With 4K DCI you get a bit more horizontal pixels which in theory, in numbers, is better.
You see your HD resolution change because the aspect ratio you record is 16:10, not 16:9.
This means that if someone needs to fit your video, regardless of resolution, to a UHD or HD project, he will probably crop some pixels. Maybe you need to shoot a bit wider to cover this possibility.
Almost the same is valid if you are using Super 35 mm mode.
Also, check if you record exactly 24 fps instead of 23,976.
Just a thought to conclude: Since 4K DCI is considered cinema mode and probably records at higher bitrate, you might benefit in stock from that if you shoot content that might fit a documentary or film production.

Quote from: grejak on November 16, 2019, 07:12

Quote from: bestravelvideo on November 16, 2019, 07:06

With 4K DCI you get a bit more horizontal pixels which in theory, in numbers, is better.
You see your HD resolution change because the aspect ratio you record is 16:10, not 16:9.
This means that if someone needs to fit your video, regardless of resolution, to a UHD or HD project, he will probably crop some pixels. Maybe you need to shoot a bit wider to cover this possibility.
Almost the same is valid if you are using Super 35 mm mode.
Also, check if you record exactly 24 fps instead of 23,976.
Just a thought to conclude: Since 4K DCI is considered cinema mode and probably records at higher bitrate, you might benefit in stock from that if you shoot content that might fit a documentary or film production.

May i ask you what is the difference between 24fps and 23,976 thanks for the help !

23.976 = 24 - 1%
The frame rate standard has been slightly adjusted, long ago, when NTSC was launched.
Engineers noticed that color was interfering with the black and white information. The reduction of the framerate by 1% was tolerated by the existing black and white TV systems and addressed the interference.

Similarly, 29.97fps = 30fps - 1%

Quote from: grejak on November 16, 2019, 08:22

Is it logical to shoot in 4096x2160 in 24p then? Or can i just export it in 23,976?

For the buyer, 23.976 or 24 matters exactly zero (0), since a clip without audio can be played at 23.976, 24, or even 25 without any noticable difference. It is 1 click (OK, maybe 2 or 3) in any software.

If you provide 23.976, and their project is 24, it means they will play your clip 0.1% faster. This is how it's done every day in Europe (and the rest of the PAL world) with 24p movies. They all play back at 25p (4% faster).

Quote from: grejak on November 16, 2019, 08:22

Is it logical to shoot in 4096x2160 in 24p then? Or can i just export it in 23,976?

For the buyer, 23.976 or 24 matters exactly zero (0), since a clip without audio can be played at 23.976, 24, or even 25 without any noticable difference. It is 1 click (OK, maybe 2 or 3) in any software.

If you provide 23.976, and their project is 24, it means they will play your clip 0.1% faster. This is how it's done every day in Europe (and the rest of the PAL world) with 24p movies. They all play back at 25p (4% faster).

Recently i have upgraded my camera gear just for stock, and i have noticed that when i upload 4096 resolution the buyers get option for full HD in bigger resolution than 1920x1080. my question is, is it worth uploading 4096 or stick to UHD? Thanks

You can shoot 4096 and then crop to 3840.
It's like you scale down in photos. It will or might look a bit clearer, wit less noise.
Also, you can crop the edges a bit and still export in 3840 so that would not be digital zoom.
Another point is that in case you use warp stabilise you still benefit from that.
A video editor would know what to do with that resolution.
The rest might even not know the difference from different aspects or fit the video to a preset and still scale it to their preference.
All these might be more than needed for stock.
If you are using the camera for ads or other no-stock productions, better you stick to Cinema DNG and play with the colours in post.
Finally, if you are using Premiere, you can export on ProRes, already available from the previous version.
Plain ProRes (not HQ) is more than enough for stock. Just don't use LT.

Quote from: ForrestBrown on November 16, 2019, 14:32

Quote from: grejak on November 16, 2019, 06:16

Recently i have upgraded my camera gear just for stock, and i have noticed that when i upload 4096 resolution the buyers get option for full HD in bigger resolution than 1920x1080. my question is, is it worth uploading 4096 or stick to UHD? Thanks

You probably want to upload your footage as UHD. All of the stock sites will take your UHD footage and scale it down to make HD (and sometime web) options for people to download if they don't want to buy the full 4K versions. Most sites do not make HD versions based on 4096 footage. I personally shoot 4096 and crop it to UHD. That gives me some flexibility to slightly reframe the shot if I want.

but why do you crop it from 4096 to UHD why just not upload the full size?

Quote from: ForrestBrown on November 16, 2019, 14:32

Most sites do not make HD versions based on 4096 footage. I personally shoot 4096 and crop it to UHD. That gives me some flexibility to slightly reframe the shot if I want.

I've never experienced this Forrest? I've been uploading 4096 to all the major stock sites for years and they scale down to HD fine.

I always shoot 4096 whenever I can. A buyer can always "downsize" to 3840, but a buyer who needs/wants 4096 probably wouldn't buy a 3840 clip.

Most agencies downsize 4096 to HD while keeping the proportions, so a 4096x2160 clip will be 2048x1080 in HD, which is also totally acceptable (and considered "2K").  Even then, the buyer can easily drop it into a "normal" 1920x1080 timeline.  Some agencies crop 4096 to a standard 1920x1080, which is fine, but I like giving the buyer the option to have 2048.

And no, don't upscale 4000x2160 to 4096x2160.  If you can't shoot 4096, then upload as 4000, or crop to 3840 yourself.

You're right, it's only 96 pixels, but you should always give the customer the best quality possible.  And even upping 96 pixels does degrade the quality a little.  It would be a bad habit to get into.

But, even if you did, I doubt anyone would know.  If you do up it, up it proportionally.  Don't just "stretch" the horizontal to reach 4096.

If anything, upload native 4000x2160 and let the customer upsize it if they want.  But, some agencies might not like the non-standard 4000 pixel horizontal resolution.

I do well with 4K.  So far this month, I sold 16 of them.  But HD probably makes up about 90% of my downloads.  I even had 2 SD sales this month, so resolution really isn't the key factor when a buyer decides what clip to get -- it's content.