Nikon L-Fn button - what do you use it for?

[Photographer_Bill]

I've had these buttons on my lenses for some time now but have never bothered to figure out too much how to use them to my advantage. I purchased the 24-120 with my Z8 and I am really enjoying the flexibility of this lens. I noticed it too has an L-Fn (Lens Fn button) button on it and I am curious how other photographers are using this button. If you wouldn't mind explaining what you have it configured for and how it benefits you this might give me some good ideas to enhance my photographic experience using some of these lenses.

 

[John Navitsky]

i have mine for single point focus which i only use occasionally. it's my "if all else fails" button

 

[Geoff_G]

I use the LFn1 button for Subject Detection On/Off. It's on all my lenses (save 1).

 

[dabhand16]

I use mine for tracking on/off.

 

[EricBowles]

I'm currently using it for Dynamic Small + AF On - kind of a blend of Single AF area and turning off Subject Detection. I have not used it enough for it to be intuitive, but it is a good way to immediately solve a couple of potential issues. It lets me immediately focus on a small precise subject through obstructions, or an alternate AF target such as the branch a small bird is standing on or grass at the distance of my subject if it goes to the background and loses the subject.

 

[Geoff_G]

I spent a lot of time trying to figure out button assignments. It gets tricky when trying to setup several banks yet keep the button assignments similar between banks. And then there is the need to dance around some significant ergonomic differences between z Lenses - some have dedicated focus AND control rings, Some have LFn1 buttons and some don't. And some (ie, the 100-400 should have had a mem set button IMO). Arrgh....

Subject detection is one feature I wanted the capability to switch on or off quickly and I see this as more or less lens [focal length] independent. Since all my lenses (save the 50/1.8) has an LFn1 button this was a good solution for me. Conversely, my 100-400 is the only Z lens I have with an LFn2 button so I assigned this to recall focus position - I can't say I'd use that with shorter focal length lenses so the Lfn2 button works great for this (my 500/E lens has it's own button settings to save and recall focus position).

I've become accustomed to using the control ring for exposure compensation (I do miss that capability with my 500/E). I ended up choosing this over manual focus on the 50/1.8 but with such great glass it's a shame we can't have both a focus ring and a control ring. In fact I will weight this quite heavily when purchasing lenses from here on out -- it's the biggest factor for me passing over the forthcoming 180-600.

 

[Geoff_G]

I'm currently using it for Dynamic Small + AF On - kind of a blend of Single AF area and turning off Subject Detection. I have not used it enough for it to be intuitive, but it is a good way to immediately solve a couple of potential issues. It lets me immediately focus on a small precise subject through obstructions, or an alternate AF target such as the branch a small bird is standing on or grass at the distance of my subject if it goes to the background and loses the subject.

This is a clever way to turn subject detection on and off without using the RSF function. I may give this a try....it solves a couple of things as you mentioned.

 

[Photographer_Bill]

Brilliant suggestions so far, I like the different ideas.

i have mine for single point focus which i only use occasionally. it's my "if all else fails" button

I'm currently using it for Dynamic Small + AF On - kind of a blend of Single AF area and turning off Subject Detection. I have not used it enough for it to be intuitive, but it is a good way to immediately solve a couple of potential issues. It lets me immediately focus on a small precise subject through obstructions, or an alternate AF target such as the branch a small bird is standing on or grass at the distance of my subject if it goes to the background and loses the subject.

These two are similar and offer the option for more precise focus when needed. Currently I have Fn2 setup as Wide Area C1 (which I've set to 1x1 focus box similar to single point AF-S) but Fn2 is not always easy to engage so maybe L-Fn would be more ideal for this.

I use the LFn1 button for Subject Detection On/Off. It's on all my lenses (save 1).

I use the Center Joystick for turning off Subject Detection right now because my 85mm f/1.8 S does not have a button and I use this lens a lot for portrait work (where I typically will use subject detection), but maybe this makes a good use case for getting the new 85mm f/1.2 S (I could sell both my 1.8 and my 105 f/1.4E but would be hard to part with my 105, I think it will be my last holdover from my F mount lenses).

