View source for Sony FE 300 F2.8 GM OSS Preset Focus

== Overview ==
This is applicable to the Sony A1 II (but not A1). It may be applicable to other newer models, when used with the Sony FE 300 F2.8 GM OSS.

The Sony FE 300mm F2.8 GM OSS includes a Function Ring near the front of the lens.  Sony officially documents this ring as supporting:
* Power Focus  
* APS‑C / Full Frame toggle  

However, the lens also supports an *undocumented third mode*: (not mentioned in the [https://www.sony.com/electronics/support/res/manuals/5054/9160c8ce0087829b9805932cfbe6608c/50541710M.pdf FE300 F2.8 GM OSS Operating Guide])

<big>Preset Focus</big> — allowing the user to ''store'' and ''instantly recall'' a focus distance.

This feature behaves similarly to the Focus Preset system found on the FE 400mm F2.8 GM and FE 600mm F4 GM, but is implemented through the Function Ring instead of a dedicated switch.
[[File:Sony FE 300 F2.8 GM OSS Buttons and Controls.png|thumb|'''Sony FE 300 F2.8 GM OSS Buttons and Controls''']]
This article explains how to enable the feature and how to use it in the field.

== Enabling Preset Focus on the Function Ring ==
The Preset Focus mode is activated through the camera menus, not the lens switches.

=== Steps ===
# On the camera body, open the '''Setup Menu'''.
# Navigate to:  
#*Setup <br>→ Operation Customize <br>→ Dial Customize <br>→ '''Function Ring (Lens)''' ← choose this <br> (Menu names may vary slightly depending on camera model.)
# Select '''Preset Focus''' from the available options:
#* Power Focus (default)  
#* APS‑C / Full Frame  
#* '''Preset Focus''' ← choose this

Once selected, the Function Ring on the lens will operate in Preset Focus mode.

== How Preset Focus Works ==
Preset Focus mode gives the Function Ring two behaviours:

* **Turn + Hold** → Saves (registers) the current focus distance  
* **Turn briefly** → Recalls the previously saved focus distance  

The recall is nearly instantaneous and works in AF‑C, AF‑S, and MF.

When saving a preset, the camera will display a brief on‑screen message such as:  
''Preset Focus / Zoom Position Set''

== Setting a Preset Focus Distance ==
To store a focus distance:

# Aim the camera at the subject or area you want to store.
# Use AF or MF to achieve accurate focus.
# **Turn and hold** the Function Ring for about one second.
# Wait for the on‑screen confirmation message.

The current focus distance is now stored until you overwrite it with a new one.

== Recalling a Preset Focus Distance ==
To instantly return to the stored distance:

# **Turn the Function Ring briefly** (a short twist in either direction).
# The lens will snap to the saved focus distance.

This works even if:
* You are currently focused at a completely different distance  
* AF‑C is active  
* The subject is moving  
* The scene has low contrast or clutter  

== Overwriting the Preset ==
To update the stored distance:

# Focus on the new target distance.
# **Turn and hold** the Function Ring again.
# Wait for the confirmation message.

The previous preset is replaced.

== Practical Applications ==
=== Birds in Flight (e.g., swallows) ===
* Pre‑focus on a predictable flight lane or feeding zone.  
* Track birds freely.  
* Instantly snap back to the lane when a bird enters it.  
* Avoids AF hunting in empty sky.

=== Perched Birds in Clutter (e.g., eagles in branches) ===
* Store the exact distance of the perch.  
* If AF jumps to foreground branches, recall instantly.  
* Useful when the subject is partially obscured.

=== Low‑Light or Pre‑Sunrise Shooting ===
* AF may hesitate in dim light.  
* Preset Focus ensures instant reacquisition of a known distance.

=== Repetitive Behaviour Patterns ===
* Herons returning to the same landing spot  
* Cranes walking predictable paths  
* Ducks surfacing in the same area  

Preset Focus allows you to prepare for the moment before it happens.

== Notes and Limitations ==
* Only one preset distance can be stored at a time.  
* The feature is camera‑driven, not lens‑driven, which is why it is not documented in the lens manual.  
* Works with or without teleconverters.  
* Works in all AF modes.  
* Does not interfere with OSS or focus limiter settings.

== Summary ==
The FE 300mm F2.8 GM OSS II includes a powerful but undocumented **Preset Focus** capability accessible through the Function Ring.  
Once enabled, it provides:
* Instant recall of a stored focus distance  
* Fast reacquisition in challenging conditions  
* Behaviour similar to the 400mm/600mm GM Focus Preset system  
* Significant benefits for wildlife and action photography

This feature can dramatically improve keeper rates in situations where subjects move unpredictably or where AF may struggle with clutter or low contrast.


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[[Category:Sony]]
[[Category:Lens]]