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Fuji X-E3: different exposures whether using Focus-Check or not

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Karlson-B

Karlson-B

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Hi there,

I realized that the exposure measuring is different when I use the focus check (rear command dial) to zoom in and then pressing and releasing the shutter in opposition to not use the focus check and taking a picture.

The effect is easily to figure out:
  1. Place a white paper on a dark underground.
  2. Zoom in with the focus check (pressing rear command dial) and let the white paper just fill out the view finder.
  3. Take the shot.
  4. do not reposition the camera
  5. Take a second shot without focus check, so that the surrounding dark background is in the frame to.
  6. The exposures will be noticeable different.


Question:
  1. Is this by intention?
  2. Is this only with the X-E3?
  3. Do I always have to AE-lock the original exposure before zooming in with focus check? --> would be very inconvenient and counterintuitive...


normal exposure without focus check
normal exposure without focus check



exposed when using focus check
exposed when using focus check
 
There is no reason why this should happen

It does not with my XT2

Try also to either fix the aperture or the speed avoiding they both move

Obviously something happened when changing on off focus check
 
Karlson-B said:
Hi there,

I realized that the exposure measuring is different when I use the focus check (rear command dial) to zoom in and then pressing and releasing the shutter in opposition to not use the focus check and taking a picture.

The effect is easily to figure out:
  1. Place a white paper on a dark underground.
  2. Zoom in with the focus check (pressing rear command dial) and let the white paper just fill out the view finder.
  3. Take the shot.
  4. do not reposition the camera
  5. Take a second shot without focus check, so that the surrounding dark background is in the frame to.
  6. The exposures will be noticeable different.
Question:
  1. Is this by intention?
  2. Is this only with the X-E3?
  3. Do I always have to AE-lock the original exposure before zooming in with focus check? --> would be very inconvenient and counterintuitive...
normal exposure without focus check
normal exposure without focus check

exposed when using focus check
exposed when using focus check
Click to expand...
Assuming the exposure is being read when zoomed-in for focus check the exposure will read off the white envolope and then reduce it to (approx) 18% grey resulting in under-exposure. When reading without focus check and taking exposure from the whole scene the exposure is about right. Try both using spot metering (which is almost what the focus check reading is doing).

Al this assuming the readings are actually changed with and without focus check..

--
The sky is full of holes that let the rain get in, the holes are very small - that's why the rain is thin.
Spike Milligan. Writer, comedian, poet, Goon. 1918 - 2002
 
This is why in spot AF I see no diff
 
Because of the link between the AF sensor and the exposure so even with the matrix option instead of spot measure the difference is minimal unless ther frame has many different zones of lights

Anyway I am not playing all the time to find what could be wrong in my beloved Xt2 (already 18000 shots after one year) a great system indeed

Still waiting some good weather to test the new FW with regard to AF..
 
baobob said:
Anyway I am not playing all the time to find what could be wrong in my beloved Xt2 (already 18000 shots after one year) a great system indeed
Click to expand...
:) Agreed.

Vic
 
To see this effect you have to set Button/Dial -> Shutter AE -> AF-S/MF to OFF.
 
Karlson-B said:
To see this effect you have to set Button/Dial -> Shutter AE -> AF-S/MF to OFF.
Click to expand...
Looks like a defect. Good catch, hopefully somebody from Fuji is watching.

Just shrug off the criticism. It's pretty much standard operating procedure around here.
 
There's so many permutations of how various features impact each other (spot AF, eye/face AF, metering mode, blah blah) that one might need to exactly duplicate your in-camera configurations.

I don't have an X-E3, yet I just duplicated the scene and method, and both exposures were equal with an X-T2. Our cameras shouldn't be that different in this area.

You might first see if you can reproduce this in other scenes. You might walk through all you settings to see if any metering or AF mode changes show you different results. Or, reset the camera and re-configure to your liking in small steps, along the way see if and when you can reproduce it at will.