I spent a lot of time trying to figure out button assignments. It gets tricky when trying to setup several banks yet keep the button assignments similar between banks. And then there is the need to dance around some significant ergonomic differences between z Lenses - some have dedicated focus AND control rings, Some have LFn1 buttons and some don't. And some (ie, the 100-400 should have had a mem set button IMO). Arrgh....

Yes, that is kind of where I'm at with regard to the different L-Fn options on different lenses.

Subject detection is one feature I wanted the capability to switch on or off quickly and I see this as more or less lens [focal length] independent. Since all my lenses (save the 50/1.8) has an LFn1 button this was a good solution for me.

My 14-30 f/4 S also doesn't have L-Fn and I would want to turn off subject detection with this lens, but not being an "action" lens I can always turn off through i or my menu if need be.

Conversely, my 100-400 is the only Z lens I have with an LFn2 button so I assigned this to recall focus position - I can't say I'd use that with shorter focal length lenses so the Lfn2 button works great for this (my 500/E lens has it's own button settings to save and recall focus position).

Similar to you, my 70-200 S also has both L-Fn and L-Fn2 which is why I've setup L-Fn to "Save Focus Position" and L-Fn2 to "Recall focus position"; however, when using lenses that do not have L-Fn2 this seems redundant - a lot of good it does to Save a position that I cannot recall when using a lens that only has one button...

I've become accustomed to using the control ring for exposure compensation (I do miss that capability with my 500/E). I ended up choosing this over manual focus on the 50/1.8 but with such great glass it's a shame we can't have both a focus ring and a control ring. In fact I will weight this quite heavily when purchasing lenses from here on out -- it's the biggest factor for me passing over the forthcoming 180-600.

Well, you bring up a good point here. The 180-600 is on my list; however, with it only having one control ring (and no dedicated MF ring) that could be an issue because like you I've setup my control ring function on all my Z lenses to be exposure compensation and it would be a pain to have to re-map this control to MF only when I use the 180-600. I guess that is the penalty for the non S lenses - you get less features. I suppose I could customize the control ring to be MF and the MF ring to be exposure compensation but I am so used to MF being forward of the lens I'm not sure if I could get used to that.

If anything all this has me thinking of different use cases and what might help my style of shooting best, thanks for all the input.

 

[John Woodworth]

I use the Fn-L button on the lens for Playback. I can quickly review the last (few) pictures for sharpness and exposure without taking my eye from the viewfinder.

I originally chose this setting when I was shooting the Z6/7ii which have the dedicated Playback button in an awkward position requiring hand movement to activate. If shooting the Z8/9 this is not so much an issue as the Playback button is now moved so that the right thumb can activated quickly without moving hands.

 

[Photographer_Bill]

I'm currently using it for Dynamic Small + AF On - kind of a blend of Single AF area and turning off Subject Detection. I have not used it enough for it to be intuitive, but it is a good way to immediately solve a couple of potential issues. It lets me immediately focus on a small precise subject through obstructions, or an alternate AF target such as the branch a small bird is standing on or grass at the distance of my subject if it goes to the background and loses the subject.

I'm not sure I fully understand the "+ AF On" piece? I use Back Button AF On for focusing everything (except MF) so how does Dynamic Small + AF On help in this situation? Oh wait, I think I may have just figured it out thinking about it - you don't have to use the BBAF at all if you press the L-Fn because it also activates AF along with Dynamic small which ignores subject detection. Did I get that right?

 

[BarkingBeans Coffee]

FX DX switch on my 100-400.

 

[Geoff_G]

Brilliant suggestions so far, I like the different ideas.




These two are similar and offer the option for more precise focus when needed. Currently I have Fn2 setup as Wide Area C1 (which I've set to 1x1 focus box similar to single point AF-S) but Fn2 is not always easy to engage so maybe L-Fn would be more ideal for this.


