7D high fps

[fillman86]

I'm looking at upgrading from my 50D to either a 7D or a 5D ii, I keep looking at the capabilities sheet, and I like full frame, but I like that it says that the 7D can do 50/60 fps, but I can't find any tests.... why is this? does it not actually work?

And why isn't the 7D on this regular list? http://www.magiclantern.fm/downloads.html

I'm fine with the lower resolutions, because it comes up higher than 1080 when upscaled anyway from the 50D anyway, so that's not factoring into my equation .

[fillman86]

so no one has ever seen 50/60fps 7D raw footage?

[vyskocil]

I already saw some posts about 50/60 fps footage on 7D here.
However, I just tried it on a nighty build and it seems to work ok but you have to :
- set the video mode in the Canon Menu to 720p (1280x720@50/60fps)
- you can adjust the real capture resolution in ML menu (MLV), I could record continuously using 1344x540@50fps
- the recorded footage is stretched vertically by a factor x1.4 (or x1.666 ?), you have to fix it in post prod which may introduce some more aliasing.

[fillman86]

I tried to search for it but came up with nothing, not even on youtube....

can you put up an example, I want to see how bad it looks and to see if it's usable or worth it?

[ansius]

really searched? http://www.magiclantern.fm/forum/index.php?topic=12075.0

[Midphase]

really searched? http://www.magiclantern.fm/forum/index.php?topic=12075.0

I think they should start teaching "How to search on the internet" in public schools. I'm not kidding, and this doesn't only apply to the ML forums. I think there are some people (many of them actually) who either don't know how to enter appropriate search words, or get so easily frustrated that if their top result doesn't match exactly what they're looking for, they give up.

[fillman86]

its true, I gave up after the 3rd page, but most searches at the time were giving no results, and having to wait the 15 seconds each time was just a bit of salt in the wound, but thanks for making a relevant post to the conversation.

That link you posted shows really bad aliasing, but it's also really really compressed. It's also a bad example, showing high fps with still subjects? But it showed low rolling shutter problems. Is there some way to set it to shoot at a letter box ratio that doesn't need to be stretched? other wise I don't think the 7D would be worth it for me.

[Audionut]

or get so easily frustrated that if their top result doesn't match exactly what they're looking for, they give up.

Blame Google for returning the requested page as the top search result, even when your search parameters are really bad.

but thanks for making a relevant post to the conversation.

Google even has an advanced search, so you don't have to remember the search string for searching a site.

[Midphase]

Is there some way to set it to shoot at a letter box ratio that doesn't need to be stretched? other wise I don't think the 7D would be worth it for me.

If you're looking for a slow motion raw solution, you really should consider the 5D3. IMHO the 7D has too restrictive of a write speed to achieve slow motion footage that doesn't suffer from needing to be stretched and up-rezzed in post.

With the current crop of technology, I think asking for slow motion and raw shooting might be a bit too much. Perhaps something like the Panasonic GH4 might appeal to you, even though it's most definitely not shooting raw.

[vyskocil]

Here is a sample video I just made using 720p@50fps in RAW (when Vimeo will finish to render it) :

[UPDATE] I don't know why but Vimeo seems to not offer HD resolution for this video (why ?)

Another test, this time in Full HD@25fps (1920x1080) recorded in crop mode :

[fillman86]

hmm yeah, really harsh compression.... and it's hard to get reference on how slow it is with just beez, but it's the quality I'm looking at. what I said about stretching is, what if I wanted the aspect ratio to be that, is there a way to get it to be normal at that res? and if possible, how bad is the quality loss? can this be achieved by changing the recording aspect ratio in the ml menu?

how about upping the bitrate multiplier? in normal h.264 what is the highest bitrate (Mb/s) you can get for 50fps?

[vyskocil]

Here is a sample video I just made using 720p@50fps in RAW (when Vimeo will finish to render it) :

[UPDATE] I don't know why but Vimeo seems to not offer HD resolution for this video (why ?)

Another test, this time in Full HD@25fps (1920x1080) recorded in crop mode :

Didn't know this : "Vimeo allows Basic members to upload only one HD video per week, so if you upload two HD videos within the same week, only the first will show in HD. The other will appear in SD only."

I'll try to repost these videos in HD...

[dpjpandone]

I think this topic should grow now that FPS override has been implemented for 7D!

Can someone please clear up the following:

On some cameras (600D) the fps override menu has a "high fps" option that allows for overcranking from 23.97 to 36 fps. I really loved using this setting, because it was just enough for a subtle slow-mo without any loss of vertical resolution.

It seems that the only way to get this framerate on the 7D is to set to 720p mode and undercrank from 60fps. The footage seems to take a hit in quality, as it's recording non-square pixels in this mode, it's recording pixels that are compressed 1.4 instead of a 1.0. When they are stretched back in post the same increased aliasing is present (that you always get in 720p mode) even when the resolution is set to higher than 1280x720 (1728xwhatever for example)

Of course, this is just my impression, I'm hoping someone can confirm that this is correct.

Is it possible to bring high fps mode to the 7D? With this build, I can only overcrank to 25.xx fps from 23.97. I can get 31 fps from 30, but I'm really missing those 5 extra frames. Lastly, is it likely that fps override will ever work with .h264 on 7D?

