Canon HF G30 Cinema Mode
 

Having tried Cinema Mode, I find in very bright situations I sometimes get banding in clear blue sky, much like when I tried Cinestyle on my EOS 60D. In the case of the 60D I just accepted that I was pushing the codec a bit too far with the add-on profile and stopped using it, but this is a built-in effect and it is essentially the same camera as the professional XA 10!

I used Cinema Mode Standard with Contrast at -2, Colour Depth -1, Key M, Softening Filter off and manual exposure set to just remove 100% zebras in the brightest highlights. I use a Hoya ND8 over the lens, but it does not cause the problem in Manual Mode, so I have to assume it is not the problem (!). The banding is definitely baked into the camera output. As much as I'd like to, I cannot get back to the location to test adjustments for a year or two, so I ask if anyone else has had this and can either tell me whether this is a common problem, or suggest what CM settings I may need to change.

I've never had this happen in Manual Mode and this is how I am now shooting. If you can help, thanks.

Re: Canon HF G30 Cinema Mode
 

I think the camera pushes the codec a bit too far. Probably something Canon was aware of when they restricted Cinema mode to 25P. It's a great field camera, but shouldn't be mistaken for a cine camera. I long ago came to the view that Cinema mode is a bit of a gimmick and despite the limits of the codec you're better off shooting manual and getting effects in post.

Re: Canon HF G30 Cinema Mode
 

I have three Canon HF200 level Legria recorders and use Cinema Mode all the time. But the explanation of what this does for your footage is a mystery. To quote from the manual:

Give your recordings a more cinematic look by using the [Cinema Mode] recording program.Combine the recording program with the 25fps progressive frame rate [PF25] to get the enhanced effect of the 25p Cinema Mode.

It tells you exactly "squat" about what this setting is doing to your footage. As I set manual exposure, colour balance, focus, frame rate (25p) and audio levels as well as manual picture profile settings, limited though they be on these amateur cameras, what part of the controls of the camera is left to the Cinema Mode? Maybe shutter speed?. I do not tend to shoot in bright outside conditions and these cameras have no zebra levels, but I have never seen any banding effects on my footage. I tend shoot indoors event type footage where light is rather under present than over present.

The point of all this ramble is why can't Canon give us more information on what this mode is supposedly doing to and for our footage, instead of the circular logic of their manual wording.

Re: Canon HF G30 Cinema Mode
 

Rainer: I agree with you. I had always shot in Manual Mode using my own custom settings, but seeing how Cinema Mode raw footage measures on the WFM, I had to try it. After all, Canon wouldn't include something in one of their cameras that didn't work 100% would they? Would they? Really?:-) I have made the adjustment you suggest, back to Manual Mode!

Tim: I had an HF S100 and it had exactly the same useless "instruction" in the manual. I never used CM on that camera, only tested it and wasn't impressed.

I have searched for some information about CM but found nothing, so I thought I would ask here on the off-chance that someone might know a bit more. Oh well, thanks anyway.

Re: Canon HF G30 Cinema Mode
 

There have been a number of past discussions going back more then 10 years on the CINE modes in various Canon camcorders. The following is but one of them.
http://www.dvinfo.net/forum/canon-vi...-mode-not.html
With search you will find more.

As I understand it video from the camcorders in question is 8-bit, about one bit more than would result in apparent banding in normal images viewed by people with normal eye sight under normal video recording. Thus banding can result from too few bits being allocated to the brightness range of concern resulting in visible brightness steps on playback. This is especially noticeable where there are large image areas involved. CINE mode softens the contrast in darker image areas and emphasizes gradation changes in lighter image areas, When digitized with a limited bit depth and then displayed - banding.

A solution is to migrate to 10-bit recording.

Re: Canon HF G30 Cinema Mode
 

Cheers Don

The older camcorder Cine Modes are different to that of the HF G30, so much of what is writtten does not apply. My old HF S100 had a Cine Mode, which I never used, much like the HV series where the camera controls everything, but the G30 allows manual control of shutter, gain etc.

