Thanks, Serena.

Guys, do you see now why I'm using STD1/STD4 for low-light indoor shooting? Especially with Letus adapter...

The moral of my post was don't worry how the engine works, just get out there and enjoy the ride.

Whilst I appreciate that fully understanding how each of the gammas effects the picture quality, and your detailed knowledge on this matter. I feel that many people spend far too much time with their heads under the bonnet rather than getting out and using their gear. The same holds true for most matters related to digital photography, I am not sure why, perhaps it is the very technical nature of the industry that attracts a tinkering mind.

Serena...
Can you share with us how you abtained this data? Is it empirical or predicted? The knee of the S1 curve shows a bit of overshoot, which I would guess is data scatter? If it's real, there will be some serious distortions(non linearities) in high-lites of the image. Plotting this with a log scale on the abscissa makes the data look less serious than it may be.

Vincent....
you are referring, of course, to pixel peeping.
it's a good thing to find balance and moderation in all things. however, since this thread is about some of the more technical aspects of filming, and not the esoterics, I do wonder what reminding us of aesthetics brings to the table.

Vincent, a good analogy when a useable/workable/real-world manual is provided to explain how to use its features. In Sony's case, they have failed to provide us with any meaningful documentation on how to actually make good practical use of all the features contained in the Picture Profiles. This same point was mentioned earlier (above) with the question as to why Sony is so secretive on this subject. While Sony's "Creative Shooting Techniques" are an attempt to shed some light on the topic, they only scratch the surface. Hence, we left to explore-share-debate-learn from real world experience.

Thankfully we have this forum to express the need for this thread, as well as the good folks who are willing to generously give of their time-talent-experience for the benefit of all. Cheers!

Bill, without your and others knowledge we would be totally stuck, or at worst not get the best results from our gear. Despite my comments, I do appreciate your input. I just want to remind people that the goal of the technical knowhow must be to add to the end result, and that surely must come back down to creative "filming" (sorry an old fashioned term for shooting pixel data).

Everything in moderation, but not to the point that some of us are losing the plot.

Thanks for completing the plots Serena. It confirms what we are all seeing with the CG's, lifted blacks, linear mid section and compressed highlights.

Hi Serena,
Could you plot the chart for Cine gammas 2 and 3 if you have time.

Cheers

Thanks Alister. Thats more then I thought. I was expecting around 10 or so...

Empirical data only and a different technique to that used previously to try to keep things simple.
That overshoot on S1 is an error (a small but important slip in transferring data) and thanks for raising the question. I might have queried that myself had I not been required to do other neglected things. I've replotted the corrected results in the attached (and checked I hadn't done the same elsewhere). Also repeated S1 to provide an indication of error magnitude, and added S1 with default auto-knee "on" (unintentionally).

The methodology is simple, repeatable and I think useful. Employs only data on the LCD. Requires a uniform constant light source large enough to fill the FOV, with the camera locked down. I used the lens wide to ensure max effective aperture, but the f/stops are relative anyway. The camera gives you a %brightness reading and the f/stop, so starting with the f/stop giving 109% I close down in half stops recording brightness at each change in f/stop reading. The change in f/stop reading is finely repeatable and I took that point (closing) as being the actual aperture value. The process is equivalent to decreasing the test subject's brightness in half stop increments, and because it is all relative it is unimportant whether the f/number is the true value, provided the increments are accurate (which they might not be towards the high f/stop end). I used ND filters to work aperture over a limited range.
In plotting the results the geometric value of the f/number was used in place of the rounded figure which is displayed.
The usefullness of the plots is in understanding the gamma options. There are aspects of the method which I'm still evaluating and I'm sure there will be discussion about its validity.

EDIT: A slight problem with my plots attached to this post. They are all normalised for subject brightness, so making the standard gammas very similar to the cine gammas (in terms of sensitivity), a matter which I'm sure Piotr doesn't believe! Rightly so. However I won't delete this plot, since people have already considered it and once the normalisation is known it still contains useful information. A new post below shows all cine gammas compared to STD 1 gamma, and this time not normalised!

