Sigma fp cine mode: 4:3 full sensor mode missing (for anamorphic lenses)

[kay_oz]

I'm quite desperate because I want to get the most out of my sigma fp: But there's no 4:3 mode for filming in CINE - it's there only for the photo "still" mode. But using the "still" mode profile in the cinema mode profile (this is possible!), there's still no 4:3 shooting... Or does anyone have an idea how to find this? I would like to use my anamorphic lenses Sirui and GreatJoy by using the full sensor... Not even their newest firmware upgrade made this possible so at this point I'm frustrated not having bought the Pana S1H... Is there anyone out there with an idea or hack or calming words for me?? THX

[TomTheDP]

Cropping isn't the worst thing, but yeah open gate on the S1H is a better option for 2x anamorphic lenses.

[OleB]

Full 6k 3:2 is not possible with cDNG because of the enormous data rates which need to be transferred to the USB-C drive - drives are too slow over USB-C for that.

The sensor is natively able to produce something like 3k in 3:2 though, hoping for SIGMA to implement that mode. For the SIRUI 1.6x that would be a perfect match. 😉

[TomTheDP]

It is a shame they can't do slight compression like 2:1 or 3:1 like the old BMPCC

[Llaasseerr]

Open gate for the fp is not needed for 35mm anamorphic as is usually shot - just crop the sides.

The current height of a 16:9 recording on the fp and similar affordable full frame cameras matches the height of an Alexa 35 camera recording in open gate. You do lose some resolution from cropping the sides, but it's fine and it also improves rolling shutter speed.

[Nostromo2023]

On 4/17/2023 at 11:40 PM, Llaasseerr said:

Open gate for the fp is not needed for 35mm anamorphic as is usually shot - just crop the sides.

The current height of a 16:9 recording on the fp and similar affordable full frame cameras matches the height of an Alexa 35 camera recording in open gate. You do lose some resolution from cropping the sides, but it's fine and it also improves rolling shutter speed.

Hadn't thought about it that way. how does cropping the sides improve Rolling Shutter... or you mean, shoot in FF to match Alexa 35 sensor height and crop the sides. But you still get the rolling shutter of approx 20ms when shooting in 4K FF... Could you please explain a bit more? Thanks

[Llaasseerr]

On 12/21/2023 at 11:59 PM, Nostromo2023 said:

Hadn't thought about it that way. how does cropping the sides improve Rolling Shutter... or you mean, shoot in FF to match Alexa 35 sensor height and crop the sides. But you still get the rolling shutter of approx 20ms when shooting in 4K FF... Could you please explain a bit more? Thanks

I meant shoot full frame without a dedicated anamorphic mode and you are mainly cropping the sides in post, but with about a 12% crop vertically. So although you can't do a sensor crop in camera, you can use guides and then crop in post and get the better readout of the cropped window.

I did misunderstand the rolling shutter speed improvement impact of cropping the sides though. Apparently it's more based on vertical cropping than horizontal where there is a slight but less noticeable improvement. So it's more about reducing the total amount of lines read and to a lesser extent how long it takes to read a line. But you will still get a benefit in both directions.  

The 2x anamorphic stretch helps reduce the perceptual effect of the rolling shutter too because it's so wide in the horizontal, especially on a 2x setup.