I use the Center Joystick for turning off Subject Detection right now because my 85mm f/1.8 S does not have a button and I use this lens a lot for portrait work (where I typically will use subject detection), but maybe this makes a good use case for getting the new 85mm f/1.2 S (I could sell both my 1.8 and my 105 f/1.4E but would be hard to part with my 105, I think it will be my last holdover from my F mount lenses).


Yes, that is kind of where I'm at with regard to the different L-Fn options on different lenses.

My 14-30 f/4 S also doesn't have L-Fn and I would want to turn off subject detection with this lens, but not being an "action" lens I can always turn off through i or my menu if need be.

Similar to you, my 70-200 S also has both L-Fn and L-Fn2 which is why I've setup L-Fn to "Save Focus Position" and L-Fn2 to "Recall focus position"; however, when using lenses that do not have L-Fn2 this seems redundant - a lot of good it does to Save a position that I cannot recall when using a lens that only has one button...

Well, you bring up a good point here. The 180-600 is on my list; however, with it only having one control ring (and no dedicated MF ring) that could be an issue because like you I've setup my control ring function on all my Z lenses to be exposure compensation and it would be a pain to have to re-map this control to MF only when I use the 180-600. I guess that is the penalty for the non S lenses - you get less features. I suppose I could customize the control ring to be MF and the MF ring to be exposure compensation but I am so used to MF being forward of the lens I'm not sure if I could get used to that.

If anything all this has me thinking of different use cases and what might help my style of shooting best, thanks for all the input.

Lots of good ideas here. We each have our own preferences and shooting style so one size definitely does not fit all. In my case I also have a Z9 and want that mapped identically to the Z8. That said the Z9 has extra buttons I can assign so there are more options with that cam.
I use the Center Joystick for Save focus position. It's not my favorite button to use but then I only use it with the 100-400 lens.
Fortunately you do not need to change the control ring for all lenses. Lenses with the dual purpose focus/control ring has its can be assigned differently in setting f2.

I should also say when I was going thru this process I kept "My Menu" in mind along with the iMenu. Fn3 recalls My Menu and the top item gives me the SD options (I have top of my menu saved on a Z9 button). Qiick and easy to change SD modes. And deviating from my goal to map all buttons similarly between banks I have no issue assigning different items to the iMenu (certainly don't need focus stacking in my action bank or AF tracking options in my Scenic bank.

In the end I felt I arrived at a good logical setup (I can remember....: ) for the itemsI use most. But it took a lot of tinkering and time.

I ended up enjoying the process even tho I got confused a few times before I arrived and my settings.

New cameras are a lot more work than new lenses!!

I hope you enjoy the process...!!

 

[Geoff_G]

I'm not sure I fully understand the "+ AF On" piece? I use Back Button AF On for focusing everything (except MF) so how does Dynamic Small + AF On help in this situation? Oh wait, I think I may have just figured it out thinking about it - you don't have to use the BBAF at all if you press the L-Fn because it also activates AF along with Dynamic small which ignores subject detection. Did I get that right?

Yes...the +AF On part turns on AF.

 

[Geoff_G]

FX DX switch on my 100-400.

Good choice as well....Not something I would have thought to do without reading Steve's Z8/Z9 guide....lots of good ideas in there are well (and reading Steve guide got me started in the right direction with the Z9)

 

[Geoff_G]

One thing to keep in mind when setting up buttons is that focus persistence handoff can only occur when you start the handoff process with the focus mode as set using the focus mode button and command dials (I'll call this the system/base focus mode). And there are 'two' ways to do that...1/2 shutter button press or any button assigned to AF-ON.

The AF Area Mode or AF Area Mode + AF-On selections that can be assigned to most buttons Override the system focus mode and they cannot be used to initiate focus persistence handoff.

