How do you keep blown highlights from looking so bad?

[Nirv]

so... I'm a little confused. Is setting the knee to 105 a solution or a no-no?

Where you set the knee is scene dependent.

If the knee is too low and too shallow you get banding but have an increase in dynamic range. It's a trade off. Trying to bring back a light bulb or the sun with the knee will result in the ugly banding. To avoid this, use the cinemagamma curves, drop your exposure down and stretch the black up with the black gamma controls then choose a knee that is higher and not so shallow.

Some highlights cannot be saved as there's just too much DR in the image. The knee's function is to smooth out a specular highlight not a direct source of light.

An external recorder recording in 10 bits gives you the ability to under expose slightly more to preserve highlights and the rest of the image can be brought back up in post.

I have seen some examples where people are not using the full DR of the camera and clipping whites. Use the histogram and make sure you are filling the full range and aren't leaving a gap at the black end. It makes no sense to crunch your whites if you've still got room to come down on your exposure. Don't go so low you clip your blacks though, once they're gone they're gone.

These faux log profiles are unnecessarily lifting the black levels to the point that people are missing out on as much as 20% of their DR. Check your histos and waveforms in post to make sure you're exposing correctly and getting the most from your 8 bits especially if you're recording internally.

If I get time today I'll post some waveforms of some things to look out for.

 

[morgan_moore]

If I get time today I'll post some waveforms of some things to look out for.

That would be interesting to see

S

 

[paulcurtis]

Where you set the knee is scene dependent.

These faux log profiles are unnecessarily lifting the black levels to the point that people are missing out on as much as 20% of their DR. Check your histos and waveforms in post to make sure you're exposing correctly and getting the most from your 8 bits especially if you're recording internally.

There's some great advice in there and correlates to what i'm experimenting with. Although you mentioned 10bit external recorder but as i'm sure you know the output is only 8bit.

There is also the scenario where you know you're going to blow one of the channels first but, depending on the scene, you can recover some detail in post by mixing that from the channels that haven't blown. Resolve can do this as well as various plug ins for FCP etc,.

I quite often see footage where the black levels are high, it seems that the camera in its preset state likes to do that, and as you say you're missing 20% of the DR which in 8 bits is really important.

I think the biggest issue is monitoring for this, because the histogram provided is inadequate for that job. I have a DP6 and with the false colours it's a bit easier but even so a better understanding of how the exposure range is for a given scene would help make the best of it.

cheers
Paul

 

[Nirv]

There's some great advice in there and correlates to what i'm experimenting with. Although you mentioned 10bit external recorder but as i'm sure you know the output is only 8bit.

Gulp!

I've been misled by a UK dealer as they specifically said the O/P was 10bit. Oh well I haven't gone down the external recorder path yet anyway as I don't find the AVCHD compression objectionable or limiting yet. Thanks for correcting the mistake. You might've saved me unnecessarily buying extra toys!

Cheers

 

[Nirv]

Sam

I was wondering if some of the posterising could be due to how your NLE is setup to deal with super brights. Some NLEs just clip anything above 100ire. I'm just trying to think what else could cause poor highlight handling.

This video by Cody Cha seems to show no such issues https://vimeo.com/25851138.
He used an AbelCine profile which one he couldn't remember. I believe the washed out look was achieved in post and not a faux log profile.

Over the weekend I might put a linear gradient up on the monitor and record different gamma and knee settings to see at what point the knee slope starts to posterise. Not scientific but indicative.

 

[paulcurtis]

Gulp!

I've been misled by a UK dealer as they specifically said the O/P was 10bit. Oh well I haven't gone down the external recorder path yet anyway as I don't find the AVCHD compression objectionable or limiting yet. Thanks for correcting the mistake. You might've saved me unnecessarily buying extra toys!

Cheers

Sadly not 10bit, having said that there is extra resolution there, especially on fine moving detail (which AVCHD can't handle so well) and if you're seriously grading then the extra quality offered by uncompressed/low compression could be worth it for you. (Pulling a secondary on a pan over high detail would be a grand example of how AVCHD could hurt)

New owner then? Burned by the 700? I know, i know...

cheers
Paul

 

[Nirv]

New owner then? Burned by the 700? I know, i know...

cheers
Paul

New to FS100 long time experience with all levels of Sony cams though so the PPs are quite familiar.

