CX350 Knee & Highlights Discussion

[Bassman2003]

Hello,

I have been working the CX350 into my cameras for a year and a half now and I am still working on highlights. I wanted to start a discussion to hear from other owners on their impression of the highlight handling and the gamma they are using. Here are my thoughts and experiences. Hopefully we can share some info that will improve the images for all.

I have settled on using the HD gamma. I think this is the most straight forward balanced image for SOOC good results. BUT, I can not seem to control highlights when I want to expose where I see fit. I prefer what I would call an "open gamma" type image. No crushed blacks and fairly bright mids and low mids. My PX270 achieves this because it has a really graceful highlight roll off. When I try to achieve this type of image on the CX350, everything looks great from the highlights on down. The highlights themselves look like a consumer camera from 10 years ago. Bright with low detail and saturation. Strained and the first thing one's eye goes to in a frame imho.

Here is what I am struggling with - it seems to me that the highlight tools in the camera just do not do very much. DRS has been improved but it still barely has an impact when applied. White clipping does not really show a visual difference and the Knee seems the same. So I find myself back in time, exposing to compensate for the overly bright highlights and then boosting master ped. and black gamma settings to account for the lower than should be exposure level. If I shoot and bring home to edit, I find I am doing just that when I process the footage - turn the WFM on, lower highlights and boost up the low end. This results in a very nice image. But that is from home. I would prefer to be able to do that in-camera but a not having as much luck as I would like.

As a side note, when I turn on Auto Iris, to get the camera to match my manual exposure have to set the EX comp to -13 to -18.

Is this camera limited in dynamic range? Meaning that it just can't do what I want it to do?

Thanks for your input and experiences. I am really liking the rest of the camera now that the rear zoom controller action is much improved.

 

[NorBro]

I hope you receive some good answers from owners - but in short, IMO, you need to be shooting V-Log on this camera for the best dynamic range.

They don't make cameras like they used to anymore and whatever you liked or were seeing in the the 270 is irrelevant because hardware/business changes. You see it all of the time on this forum...how second, third versions of a model are "different" than its predecessors (I know the Panasonics are different models).

If you haven't found a solution after 1.5 years then there probably isn't one, and the DR is simply limited - even more so than the 270 - when you're not utilizing the logarithmic gamma curve.

 

[Guest]

Hello,

I have been working the CX350 into my cameras for a year and a half now and I am still working on highlights. I wanted to start a discussion to hear form other owners on their impression of the highlight handling and the gamma they are using. Here are my thoughts and experiences. Hopefully we can share some info that will improve the images for all.

I have settled on using the HD gamma. I think this is the most straight forward balanced image for SOOC good results. BUT, I can not seem to control highlights when I want to expose where I see fit. I prefer what I would call an "open gamma" type image. No crushed blacks and fairly bright mids and low mids. My PX270 achieves this because it has a really graceful highlight roll off. When I try to achieve this type of image on the CX350, everything looks great from the highlights on down. The highlights themselves look like a consumer camera from 10 years ago. Bright with low detail and saturation. Strained and the first thing one's eye goes to in a frame imho.

Here is what I am struggling with - it seems to me that the highlight tools in the camera just do not do very much. DRS has been improved but it still barely has an impact when applied. White clipping does not really show a visual difference and the Knee seems the same. So I find myself back in time, exposing to compensate for the overly bright highlights and then boosting master ped. and black gamma settings to account for the lower than should be exposure level. If I shoot and bring home to edit, I find I am doing just that when I process the footage - turn the WFM on, lower highlights and boost up the low end. This results in a very nice image. But that is from home. I would prefer to be able to do that in-camera but a not having as much luck as I would like.

As a side note, when I turn on Auto Iris, to get the camera to match my manual exposure have to set the EX comp to -13 to -18.

Is this camera limited in dynamic range? Meaning that it just can't do what I want it to do?

Thanks for your input and experiences. I am really liking the rest of the camera now that the rear zoom controller action is much improved.

When I was working with a Sony camera that needed to go straight to air, I design a rec709 profile that started with the most rolled off hyper gamma. This looked really gray and flat, so I had to then adjust the black level, contrast, and saturation etc to push it back into something that looked good SOOC.

So, consider if there is a REC709 image setting that might take things too far, but then push some contrast back in. Not sure if that is an option on the Canons. Thought perhaps dialing contrast back, adjust the knee and then pushing the black point back to something usable? idk, just spit balling.

