Focus Point Plug-in

Forum|Forum|5 years ago
October 18, 2020
5 replies
16472 views

I would like to see the Focus Point in my photos in LR and my understanding is that the only option is to install a plug in (this one? https://github.com/musselwhizzle/Focus-Points).

I'm weary of thrid-party additions and I am not sure it will work for me. Can someone advice?

Camera: Olympus OM-D EM1-MkII

Computer MacBook Pro (alsmost new) with latest Catalina OS upgrade.

Thanks

Feature request

Correct answer D Fosse

The only thing that can possibly be in metadata is the camera's record of where it put the focus points. And keep in mind that any camera's autofocus will miss quite frequently.

As for someone saying "this is in focus and that is not", that's just good eyes and experience.

You can of course use filters in Photoshop (like e.g. high pass or find edges) to exaggerate high frequency detail and visually determine what looks sharpest. But zooming in to 1:1 is just as reliable. With modern high resolution sensors (36 - 60 MP), the plane of critical focus can be paper thin, even with wide angle lenses. The term "depth of field" doesn't really apply anymore: it's either in focus, or not. So very often you simply have to decide when it's enough in focus.

Mirrorless systems have an advantage here: autofocus is measured directly off the sensor, not indirectly by a separate phase detection sensor. So no fine-tuning for each lens is necessary, and it's usually more accurate with a higher hit rate.

B

Bob Trlin

Inspiring

Yes it works with images from an OM-1 viedwed it LrC. However, it needs to be initiated each time and it's shown by creating a new image. This is not good. Also, it does a calculation which implies to me that it's assessing the sharpest point in the image rather than taking the camera's EXIF data for the location of the focus point. OM Workspace does it automatically and instantly. Come on Adobe, it's easy.

Karsten.G

Known Participant

@Bob Trlin

In fact the plugin does not calculate the location of the focus point but it retrieves AF information from the so-called "maker notes" section in EXIF data. This information is not available inside LrC (Adobe skips maker notes data entirely) that's why it needs to be read from the file on disk (using exiftool). This is what happens while the progress bar is displayed. I agree that the text "Calculating focus point" can be misleading here - it's not a calculation in terms of determining the focal area / focus point but mapping the focus point coordinates from EXIF AF data to the displayed image (which can be cropped, rotated, flipped).

I also agree that invoking the plugin can be a bit cumbersome because you need to go to the menu everytime (as it is for any other plugin). I'm using AutoHotkey to automate my LrC workflow and have assigned ShowFocusPoint and MetadataViewer to specific keys so I can invoke them at the press of a button.

Even though I would be happy to see Adobe implement focus point visualization in LrC I don't think we will ever see this. Thist would require interfacing with EXIF maker notes data which is proprietary to every camera maker. Some parts are known, others are undocumented. I would be very surprised if Adobe would be willing to deal with this.

The camera maker's RAW converters can make full use of this proprietary information. BTW, if you carefully compare the focus point display in OM workspace and the plugin for OM-1 you will notice that there are slight deviations. Which indicates that the EXIF fields used by the plugin as part of "known" maker notes data do not contain precise AF information which is very likely kept in the undocumented part.

Karsten.G

Known Participant

@Jose5D2D

I am using the plugin you mentioned with my Olympus OM-D E-M1-II/III, and it works like a charme for me.

This plugin is not about visualizing which parts are the sharpest ones, and which are less sharp.

Instead, it will display the active focus point at time of capture.

Which is important information when trying to figure out why an image (or more specific, the part of the frame where you put the focus) is not as sharp as expected. Of course this will not rescue the image, but it can provide information how to better deal with similar situations next time and get the desired result.

This is especially true for cameras with contrast detection AF modes (like OM-D). You can limit the focus point to a small box, but you have no control where exactly inside this box the camera will set the focus; it will just pick the edge with highest contrast. So, in your example, if the AF point covers only a small part of a branch before the bird with white plumage, it will focus on the branch and not the bird. Same is with photographing waterbirds in a distance; there is a high chance that the camera will better like hard edges on the water and not the bird if you can't manage your subject to fully occupy the AF point area.

The plugin is to understand what went wrong during the capture, either because the photographer failed or your camera just could handle the situation, to learn and to avoid the same thing happening again.

The plugin has helped me a lot to understand the limitations of my gear (especially taking images of distant wildlife at 840/1200mm FF equivalent), so I understand them and can try to workaround in the field. Plus, it reveals my own shortcomings if it comes to blurry images captured at 1200mm handheld 🙂

P.S.:
The plugin does not work in case of manual focus (because there is no AF point), and in cases where you swivel the camera with a half pressed shutter button.

P.P.S.:

I have assigned the two main function (Focus Point viewer, Metadata display) to "/" and "*" keys on the numpad, so I can invoke this information at the touch of a button. Very convenient addition to my workflow.

J

Jose5D2DAuthor

Participating Frequently

Actually, I am not sure these plug-ins provide what I was looking for. If I understand, they reveal which of the "focus areas" defined in the camera has been "hit" in the photo. But take the example of a bird in a tree. You may have severa objects within an area at different distances; the bird may appear less sharp that you would expect, and it may be hard to figure out if it is due to movement, camera vibration or simply because instead of the bird you ended up focussing on the foliage. Sometimes it is obvious what happened but others is not. Also, this seems to be an information stored as metadata, but I thought that there are programs that can detect that are in the photoc that looks the sharpest. I say this because in FB sharing pages sometimes and expert tells you "the problem with that photo is that the focus is on X instead of Y". I was wondering if they were using some focus-detection software, but I guess it is just good eyes and experience.