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Q2 Focus Peaking -- Doesn't change when I move the aperture?


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Hi there. Have had my Q2 for about a week and am loving it, but something isn't totally making sense to me. 

So, the aperture stays wide open until you half press. Yes? (Just want to confirm my camera is indeed functioning as it should.)

If yes, how can focus peaking work accurately? E.g. for me, while I'm manually focusing and the screen/EVF is zoomed in, my focus peaking indicator (red, for me) DOES NOT CHANGE even if I move the aperture ring from f1.7 all the way to f16. It should change, right? 

How can the focusing be accurate if the camera stays wide open until I half press? 

(And, for that matter, how can my exposure be correct if the aperture stays wide open until I half press? Is the camera just guessing how the image will look without actually changing the aperture?)

Am I missing something? 

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Yes: depth of field. Depth of field lies both in front of and behind the object in focus. Look at the depth of field you typically use for zone focusing in manual. As you can see the distance in front of and behind the focal plane is at its narrowest wide open and at its greatest closed down.

The camera is making a calculation for exposure based in light falling on the sensor and the aperture set. What you see  as the exposure setting is the result of the calculation.

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2 hours ago, SirBlunder said:

Hi there. Have had my Q2 for about a week and am loving it, but something isn't totally making sense to me. 

So, the aperture stays wide open until you half press. Yes? (Just want to confirm my camera is indeed functioning as it should.)

If yes, how can focus peaking work accurately? E.g. for me, while I'm manually focusing and the screen/EVF is zoomed in, my focus peaking indicator (red, for me) DOES NOT CHANGE even if I move the aperture ring from f1.7 all the way to f16. It should change, right? 

How can the focusing be accurate if the camera stays wide open until I half press? 

(And, for that matter, how can my exposure be correct if the aperture stays wide open until I half press? Is the camera just guessing how the image will look without actually changing the aperture?)

Am I missing something? 

The most accurate focusing is with the aperture wide open (shallowest DOF), except for the issue of focus shift which happens with some lenses.
Most cameras implement AASD (automatic aperture stop-down): focus wide open and close to working aperture only when taking a shot. 

The camera can compute the correct exposure with the aperture wide open. No guessing is involved.

 

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Thanks guys -- I was just writing a response to this, as I finally found a good answer elsewhere. I'm coming from the Sony Alpha system, and this was not a thing over there. (I.e., when manually focusing, the aperture ring would change real-time.)

This seems... less than ideal, no? Wouldn't you want to see an accurate depth of field while manually focusing? (I guess if you're able to get close to correct focus wide open, you'll be fine with the aperture more closed, but still...)

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3 minutes ago, SirBlunder said:

Thanks guys -- I was just writing a response to this, as I finally found a good answer elsewhere. I'm coming from the Sony Alpha system, and this was not a thing over there. (I.e., when manually focusing, the aperture ring would change real-time.)

This seems... less than ideal, no? Wouldn't you want to see an accurate depth of field while manually focusing? (I guess if you're able to get close to correct focus wide open, you'll be fine with the aperture more closed, but still...)

Only subjects in the focal plane are in focus. Everything closer and further from the focal plane is out-of-focus at a varying amount of unsharpness. The most precise way to place the focal plane is to focus wide open (unless focus shift is an issue). 
When shooting with digital Ms and EVF, many open the aperture wide to focus and close it to the working aperture before taking the picture.
I may want to see the DOF preview after I have focused, though my eyesight is not reliable enough to discern acceptable sharpness from the EVF.

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It is hard to impossible to judge DoF sharpness looking at an EVF. Even less so with focus peaking on. The best way to put focus where you want it is to focus wide open. And that is what the camera does. If you want to know the DoF, look at markings on the lens. They are pretty accurate.

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Focus peaking is to show focus, not depth of field. Using focus peaking to estimate depth of field can only be a wild guess - the focus peaking is affected by too many factors in the scene (other than distance, focus setting and aperture). The fact that Sony stops down for focusing doesn't mean that it gives you a sensible depth of field. And stopping down for focus would make focusing harder as light levels drop.

Edited by LocalHero1953
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13 hours ago, SirBlunder said:

while I'm manually focusing and the screen/EVF is zoomed in, my focus peaking indicator (red, for me) DOES NOT CHANGE even if I move the aperture ring from f1.7 all the way to f16. It should change, right? 

on the SL with manual focus, and canon and sony and fuji >>

the focus peaking gives an approximate DOF zone "preview" so e.g if i'm set to 10meters, and rotate the aperture ring, the focus peaking zone will become narrow or wide, then if i change distance, the "chunk" of peaking will move far or near

its a good idea to try the peaking settings low/high  because the thresholds are very different

its very handy for shooting on the street! i use it all the time especially with 90/135/180mm

Edited by frame-it
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On 7/14/2022 at 12:09 AM, Krusty said:

You have to release and press again the shutter button half and then it makes focus peaking with your new aperture value

This does not work for me. Focus peaking (and everything I see when I'm in MF mode) is always based on wide open aperture. 

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