Can someone explain crop modes and how they relate to resolution?

Started by wwoolf, April 26, 2023, 06:50:36 PM

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wwoolf

For reference, I'm using the EOS M, and my SD card can handle about 75MB/s write speed.

When using ML on the EOS M so far, I've stuck to the HD 1080p mode. Regardless of aspect ratio, this locks the horizontal resolution to 1736 or similar, so in 3:2 it has a vertical height of maybe 1100 and in 2.39 it scales down to around 700. I don't have the camera on me as of writing so these aren't exact.

I know different modes such as the 5K, 2.5K and 2.8K options can record at higher resolutions, but also apply a crop to the sensor. Since my go-to lens is a 50mm, I want to stick with modes that have minimal crop.

Is it possible to increase resolution if my aspect ratio is bounded, without increasing the crop? Ideally I'm looking for:
1. A mode that records in 2.39 aspect ratio, 23.98fps, zero or minimal crop, highest possible resolution.
2. A mode that records in 3:2 aspect ratio (full sensor), 23.98fps, zero or minimal crop, highest possible resolution.

I would hope that it were possible to increase overall resolution if I'm scaling down the aspect ratio to something wider. For example, if I can record in 3:2 at 1736 by 1100 (approx), then could I maintain resolution by scaling down the aspect ratio, and obtain something like 2130x850? Both of these resolutions have similar overall pixel counts.

When I say "crop", I mean zooming in on the sensor and excluding an outer region. I don't include cropping as in shooting in 2.39:1 or 1.78:1 if they still use the entire sensor width.

I'm relatively new to filming with magic lantern, so apologies if I'm missing key information. Thanks!
EOS M, Olympus 50mm f1.4, Tamron 24mm f2.5

theBilalFakhouri

Quote from: wwoolf on April 26, 2023, 06:50:36 PM
1. A mode that records in 2.39 aspect ratio, 23.98fps, zero or minimal crop, highest possible resolution.
2. A mode that records in 3:2 aspect ratio (full sensor), 23.98fps, zero or minimal crop, highest possible resolution.

In crop mood build you have have:

1. Highest possible resolution: 5.2K preset which gives 1736x2178 (5208x2178 after de-squeezing) 1x3 in 2.39:1 AR at 23.976 FPS (Full sensor width).
2. The only preset which gives 3:2 AR and full sensor @ 23.976 FPS is 1080p preset which gives 1736x1160 resolution in 3x3.

Quote from: wwoolf on April 26, 2023, 06:50:36 PM
1736 by 1100 (approx), then could I maintain resolution by scaling down the aspect ratio, and obtain something like 2130x850? Both of these resolutions have similar overall pixel counts.

This way you will break sensor physics,
1736 is full sensor width already, you can't get more than 1736 in 3x3 (in none crop mode), and wider aspect ratio isn't related here . . the maximum width will always be 1736 in none crop mode (3x3).

ML700D

Quote from: theBilalFakhouri on April 29, 2023, 10:58:56 PM
In crop mood build you have have:

1. Highest possible resolution: 5.2K preset which gives 1736x2178 (5208x2178 after de-squeezing) 1x3 in 2.39:1 AR at 23.976 FPS (Full sensor width).
2. The only preset which gives 3:2 AR and full sensor @ 23.976 FPS is 1080p preset which gives 1736x1160 resolution in 3x3.

This way you will break sensor physics,
1736 is full sensor width already, you can't get more than 1736 in 3x3 (in none crop mode), and wider aspect ratio isn't related here . . the maximum width will always be 1736 in none crop mode (3x3).

how about recording in 3:2 with 1x3?
EOS 700D