Yes, the output is 8-bit Suggesting it is just possible that my turning Contrast down to minimum may exascurbate the problem? We just don't get those bright, deep blue Mediterranean skies here, so no amount of adjustment and testing will tell me if I have, or have not, cured it. Naturally I will have to have a fiddle!

I know you are correct about 10-bit being the answer, but retirement concentrates the mind wonderfully on what is to hand rather than what is available to buy. I get some jolly fine results from the G30 in Manual Mode but, you know, there's always that "can I wring a little more out of it?", which is why Cinema Mode came into the equation as an experiment.

Re: Canon HF G30 Cinema Mode
 

The G30 is similar to the XA20, and the XA20 manual is similarly skimpy on what CINEMA mode means.

However, if one looks at the XF100 which has more image controls you will find there are a gamma setting, some of which are identified as "Cine." I suspect the net effect is about the same, with the higher end camcorder offering more adjustment options. Attached is an extract from the XF100 user manual that shows two Cine positions and their effect of gamma.

It is a trade off - for more bits allocated to shadow detail you give up bits for highlights. You have to fiddle around until you find the compromise that works for your projects.

Re: Canon HF G30 Cinema Mode
 

I ran a series of tests a while back comparing the luminance curves in Normal and Cinema Mode on my HF-G30. It was a pretty crude set up. Took shots of a printed greyscale ramp on a wall under daylight balanced illumination, brought the clips into DaVinci Resolve and examined the Waveform and Histogram plots. I deleted most of the data subsequently, but kept this one for prosterity - comparing Normal Mode (at default and with altered Image Effect settings) and Cinema Mode (Standard Filter 1, default 'Mid Key') all shot in Program AE (+12db AGC limit):

https://i.imgur.com/3GeFAPh.png

There's a fair bit of scatter on the plots (due to uneven illumination primarily) and I just could not produce a print of the gradient that reproduced 'true black', but it gives some insight at least into what Cinema Mode gamma does, which is consistent with Don's comment above:

Actually I found that the default Cinema Mode (Mid-Key) profile could be manipulated in Resolve to something close to Normal Mode (with default 'Image Effect' settings) simply by adding Contrast (S-curve with lowered pivot point) and Gain. I still have the Resolve custom preset ('Power Grade') I created for that, but unfortunately not the waveform and histogram comparisons. That's not accounting for the 'softer' image in Cinema Mode though, which I concluded could not be satisfactorily compensated for by sharpening in post, with or without these global contrast adjustments.

Really, the only value I could see in shooting Cinema Mode (Standard Filter 1, that is) was that the flatter profile gives a bit more latitude for stylized grading. And obviously that's something one would anticipate and prepare for under controlled lighting conditions.

Incidentally, I see that Canon dropped Cinema Mode per se on the HF-GX10, and also Highlight Priority mode; but added 'Monochrome' as an alternative 'look' along with Wide DR. I wonder if they'll be following suit with successors to the HF-G40 and HF-G21, assuming there will be one or the other ?

As for Dave's query - as much as I'd like to be languishing on a beach somewhere in the Mediterranean (well maybe not this time of the year), weather conditions here in Quebec (emerging from a particularly harsh winter) don't permit me to verify the observations about the banding in Cinema Mode in very bright situations, but I think Don's explanation is most likely the case.

Re: Canon HF G30 Cinema Mode
 

Don: Thanks for the chart. Whether or not the G30 CM is the same as one of the curves, I would guess it is unlikely there would be much difference. All I know is CM Standard (default settings) looks and measures substantially flatter than can be achieved in Manual Mode using custom settings. At least in theory, it ought to be the best mode for wiggle room in post.

I had a play, conditions were nowhere near when I had the problem, just to get some idea of what CM adjustments will do. As you say, I will have to fiddle with it until I get it to suit, if I do, but my disadvantage is in having to wait until I get somewhere where the right conditions can be found. I shall try again here when we get a bright sunny day, but I believe I shall probably stick with modified MM.

