Crop Factor

[Rodrigo Violante]

Im just wondering if in the roadmap of RED they are going to remove the crop factor as you use different FPS and resolution.

It really sucks that my wide angle at 120 FPS becomes a 50mm

I had hope with prores maybe that wasn’t going to be the case but how everyone manages wide angle slow motions

 

[Michael Lindsay]

Hey Rodrigo

It is sometimes annoying and I have even shot on Arri Ultra 16 lenses to be able to get the best slowmo result I needed with early Red cameras. However it isn't just Red that suffers this... Sony, Arri and Vision Research all have HS options when the sensor size read out gets smaller.

If Red binned pixels there perhaps could be lower rez non crop options but the picture consequence are just not worth it from my POV.

Slowmo crops is one of the reasons we don't own a Helium.. and also why we bought some high quality wide lenses

I always have my fingers crossed they may, with some futre FW update, get a little more out of the current bodies frame rate wise..

 

[Rodrigo Violante]

I was thinking in downgrading to dragon 6k sensor because of that reason. It’s sad that we just can’t get higher frame rate at wide angels

 

[Misha Engel]

This might help https://store-abt.de/product/speedmount-mk2-pl-dsmc2/

The SpeedMount reduces the full frame (43.3mm) image circle to S35 format (x0.72) while speeding up the lens for nearly one f-stop.

3.65 um / 0.72 ~ 5.07 um pixel size, about the same as the monstro and dragon 6k.

 

[Mandela Gregoire]

Try GEMINI. 96fps at 5K....I recommend with a Sigma 14mm F/1.8 or Sigma 18-35 1.8

 

[Patrick Tresch]

You have the choice, either VV Monstro in S35 or the Dragon 6k.

 

[Ugo Del]

The compression is also frustrating. The Arri Alexa XT records 120fps in S35 16/9 uncompressed Arriraw by comparison.

 

[Misha Engel]

The compression is also frustrating. The Arri Alexa XT records 120fps in S35 16/9 uncompressed Arriraw by comparison.

16:9 ARRIRAW 2.8K: 2880 x 1620 0.75 - 120 fps
16:9 ARRIRAW 3.2K: 3168 x 1782 0.75 - 120 fps

Good enough for 4k RGB output.

 

[Phil Holland]

The compression is also frustrating. The Arri Alexa XT records 120fps in S35 16/9 uncompressed Arriraw by comparison.

16:9 ARRIRAW 2.8K: 2880 x 1620 0.75 - 120 fps
16:9 ARRIRAW 3.2K: 3168 x 1782 0.75 - 120 fps

Good enough for 4k RGB output.

Just for clarity's sake. Current DSMC2 Unified bodies can do DCI 4K 4096x2160 at a REDCODE RAW Compression Level of 6:1 for 120fps, which is hitting around 272MB/s.

This is mirrored across all current sensor technologies at the moment, but the variance in sensor size at 4K resolution is where things are more notable. Gemini has the largest pixel pitch at the moment and is pretty much approximately a Super 35mm 3-perf format size at this frame rate.

RED DSMC2 Sensor Approximate Format Sizes and Resolutions with Maximum Frame Rate at DCI FF Format and Widescreen:

- Monstro 8K VV - S35 3-Perf Analog = 5K FF (Max FPS 96.39) & 5K WS (Max FPS 120.38)
- Dragon-X 5K S35 - Features the same pixel pitch as the Monstro 8K VV sensor and the format sizes here would be the same as well as the max FPS, 5K.
- Helium 8K S35 - S35 3-Perf Analog = Slightly larger at 7K FF (Max FPS 68.93) & 7K WS (Max FPS 85.94)
- Gemini 5K S35 - S35 3-Perf Analog = 4K FF (Max FPS 120.83) & 4K WS (Max FPS 150.72)

All of this is based around the sensor readout and the minimum compression ratios for REDCODE RAW are all pushed to the maximum data rates the camera bodies can handle as of 2019.

Looking forward, especially for commercial and VFX applications I'd personally love a higher FPS and "thicker" data rate, but all of that means new bodies, sensor technologies, media, etc... At the moment one of the biggest reasons outside of the insane data rates of something like 240 fps 8K is the limitations on the sensor technologies themselves. It's doable, but you'd likely be looking at far less dynamic range as well as a more noisy image, not to mention a hotter and more power hungry beast required to do that. That's just with what's possible today however. Very curious to see how the industry evolves from the typically max 4K at 120fps world outside of the specialty cameras or "tuned" burst modes.