SL2 AF half-press blurs EVF

[jaapv]

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No I know the difference between blur and resolution. Read the thread. The complaints are about “blur” It is quite possible that you are right and the effect is a lowering of resolution, although that would be a strange thing to do, but that is not what the posters are claiming to see. 

[digitalfx]

1 hour ago, jaapv said:

No I know the difference between blur and resolution. Read the thread. The complaints are about “blur” It is quite possible that you are right and the effect is a lowering of resolution, although that would be a strange thing to do, but that is not what the posters are claiming to see. 

I think they are using the wrong term, or they have a separate issue. The issue I have experienced is exactly as bsmith described. It appears as if the resolution of the evf drops significantly enough that you cant tell if you are in focus or not.

 I have been mostly using mf to avoid this.

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[Rob L]

The only thing I'm seeing is that in AFc the SL2 will continue to "quiver" as long as you hold the half press. This is the lens focusing in and out very slightly and rapidly. Also very audible. In AFs it focuses once and stops, as expected. No visible loss of resolution in ether case. I have had consistently in-focus results with both methods.

[bsmith]

17 hours ago, digitalfx said:

I think they are using the wrong term, or they have a separate issue. The issue I have experienced is exactly as bsmith described. It appears as if the resolution of the evf drops significantly enough that you cant tell if you are in focus or not.

 I have been mostly using mf to avoid this.

Yes, exactly. Call it what you wish, but the point is the optical viewfinder resolution is TOO low during AF  focusing to discern in or out of focus until playback.  ( no visible loss of resolution, just visible loss of accurate focus haha) I agree it's a strange and an unfortunate thing to do, but that's what's happening. Outstanding lenses, great all around file quality, but no where close to the optical usability and experience of Nikon or Canon DLSR viewfinders. I and others are use to instantaneous visible AF feedback that is not a "green light". For unknown reasons that's apparently not possible at this time with this otherwise excellent SL2 camera. For those who don't see it, demand it or understand it, what can I say? I stand by my almost 50 year professional experience and the requirements needed to deliver "the decisive moment"

[Donzo98]

1 hour ago, bsmith said:

Yes, exactly. Call it what you wish, but the point is the optical viewfinder resolution is TOO low during AF  focusing to discern in or out of focus until playback.  ( no visible loss of resolution, just visible loss of accurate focus haha) I agree it's a strange and an unfortunate thing to do, but that's what's happening. Outstanding lenses, great all around file quality, but no where close to the optical usability and experience of Nikon or Canon DLSR viewfinders. I and others are use to instantaneous visible AF feedback that is not a "green light". For unknown reasons that's apparently not possible at this time with this otherwise excellent SL2 camera. For those who don't see it, demand it or understand it, what can I say? I stand by my almost 50 year professional experience and the requirements needed to deliver "the decisive moment"

I discussed this issue months ago... only to be shot down very decisively. It happens on the Q2 as well. I described it as what looks like pixelation. 

[hillavoider]

this guy discusses it at 8 minutes, "limits of CDAF " 

 

[jaapv]

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2 hours ago, hillavoider said:

this guy discusses it at 8 minutes, "limits of CDAF " 

 

So it is a momentarily flickering of the EVF caused by CDAF and very high resolution screens and sensors, not brand-specific, which does not affect focus accuracy and speed, according to this reviewer. In that case there is little to complain about, apart from proclaiming superiority for SLR viewfinder technology.

I thought resolution loss an unlikely scenario. This is a much better explanation.

[hillavoider]

I agree jaap, but it is still annoying that what’s in focus looks blurry coz it’s jumping back and forth, if anything this make phase detect look even better 

[Jeff S]

6 hours ago, hillavoider said:

this guy discusses it at 8 minutes, "limits of CDAF " 

 

I like his reviews...knowledgeable, objective, and covers a lot of ground without wasting time.

Jeff

[bsmith]

On 2/19/2020 at 1:50 AM, jaapv said:

So it is a momentarily flickering of the EVF caused by CDAF and very high resolution screens and sensors, not brand-specific, which does not affect focus accuracy and speed, according to this reviewer. In that case there is little to complain about, apart from proclaiming superiority for SLR viewfinder technology.