Bryan: Thanks for taking the trouble to drag those Resolve 'scope traces out, they reinforce what I see on the Cinelerra Videoscopes.

Since the over exposure warning on my Cyprus trip a couple of years ago, the one you know about where I had to increase shutter speed and the water in the waterfall looked as though it was coming down some kind of ratchet device, I've been experimenting with different remedies including CM. I have shot a couple of projects in it, one of which, shot in this country, was perfectly OK, the other had the banding in a small number of clips. Yes the codec was being stretched, clear blue Greek sky and being shot from a boat at sea, even though I had an ND8 filter fitted.

Later the same year, after Cyprus, I was in Kefalonia and used my Cokin filters, but I found them not practical for run and gun video, too often the sun got behind the filter as I moved the camera about and caused flare. I bought a screw-in ND8, which means I will not have the Cyprus exposure problem again and, as I have never seen banding in MM, I shall be using it in again in the future.

I am recently back from "languishing on a beach" in Tenerife, as Greece closes for the Winter. It gave me the chance to meet Barry too, if you remember him. I took the opportunity to shoot some comparison shots, MM with various adjustments, and CM with default settings. I couldn't reproduce the banding unfortunately, however it did show me instances where CM could be preferable to MM.

Re: Canon HF G30 Cinema Mode
 

As this thread is quite active but is nothing to do with cinema mode but is to do with g30 newer camera the g40 I wonder if any body else has had this happen to them, while filming today at the tele end of the lens the camera zoomed out to wide on its own I was not touching the rocker? it did this quite a few times the only way to stop it was to hold the rocker at the tele end, did a reset but no different anybody have any suggestions please

Re: Canon HF G30 Cinema Mode
 

Ian, that might be an issue for Canon service.

Refer to https://www.canon.co.uk/support/rcc/

Re: Canon HF G30 Cinema Mode
 

Can't speak for the HF-G40 but I've never observed that on my HF-G30. Something not right there.

Re: Canon HF G30 Cinema Mode
 

I know we've had this discussion before, but I just couldn't live with that soft-flat Cinema Mode look (which is hardly 'cinematic' from a contemporary perspective) and would always be looking to add contrast and sharpening. So the 'wiggle room' would mostly be in what headroom is left for Gain.

Still wonder what benefits 'Highlight Priority' (on the HF-G40) might bring in such instances. I only had limited opportunity to compare Normal, Wide DR and Highlight Priority on the HF-G40 with some hastily shot samples taken in a camera store. Based on what I could glean from the Histogram profiles (YUV in this example) it looked like 'Highlight Priority' could be useful in very bright conditions. Posted this example before, but here it is again:

https://i.imgur.com/X3Y7WQv.png

On balance though I didn't think the HF-G40 added enough value, in terms of performance and 'must have' new features, to make upgrade from the HF-G30 worthwhile. In addition I didn't particularly like the subtle change in colour tone which definitely added more magenta to the mix.

Re: Canon HF G30 Cinema Mode
 

That we have, but then I had only done a few tests locally rather than use it on a project.

The first project with it was shot in this country, there were no obvious problems and it intercut quite well with GoPro footage which was shot flat. I therefore decided to try it in Crete later in the year and found the banding once I got home. In fairness it was only in three clips, but that's three too many.

As no-one has come up with CM settings that are better, it is up to me to find out for myself. I shot a few clips at different settings yesterday, because it was sunny, looked at them in the scopes and tried CC. Interesting, but I doubt I shall get any really meaningful results until I am in Rhodes later this year.

Re: Canon HF G30 Cinema Mode
 

Back to banding. Is it regardless of display used, or only on one display?

I ask because some displays are constrained to displayed bit depth; e.g., they take an 8-bit input and squash it down to 6-bits with dithering as a working approximation that works for most purposes and allows faster displays. That might contribute to the of banding as well.

