Dynamic zooming zooms in too much for lens correction strengths other than 0 and 100%

[avsaase]

Is there an existing issue for this?

• I have searched the existing issues

Have you tried the latest build?

• I have tried the latest build

Gyroflow version

72b8eb6

What operating system are you using?

Windows 10

What GPU are you using?

No response

What happened?

When selecting lens correction strengths other than 0 and 100% dynamic and fixed zooming zooms in too much. Take for example this clip without motion from the Firefly X Lite II on 2.7K 4:3.

0% lens correction:

100% lens correction:

50% lens correction:

As you can see in the 50% lens correction example there is FOV "left on the table". This happens with all settings between 0 and 100% but seems to be maximized at or around 50%.

I increased the FOV to 1.5 to make it more obvious but it's not a bug in the Safe area guide because it also happens with FOV=1. It's also not related to the output size setting because I tried setting that to the input resolution but that didn't make a difference. I tried a couple of different lens profiles for this camera and setting, all with the same result. I recall seeing this with the Mobius Maxi 4K as well.

Here's the clip and .gyroflow file: https://mega.nz/folder/00NwGYwL#TAKzsDrmqTZ-FLzTkrvhIg

Relevant log output

No response

[AdrianEddy]

I know, this is because I don't know how to calculate camera params when adding lens distortion back, so currently it's something approximated, see:

gyroflow/src/core/gpu/opencl_undistort.cl

Line 275 in 088b02c

float2 factor = (float2)max(1.0f - params->lens_correction_amount, 0.001f); // FIXME: this is close but wrong

This will likely stay this way until someone smarter than me figures it out

[AdrianEddy]

/bounty $150

[algora-pbc]

💎 $150 bounty • Gyroflow

Steps to solve:

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Attempt	Started (GMT+0)	Solution
🟢 @aazam-gh	Oct 1, 2023, 8:50:00 AM	WIP
🔴 @Rutik7066	Dec 25, 2023, 8:21:50 AM	WIP

[aazam-gh]

/attempt #384

Options

• Cancel my attempt

[Rutik7066]

/attempt #384
got it.

Options

• Cancel my attempt

[algora-pbc]

Note

The user @aazam-gh is already attempting to complete issue #384 and claim the bounty. We recommend checking in on @aazam-gh's progress, and potentially collaborating, before starting a new solution.