If interested here is a quick way to follow along and visually see the difference between focus persistence handoff and no handoff:

Intial setup:

• Set the system/base focus mode (focus mode button and command dials) to Wide-S
• Set Fn1 to 3D Tracking + AF On

Focus Point Handoff works (AF-ON):

• Set the BBAF (or AF-ON) button to AF-ON

Press the BBAF button while focussing on a smallish object. When it has focused maintain that press and also press the Fn1 (3D) button. Notice how the larger green Wide-S area box turns into a small green 3D box even with both buttons pressed. This is handoff.​

Shutter Button Handoff works:

• (Shutter half press - if shutter is activated for AF)

Press the shutter half way while focussing on an object and then press the Fn1 button at the same time. The larger wide area green box turns to a smaller green 3D box. This works exactly the same as the BBAF approach.​

Focus Point Handoff does not work:

• Set the BBAF button to AF Area Mode + AF-On -> Wide-S (same as base focus mode set above)

Press BBAF button while focussing on that same object above. When focused the Wide Area box turns green. Now maintain that press and also press the Fn1 button. The box does not change size as there was no handoff to 3D. Nothing happens. The Wide-S box remains while both the BBAF and Fn1 buttons are pressed simultaneously. Releasing the BBAF allows 3D to kick in and re-acquire focus and the larger Wide area box quickly turns into the small green 3D box. But this is not handoff and does not rely on focus persistence.​

The difference: in one case the BBAF button is set to AF-ON and handoff works. In the other example it is set to Wide-S+AF On and handoff does not work.

The key is that for focus persistence to happen it has to start with the base/global focus system (AF-ON), be it any button assigned to AF-ON or the shutter button. The AF Area Mode and AF Area Mode + AF-On settings are simply a specific AF Area Mode setting to override the base/global focus mode. And they do not override one another (first one pressed wins).

 

[BarkingBeans Coffee]

Good choice as well....Not something I would have thought to do without reading Steve's Z8/Z9 guide....lots of good ideas in there are well (and reading Steve guide got me started in the right direction with the Z9)

Honestly all I had on my Africa trip was the 100-400 and the FX/DX switch on the L-FN really helped on the bird shots and other smaller mammals. Yes I know I can crop in post but it helped with AF and composition. I am very used to that now on my zoom.

 

[Geoff_G]

Honestly all I had on my Africa trip was the 100-400 and the FX/DX switch on the L-FN really helped on the bird shots and other smaller mammals. Yes I know I can crop in post but it helped with AF and composition. I am very used to that now on my zoom.

I set the Video Record button for image area in both my scenic and action banks but in the action bank I limit choices to FX or DX so as to toggle between just those two areas (I was 'concerned' I might switch it inadvertently and not notice, hence the approach)

 

[Photographer_Bill]

Lots of good ideas here. We each have our own preferences and shooting style so one size definitely does not fit all. In my case I also have a Z9 and want that mapeed identically to the Z8. That said the Z9 has extra buttons I can assign so there are more options with that cam.

One size does not fit all, I think that's why Nikon is giving us options to re-map almost everything to anything you want. I appreciate drawing inspiration from how others have used it and sometimes I find something I did not think of previously.

I use the Center Joystick for Save focus position. It's not my favorite button to use but then I only use it with the 100-400 lens.

Interesting, so if you use center for save focus which button do you use for recall?

Fortunately you do not need to change the control ring for all lenses. Lenses with the dual purpose focus/control ring has its can be assigned differently in setting f2.

Right, but it's more for consistency, if control ring was used for one thing on one lens and something else on another I know my brain would get confused.

I should also say when I was going thru this process I kept "My Menu" in mind along with the iMenu. Fn3 recalls My Menu and the top item gives me the SD options (I have top of my menu saved on a Z9 button). Qiick and easy to change SD modes. And deviating from my goal to map all buttons similarly between banks I have no issue assign different items to the iMenu (certainly don't need focus stacking in my action bank or AF tracking options in my Scenic bank.

I have this in my i menu

In the end I felt I arrived at a good logical setup (I can remember....: ) for the itemsI use most. But it took a lot of tinkering and time.

I ended up enjoying the process even tho I got confused a few times before I arrived and my settings.

New camera are a lot more work than new lenses!!

I hope you enjoy the process...!!

Enjoying the process for sure. The Z8 has opened new doors that I never ventured into with the Z6 before it.

 

[fcotterill]

I use the Fn buttons on my Z Nikkors to focus on a Preset distance; this is sometimes essential if the Z9 Autofocus grabs the background.