Some online material for leisure reading pleasure.

TFT Central Monitor Panel Part Database
Provides information of various displays.

https://en.wikipedia.org/wiki/Colour_banding.
Monitors and Color Bit Depth Explained with Andy AstburyAndy Astburys' Photography Blog
Remove the Ugly Color Banding from Your 8-bit Footage with This Simple Trick | 4K Shooters

Re: Canon HF G30 Cinema Mode
 

That's the one Don!

One display in particular shows bad banding, on the laptop I bought for editing a few months ago. A display I hooked to it shows a touch of it on one clip (raw camera clips), the display on the other laptop, which is not for video although capable, doesn't show it on any of the clips. A transcode of a few clips didn't improve things, neither did any driver settings. So not entirely Cinema Mode then!

One problem solved and another one to consider. The idea of a laptop for editing rather than a new desktop is so I can do some editing while away from home, but it certainly won't be much fun like that. I don't see it as a warranty claim, it hasn't broken, so I'm stuck with it as it is for now.

Thanks Don, I hadn't considered the display. Why would I, it's a new top of the range laptop? I have bookmarked the links for an in-depth read later.

Re: Canon HF G30 Cinema Mode
 

Glad you solved it. And there was me seeing if I had any Cinema Mode footage from my old HV30 or HV20 archived somewhere - which I don't, but I seem to recall there was an issue there with posterization on fine gradients, not too mention increased noise in the shadows. There again it could have been my monitor ;-)

Re: Canon HF G30 Cinema Mode
 

Cheers Bryan.

It looks like I shall be trying another Linux distro on that laptop, the other (good display) one has a
different distro. It could be that simple. If not, I shall have to swap them over.

Re: Canon HF G30 Cinema Mode
 

been out today with the g40 and had no problems with the zoom bit strange to say the least!!!!!

Re: Canon HF G30 Cinema Mode
 

Update for Don and Bryan

It isn't the display, it's the driver. I booted a live distro and the offending clips played beautifully, so I installed it, still good and I'm now putting all my stuff on it. It's a relief it's only one machine!

At least I now know I can use Cinema Mode on my G30 if and when I like. Thanks again gents.

Re: Canon HF G30 Cinema Mode
 

More bits to shadows can lift noise out of the black and it becomes visible.

Re: Canon HF G30 Cinema Mode
 

Bizarre. Makes you wonder about possible environmental interferences - vibration, electromagnetic etc.

That would make a good bumper sticker..........for the wife that is :‑o

Right - I noticed it a bit in Cinema Mode on the HF-G10 also, but it's much cleaner on the HF-G30. Didn't check out Cinema Mode on the HF-G40 but increased shadow noise was one of the things I didn't like about Wide DR mode. Seemed to be pushing the gain/noise floor dynamics to the limits.

Re: Canon HF G30 Cinema Mode
 

Not sure I'd want to tell mine that!:-)

I'm not so bothered about noise in the shadows and it's not just shadows, the whole image is noisier than MM, but a little denoiser can work wonders, depending on how bad it is of course.

I proved it was the Nvidia proprietary driver by installing it and getting the banding back, but it won't go away just by uninstalling. I'm sorting that out now. For the record, I will post the details when I've finished in case anyone else has a similar problem.

Re: Canon HF G30 Cinema Mode
 

I've tried everything else.

Except when there is 'real' banding, in which case denoising may make matters worse, at least in an 8-bit integer processing environment. And what benefits can be gained from processing 8-bit YUV sources in a high bit depth/floating point imaging system (like Resolve) rest largely on dithered noise in the source. Likewise there's no magical transformation that takes place on converting an 8-bit source to a 10-bit intermediate - that would be alchemy; it's still 8-bit data, just padded to 10-bit. It's dithering in the inter-conversion that makes any difference. FFMPEG (and so MLT, in the context of KDenLive) applies dithering (by default) when converting 10-bit to 8-bit, btw.

