of a back AF button. In that case, it also does not meter, but it will lock the exposure meter that has been set already by metering. This is used under various conditions where a metered value is needed to be preserved, while lighting situations may be changing. When the button is set for that use, then you get your AF via the front shutter release button by using the half/press to obtain AF and to hold focus.

Metering takes place in a manner according to where you have set your mode dial. If you want your camera set for fully automatic exposure metering, where both the shutter speed and the aperture will be set by the camera according to the camera's meter reading of the lighting, then the mode dial can be set either on the green AUTO mode, or on the "P" mode. The "P" mode is better because the green AUTO mode does not allow access to many adjustments and to many control features, including the exclusive Pentax Hyper Program operation, where you can override the camera's setting of either aperture or shutter speed. You can also have the camera automatically adjust the ISO according to the light meter reading as well in this mode.

There are other automatic exposure metering modes on the mode dial to choose from, which are not fully automatic because you play a role, such as selecting a preference of aperture or shutter speed, while the camera automatically compensates by setting the other. These are the Tv or Av modes. Consult your handbook for the other modes. There are good reasons for being able to take control of these aspects of photography instead of always just having your camera on auto-pilot.

Not a Number · 04-11-2019, 06:01 PM

I think what the OP is asking is when back button AF is set does the button still perform AE-L.

04-09-2019, 07:17 PM	#1
lindseyd New Member Join Date: Apr 2019 Posts: 2	How do I meter after setting up back button focus? I have a Pentax K-70. I've set up back button focus (AF2). How do I meter now? Will I still be able to see the * in the viewfinder?

04-10-2019, 07:57 PM	#10
monochrome Loyal Site Supporter Join Date: Mar 2008 Location: Working From Home Photos: Gallery \| Albums Posts: 26,276	Just happened to have my KP next to me. Either half-pressing the shutter button or pressing the back button turns on the meter for three seconds, Last edited by monochrome; 04-10-2019 at 09:39 PM.

04-10-2019, 08:09 PM	#11
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Originally posted by lindseyd So is it still metering even if I don't see the * in the viewfinder? Yes. The * only denotes AE-L, I believe. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
How do I set up back button focus on a K-70	Joyce Keay	Troubleshooting and Beginner Help	9	01-25-2022 10:54 AM
Back button Focus	adsouza	Pentax K-3 & K-3 II	31	04-19-2021 10:17 AM
Front focus and back focus problems with manual focus lenses	hatsofe	Photographic Technique	17	11-05-2017 07:29 AM
Back to default after "Raw-Fx" button Customization to HDR?	uday029	Pentax K-3 & K-3 II	19	03-16-2015 01:40 AM
Green button or +/- button for meter?	kidblue	Pentax SLR Lens Discussion	15	07-29-2011 07:10 PM

04-10-2019, 07:00 AM	#2
DW58 Loyal Site Supporter Join Date: Dec 2015 Location: Rural Oregon Photos: Gallery \| Albums Posts: 7,064	By pressing the back button.

04-10-2019, 11:55 AM	#3
pete-tarmigan Veteran Member Join Date: Apr 2009 Location: Conception Bay South, New-fun-land Photos: Gallery Posts: 1,272	I thought you still had the press the shutter down half-way. Check the user manual.

04-10-2019, 12:49 PM	#4
TerryL Pentaxian Join Date: Jan 2018 Location: Virginia, USA Photos: Albums Posts: 850	I would like to know, too. It would be useful when using ND filters. Terry

04-10-2019, 01:18 PM	#5
DW58 Loyal Site Supporter Join Date: Dec 2015 Location: Rural Oregon Photos: Gallery \| Albums Posts: 7,064	Originally posted by pete-tarmigan I thought you still had the press the shutter down half-way. Nope.

04-10-2019, 02:16 PM	#6
StarTroop Senior Member Join Date: Feb 2018 Posts: 175	Are you sure you're pressing it down enough? Did you turn off metering by accident? By default on the KP, metering is set to be active for 3 seconds on half-shutter press, even if back button focusing is used. I assume the K70 should be identical.

04-10-2019, 07:10 PM	#7
PDL Pentaxian Join Date: Oct 2006 Location: PNW USA Photos: Gallery Posts: 2,127	Given my experience with Pentax ( *ist Ds, K10D, K20D and K-3Ii) and back button focus it works as follows. Pressing the shutter button activates the metering system. That's all. The use of back button focus does not effect the metering system at all.