Edit:
Karlson-B said:
To see this effect you have to set Button/Dial -> Shutter AE -> AF-S/MF to OFF
Click to expand...
Ah. Mine was set On. When set OFF, I still saw no change between the two exposures. Hope that helps.
 
Last edited:
georgehudetz said:
Karlson-B said:
To see this effect you have to set Button/Dial -> Shutter AE -> AF-S/MF to OFF.
Click to expand...
Looks like a defect. Good catch, hopefully somebody from Fuji is watching.

Just shrug off the criticism. It's pretty much standard operating procedure around here.

--
http://georgehudetzphotography.smugmug.com/
My Flikr stream: http://flic.kr/ps/Ay8ka
Click to expand...
You should read the posts before making such comments George because now you've become the person misplacing your criticism.

Baobob merely made a tongue in cheek comment about users looking for problems with their Fuji cameras and even finding things that make no difference to their use rather than just shoot them - and I agreed and added a smiley.

I really don't know why the OP is wetting his pants unless he's managed to read something into the comment that wasn't there but then some people look for offence as they do problems with their cameras I guess.

Vic

--
The sky is full of holes that let the rain get in, the holes are very small - that's why the rain is thin.
Spike Milligan. Writer, comedian, poet, Goon. 1918 - 2002
 
Last edited:
Vic Chapman said:
georgehudetz said:
Karlson-B said:
To see this effect you have to set Button/Dial -> Shutter AE -> AF-S/MF to OFF.
Click to expand...
Looks like a defect. Good catch, hopefully somebody from Fuji is watching.

Just shrug off the criticism. It's pretty much standard operating procedure around here.

--
http://georgehudetzphotography.smugmug.com/
My Flikr stream: http://flic.kr/ps/Ay8ka
Click to expand...
You should read the posts before making such comments George because now you've become the person misplacing your criticism.
Click to expand...
He has certainly read the posts and his comments are deserved.
Vic Chapman said:
Baobob merely made a tongue in cheek comment about users looking for problems with their Fuji cameras and even finding things that make no difference to their use rather than just shoot them - and I agreed and added a smiley.
Click to expand...
Users looking for problems ????

So you think the op has looked for problems, he tried everything until he could find a problem just for fun ?
Vic Chapman said:
I really don't know why the OP is wetting his pants
Click to expand...
Heu are you a gentleman ?
Vic Chapman said:
unless he's managed to read something into the comment that wasn't there but then some people look for offence as they do problems with their cameras I guess.
Click to expand...
Whatever you may think, the op wants to share his experience. So you can help if you want but the op does not expect such unpleasant answers.

Here is my answer to you:



48dd09b979c44d4ca6ba4af09238ae99.jpg.png

Vic Chapman said:
Vic

--
The sky is full of holes that let the rain get in, the holes are very small - that's why the rain is thin.
Spike Milligan. Writer, comedian, poet, Goon. 1918 - 2002
Click to expand...
 
Christof21 said:
Vic Chapman said:
georgehudetz said:
Karlson-B said:
To see this effect you have to set Button/Dial -> Shutter AE -> AF-S/MF to OFF.
Click to expand...
Looks like a defect. Good catch, hopefully somebody from Fuji is watching.

Just shrug off the criticism. It's pretty much standard operating procedure around here.

--
http://georgehudetzphotography.smugmug.com/
My Flikr stream: http://flic.kr/ps/Ay8ka
Click to expand...
You should read the posts before making such comments George because now you've become the person misplacing your criticism.
Click to expand...
He has certainly read the posts and his comments are deserved.
Member said:
Baobob merely made a tongue in cheek comment about users looking for problems with their Fuji cameras and even finding things that make no difference to their use rather than just shoot them - and I agreed and added a smiley.
Click to expand...
Users looking for problems ????

