A6500 issue with focus when using the viewfinder

[Rockline]

hi all, I've got an A6500 with a Sigma lens (30mm 1.4 DC-DN).

When I take a picture of a landscape (all green squares appear when focusing) it works nicely. However, if I take the same picture (with again all green squares when focusing) but this time looking through the ViewFinder (rather than looking at the screen) then the output picture isn't sharp anymore.

Any idea? (I have the latest firmwares installed)

[danardeng]

Are you able to post both images in full resolution?

[IamNic]

Hello @Rockline,

are you re-viewing the photo in the viewfinder as well?

If so - maybe just the viewfinder is set out of focus - then everything should be out of focus in there.

The viewfonder can be adjusted to compensate for far- and near-sighted people, so that might be the case here.

If both  photo is viewed back on the screen and just the one taken through the viewfinder is out of focus, then as @danardeng already mentioned it would be good to see sample images.

- Nic

[Rockline]

More details:
-Camera used in Manual Mode
-Autofocus set to AF-S (Single-Shot AF)
-Focus Area: Wide

 Link to pictures (resized to 60% and RAW converted to jpg): https://drive.google.com/drive/folders/1fDJL31gtBonSNLVOwkWaJaMV20zfocu2?usp=drive_link 

[danardeng]

Julien Riquelme has rejected my request for access to the folder. 🤷‍♂️

See you

[Rockline]

Apologies, I forgot to allow access. You should now be able to access the folder. 😁

https://drive.google.com/drive/folders/1fDJL31gtBonSNLVOwkWaJaMV20zfocu2?usp=drive_link

[danardeng]

Yes, now I can see.

Those are converted jpg from raw files, so not all exif are presents. Anyway, i you are using AF-S mode I share my experience.

Actualy I don't use AF-S mode from a long time. When I had tested this modality on my A7RII (that is close to the release of A6500), I found AFS mode really unsafe for photography. There was a lot of photos out of focus despite to the focus confirmation on the camera, also far away from the actual object.
It's a characteristic of the houge use of contrast sensors instead of phase sensors: inaccurate on big errors, accurate when the focus is right.

At this I add a consideration: you are using really closed diaphragm, so with a wide dof. It's a difficoult situation for focus of that generation of cameras.
My suggestion is to don't use AFS with sony's camera, but AF-C instead.

Coming to your problem: my meaning is that is a random focus fail. Are you sure that every time you shot with display the focus is right, and every time you shot with evf is out of focus?

[Rockline]

Thanks for looking into it.

The raw files are too big to store but I've placed the xmp files in the folder. When I compare them I don't see anything obvious.

I've used the AF-S mode for years and never had any issue. I wasn't using the ViewFinder. I've decided to try using the ViewFinder a few weeks ago and noticed the issue.

All pictures with Autofocus set with all green squares appear sharp within the ViewFinder itself but end-up blurry in the output picture, regardless of the distances or triangle settings.

That said, when the Autofocus focuses on specific things (smaller green rectangles), the output picture is fine (even using the ViewFinder).

[danardeng]

Maybe, but it can’t depend from evf use

[Rockline]

The problem is still unresolved:

1. The issue appears in all pictures for which I use the EvF
2. The Eye Start AF feature (not to be confused with the Eye AF feature) could have an influence but it is not available for this lens (I can't change it). I tried with another lens (Sony pancake): Eye Start AF cannot be changed either BUT the images are perfect with the EvF. Very strange!