 

[Bassman2003]

Thanks for your replies. I will look at the different gammas again but I think the trend would be more crush of the blacks instead of flat. But to be honest, changing the gamma does not do very much either... This a reason I am asking here, so much of the stuff in the menu does not result in much change in the image. I initially thought the Varicam Film-REC gamma was going to be useful but it does not offer much if any improvement over the normal HD gamma.

I have tried V-LOG on this camera and it does not respond for me the way the GH5 V-LOGL responds. I need to experiment some more but the mode just did not result in a better looking image. In medium to low contrast situations or when I come home and process the footage I can get really nice images with my current settings. The camera is a nice upgrade in this respect and in noise performance. These cameras are not cool anymore so they do not get very much attention. So I wanted to see how other owners (if there are any) are getting on with the image. I know this is a one-chip compared to a three chip design as well as costing less than the previous generation.

 

[Greg Smith]

I purchased my CX350 in April of this year, so you have about a year's lead on me in trying to tame it. But I noticed the problem with overexposed whites right from the beginning, and have been working since to come up with some scene file settings that would get it under control.

COVID has pretty much prevented me from doing any indoor shooting. So I concentrated on trying to create a scene file that would work best in bright sunlight. The test subjects have been the biweekly launches of our model rocket club, some airshows and aircraft in flight, and the occasional pickup soccer game at our local park, plus houses and cars in my neighborhood. The idea was to make something that would work SOOC but also have room for some further tweaking in post for when I'm more serious about the project. This required a deeper dive into the settings than I expected, but I'm beginning to be satisfied with the results. Surprisingly, this also cuts reasonably well with factory scene file 1 on my UX180.

I have done a little shooting indoors with this using mostly daylight LED lights and have been reasonably satisfied, but haven't really set up any tests rigorously enough to recommend it for that purpose yet. Outdoor daylight sports-type work was (by necessity) the main concern.

Because shooting rockets and airshows frequently involves panning rapidly from ground level to objects in the sky, I wanted something that would handle the gradations of white clouds against a blue sky well, and work acceptably with auto iris in effect.

Here's what I've come up with so far. I don't in any way consider this a finished product, but it may contain some hints that you'll find useful:

SCENE FILE menu
CHROMA LEVEL +20%
MATRIX
MATRIX TYPE NORMAL1
ADAPTIVE MATRIX OFF
MATRIX SETTING
ALL 0
COLOR CORRECTION
ALL 0
MASTER PED +16
GAMMA MODE SEL VIDEO-REC
GAMMA SETTING
MASTER GAMMA 0.47
V-REC KNEE SLOPE 500%
V-REC KNEE POINT 50%
BLACK GAMMA -3
B.GAMMA RANGE 1
KNEE SETTING
KNEE MODE MANUAL
A.KNEE RESPONSE 4
KNEE POINT 93%
KNEE SLOPE 99
WHITE CLIP SETTING
WHITE CLIP ON
WHITE CLIP LEVEL 102%
DRS OFF
DRS EFFECT DEPTH 1
DNR 1
A.IRIS LEVEL OFF
A.IRIS LEVEL EFFECT 0

(Any settings not listed here are unchanged from the default scene file 1.)

Note especially the GAMMA MODE, GAMMA SETTING and WHITE CLIP SETTING items. These made the biggest differences. Those V-REC KNEE settings seem pretty extreme but seem to work well - an alternative to DRS.

I still keep thinking I might want to crush the blacks a little more to increase the overall contrast, but I do enjoy seeing some of the detail this pulls out of the shadows. And I haven't really touched color yet. Skin tones are pretty good, but I find the greens of foliage are rendered a little too yellow and with low saturation. I also think the results tend to look a little weak under cloudy or overcast conditions. I may have to create a slightly contrastier version to handle that. Kind of a bummer when conditions change back and forth several times over the course of an afternoon.

Try it out and let me know what you think.

Here are a few images that were problematic with the original factory settings but seem to be well managed by this scene file. Shot at 2160p60 but reduced in size, otherwise SOOC. All with auto iris and fixed 5600K white balance. Intended to be viewed on a Rec709 calibrated monitor. Uploading them here seems to have made all the pictures a little darker, but hope you can still get the idea.

 

[Bassman2003]

Thanks for your reply Greg. Glad to see you have found some settings that are working better for you. I will give your settings a shot as well as share what I have been using. This week is busy but I will have some more time going forward. My hope is to make a comparison video so the differences will be easier to see. Youth football with white uniforms in the sun has been a great testing ground for this problem!