The Fn buttons on my 500 PF and 800 f5.6E are set to AFmode+AFOn.
Many F-mount telephotos permit more flexibility - switching the Focus Selector from AFLock to Memory Recall enables jumping to a Pre-focused position.

 

[fcotterill]

The Custom setups of my Z9's differ in the finer details between the 3 pairs of Shooting Banks: Wildlife, Action, Macro/Landscapes. A high proportion of the menu settings are set Once, but the Autofocus custom settings are different. It pays off to experiment in order to optimize the setup(s) that works best for you and your subjects, in local conditions.

As we know, there are many different ways the photographer can Customize their Z9, and/or Z8. Compared to other Mirrorless cameras, and also the advanced DSLRs (D5 Triumvirate) - D6 being one exception - the main differences have proven to be the Custom Area AF modes and 3D Tracking - all empowered by Subject Recognition.

More than any other, it's these primary features that stand out, in differentiating how to optimize & customize the Z9 Autofocus system. IME, these are the primary settings where it's paid off experimenting to refine how to handover between 3D Tracking (Auto AF sometimes) with the pair of Custom Area modes [edit: and now I plan to test out the method of @EricBowles - use a Dynamic mode in place of Recall Focus position ].

And I'm another one of the Z9 owners who has replaced Single-point mode with CA 1*1..... this was a big lesson over a year ago, when FW 2.0 landed (April 2022).

The processes underlying the HandOver Focus method - leveraging Focus Persistence - are discussed in detail in this thread and linked information :

Nikon Z9/8 Hybrid Handover Question

I want to confirm this. (in Ver. 3.10) BBF will ONLY override/hand over from the shutter button. When pressing any FN buttons set to a different AF Area mode or AF Area mode + AF ON, Pressing BBF or half-press shutter will NOT override the FN button. In other words, the way to hand it over is...

bcgforums.com

 

[Geoff_G]

One size does not fit all, I think that's why Nikon is giving us options to re-map almost everything to anything you want. I appreciate drawing inspiration from how others have used it and sometimes I find something I did not think of previously.

Interesting, so if you use center for save focus which button do you use for recall?

Right, but it's more for consistency, if control ring was used for one thing on one lens and something else on another I know my brain would get confused.

I have this in my i menu

Enjoying the process for sure. The Z8 has opened new doors that I never ventured into with the Z6 before it.

I use LFn2 for recall focus distance. That button is only on my 100-400 but I don't care about saving and recalling focus distance with my 24-120 and shorter lenses.
I can save and recall focus distacne on my 500/4E without usign any camera controls.
It is possible to save multiple focus distance settings but I don't have a need to expand beyond the one setting.

 

[Geoff_G]

The Custom setups of my Z9's differ in the finer details between the 3 pairs of Shooting Banks: Wildlife, Action, Macro/Landscapes. A high proportion of the menu settings are set Once, but the Autofocus custom settings are different. It pays off to experiment in order to optimize the setup(s) that works best for you and your subjects, in local conditions.

As we know, there are many different ways the photographer can Customize their Z9, and/or Z8. Compared to other Mirrorless cameras, and also the advanced DSLRs (D5 Triumvirate) - D6 being one exception - the main differences have proven to be the Custom Area AF modes and 3D Tracking - all empowered by Subject Recognition.

More than any other, it's these primary features that stand out, in differentiating how to optimize & customize the Z9 Autofocus system. IME, these are the primary settings where it's paid off experimenting to refine how to handover between 3D Tracking (Auto AF sometimes) with the pair of Custom Area modes [edit: and now I plan to test out the method of @EricBowles - use a Dynamic mode in place of Recall Focus position ].

And I'm another one of the Z9 owners who has replaced Single-point mode with CA 1*1..... this was a big lesson over a year ago, when FW 2.0 landed (April 2022).