So you think the op has looked for problems, he tried everything until he could find a problem just for fun ?
Member said:
I really don't know why the OP is wetting his pants
Click to expand...
Heu are you a gentleman ?
Member said:
unless he's managed to read something into the comment that wasn't there but then some people look for offence as they do problems with their cameras I guess.
Click to expand...
Whatever you may think, the op wants to share his experience. So you can help if you want but the op does not expect such unpleasant answers.

Here is my answer to you:

48dd09b979c44d4ca6ba4af09238ae99.jpg.png
Member said:
Vic

--
The sky is full of holes that let the rain get in, the holes are very small - that's why the rain is thin.
Spike Milligan. Writer, comedian, poet, Goon. 1918 - 2002
Click to expand...
Click to expand...
As I am a gentleman (or try to be), I remove the thumbs down, though I can not edit my post anymore;

But please be nicer with people just wanting to solve real problems in the real world.

If this is a bug, it deserves to be fixed. Workarounds are usually not as good.
 
Vic Chapman said:
Karlson-B said:
Hi there,

I realized that the exposure measuring is different when I use the focus check (rear command dial) to zoom in and then pressing and releasing the shutter in opposition to not use the focus check and taking a picture.

The effect is easily to figure out:
  1. Place a white paper on a dark underground.
  2. Zoom in with the focus check (pressing rear command dial) and let the white paper just fill out the view finder.
  3. Take the shot.
  4. do not reposition the camera
  5. Take a second shot without focus check, so that the surrounding dark background is in the frame to.
  6. The exposures will be noticeable different.
Question:
  1. Is this by intention?
  2. Is this only with the X-E3?
  3. Do I always have to AE-lock the original exposure before zooming in with focus check? --> would be very inconvenient and counterintuitive...
normal exposure without focus check
normal exposure without focus check

exposed when using focus check
exposed when using focus check
Click to expand...
Assuming the exposure is being read when zoomed-in for focus check the exposure will read off the white envolope and then reduce it to (approx) 18% grey resulting in under-exposure. When reading without focus check and taking exposure from the whole scene the exposure is about right. Try both using spot metering (which is almost what the focus check reading is doing).

Al this assuming the readings are actually changed with and without focus check..

--
The sky is full of holes that let the rain get in, the holes are very small - that's why the rain is thin.
Spike Milligan. Writer, comedian, poet, Goon. 1918 - 2002
Click to expand...
That is an interesting effect. I don't see the issue on my X-T20. I would find it hard to believe that the Fuji software would use only part of the sensor for focus check rather that just change what is displayed in the viewfinder. Having done software programming for many years I would see that as real newbie programming error and I don't think Fuji makes that kind of errors. Also it would probably show up on all models. Now of course, I never programmed a digital camera so I could be totally wrong and there could be a very good reason to use only part of the sensor for focus check.

My guess is if the multi metering is uses the focus points in its algorithm to set the exposure then the second image focus locked on a slightly different place. One way to test this would be to use average metering. Since average metering looks at the full sensor if it still does it then what the meter is looking at changes with focus check. If with average metering the exposure doesn't change then it might be related to the multi-metering.
 
nuzzart said:
That is an interesting effect. I don't see the issue on my X-T20. I would find it hard to believe that the Fuji software would use only part of the sensor for focus check rather that just change what is displayed in the viewfinder. Having done software programming for many years I would see that as real newbie programming error and I don't think Fuji makes that kind of errors. Also it would probably show up on all models. Now of course, I never programmed a digital camera so I could be totally wrong and there could be a very good reason to use only part of the sensor for focus check.

My guess is if the multi metering is uses the focus points in its algorithm to set the exposure then the second image focus locked on a slightly different place. One way to test this would be to use average metering. Since average metering looks at the full sensor if it still does it then what the meter is looking at changes with focus check. If with average metering the exposure doesn't change then it might be related to the multi-metering.
Click to expand...
Well I just confirmed that the metering changes when image magnification is engaged on both my X-T20 and GFX. When you think about how the exposure system works this makes perfect sense as with magnification set you are essentially switching to a spot meter. With a mirrorless camera there is no separate exposure sensor it comes from the sensor. I suspect that it would be a very heavy lift (if even possible) to have two simultaneous feeds from the sensor, one full frame for metering and one for magnified view. I mostly shoot full manual so it is not an issue for me but I don't see that it would that much of an issue to not lock metering when when magnification is engaged.
 