So very true.
This is the first camera I have owned that provides for this level of profile adjustment. Virtually all of the little bit I know about this subject comes from trolling thru posts by the generous experts on this forum, cranking in the various settings, looking at the footage, and slowly, slowly finding what I like, and what settings get the job done. I would have not even known where to begin otherwise- certainly not from Sony.

Serena...

Thanx for having done this. And thanx for providing your test method.

I'm using cine2 all the time, because I don't want to have to deal with above 100IRE information. Also cine1/2 looks most linear/neutral.
Cine4 has heavy highlights-compression (too much in most situations). Cine3 also has a lot of highlights-compression, but additionally the darks get pushed down a bit relatively to cine1/2 leading to contrasty low-mids. Therefore cine3 actually is the most complex curve.

Btw, I guess that the dynamic range/latitude gets maximized with cine1/2, because the noise of the ex1 is too much that black-stretching could actually retrieve extra-information in the darks which else would get lost because of 8bit-quantization. But heavy highlights-compression of cine4 together with 8bit quantization will definitely crush highlight-information.

Thank you Serena, Bill, Alister and all who have shed more light on the Cine Gamma settings.

i second that. i wouldn't be where i'm at today without the contributions from all of you. i've learned more in the last year since i bought my EX1 then just about all the previous years combined. I don't really consider myself a Newbie anymore. maybe a veteran Newbie.

This is the Alan Roberts review of the Cines in the EX1.
I have copied and pasted this so I hope that this is ok?

Cine2 is the only curve suited to production without grading, since it clips at 100%.
Cine1 is similar but copes with overexposure by extending beyond 100% video level.
Cine3 and 4 differently share the contrast range, use these to taste.

If using Cine1, 3 or 4, make sure that video will not be clipped in post-production. Or that grading can cope with the over-voltages.

Here is a plot of the four cine gammas plus standard 1 gamma. Given in two forms: the usual log of subject brightness, plus with a linear subject brightness which is the form in Sony's sketches.
The data was taken with the following conditions:
subject surface brightness: 16000 lux; 5600K; white; broad; diffuse.
Effective subject brightness at 1.0 on curves 900 lux approx.
WB: 5600K
camera gain: 0dB
shutter speed:1/50
HQ mode, 25fps
PP properties: default with knee "off" and changing only the gamma selected.
When iris was closed the brightness reading was 3%. This could have been adjusted using black level, but I left defaults as is.

The LCD shows image % brightness to a whole number, so accuracy decreases with decreasing reading. The readings are repeatable within 1 digit (generally get the same reading).

Thanks serena.
Looking at the graph's I really like the curve of Cine 2.
I'm really suprised that Cine 1 peaks at 110 as I thought the top end droped off a bit in brightness.

Thanks agina for your effort.

Fantastic info, Serena. Thank you very much.

I'm happy to see that Cine2 uses a knee rather than a hard clip to be asymptotic to 100%. The drawback is the "somewhat" flattening of the midrange(contrast reducing), relative to C1, to get the knee that I wonder about.

Sometime back when I first tried to evaluate the gamma curves the SAW curve generation facility made me suspect that the EX camera is natively balanced to 3200K. Still I don't know the answer to that, but the SAW facility did suggest that the gamma curves vary with WB. Out of curiosity, using my more direct method, I've looked again at the effect of changing WB and the results are attached.
I used the same subject source and added a full orange gel, which cut the source by a stop. The camera white balanced at 2800K, so I accepted that.
The effects are greater than I expected. The camera showed greater sensitivity and the results are plotted to retain relative subject brightness of 1.0 matching the previous plots. STND 1 gamma exhibits a steeper roll off (or knee) prior to clipping.

In the 5600K plots the plotted dynamic range is 10 stops, with some unreliable data going down another half stop with black half a stop further down. So you could say 11 stops, with a bit of a stretch. However at 2800K the range (with the same considerations) is 12 stops, so the BBC statement of 11 stops dynamic range certainly holds under tungsten.

I'm interested in any comments on these observations.