04-10-2019, 07:18 PM	#8
paulh Site Supporter Join Date: Sep 2010 Location: DFW Texas/Ventura County, CA Photos: Gallery \| Albums Posts: 33,263	Originally posted by PDL Given my experience with Pentax ( *ist Ds, K10D, K20D and K-3Ii) and back button focus it works as follows. Pressing the shutter button activates the metering system. That's all. The use of back button focus does not effect the metering system at all. My experience as well.

04-10-2019, 07:33 PM	#9
lindseyd New Member Join Date: Apr 2019 Posts: 2 Original Poster	Originally posted by PDL Given my experience with Pentax ( ist Ds, K10D, K20D and K-3Ii) and back button focus it works as follows. Pressing the shutter button activates the metering system. That's all. The use of back button focus does not effect the metering system at all. So is it still metering even if I don't see the in the viewfinder?

04-10-2019, 08:14 PM	#12
DW58 Loyal Site Supporter Join Date: Dec 2015 Location: Rural Oregon Photos: Gallery \| Albums Posts: 7,064	Am I missing something? I set my K-70 for back button focus on day one. I pick a brightly lit subject and press the back button. Subject comes into focus and I see exposure values in the viewfinder. If I move to a darker subject one of the exposure values in the viewfinder changes. Even without pressing the back button again. Which value changes depends on my setting. T. Av. TaV. Etc. I have not touched the shutter release button since I turned the camera on.

04-11-2019, 01:14 PM	#13
PDL Pentaxian Join Date: Oct 2006 Location: PNW USA Photos: Gallery Posts: 2,127	Originally posted by DW58 Am I missing something? I set my K-70 for back button focus on day one. I pick a brightly lit subject and press the back button. Subject comes into focus and I see exposure values in the viewfinder. If I move to a darker subject one of the exposure values in the viewfinder changes. Even without pressing the back button again. Which value changes depends on my setting. T. Av. TaV. Etc. I have not touched the shutter release button since I turned the camera on. No, you are not missing something. Using the back button for focus starts the process to start the focus process, which is basically the same thing as ""starting the camera". When either the shutter button is pressed to "start the camera" or the back button is pressed to start focus - which is essentially "starting the camera" the meter will be started. Now I have noticed that pushing the back button focus on my K-3II will be somewhat delayed when the battery has been used for some time. Add into this I have the dust-removal running on each power up so there is a delay punching the button (either one) and having the system respond. When the camera "goes to sleep" it will come back to the present (rather than the trite term come back to life) by pressing either the Menu button, info button, AF button etc. When you press a either the LV button/switch, AF button or shutter button, the meter starts and the camera is getting ready to take a picture. As Adam stated above the * in the viewfinder is the AEL lock (exposure lock) and the exposure meter has to be operating for the * to show up.

04-11-2019, 05:31 PM	#14
mikesbike Site Supporter Join Date: Dec 2016 Location: Southeastern Michigan Posts: 4,549	Originally posted by lindseyd I have a Pentax K-70. I've set up back button focus (AF2). How do I meter now? Will I still be able to see the * in the viewfinder? The back AF setup is not for metering. It is for focusing- Auto Focus to be specific. But the button is alternately used as an AE-L button instead of a back AF button. In that case, it also does not meter, but it will lock the exposure meter that has been set already by metering. This is used under various conditions where a metered value is needed to be preserved, while lighting situations may be changing. When the button is set for that use, then you get your AF via the front shutter release button by using the half/press to obtain AF and to hold focus. Metering takes place in a manner according to where you have set your mode dial. If you want your camera set for fully automatic exposure metering, where both the shutter speed and the aperture will be set by the camera according to the camera's meter reading of the lighting, then the mode dial can be set either on the green AUTO mode, or on the "P" mode. The "P" mode is better because the green AUTO mode does not allow access to many adjustments and to many control features, including the exclusive Pentax Hyper Program operation, where you can override the camera's setting of either aperture or shutter speed. You can also have the camera automatically adjust the ISO according to the light meter reading as well in this mode. There are other automatic exposure metering modes on the mode dial to choose from, which are not fully automatic because you play a role, such as selecting a preference of aperture or shutter speed, while the camera automatically compensates by setting the other. These are the Tv or Av modes. Consult your handbook for the other modes. There are good reasons for being able to take control of these aspects of photography instead of always just having your camera on auto-pilot.

04-11-2019, 06:01 PM	#15
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	I think what the OP is asking is when back button AF is set does the button still perform AE-L.