If conspicuous noise is confined to the shadows, I'd be more inclined to treat it selectively with a mask. If it's in the highlights, I'd look at the trade-off.

Re: Canon HF G30 Cinema Mode
 

Noise is easier to notice/see in shadows. Two IRE units of noise fuzz on a 10 IRE image is 20%, while the same 2 IRE units of fuzz on an 80 IRE signal is only 2.5% and less obvious to the eye.

Re: Canon HF G30 Cinema Mode
 

Thanks for that bit of info Don.

That's always been apparent to me but I've never had it explained in empiric terms before.

Re: Canon HF G30 Cinema Mode
 

As a quick test using an XA20 I shot video of the 6 gray blocks on a Macbeth Color Checker Chart in Manual and in Cinema modes. I set the brightest white (90% reflectance) square just into 100% Zebra (set to I00 IRE). Shutter was 1/30, aperture about F/4.0 adjusted to provide zebra, with 12 dB gain, halogen light.

The attached chart below shows the resulting IRE levels of the six gray squares for each mode. It is apparent that Cinema allocates lot more IRE range/space for shadows with under 3% reflectance.

Re: Canon HF G30 Cinema Mode
 

Interesting. You can also make that out in those fuzzy waveform plots I posted earlier - the Cinema Mode curve has that upturn at the bottom end - what would you call that in terms of gamma curve 'anatomy' - "toe-stretch" or something ?

Re: Canon HF G30 Cinema Mode
 

That noise comparison is interesting, thanks Don.

For the record:

I do not have the make/model of the laptop display, but the machine itself is a StationX Lancaster, the 15.6" display is matte, 1920 x 1080 IPS.
The graphics card is NVIDIA GP 106M (Geforce GTX 1060 Mobile 6GB)
The driver is the Video-Nvidia proprietary Linux driver.

To reiterate, banding in certain video clips showed up badly when the Nvidia proprietary driver was installed, but not without. Simply uninstalling the driver did not stop the banding. The OS was Manjaro KDE, but I found the same effect with other distros. A re-installed Manjaro without the driver does not have the problem and I have disabled the card in BIOS.

Just to make life more interesting, my backup drive had suddenly become read-only and unmountable, so I have just spent several hours attempting to recover the files. A success thankfully, good old Puppy Linux, I always keep a copy on hand just in case!

Re: Canon HF G30 Cinema Mode
 

[Quote]...what would you call that in terms of gamma curve 'anatomy' - "toe-stretch"...{/Quote]

Here is how Canon describes it in the XHA1 manual. Black, knee and gamma all interact.

As to why the banding it is more apparent in Laptops, I suspect that in the interest of saving power they try do things in the least processing intensive way, and use displays that draw less power. The additional processing to do a full 8-bit or dithering is not necessary for most purposes, so they save a bit of power by doing 7- or 6-bit and skip on the dithereing. Then banding can become apparent under certain image circumstances. Changing drivers and/or firmware may adjust this, but at a power consumption cost.

I wonder if just uninstalling the drive did not effect it because the drive installation may have included a firmware update. I know that happens with the BlackMagic Design Intensity cards.

Re: Canon HF G30 Cinema Mode
 

Update

I just found this on the Nvidia forum and judging from the number of complaints, this is a very common problemStrangely enough, knowing I'm not the only one is not particularly comforting!

Someone has posted a possible fix entailing the contrast setting. The trouble is, if I install the driver and this doesn't work, I've got another few hours work to put it right again.

Edit: I did try it, it doesn't work. Odd that it works better with the Linux driver than the Nvidia one.

Re: Canon HF G30 Cinema Mode
 

Does changing the dithering 'depth' in the NVIDIA settings utility help at all ? As per:

https://askubuntu.com/questions/5957...drivers-gt750m

Re: Canon HF G30 Cinema Mode
 

In a word, no. I tried that before, although not for the right reason, then.