I thought resolution loss an unlikely scenario. This is a much better explanation.

I never said resolution loss. Stop saying "little to complain about" . For those of us that feel it's important to SEE , not just TRUST by a green light that our SL2 has AF correctly,  it's important.  I trust my eyes, not solely Leica's green AF light. I'm use to "seeing" that my Nikon AF correctly, I would like to "see" that my SL2 has focused correctly.  Some of us shoot under pressure and don't have time to push playback to check the accuracy of the green AF light after each shot.  If it's possible, I would like Leica to fix this issue. 

[jaapv]

If that is the case, wouldn't you prefer manual focusing in general? I know that I do. More control.

[thighslapper]

Mmmm .... yet another issue where the cheaper and mostly ignored S1R beats the SL2 hands down ..... the magnified central portion of the image when you focus allows perfect and instant confirmation that your subject is sharp. I sometimes wonder if engineers at Leica ever bother to look at how other manufacturers have implemented features.... 

[Exodies]

Don’t cameras need two eye pieces, one for framing and one for focus? They would have to be on a slider to fit different face widths.

[ChasMP]

On 2/21/2020 at 9:39 AM, bsmith said:

I never said resolution loss. Stop saying "little to complain about" . For those of us that feel it's important to SEE , not just TRUST by a green light that our SL2 has AF correctly,  it's important.  I trust my eyes, not solely Leica's green AF light. I'm use to "seeing" that my Nikon AF correctly, I would like to "see" that my SL2 has focused correctly.  Some of us shoot under pressure and don't have time to push playback to check the accuracy of the green AF light after each shot.  If it's possible, I would like Leica to fix this issue. 

This is interesting, I currently shoot weddings with Nikon d850’s and an M10. I am thinking about jumping into the SL2 to have access to the glass, but not at the cost of usability. The EVF sounds like it would bug me and make me nervous about what I was actually capturing...
 

Oh but the glass. A 90mm Summicron and a 28mm Summicron when it arrives would be beautiful...😏

[bsmith]

On 2/19/2020 at 1:50 AM, jaapv said:

So it is a momentarily flickering of the EVF caused by CDAF and very high resolution screens and sensors, not brand-specific, which does not affect focus accuracy and speed, according to this reviewer. In that case there is little to complain about, apart from proclaiming superiority for SLR viewfinder technology.

I thought resolution loss an unlikely scenario. This is a much better explanation.

But his explanation of  "momentarily flickering of the EVF caused by CDAF" between AFi and AF is not correct. There is still a  "momentarily flickering of the EVF caused by CDAF"on static objects when set to AFi. When on AFS the EVF is considerably clearer. The "flickering still exist with AFi.  You can easily see it if you set your SL2 to use the rear button on AFS and the shutter release button set to  AFi. On a static person or object, AFi looks slightly OOF,  AFS looks tack sharp.  They both are in focus,  (most of the time, ) but I prefer to know my subjects are in focus rather than pray they are. To me the issue is really disappointing and irritating . AFi would be more useful if the high res EVF could visually confirm focus. 

[bsmith]

10 minutes ago, bsmith said:

But his explanation of  "momentarily flickering of the EVF caused by CDAF" between AFi and AF is not correct. There is still a  "momentarily flickering of the EVF caused by CDAF"on static objects when set to AFi. When on AFS the EVF is considerably clearer. The "flickering still exist with AFi.  You can easily see it if you set your SL2 to use the rear button on AFS and the shutter release button set to  AFi. On a static person or object, AFi looks slightly OOF,  AFS looks tack sharp.  They both are in focus,  (most of the time, ) but I prefer to know my subjects are in focus rather than pray they are. To me the issue is really disappointing and irritating . AFi would be more useful if the high res EVF could visually confirm focus. 

AFi only shuts off the AF motor until you recompose or your subject moves. The  "momentarily flickering of the EVF caused by CDAF" is the same as on AFC. AFi seems to be only a energy saving function. 