No not burned at all. I actually bought the day the FS700 was announced. I knew the FS700 was coming just didn't know what the specs were and knew it didn't interest me. 4K and super slo-mo is not something I have any need for and slo-mo is going to get old fast. NDs would be nice but I can buy some very nice glass, matte box and filters for the price difference between the FS100 and FS700. I really don't see any requests for 4k coming anytime soon for 4K. I think Sony played a blinder with advertising by going early with their announcement. Last year's NAB was stereo this year it'll be affordable 4k everywhere. Specs sell!

 

[Nirv]

Sam

Check this out. @EOSHD on Twitter has just received his FS100 and has posted this image. He is having harsh highlights in Premiere Pro on Mac when editing AVCHD files.
http://isgo.co.uk/fs100.jpg

This could be the reason why some people are seeing poor highlights and others not.

 

[morgan_moore]

Im chatting offline to andrew !

Im sure my NLE is fine - I can see the effect on my montor and scopes show up to 110 being recorded

Remember the videos I have posted are all 'stress tests' where I have 'abused' the camera in an effort to get to know it

Such abuses make me forewarned and forarmed.. for the client who is dumb enough to want that midday on the beach shoot

S

 

[Nirv]

Sam,

I've tried as much as I can to replicate your stress test but can't get anywhere reproducing those yellow halos round the highlights. I did however seem to see some more pronounced colour shift in the highlights when using the 709 gamma curve. I found using the Cinetone 2 setting dampened it down. However I am beginning to suspect My genus ND fader may have some part to play. I seemed to get different results when stopping down with the aperture than when stopping down with the fader.

I'm not a photographer (just the usual broadcast cams mostly fixed lenses) or been a part of the DSLRs craze nor have any experience with ND faders so this is still quite new to me. I much preferred the standard gamma over the 709 as there was a quite noticeable warmth to the highlights when viewing in 709 space on my Dreamcolor via HDMI. I don't have a fixed ND filter to compare the relative performance though.

I looked at the knee settings as much as I could and felt that 80-85 was as low as I'd want to go and -2 slope was in some circumstances too far. For a general profile -1 and 85 seemed about right. But of course it's heavily depended on the chosen gamma curve and what you're shooting. I took the knee down to 75 and -2 and got some lovely sky and clouds which were rich in graduations but panning down to the field was a disaster! Acres of astro-turf lay before me.

Can I ask your advice, please?

When you that midday shoot on the beach and you've got a nice fast lens on the FS100 and you want a shallow dof what will you use to control the light? My Genus fader on this dog of a kit lens (I can't believe I bought it!) still needs stopping down to F9-10 in mid morning daylight? I want to get some nice glass on this camera as it deserves it

Any advice you can give on NDs would be gratefully received.
Cheers

 

[paulears]

Even the BBC can't cure it. Breakfast TV today from Aintree had some of the nastiest pictures I've seen for a long time. Lenses opened up wide for the interviews with the backgrounds a swim my white mess. Looked horrible.

 

[morgan_moore]

Any advice you can give on NDs would be gratefully received.
Cheers

There are million threads on the board - cheap expensive issues no issues whatever - I just bought Tiffen on the brand name and local avaialbailty - they seem fine but are not cheap

S

 

[Nirv]

There are million threads on the board - cheap expensive issues no issues whatever - I just bought Tiffen on the brand name and local avaialbailty - they seem fine but are not cheap

S

Wow, thanks for your help.

 

[Nirv]

Even the BBC can't cure it. Breakfast TV today from Aintree had some of the nastiest pictures I've seen for a long time. Lenses opened up wide for the interviews with the backgrounds a swim my white mess. Looked horrible.

It's because they'll be shooting with a 709 gamma with zero headroom for whites. You wouldn't expect them to be shooting OB with hypergammas.

 

[morgan_moore]

Wow, thanks for your help.

Now im not sure if you are joking - I cant really comment further because Ive never done any comparative testing - I know there are a lot of topics on the board that may be worth a read..