Looking closely at the offending footage, there is a lot of noise in the sky which just isn't there in MM footage. I will have to compare similar clips shot in Mediterranean conditions in both modes to see what the difference is, but I doubt I will be shooting in Cinema Mode in those conditions again. Whether I shall ever use it again I can't say, but the option is there now the problem has been discovered.

Re: Canon HF G30 Cinema Mode
 

Thought you probably had.

Re: Canon HF G30 Cinema Mode
 

For some reason, any colour control settings I make in the Nvidia settings window and confirm, do not hold and there is a warning that colour settings are made elsewhere, meaning the KDE Display settings. Neither Dithering nor Contrast (Nvidia window, they are not in the KDE settings) made any tangible difference.

By way of an update, I had some other display problems and had to re-enable the graphics card in BIOS. I found some similar shots to the ones that show banding on the laptop display, all shot in Manual Mode, from old projects. As I have found a quicker way to install or remove the Nvidia driver, involving a reboot each time, I reinstalled it and examined the footage. There is banding showing in all of them, although not quite as bad. Remove the driver, gone!

Something I forgot to mention, when I install the Nvidia driver all fonts increase in size by several points. There are times I wish I'd stuck to my older, slower tower.:-(

Re: Canon HF G30 Cinema Mode
 

As I understand, the principal reason why the proprietary NVIDIA driver is 'recommended' is because it accesses the full OpenGL functionality of the card, which may be required by Linux applications that use OpenGL extensively and/or to run certain Windows applications on Wine.

If the NVIDIA driver is proving so problematic and you don't notice impaired performance or functionality (otherwise) with the Linux applications you are running (KDenLive, Cinelerra etc), why not stick with the Nouveau driver ?

Re: Canon HF G30 Cinema Mode
 

That's what I'm doing. I've only re-installed the Nvidia driver to do some tests, removing it afterwards each time.

I've abandoned Kdenlive, Cinelerra is doing what I want it to. It can be set to use OpenGL, how I run it, but I have seen no performance hit without the Nvidia driver.

I normally use the laptop hooked up to an external display and the banding doesn't show up on it, suggesting what Don says about laptop displays is correct. The only reason I'm fighting this is because I want to do some laptop editing when away from home, as I said. I'm just so pleased it isn't the camera.

Re: Canon HF G30 Cinema Mode
 

The sort of good (glass is half full) news is that you can do a lot of basic editing even with the funky displays in the laptop. You just have to find a good system display for the finer work like color grading.

Re: Canon HF G30 Cinema Mode
 

Where I finish up is, I must have the Nvidia driver installed in order to get the external display to work when plugged in (HDMI) and also to control the laptop screen when the lid is closed (as it needs to be when using the external display or it gets in the way), otherwise when re-opened it stays blank. Now I know how to relatively quickly install or remove the driver, it's a simple job to remove it if I wish to edit using the laptop screen when away.

Knowing there is nothing amiss with the camera other than the extra noise in Cinema Mode, I think I have a relatively good outcome. Thanks all!

Re: Canon HF G30 Cinema Mode
 

I thought I would resurrect this thread to give you an update.

Having been playing with the offending clips for the last few weeks, sad I know, I just couldn't get a satisfactory result. As my other laptop has a similar specification, bought to be able to edit video if my old PC died, I decided to swap them over. While it also has an Nvidia GPU (GTX 960M) it can output to an external monitor without the Nvidia driver installed.

The reason I persisted is, while in Tenerife a short while ago I took the opportunity to shoot some varied test shots side by side, in Manual Mode with various settings and customised Cinema Mode Standard. On the whole I preferred the finished CM clips. So, if I could sort out those difficult clips, easy ones should be no problem.

After the swap I can get very satisfactory results from (what used to be) the problem clips. Now I can see things clearly I find if I change the effects I use for CC in Cinelerra and change my modus operandi a little, things improve a lot.

Once again, thanks for your help.