[Macberg]

I don't think it is a momentary flickering, I guess that the EVF really lowers the resolution at that moment. The Q2 is doing the same, unless you choose 60fps for the viewfinder (instead of 120 fps), then the viewfinder isn't blurred at any time. I guess it has to do with available processing power. I don't have my SL2 at hand right now, but maybe you can lower the EVF's frequency to 60 fps for the SL2 as well? I will try that tomorrow.

Edited March 17, 2020 by Macberg

[Macberg]

Am 17.2.2020 um 01:30 schrieb jaapv:

The blur indicates that the image is out of focus. The only thing the EVF does is showing you the readout of the sensor. And yes, an out of focus image is distracting, not useful and irritating. So, the blur disappears as the camera focuses. When you are focusing manually you go from blur to sharp as well, even if you are a pro. And yes, like the photographer on an optical SLR viewfinder, the SL focuses the image before it trips the shutter. What a surprise 🙄

I see the blur in the EVF but the picture which is actually taken is tack sharp. So the EVF does not show the readout of the sensor (in the EVF) but a readout with a momentarily reduced resolution, probably in order to save processing power for other, more vital processes, I guess. If you look at the same picture in the EVF later (in play-mode), you see that the resolution is much better.
Why that is necessary? No idea, but the Q2 had shown a slightly blurred image in the EVF as well until the last firmware update, which now makes it possible to reduce the framerate of the EVF from 120 fps to 60 fps - if you set it to 60 fps, the EVF image is sharper (Q2). By the way, the reduced framerate of my Q2 isn't visble to my eye so far, but it might play a role in low light situations.
That's why I think that they can fix the EVF-blur on the SL2 with a firmware update, too.

Edited March 18, 2020 by Macberg

[bsmith]

Yes, I'm hoping a firmware update will correct the issue.  The reality is the SL2 AF doesn't always focus correctly, (even when green light is lit) so it's important that we can observe correct focus "before" shooting. If not, what's the point of the hi res EFV or the diopter correction dial? 

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[Jared]

Looks like some think the explanation is an actual change in what the viewfinder presents during a half press, while others think it is the contrast detect AF-C pulsing back and forth as it constantly re-confirms focus.  I think it is actually both.

If I have the camera in AF-C there is an obvious loss in visible detail as the AF-C continuously moves things in and out of focus as it re-confirms best focus.  That is definitely happening.  But it’s not the only thing that happens.

If I have the camera set on iAF (where it is only supposed to re-focus if the composition changes), the AF pulsation stops, but there is still a significant blurring of the image while the shutter is half pressed.  The viewfinder literally shimmers just a little bit.  This happens regardless of whether IBIS is turned on and whether the EVF refresh rate is 60fps or 120fps.

If I switch to AFS or to manual focus, the shimmer goes away entirely.  

With AF-C, the stuttering of the focus, which is an integral part of both Panasonic’s and Leica’s continuous, contrast detect auto focus, makes it impossible to judge focus accuracy.  For me, though, and I’m not suggesting this is the case for other photographers, the situations where I use AF-C are dynamic enough that I can’t tell AF accuracy anyway without chimping.  Any time I resort to AF-C, I am entrusting the camera, for better or for worse.  I find it is generally pretty good though not close to the level of a professional sports camera.

I don’t happen to use iAF in any of my profiles, so I hadn’t noticed the shimmering until I tried out various settings today.  In AF-S and manual focus, no issues.

I remember something similar when I got my Q2.  It, I believe, lowered resolution in the EVF at all times except playback.  You could even see it as “stair stepping” in diagonal lines in the information displays such as ISO or shutter speed.  That was/is a different issue.  That issue appears to have been resolved in some firmware release or other since I no longer see it.  That, or my eyesight has significantly deteriorated in the last few months!  The Q2 does have the same AF-C stuttering as all current Panasonic based AF-C systems.  Since the Q2 doesn’t have iAF, it doesn’t seem to have the in-between “shimmering” effect separate from AF-C.