Expert raw focus issue S25U

[Jeff_Foliage]

I've been noticing an out of focus issue with my S25U. I haven't noticed it before now and I assume an update over the past couple of months caused it.

I will admit now that I can't confirm all settings but thought we as a group could see if it is reproducible among different S25Us.

I was out this morning with morning fog. I shot with normal camera at 12mp, 50mp with no focus issues. I switched to expert raw and was on the 24mp setting and 1x and took a shot and then not liking the composition, I pinched and expanded to around 3.2x and took a couple shots (I also shoot raw + jpeg) and then it appears I switched to 50mp and pinched to change the composition a little more and might have gone out to 1x (49.9mp) 

Only the finger expanded zoom in to 3.2x (I believe) was out of focus (massively) I didn't do the 5x because that was in too far.

I will go and take some more expert raw images at 24/50mp both at 1x and then finger zoomed to 3.2 to see if this is what is causing my issue...

Has anyone run into something similar? I also will say I had a rainbow this past Thursday, and the same issue presented itself (pics below)

[maird]

A few things occur to me. First I suggest pressing and holding a finger on a "subject" until it shows the yellow circle for the locked focal and exposure references on a preferred scene. I understand the S25U has an infrared laser rangefinder that is used automtically and if it was used it should have been dispersed and resulted in premature reflections from the fog but I would expect that to put the focal point in the near field. I viewed all your pics at maximum image size and browsing around them I couldn't find signs of a focal point, in any of them. I would have expected it to be visible either in a sharper area on the large grass area or wood fence in two or on the rock wall in two others. It would be hard to see in the grass anyway for what look like jpegs on the web-site images (I can see what look like jpeg artifacts at high contrast points, so even if you could and did upload raw images the web site may have downgraded them to jpegs). As a last resort, dispersion due to fog will probably be a real chore for autofocus so you could either try the AF-M (multi-point) rather than AF-C center based focus. Or, if even that doesn't work, resort to using M (manual) focus for and set the focus by hand for such scenes. Since the rainbow happens due to water droplets in the air the same problems might occur without a visible fog in the air.

It's also worth knowing that if you work outside the optical zoom range of each camera you will undoubtedly get reduced image resolution, worst case I see is 12MP (4k) frames from all of the cameras. I prefer to select the camera either by selecting the MP setting in Expert Raw, or the camera name (UW, W, T or ST). I almost never use the ST, it's 12MP at 111mm equivalent focal length with only 1x to 3x optical zoom. The T has 4 times the sensor resolution, 50MP, with an equivalent focal length of 67mm and 1x to 5x zoom. So almost all ST scenes have higher resolution on the T camera within it's optical zoom range and cropping outside the camera app (in Photos, Lightroom etc.) tends to give higher resolution results. I almost never use anything but 1x zoom on the 200MP W camera, it has no optical zoom so anything other than 1x is cropped from the real scene and sometimes expanded to no more than 12MP. The 200MP W camera has optical image stabilization, it could be a factor if the fog was moving fast and all pictures were taken using it (obviously not the case from your description). For the 50MP UW camera the optical zoom range is only 0.6x, any other setting is cropped and for some zoom settings expanded back to 12MP. Any of these automatic crop/expand behaviors could cause blur that would look like out-of-focus pics. So, personally I mostly use the 200MP W as if a standard lens for close subjects, the 50MP T as a zoom but mostly leave it at 1x. I use the 50MP UW mostly for broad scenes due to the huge field of view but there is little detail at much distance so the 200MP W is often better for those scenes. I almost never use the 12MP ST because most scenes it can compose within it's optical zoom range have 4x the resolution on the 50MP T and can usually be cropped at higher resolution than 12MP.

I also turn off or down to a minimum the AI photography features (image enhancement), some are in the camera app or camera mode, some are in the phone settings.

[Tom6068 · Accepted solution]

Next time you go out to take shots, clear the camera cache before using it. Go to settings/apps/camera/storage then clear the cache. May as well clear the data too. That will just set the software to open in its default settings and it can be changed back in seconds. Also, keep the lenses clean in such conditions haivng a soft dry cloth at hand. Even the tiniest water droplets on the lenses can cause focus issues. Then take some shots and if that keep taking bad photos, I would call Samsung (1 (800) 726-7864) regarding this.