I know that everyone has been begging for fps override on 7D, and one day after it's implemented, I am already asking for more.... sorry to be that way...

I did get the development environment set up on my laptop (wish I could use my whole display) and I can compile, so I'm hoping to be more helpful soon.  In the meantime, here is some smow-mo tests I shot last night with the new build:

  - dont know why this wont work
Not a valid vimeo URL - this either?

[vyskocil]

Didn't know this : "Vimeo allows Basic members to upload only one HD video per week, so if you upload two HD videos within the same week, only the first will show in HD. The other will appear in SD only."

I'll try to repost these videos in HD...

I just updated the 50 fps video :

[dpjpandone]

hey vyskocil,

 have you experienced a  corrupted live view when fps  is set higher than 60? My 7D screen turns pink when I set it to the fps that's just over 60. 

[vyskocil]

hey vyskocil,

 have you experienced a  corrupted live view when fps  is set higher than 60? My 7D screen turns pink when I set it to the fps that's just over 60.

I haven't tried to push the override above 50/60 FPS. Will try it and tell you.

[dpjpandone]

Yes, I just tried it again, and 59,94 is fine, but 62.974 (which is the last and final increment) causes live view to become corrupted. Perhaps it should be limited to 60fps.

Thank you so much for getting the ball rolling on FPS Override!

Do you have any interest in adding the "High FPS" option that is present in other builds? 

- high FPS (NEW_FPS_METHOD): try to decrease timer B first (no side effect on shutter speed)

I know I read your opinion that overcranking is not very useful, but I strongly urge you to reconsider. Undercranking is only half of the story. I know that this is really important for users who shoot in crop mode, but I think it's equally important to be able to overcrank at full resolution. Switching to 720@60P and undercranking to 36 is not a good workaround because the increased aliasing from using 720p mode is painfully apparent in slow-mo shots where the action is slowed down and the viewer has more time to see these artifacts.


Since you don't really use this mode I should give some additional information, usually when you overcrank, you still want to maintain a 180 degree shutter speed, so that when the clip is played back at 24fps it has the same amount of motion blur as a clip that was recorded at 24fps 1/48 shutter. So if shutter speeds must change with higher fps,  we should favor values that are close to 180 degress or 2*FPS.

Again, thanks for working on 7D! Please let me know if there is anything I can do to help. 

[blackjack102]

Yes, it is can be challenge to find 60 fps on 7D subject. I just use old built version which is working well. New version is not stable for 60 fps.  All them were a bit different set but I found a good setting for me. I used 1280x494 at 1.85:1, stretched at 1.66 and cropped at 1280x720. I hoped new FPS override will fix on 60 fps but it doesn't work on my 7D. Maybe it will work on different 7D.

here are links that I filmed at 60 fps on my 7D.

[dpjpandone]

blackjack, what problem are you having with fps override? 60fps works fine for me, it's 62 that corrupts live view

[blackjack102]

blackjack, what problem are you having with fps override? 60fps works fine for me, it's 62 that corrupts live view

Never mind, I tried another test and found it works. I think I screwed some setting last night.

[vyskocil]

Yes, I just tried it again, and 59,94 is fine, but 62.974 (which is the last and final increment) causes live view to become corrupted. Perhaps it should be limited to 60fps.

Thank you so much for getting the ball rolling on FPS Override!

Do you have any interest in adding the "High FPS" option that is present in other builds? 

- high FPS (NEW_FPS_METHOD): try to decrease timer B first (no side effect on shutter speed)

As I understand it, the NEW_FPS_METHOD needs the location in memory of some tables that must be found for each platform (SENSOR_TIMING_TABLE, VIDEO_PARAMETERS_SRC_3,... ?) if ever they exists on the 7D ?
I don't have the tools and the time to look deeply at this, but perhaps someone know how to discover these tables on the 7D ?

[dpjpandone]

ok, is there is a limit imposed on the max fps with the currently supported fps modes on 7D? Can we remove this limit and do some testing, it must be able to safely overcrank a little bit more than It does currently.

[dpjpandone]

ok so, we need info here:

Code: [Select]

#elif defined(CONFIG_7D)
    #define TG_FREQ_BASE 24000000
    #define TG_FREQ_SHUTTER (ntsc ? 51120000 : 50000000) // todo, just copied
    #define FPS_TIMER_A_MIN MIN(fps_timer_a_orig - (ZOOM ? 0 : 20), ZOOM ? 0x262 : 0x228) // todo

and here:

Code: [Select]

#ifdef CONFIG_600D //but make one for 7D
    #define NEW_FPS_METHOD 1
    #define SENSOR_TIMING_TABLE MEM(0xCB20)
    #define VIDEO_PARAMETERS_SRC_3 0x70AE8 // notation from g3gg0
    #undef FPS_TIMER_B_MIN
    #define FPS_TIMER_B_MIN MIN(fps_timer_b_orig, 1420)

if I can find this info we can implement it? Is this something I can find with the CMOS/ADTG module? Is it ok to use that module with 7D?

[N/A]

Any more findings with this? 7d would be the perfect candidate for overcranking fps, would love to have 36 or more fps for raw in 24p/30p mode.