 

[Bassman2003]

Hello Greg and other CX350 owners,

I have been experimenting with Greg's settings and I think the camera's image has been improved with regards to highlights. Thanks for sharing your setup Greg! I tried Video-REC early on but did not tweak the right parameters to see how it really works. In my tweaking, the "Gamma Setting" menu is the most important set of options for highlight adjustment. This little menu does more than Knee, White Clip & DRS combined.

I have a night football game tomorrow and games all day on Saturday in the sun, so I should have a good representation in a few days time. Here are all of the settings I have customized. Please give them a shot and see what you think. Hopefully we can all work together and get this camera to live up to its otherwise impressive feature set.

MASTER DETAIL -22
DTL CORING 0

--DETAIL SETTING--
DETAIL OFF
V DETAIL +1
DTL FREQ +7
LEVEL DEP 0
KNEE APP LEV 2
DTL GAIN+ -28
DTL GAIN- -24

CHROMA LEVEL +14
MATRIX CINE-LIKE
MASTER PED +30
GAMMA MODE VIDEO-REC

--GAMMA SETTING--
MASTER GAMMA .45
V-REC KNEE SLOPE 500%
V-REC KNEE POINT 68%
BLACK GAMMA 0
B GAMMA RANGE 1

--KNEE SETTING--
KNEE MODE MANUAL
A KNEE RESPONSE 3
KNEE POINT 90%
KNEE SLOPE 99

WHITE CLIP OFF
DRS ON
Level 3

--COLOR CORRECTION--
R -8 +1
RR MG 0 -1
R MG +21 0
MG +8 -5
MGB -2 -8
B -25 -15
BCY +7 -4
CY +20 +10
CYG +15 -1
G +16 -10
GY +6 -55
GYY +10 +7
Y -4 -8
YYR +2 +1
YR 0 0
YRR -8 0

These settings are for a nicely saturated video look with pretty light shadows, but with enough contrast to not look like LOG etc... Still a work in progress. I dialed back the V-REC KNEE SLOPE to 350% as the higher numbers lost saturation in the highlights as well as everything looking sort of dull in the upper frequencies.

Edit - I turned on DRS Level 3 as I like the color a bit more. See what you think. Thanks again!

 

[Peter C.]

I've had the opposite usage only filming indoors. As a ux90 owner I was happily surprised by 2 extra stops of light sensitivity, the better codecs, and no crop at 4k. I saw an open box for $3k, but held off, because if I was able to sell my ux90 for $1,2k that would still cost me $1,8 to upgrade.

I've never felt it was worth fooling around too much with the settings. To me it's a camcorder, a nice one but still a camcorder, it's no cinema camera. A month ago I did shoot some test with the different profiles and the differences are very subtle. I don't expecting a large DR, but who cares, the camera has so many other strength...

 

[Greg Smith]

Great! I'll try some of your tweaks and let you know.

- Greg

 

[Bassman2003]

Hello,

I wanted to update this thread as I had a chance to shoot with these new settings Friday and Saturday. I tweaked the image a lot over the two shoots and have settled upon the settings listed above. (I went through and updated the list, so if you try the settings, make sure you have the new ones on 12-6-2020). I reverted back to 500% in the gamma area for maximum highlight rolloff. I also adjusted the master ped & gamma by a point or two as well as some color correction values.

Overall, I am very please with the improvement. Thank you very much Greg for sharing your settings which really helped me find a way forward with this camera! I am unsure of the skin rendering as some of it looks a little posterized. But this was only shooting American football from the stands.

I am including a link to some footage I shot yesterday with the new settings. It shows white uniforms in the sun and the camera is now handling the scene with grace. White no longer dominates your attention when you see the frame. This was shot in 1080p60 .MOV 10bit 4:2:2 long GOP. I put in on the Edius timeline and exported an 25mbps MXF file for upload to YouTube. So pretty close to straight out of the camera.

I was also testing the auto IRIS settings in the camera and settled on "Normal" as the area and "Slow" as the speed. Honestly, I can't remember where the auto IRIS settings were in this clip, but the Normal and Slow were the most reliable and least noticeable at the end of the day. I do have some exposure compensation dialed in as well, something like -6 or -10.

https://youtu.be/rjANySA5Lww

 

[Doug Jensen]

That does look pretty good. The whites are being handled better than what we often see on big league network sports broadcasts. Well done.

 

[Bassman2003]

Thanks. I experimented a lot which as you know is part of the process, but have to give credit to Greg as I had left the Video-REC gamma in the dust a long time ago.

 

[puredrifting]

I agree with Doug, that looks great for bright daylight with those football kids. Nice tuning.