Peter Foiles said:
nuzzart said:
That is an interesting effect. I don't see the issue on my X-T20. I would find it hard to believe that the Fuji software would use only part of the sensor for focus check rather that just change what is displayed in the viewfinder. Having done software programming for many years I would see that as real newbie programming error and I don't think Fuji makes that kind of errors. Also it would probably show up on all models. Now of course, I never programmed a digital camera so I could be totally wrong and there could be a very good reason to use only part of the sensor for focus check.

My guess is if the multi metering is uses the focus points in its algorithm to set the exposure then the second image focus locked on a slightly different place. One way to test this would be to use average metering. Since average metering looks at the full sensor if it still does it then what the meter is looking at changes with focus check. If with average metering the exposure doesn't change then it might be related to the multi-metering.
Click to expand...
Well I just confirmed that the metering changes when image magnification is engaged on both my X-T20 and GFX. When you think about how the exposure system works this makes perfect sense as with magnification set you are essentially switching to a spot meter.
Click to expand...
Why ?

This does not make sense to me, you just check focus, nothing more.

I try to work on focus and exposure separately, the problem is that with focus check, it has an unwanted and unexpected impact on exposure.

The op was not on spot metering mode.
Peter Foiles said:
With a mirrorless camera there is no separate exposure sensor it comes from the sensor. I suspect that it would be a very heavy lift (if even possible) to have two simultaneous feeds from the sensor, one full frame for metering and one for magnified view. I mostly shoot full manual so it is not an issue for me but I don't see that it would that much of an issue to not lock metering when when magnification is engaged.
Click to expand...
You can always find workarounds... but you have more chances of errors, each time you will use magnification you will have to lock exposure. This is a non neglectible issue imho

I really doubt other non Fuji cameras work like this . This is clearly a bug on my opinion.
 
Christof21 said:
Vic Chapman said:
georgehudetz said:
Karlson-B said:
To see this effect you have to set Button/Dial -> Shutter AE -> AF-S/MF to OFF.
Click to expand...
Looks like a defect. Good catch, hopefully somebody from Fuji is watching.

Just shrug off the criticism. It's pretty much standard operating procedure around here.

--
http://georgehudetzphotography.smugmug.com/
My Flikr stream: http://flic.kr/ps/Ay8ka
Click to expand...
You should read the posts before making such comments George because now you've become the person misplacing your criticism.
Click to expand...
He has certainly read the posts and his comments are deserved.
Member said:
Baobob merely made a tongue in cheek comment about users looking for problems with their Fuji cameras and even finding things that make no difference to their use rather than just shoot them - and I agreed and added a smiley.
Click to expand...
Users looking for problems ????

So you think the op has looked for problems, he tried everything until he could find a problem just for fun ?
Member said:
I really don't know why the OP is wetting his pants
Click to expand...
Heu are you a gentleman ?
Member said:
unless he's managed to read something into the comment that wasn't there but then some people look for offence as they do problems with their cameras I guess.
Click to expand...
Whatever you may think, the op wants to share his experience. So you can help if you want but the op does not expect such unpleasant answers.
Click to expand...
I have helped and I HAVE GIVEN AN ANSWER - YOU HAVE NOT! You have simply taken another opportunity to troll me.

If you have an alternative answer to OPs question then direct your energies towards giving it. You know where you can shove your rude answer.
Member said:
Here is my answer to you:

48dd09b979c44d4ca6ba4af09238ae99.jpg.png
Member said:
Vic

--
The sky is full of holes that let the rain get in, the holes are very small - that's why the rain is thin.
Spike Milligan. Writer, comedian, poet, Goon. 1918 - 2002
Click to expand...
Click to expand...
What is your problem?

