I'm meanwhile using firmware revision 1.22.
Jan Behrens wrote:
After asking some questions in my firmware review thread and in my other thread regarding 59.940 vs. 60 fps about the NX1 frame rate options, and after finally finding out that the camera seems to be able to record at 119.88 fps (which is somewhat hidden in the menu and the manual and was totally new for me), I would like to open a new thread to discuss the frame rate capabilities of the Samsung NX1.
After collecting all information as of firmware v1.21, it seems like the NX1 supports the following frame rates and shutter speeds:
23.976 fps with sound, 1/30s shutter (or faster), 3840x2160 resolution
This mode can be achieved by setting:
- MENU: Setup: Video Out: NTSC
- MENU: Video: Movie Size: 3840x2160 (23.98p) or 1920x1080 (23.98p)
- MENU: Video: Fast/Slow Movie: x1 (23.98p)
The video includes a 23.976 fps header, so that playback will automatically be at normal speed.
After checking the actual framerate in the header with a software that shows me 3 digits after the decimal point, I figured out that it doesn't seem to be 24.000 / 1.001 = 23.976 but 23.981. Is that intended? I would have thought that the "23.98" setting is for NTSC based 24 fps (= 24 / 1.001 fps).
What exact purpose has a frame rate of 23.981? Is this a bug? Can someone confirm my findings?
[...]
59.940 fps with sound, 1/60s shutter (or faster), 1920x1080
This mode can be achieved by setting:
- MENU: Setup: Video Out: NTSC
- MENU: Video: Movie Size: 1920x1080 (60p) or 1280x720 (60p) or 640x480 (60p)
- MENU: Video: Fast/Slow Movie: x1 (60p)
The video includes a 50.940 fps header, so that playback will automatically be at normal speed.
If I set the camera to 1920x1080 (30p) with Fast/Slow Movie set to x0.5 (60p), then the header shows 29.970 fps, which is why I believe using the x0.5 fast movie option on 30p also results in a frame rate of 59.940 fps.
However, if we increase speed further to 120 fps, the framerate seems to be 120.000 and not 119.880 fps (as I previously assumed):
119.880 fps without sound, 1/120s shutter (or faster, see note below!), 1920x1080 resolution
This mode can be achieved by setting:
- MENU: Setup: Video Out: NTSC
- MENU: Video: Movie Size: 1920x1080 (30p) or 1280x720 (30p) or 640x480 (30p)
- MENU: Video: Fast/Slow Movie: x0.25 (120p)
Sound recording isn't supported (according to my knowledge) and the video includes a 29.970 fps header, so that playback will automatically be at 4x speed.
I made a mistake here: The header shows 30.000 fps and not 29.970 fps! I wonder wheather the real frame rate is now 119.880 fps or 120.000 fps?
Has someone measured it?
Using this mode of operation, the shutter speed will be limited to 1/125s (or faster).
However, if the mode is select differently, the shutter speed might be slowed down further to 1/120s:
- MENU: Setup: Video Out: NTSC
- MENU: Video: Movie Size: 1920x1080 (60p) or 1280x720 (60p) or 640x480 (60p)
- MENU: Video: Fast/Slow Movie: x0.5 (120p)
Here, the header shows 60.000 fps and not 59.940 fps.
Again: is this a bug? Which is the true framerate being used? 120.000 fps or 119.880 fps?
In that case, the shutter speed can be set as slow as 1/60s (which seems to be a firmware bug, again). It assume that all settings from 1/60s through 1/100s will effectively yield to a shutter time of 1/120s (or 1/125s, not sure?), hence allowing a 360° shutter (or almost 360° shutter?) at 119.880 fps. The video would include a 59.940 fps header, so that playback will be automatically be at 2x speed.
Before anyone answering to this post comes up with long explanations about NTSC:
Please note that 59.940 fps and 60.000 fps are not the same.
The ITU-R Recommendation BT.2020 (UHDTV) states the following frame rates:
23.976 (not 23.981!), 24.000, 25.000, 29.970, 30.000 (in addition to 29.970!), 50.000, 59.940, 60.000 (in addition to 59.940), 120.000.
The frame rate of 119.880 fps (which I thought would be selected when setting the NX1 to 4x30 or 2x60 fps) is not listed in TABLE 2 of ITU-R Recommendation BT.2020 but is just mentioned in a footnote.
Is that the reason why the NX1 records in 120.000 fps instead of 119.880 fps? (If it's 120.000 fps at all?)
Samsung should really clarify this mess of frame rates. As I already said earlier in this thread, I would like to see a simple configuration option for the frame rate which allows you to select the true frame rate used for recording (and not 30 for 29.970, and so on).
[...]
Instead of hiding all these frame rate settings in three different menu options (PAL/NTSC, Movie Size, Fast/Slow Movie) and combining them with "Slow / Fast Motion" settings that store a "wrong" fps-value in the file header (and disable sound!), I would prefer a single setting for frame rate selection:
MENU: Video: Frame rate:
- 23.976
- 24.000
- 25.000
- 29.970
- 30.000
- 47.952
- 48.000
- 50.000
- 59.940
- 60.000
- 95.905
- 96.000
- 100.000
- 119.880
- 120.000
That would allow for an easy selection of the frame rate without the hassle (and loss of sound). I do not need to have "wrong" frame rate information stored in the header files of the NX1 video material: for me, slow-motion is something that can be done in post-processing. A wrong header information is just annoying for me.
P.S.: I think the frame rate is only indicating the playback speed and not the recording speed. Anyway, I don't need such a "slow motion" frame rate in my headers. I would prefer to have the frame rate of the actual recording in the header of my files (and to have sound available if the hardware allows that).
Offering the extra frame rates of 30.000, 60.000, and 120.000 would yield additional compatibility with systems that do not use the NTSC-based 1.001-divided frame rates or when later a conversion to other integral frame rates is desired.
Similarly the 48.000 and 96.000 fps settings would be great for video projects based on 24.000 and/or 48.000 fps.
Also, the limitation of the shutter to 1/60s should be changed to a limitation of 1/50s when recording at 50 fps (to allow for a 180° shutter when downsampling the material later, see my explanations here). Accordingly, the miminum shutter speed for 100 fps recording should be 1/100s (and not 1/60s or 1/125s).
Disclaimer and further note
DISCLAIMER: All information is provided without guarantee for correctness. This is just what I tried to gather information by browsing through the NX1 menu and looking at some of the created videos. The information may be incomplete or incorrect. Particularly further lower frame rates than those listed above seem to be achievable by using the Fast Movie function. The list above is therefore not exhaustive.