We've been exploring replacing our still usable but old technology Sony PXW-X70s that we use for live streaming when we need servo zoom lens cameras with the CX-350s.
All we care about for live streaming are XLR inputs, SDI output, decent, but not large sensor low light capability. How does the CX-350 do on constrasty, lower light interiors?
Still lit but lit with shadow and constrast, you know, nice lighting? I find these Sonys (they aren't mine, they are my livestream partners) are really sluggish with lighting,
I'd rate them at perhaps ISO 320 native so I have to use kind of ridiculous amounts of light to get them to decent exposure and there is very little subtlety
in the image as far as transition from whites to blacks. The Sonys do really well with gain though, they still look fine and usable with +12dB or even at times +18dB
but the overall image is pretty crappy IMHO as they have the old school Sony unflattering skin tones.

I prefer to use my three Fuji X-T3s for live streaming but no XLRs which means we have to bring audio audio mixer and play with the latency settings and no servo
zooms, which for some live streams, can be handy. A S35 sensor though is so much easier to dial in lighting and exposure than a 1" or smaller sensor. But the CX-350 seems
like a good choice for our live streaming needs for a servo zoom camera with Ethernet capability.

 

[Bassman2003]

Hey Dan,

I think this camera is a great tool and value for money. It has a huge list of codecs and resolutions along with all of the outputs one can need. I think the noise is good up to 18db but as I show in the video, depending upon the gamma and settings, it is a little slower than my PX270 at times. (which is only good to 6db... but has a faster lens) The color is nice and accurate (with tweaking). My hangup is the highlights which is better than I have ever had it. The rear zoom is very nice now and the viewfinder is nice as well.

I have made a little video of some scenes as I was working on my setup and matching to my PX270. I threw the GH5 in for context as well. The color of the GH5 is different but the two video cameras are quite close.

Regarding highlights:

The football video I posted was using the Video-Rec Gamma with an aggressive knee point. This really controls the highlights in high contrast situations but also eats away at color. I think I was at 40% during the football clip. So the 2nd half of the video shows a descending run of lower knee points using this gamma and using 500%. I have learned that the DRS (dynamic range stretch) has an impact on this gamma. Meaning that turning on DRS disables all of the gamma settings. As it turns out, I like the image a little more using DRS (power 3) than the aggressive knee. The 1st part of the video is with DRS on.

I have updated the settings to reflect my changes and current setup. Hope this helps all of the CX350 users to see some more settings. I am pleased that this camera is pretty much spot on to my PX270 now give or take some minor highlight handling.

https://youtu.be/5kApD0J45Fs

 

[ggrantly]

Bassman, Thanks for the work you have done. As a 270 owner, I was really surprised how well the 270 footage held up in the clip compared to the 350. Not to judge tube video too critically, but I think the footage from the 270 and GH5 looked more pleasing than the 350. It is easy for me to rationalize that as a 270 owner; said with a sly grin.

Question, in the first two clips, compared to the 270, was the 350 wide open, as it seems a bit under exposed? It also looked slightly softer compared to the 270 which was a surprise to me.

Grant

 

[Bassman2003]

Yes, I agree. The CX350 has really nice color and is sharp but the overall image is a little, strained? The low end is a bit heavy and the highlights reach overexposure early if you have good color. So you are always trading something where the PX270 is solid on all fronts imho. That is what $2,000 more gets you... I gave the example of two CX350 clips in the first lighting setup to show the difference between the PX and the CX with regards to light gathering. The CX350 had 6db of gain in the full exposure (f.3.2) and then goes to wide open 0db of gain. The PX was at 0db and wide open (f1.8, slight zoom in). The CX looks under because its lens is slower, but it handles gain much better. So in the end, the CX probably has 1/2 to 1 stop better "clean" imagery than the PX270.

As far as detail/sharpness goes, I have less dialed into the CX350 than the PX270 as when you film in 4k you really do not need any sharpening. (detail is at -22) So it might appear to be less sharp, but I think it is a nice lens with low distortion.

 

[ggrantly]

Bassman, if you have a moment, could you give away your 270 scene file for the clip in the video. I'd like to compare your special sauce to my brown gravy. Seems like my challenge with the 270 has been to find a happy place with the blacks.

Thanks Grant

 

[Bassman2003]

Hi Grant,

It took a lot to get me to share these settings for the CX350 as I do think these are related to business success, but Greg started it! His generosity and the CX350 being a problem to solve camera for me led to the sharing. So I will not be sharing my PX270 full settings but will say the two cameras are similar in the major areas outside of the color correction values and the master pedestal which I have set to 13.

If you want to try settings and discuss I am happy to do that.