Once again you choose attack me for no reason instead of responding to the OP's question. In fact, only I and one other have done this and mostly now we are being agreed with. I suggest you are an incredibly sad and small-minded person to have this need to constantly troll my posts. I also suggest you actually READ my posts above including the one which simply says "Agreed" and is accompanied by a smiley. You should also note Georges response (below) to mine in which he accepts that his remarks were misplaced and that he misread the posts. George is a gentleman though and you are not. Instead of sniping at me - MAKE A RESPONSE TO THE OP!

Loading…

www.dpreview.com

Vic

--
The sky is full of holes that let the rain get in, the holes are very small - that's why the rain is thin.
Spike Milligan. Writer, comedian, poet, Goon. 1918 - 2002
 
Vic Chapman said:
Christof21 said:
Vic Chapman said:
georgehudetz said:
Karlson-B said:
To see this effect you have to set Button/Dial -> Shutter AE -> AF-S/MF to OFF.
Click to expand...
Looks like a defect. Good catch, hopefully somebody from Fuji is watching.

Just shrug off the criticism. It's pretty much standard operating procedure around here.

--
http://georgehudetzphotography.smugmug.com/
My Flikr stream: http://flic.kr/ps/Ay8ka
Click to expand...
You should read the posts before making such comments George because now you've become the person misplacing your criticism.
Click to expand...
He has certainly read the posts and his comments are deserved.
Vic Chapman said:
Baobob merely made a tongue in cheek comment about users looking for problems with their Fuji cameras and even finding things that make no difference to their use rather than just shoot them - and I agreed and added a smiley.
Click to expand...
Users looking for problems ????

So you think the op has looked for problems, he tried everything until he could find a problem just for fun ?
Vic Chapman said:
I really don't know why the OP is wetting his pants
Click to expand...
Heu are you a gentleman ?
Vic Chapman said:
unless he's managed to read something into the comment that wasn't there but then some people look for offence as they do problems with their cameras I guess.
Click to expand...
Whatever you may think, the op wants to share his experience. So you can help if you want but the op does not expect such unpleasant answers.
Click to expand...
I have helped and I HAVE GIVEN AN ANSWER - YOU HAVE NOT! You have simply taken another opportunity to troll me.

If you have an alternative answer to OPs question then direct your energies towards giving it. You know where you can shove your rude answer.
Vic Chapman said:
Here is my answer to you:

48dd09b979c44d4ca6ba4af09238ae99.jpg.png
Vic Chapman said:
Vic

--
The sky is full of holes that let the rain get in, the holes are very small - that's why the rain is thin.
Spike Milligan. Writer, comedian, poet, Goon. 1918 - 2002
Click to expand...
Click to expand...
What is your problem?

Once again you choose attack me for no reason instead of responding to the OP's question. In fact, only I and one other have done this and mostly now we are being agreed with. I suggest you are an incredibly sad and small-minded person to have this need to constantly troll my posts. I also suggest you actually READ my posts above including the one which simply says "Agreed" and is accompanied by a smiley. You should also note Georges response (below) to mine in which he accepts that his remarks were misplaced and that he misread the posts. George is a gentleman though and you are not. Instead of sniping at me - MAKE A RESPONSE TO THE OP!

https://www.dpreview.com/forums/post/60515051

Vic

--
The sky is full of holes that let the rain get in, the holes are very small - that's why the rain is thin.
Spike Milligan. Writer, comedian, poet, Goon. 1918 - 2002
Click to expand...
OK, give it a rest. Not sure I have misread, sorry, even after reading several times.

By the way, I do not target you specifically, not at all... In terms of personal attacks, I do not use your expressions.

I simply disagree, period. And I don't like the tonality used each time somebody finds a bug or something which could be improved. I was simply interested, I have an x-e3, and I have even contributed to this post.

This is a real bug, having to lock the exposure is not a satisfying solution. This is not a minor problem if you use focus check.
 
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