Highlights get washed out - the gamma curve?
 

Hi! I have big problem with the highlights, I always get washed out skies, lamps, windows (no details, just white) when I expose so the rest of the scene is alright. If you look at the example you see that the levels shows no cliping in highlight. In the dark parts (left side of the histogram) I have to adjust to really get it black (I move the left triangle .

http://www.access.se/redrockmicro/hi...example_01.jpg

I get this with or without the M2 adapter. I start thinking this is a gamma curve thing. Is it possible to adjust this in the camera so I get a wider spectra? What I really want to do is to adjust the curve so black really gets black and the white parts in the picture still shows details. Is it possible?

Regards / Jimmy

The level is clipped. 255 is maximum for 8bit, and your on it. The sensor is capable of far more dynamic range than the codec, so you need to compress the highlights of that range to suit. Fiddle with your Knee in the PP menu. Maybe try 80-90 Point and +20-25 Slope. If it desaturates too much, bump up the Knee SAT Level some. Fiddle till your in camera histogram no longer clips.
You could also try the old fashioned way, with graduated ND filters and so on.

Yes, the whites are clipped in that frame. You didn't say what PP you used; if STD gamma, the cines will roll off the highlights. In post I think the waveform monitor (luminance) is a better tool than the histogram; you would have seen the clipped region related to scene details. My general approach is to never overexpose any portion of the scene, but that isn't possible always. Try cine4.

Thanks for the imput! I will try to make some adjustments when I get to work tomorrow. One thing I was thinking about is that there IS a difference when using the cam "clean" and using it with my Redrock Micro Adapter. I do get more clipped whites WITH the adapter. I was reading the thread "Picture Profile Recipes" half the night and I found a lot of useful stuff. But I didn't find anything about PP's when using adapters. Maybe there is no difference, it just a exposure thing?

Thanks again. I get back as I have done some testing.

Regards / Jimmy

Could be that Redrock's ground glass is blooming, thus the brightest whites appear washed out.

Yes, it could be. But ALOT of Redrock users use the Panasonic HVX200 and they don't come close to the white "blooming" on EX1. The ground glass should behave the same I think?

I have seen the white "blooming" even on Philip Blooms work, so maybe there's something the way EX1 treats light?

I hope that the input from this thread and the PP gallery can help things a little.

Regards / Jimmy

Just do what david said and set the knee, worked great for me.

And set exposure to keep the highlights from clipping, allowing the rest to be "underexposed" and then pull up the shadows and mids in post. Protect those highlights is video rule #1!
Steve

I use the Cine 4 setting, haven't done anything to the knee or anything else.

The zebras are set for 80 and 100 IRE. 80 gives me a sense that detail will be retained and 100 warns against clipping at the brightest highlights.

I'm able to get detail from the top of sunlit-cumulus clouds at noon, and still keep shadows under the bills of baseball caps.

I've even had people back-lit with sunlight glinting off the water behind them, and still saw faces. This camera is amazing. But just like any other camera, you have to avoid over exposure.

The histogram helps, too. Having the "mountain range" centered in the histogram frame helps reassure me that there will be a full range of tones.

I also use the eyepiece exclusively. The LCD is only used to access the menu items and never relied upon for exposure control or focusing.

[QUOTE=Dean Sensui;930621]I use the Cine 4 setting, haven't done anything to the knee or anything else.

Dean,

Do you also use Cine 4 for inside studio work, or shooting interiors? If not, what gamma setting do you use?

Thanks,

Forrest

Forrest...

I use Cine 4 for everything. It's like that rotisserie gadget marketed by Ronco: I set it and forget it.

Dean,

And, how do you have your picture profile set?

Thanks,

Forrest

Forrest...

I have two white balance presets. One at 5500k and the other at 3200k.

Then on both of them the detail and skin detail is turned "off".

The rest of the settings are default Cine 4 settings.

So, outside of the Cine 4 settings, are you running with the camera default settings or something like Bill Ravens' TC2?

Just as a reality check here:
Cine 4 may work great for some people, but its hardly neccessary to get good exposure , and neither are Bill Raven's matrix settings neccessary though again people may find them lovely.

However, it is perfectly fine to use a normal gamma like Std 3, simply drop the black level to -6 (where it belongs to get black) and put the saturation level where you find it pleasing - probably raising it to hi sat. That's enough to get very good pictures with this camera. There is nothing wrong with those basic settings.

That's not to say you can't improve on it. I have changed those settings myself, but they really do produce very good pictures.

Lenny Levy

Thanks, Lenny. I've been trying several different settings to see which ones suit me. This camera is truly amazing!

Forrest

Dropping the black to -6 gets you to where black should be? That is new info to me, but sort of correlates to what I've noticed (I've been setting it to -5). I've only had my EX1 for a short time but always felt the black levels were too high at 0. Did you check this with a scope? Also is this with any of the gamma settings or just the STD ones?

Did you check this with a scope?

Yes - its the first thing I check with a new camera because its so often off - similar with an HVX. I don't know why they send cameras out that way.

I have been using STD3 so its definitely accurate for the standard gammas. I think it was about right for the cine's but I wouldn't swear by that at all.

Lenny

I was using the cine's but now use std gamam's. I found that the cine's took too much light.
I now use std 1 with hi-sat, black at -5, detail -10.

Paul.