Very interesting work. For what it's worth, if you're going for accuracy I would think an offset of 400k from 32k is starting to push it a bit, assuming you're correct about the native 32k design. I'm sure you know temperature change is detectable at 200k intervals to the eye, becoming very obvious as when reach 500k. If you can't hit 32k +/-100k personally I would draw the line at 2900k for your test. I also think it'd be interesting to see how great the effect of this variance is on the results.

Fair enough comment, Max. In this instance I was more interested in observing any change and had not expected the extent of it. Now it might be worth redoing for 3200K.

I'll recheck anyway, because that apparent difference makes me a little uneasy that there may be an error in data reduction (compensating for the change in source luminance).

whoa....this whole test has set me kind of on end. I just never considered the gamma change when resetting white balance. I shoot exclusively at 5800K. If I want to dial out too much yellow, I do it in post. So, as long as the gammas I'm studying are good for 5800K, I should be OK.

Bill, it may be that I'll be embarrassed by being too quick in publishing that result. Have to find some time to check, so make no changes to your approach in the meantime!

Just for the ones that are having a hard time understanding these charts (probably only me on this entire forum) your units ascending on the left are IRE levels right? The subject brightness levels in 0.5 increments is what is confusing me the most though. If someone could just help me understand how that bottom line works that would be most appreciated.

Sorry for the dumb question in a technical thread guys...

There are no dumb questions! Sometimes dumb answers!
The vertical axis is IRE, although I understand that term as really belonging in the analogue world. So 100 is broadcast max and generally our digital cameras capture up to 109 before clipping. The horizontal axis is subject brightness relative to a chosen test set up. As the subject waxes or wanes (in brightness) so you move along the horizontal axis, each halving or doubling representing 1 stop change in brightness. The test point brightness was chosen to get 109 using cine gamma curve 4. You'll see that the standard gamma curves (1,2,3,4) reach 109 at much lower than that subject brightness.

Measuring the data is easy if a little tedious. In reducing the data allowances have to be made for changes in the test source, such as adding gels to adjust colour. I suspect my plot of the effects of WB show that I adjusted in the wrong direction, so greatly exaggerating any effects. I'll let you know! In the meantime, don't worry about the WB effects plot.

Ahhh I get it now! Thanks for explaining Serena

Unfortunately, for me, these interesting conclusions are wrong. I did indeed muck up reducing the results of that test, compensating in the wrong direction for the effects of the added gel. I redid the measurements for 3200K and differences in the curves between daylight and tungsten are small (measurement error band). Apologies for the trip up the garden path.

whew...

thanx for setting things straight. It was a mind boggler, for sure.

Image "softer" with C4?
 

I have been shooting weddings with C1 (Bill's settings), detail off and have had good results. Yesterday I used C4 instead (all other settings unchanged). I found the image substantially "softer". Is there any reason that this may occur?

I calibrated my lens after the last firmware upgrade but that was 4 weddings ago. Is it possible that the calibration needs to be repeated?

Thanks,
Mervin

I shot some footage going the other way Mervin by going from Cine 4 to Cine 3 and found Cine 3 to be softer. Oh I forgot that I shoot 720/50p with Cine 4 but on this shoot I shot Cine 3 1080/50i.
I have found that Cine 1 combined with Cine 3 yeilds the best combo in my opinion.

Hi Mervin,

When you say calibrated your lens I guess you're talking back focus. I can't say this is the cause for softness but for interchangeable lens cameras the best routine is to calibrate that not only when a lens is mounted but also after the camera is moved/transported or there is an environmental temperature shift of a few degrees. Not always practical but recommended. If you have an EX1 perhaps this rule can be relaxed (fixed lens) but I would check it before every shoot really as preflight.

Serena Thank you so much for sharing this! ;) and everyones inciteful help.

Re: Cine gamma settings in the EX1
 

I don't know how you guys derived at the "conclusion" that Cine gamma 1 is for bright/outdoor scenes, and Cine gamma 3/4 are for dark/indoor.

My tests have shown the following.

If you expose for skin tones at 70-75% in Cine 1, you will overexpose the white background/bright sky much faster, than you would in Cine 3 and 4.