The processes underlying the HandOver Focus method - leveraging Focus Persistence - are discussed in detail in this thread and linked information :

Nikon Z9/8 Hybrid Handover Question

I want to confirm this. (in Ver. 3.10) BBF will ONLY override/hand over from the shutter button. When pressing any FN buttons set to a different AF Area mode or AF Area mode + AF ON, Pressing BBF or half-press shutter will NOT override the FN button. In other words, the way to hand it over is...

bcgforums.com

My usual choices for focus mode are C1 and C2 and they never seem to stay set on 1*1 so I'm still using Single Point on Fn2. My C1 box is typically set to 1x3 or 1x5 and it's easy to resize to 1*1 if needed. But I also kind of like how SP does not include Subject Detection.

That thread had a lot of experimenting and what not before we got to the meat and real answer to the Handoff question. It's an interesting read but I've summarized focus persistence handoff in post 15 [above] for those who don't care to wade thru that thread.

 

[EricBowles]

I'm not sure I fully understand the "+ AF On" piece? I use Back Button AF On for focusing everything (except MF) so how does Dynamic Small + AF On help in this situation? Oh wait, I think I may have just figured it out thinking about it - you don't have to use the BBAF at all if you press the L-Fn because it also activates AF along with Dynamic small which ignores subject detection. Did I get that right?

Exactly. Since I only want to press the button when I want to focus, I'm not just changing area modes - I'm also focusing. In a similar manner, the AF-On button can be AF-On plus your mode of choice. It's not something I want to use all the time with every button, but just in specific places.

 

[EricBowles]

The Custom setups of my Z9's differ in the finer details between the 3 pairs of Shooting Banks: Wildlife, Action, Macro/Landscapes. A high proportion of the menu settings are set Once, but the Autofocus custom settings are different. It pays off to experiment in order to optimize the setup(s) that works best for you and your subjects, in local conditions.

As we know, there are many different ways the photographer can Customize their Z9, and/or Z8. Compared to other Mirrorless cameras, and also the advanced DSLRs (D5 Triumvirate) - D6 being one exception - the main differences have proven to be the Custom Area AF modes and 3D Tracking - all empowered by Subject Recognition.

More than any other, it's these primary features that stand out, in differentiating how to optimize & customize the Z9 Autofocus system. IME, these are the primary settings where it's paid off experimenting to refine how to handover between 3D Tracking (Auto AF sometimes) with the pair of Custom Area modes [edit: and now I plan to test out the method of @EricBowles - use a Dynamic mode in place of Recall Focus position ].

And I'm another one of the Z9 owners who has replaced Single-point mode with CA 1*1..... this was a big lesson over a year ago, when FW 2.0 landed (April 2022).

The processes underlying the HandOver Focus method - leveraging Focus Persistence - are discussed in detail in this thread and linked information :

Nikon Z9/8 Hybrid Handover Question

I want to confirm this. (in Ver. 3.10) BBF will ONLY override/hand over from the shutter button. When pressing any FN buttons set to a different AF Area mode or AF Area mode + AF ON, Pressing BBF or half-press shutter will NOT override the FN button. In other words, the way to hand it over is...

bcgforums.com

You and Geoff have made some very good points about the need to experiment and adjust AF related settings. That's why the cameras get poor reviews from casual snappers who expect the camera to make the decisions for them. Instead, there is a greater learning curve as you need to integrate what the AF functions do, how they work, how they are applied to what you photograph, and how to adjust among the various choices. It's quite a journey - and why it has taken most serious photographers several months to work through their preferences. Its not something you can simply copy from someone else without the context.

 

[Geoff_G]

You and Geoff have made some very good points about the need to experiment and adjust AF related settings. That's why the cameras get poor reviews from casual snappers who expect the camera to make the decisions for them. Instead, there is a greater learning curve as you need to integrate what the AF functions do, how they work, how they are applied to what you photograph, and how to adjust among the various choices. It's quite a journey - and why it has taken most serious photographers several months to work through their preferences. Its not something you can simply copy from someone else without the context.

Amen. I'll only add that (as expected) it's not so complicated once you get up on the learning curve. It can be tedious if you let it be but I rather enjoyed the process (an aside but the part I really hated about setting up new DSLRs was all the AF Fine tune testing it took to get it right - I sure don't miss that BS)