Good to know about the -6 on black. I agree it should be lowered. Things look a bit washed out to me at 0. I find the Cine settings tend to soften highlight clipping. Especially on strong colors. I also have a PP with STD 3 for indoor situations, because I also find the cines eat up light somewhat, actually its applying an "s" curve to the highlights, gradually clipping them instead of the hard clip of the STDs.

I'm not sure that gradually clipping is quite what you mean. Clipping occurs at 109 and gradual it isn't. The cine gamma compress the highlights (the gamma curve rolls off) and applying +gamma to cine4 will roll the curve off so it never reaches 109 (makes for very flat highlights, without any clipping). But, other than this quibble, agree with your comments.

This is directly from Adam Wilts review on ProVideo Coalition.com: Pro Cameras, Video Editing, Motion Graphics
At the bottom he says "With Cine Gammas the highlights won't clip AS HARSHLY. Meaning they still clip, but not as severely.

"The EX1 offers four STD gammas and four CINE gammas. STD3 is the default and is the basis for my comparisons; I list the brightness for the middle gray on a chip chart in each gamma for the same exposure setting, with 50% being the default. The descriptions in quotes are my own characterizations of the gammas. In all except CINE2, whites peak at 109%.

• STD1 – “bright and contrasty”. Blacks slightly crushed, whites slightly crushed, increased contrast, midgray at 55%.
• STD2 – “deep blacks”. Blacks slightly crushed, rest of tonal scale stretched downward; midgray at 48%.
• STD3 – “standard video”. Normal, midgray at 50%.
• STD4 – “black stretch”. Blacks slightly stretched, increased shadow detail, midgray at 55%.
• CINE1 – “deep cine”. Compression starts around 80%; midgray at 37%.
• CINE2 – “broadcast safe cine”. CINE1 rescaled with whites limited to 100%.
• CINE3 – “brighter cine”. Compression starts around 65%; midgray at 45%.
• CINE4 – “video-bright cine”. Compression starts around 65%; midgray at 50%.

The std gammas are all fairly standard video gammas, while the cine gammas are something special. Instead of running linearly up the tonal scale and using the knee system to handle highlights, cine gammas apply increasingly more compression the brighter a highlight gets. Sony’s Juan Martinez says the cine gammas are directly descended from the HyperGamma settings of the F900/R and F23 cameras; David Leitner reports that these are the same HyperGammas used in the PDW series XDCAM HD camcorders.

In essence, cine gammas have a S-curve in the highlights, similar in effect to the soft shoulder of film’s DlogE curve. Highlights don’t clip as harshly as in the standard gammas, they roll off much more smoothly, with gradual desaturation instead of sudden hue shifts in color."

I have to say, this is one of the best threads yet on EX1 PP settings. By accident I shot an outdoor gardent interview yesterday with PP off. I had a new assistant who didn't catch it, and while out of the box the picture is pretty good, it's not until you start tweaking that you really see the magic of this camera. Now I've got a bit of post to get this to look right. It's nice to see what others are using. Thanks for the suggestions.

Mick Haensler
Higher Ground Media

Using the Cine 4 gamma I'm able to retain detail in the tops of bright cumulus clouds while still retaining detail in faces below the brims of baseball caps.

With other video cameras that shadow detail is lost.

The black point isn't as low as it could get, but it provides me the option of either crushing the blacks in post or keeping as much detail as practical in the final product. Since I can't control the lighting in 99% of what I shoot, I opt for maximum dynamic range.

And as mentioned elsewhere in this thread, having the highlights gently preserved allows me to make shots look as good as possible in the final product. White shirts, bright clouds and even sunlight glinting off the water aren't troublesome at all.

Hi-

I don't know if this has any relationship to the problems you are having. There is apparently some issue with the gamma knees in the EX1/EX3 when using the standard gammas. Please read page 3 of Adam Wilt's review:

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

"when a highlight has a strong chroma component, the knee shuts off prematurely, allowing colored highlights to suddenly blow out."

The cine gamma are not affected by this.

Craig

Dean care to share you Cine4 preset? I enjoyed your show and would be interested in trying your preset.

Paul...

Happy to hear you enjoyed what you saw.

It's just the standard Cine 4 gamma setting that comes with the camera. I didn't tweak it at all. I just make sure the historgram shows the entire exposure range is being captured.

One of the misconceptions with using a standard histogram to decide exposure is that you can still blow out one of the R-G-B channels and the single channel B&W histogram will tell you you're OK.

Shooting HDV, after a while you'll learn how to avoid thos hot spots. Using zebra set to 90% helps. The zebra on the EX1 can be off by as much as 10%.

Although I shoot with the EX3, I second what Bill has said. With every digital video camera I've ever used, I've set the zebra at either 90 or 95% (depending on the camera). That way, I can practically guarantee that burned out whites are a thing of the past.

...and take noise. ;)
Btw, that's true for cine1-3, but not for cine4, because it's "video-bright", meaning that its slope on the lower end is identical to that of the stds.

Absolutely - this has been discussed in detail here:

http://www.dvinfo.net/conf/sony-xdca...-clipping.html

The consensus between Adam and myself has been that Cine gammas are much safer to use in those circumstances. Therefore, all my "outdoors" PP's (apart from those for very low light) are based on Cine, while those PP's for indoors - on STD gammas.