If you set zebra 1 to 75 and enable zebra 2 which is at 100, you will expose the color chart "Caucasian" square at the same time. So 75% skin = 100% white at same exposure in Cine 1

Set the gamma to Cine 3, the white square will be sitting at 97% with the skin square is at 75%

Go down to Cine 4, and the white square will sit comfortable at 95%

This all means that you will have a better chance of maintaining your bright background and deep blue sky in Cine gamma 3 and 4.

I would also argue that the same logic can be applied when the situation is turned around.
In Cine 1 you will have more exposure in the poor lit shadows when shooting indoor, while Cine 3 and 4 will be more prone to crush the blacks.
The only reason for using Cine 3 and 4 indoor must be that the curve allows for less light and therefore less gain.

This all depends on what your subject is and therefore where your main exposure lies. But in most situations we are aiming the camera at a person.
75% exposure being your target, you want to make sure that the next most important thing, either the sky or the dark room is as close as possible.

Finally you can use Cine 2 for scenes which could introduce banding in the 8bit colorspace. Since Cine gamma 2 compresses the image to 100% white clipping (which btw can be changed back to 109 if you set the gamma level to -5), You will effectively have a better "dynamic range resolution" pr stop.

Same goes for all of you who use -3 DB gain.. If you set any of the Cine Gammas to -4 (cine gamma 2 to -9) You can maintain the dynamic range at 109%

Re: Cine gamma settings in the EX1
 

Cinegammas are designed to be graded. They are not designed to be used in the same way as you would with a standard gamma and you need to adjust where you put your skin tones accordingly. Whenever you take a large range of something (in this case brightness range) and squeeze it into a narrower range (by displaying it on a TV or Monitor with a standard gamma) you are compressing the image.

Cinegammas will look flat when exposed correctly on a standard TV or monitor because the monitors gamma curve does not have the range to correctly display what the cinegamma has captured.

To restore your cinegamma footage to something that look best on a standard TV you need to grade it. Given that the main aim of the CG's is to capture more highlight information, and some of the mid-hi range is used for this extra highlight data, then you need to be prepared to move your CG midtones and skin tones upwards to traditional levels in post.

If you shoot using a CG and you have your skin tones at the traditional 70 ire (which is rubbish anyway as everyones face is different) then those skin tones are in the compressed part of the gamma curve and no amount of grading will ever make them look as good as they should. You must keep skin tones and natural textures at a lower level when using the CG's to avoid this compression. When using CG's you need to modify the way you expose to get the most out of them.

Re: Cine gamma settings in the EX1
 

Rats. Just when I thought I understood what to use. I've been using Cine3 and 4 setting the skin highlights to 60-70 using false colors. Alister, for caucasian skin in a studio with black background, what ire would you use for skin highlights?

Re: Cine gamma settings in the EX1
 

I'm exposing faces up to 65, and I'm good with it.

But that's just me,,, Alister?

Re: Cine gamma settings in the EX1
 

Here is a good article by Adam Wilt on the effect of Cinegamma on images.

ProVideo Coalition.com: Camera Log by Adam Wilt | Founder | Pro Cameras, HDV Camera, HD Camera, Sony, Panasonic, JVC, RED, Video Camera Reviews

Re: Cine gamma settings in the EX1
 

Yes I realize that, but it does not change the fact that you OVEREXPOSE your bright background quicker (If exposing for Caucasian skin tones at 75%) when using cinegamma 1.. Even beyond 109%, then you cant grade yourself out of that.

Re: Cine gamma settings in the EX1
 

Wow, I didn't realize everyone in Poland had the same shade of skin. In my country, we have whites, blacks, latinos, asians, and all different kinds of skintones to deal with. 65% on one guy might be fine, but totally wrong for the next guy. No matter how you slice it, using zebra on skintones just comes down to guessing because every face is different. Sure, an experienced shooter can still guess right most of the time, but it's still just guessing. I can do that without zebra. Zebra is one of the most important functions on a pro video camera, but it is only correct if you know the value of WHAT you are measuring -- and usually that should be white card, gray card, or chip chart. Anything else is just guessing.