FS7: ISO settings with mLUT, what to use?

[Tass]

Hi!

So I have rented an FS7 for a couple of days to play with, and today I was shooting with the REC709 (800%) mLUT and it works great. I had the ISO setting at 2000, as that should give me a "what you see is what you get image" in post if the same LUT is applied in post, right?

Now when I'm reading all over different forums people seem to like to rate it at a lower ISO such as 800 in order to get rid of some of the shadow noise?

Whats the best and safest way when it comes to mLUT's and the ISO? In my mind it would be to use the native one (2000) as that won't give me any surprises in post and I dont need to remember what shot was on a higher or lower ISO since Premiere cant read the metadata anyway. Or would it be better to always just go with ISO 800 and correct it in post?

I also set my zebra 2 to 88% and simply keep the stripes of the object I'm shooting to protect it and it has given me a great result this far, nothing is overexposed and if it is, it's quite easy to correct it in post.

I hope that my question isn't way to stupid!

 

[Donny 123]

Hi!

So I have rented an FS7 for a couple of days to play with, and today I was shooting with the REC709 (800%) mLUT and it works great. I had the ISO setting at 2000, as that should give me a "what you see is what you get image" in post if the same LUT is applied in post, right?

Now when I'm reading all over different forums people seem to like to rate it at a lower ISO such as 800 in order to get rid of some of the shadow noise?

Whats the best and safest way when it comes to mLUT's and the ISO? In my mind it would be to use the native one (2000) as that won't give me any surprises in post and I dont need to remember what shot was on a higher or lower ISO since Premiere cant read the metadata anyway. Or would it be better to always just go with ISO 800 and correct it in post?

I also set my zebra 2 to 88% and simply keep the stripes of the object I'm shooting to protect it and it has given me a great result this far, nothing is overexposed and if it is, it's quite easy to correct it in post.

I hope that my question isn't way to stupid!

You don't have to apply the same LUT that you are using as a MLUT.. I use the same REC709 800 MLUT for judging exposure and focus.. but what LUT is applied after can be different..

Re the ISO.. I usually keep it the same as what it says on the box 2000.. to some extend because as you say, I think only the Sony software can read the data anyway.. so then I,ll have all the editors I send footage away to ,thinking I cant get my exposure right !
If you are doing it yourself I think you don't have to worry.. but easier I guess to shoot everything as e.g. 800.. then you will know where you stand in the edit rather than changing it around all over the place..

 

[Tass]

You don't have to apply the same LUT that you are using as a MLUT.. I use the same REC709 800 MLUT for judging exposure and focus.. but what LUT is applied after can be different..

Re the ISO.. I usually keep it the same as what it says on the box 2000.. to some extend because as you say, I think only the Sony software can read the data anyway.. so then I,ll have all the editors I send footage away to ,thinking I cant get my exposure right !
If you are doing it yourself I think you don't have to worry.. but easier I guess to shoot everything as e.g. 800.. then you will know where you stand in the edit rather than changing it around all over the place..

Thanks for the input man!

For the most part I edit my own material, and as I am coming from the DSLR world i'm used to the fact that the exposure is the same on the screen as it is in the edit.

Funny thing is that I somehow managed to switch to 800 iso while in the mLUT and once I reviewed the material in post it still looked fine to me, where it should have been overexposed if I understand it correctly.
I am applying luts from Impulz and also experimenting with Filmconvert, bith giving really nice looks to the image!

How do you judge exposure while having a LUT applied to the viewfinder, just by eye or do you use zebras (at what percentage?)

 

[Donny 123]

I have an F5 but Im sure the FS7 is the same..
You must be in Cine EI mode I presume as you have LUTs available ... in this mode the ISO stays the same.. ISO2000 .. in F5/Fs7.. what I do with the F5 is if say I change from ISO 2000 to 1000.. the recording is staying 2000.. the image in my VF,(with the REC709.800 MLUT) becomes darker by 1 stop.. I open up the iris to compensate.. things look right in the VF.. in the F5 all zebra,s WFM etc are reading the LUTed image in the VF..
So in effect Im over exposing the 2000 recorded footage by 1 stop.. when corrected in grade the image will be "cleaner" and less noise .. at the expense of 1 stop in the highlights.. but with about 6 stops over grey.. usually not a big problem.. BUT I usually don't do it.. as Im not grading my own footage.. and the data is not read by post prod edit software.. if i do, do it.. I do it for every shot and notify post.. best thing with Log keep it uniform as possible .. hence the only be allowed the 3 preset WB..
The LUTS are mapped to LOG exactly so if your MLUT VF image is exposed correctly so is the Log you are recording.. draw back you are seeing a REC 709 image.. well much wider in the high end.. but not the log image obviously.. so you are not seeing the total DR in your VF.. some people don't like this and just go with the Slog image in the VF.. but personally I think that makes judging focus especially hard.. and lighting for that matter.. but no right or wrong way.. but I thing the easiest in the MLUT road.. I don't like to see zebra,s in my frame.. and certainly not a WFM taking up a big lump of the frame.. have it on an ext monitor sure.. so I base exposure by eye.. but Im an old guy and have been doing so for about 20 yrs now.. and well its worked fine so far.. if Im in doubt about a certain shot or green screen I,ll throw in the Zebra,s and WFM.. the High/low assign function is very handy for a quick check shooting Slog with an MLUT..
But each to their own.. and many people will hate this system.. But it works and its very simple and easy if you have shot a lot of REC 709 already.. and even not i think its an easy way to go.. compared to shooting with a log image in your VF.. and peaking at 101%.. and judging lighting I have no idea how..
Anyway as with anything .. try the both ways and see what works for you.. the way i do it is NOT right and the only way.. BUT it does work.. I guarantee that..

As to why your 800 Iso footage wasn't over exposed.. yes odd.. if you had adjusted your iris due to a darker picture.. if you didnt then it would have been fine.. as its recording 2000 all the time.. or you are using Sony software and its reading the metadata and correcting it for you.. the way i wish Resolve etc would do !!

 

[Tass]

I have an F5 but Im sure the FS7 is the same..
You must be in Cine EI mode I presume as you have LUTs available ... in this mode the ISO stays the same.. ISO2000 .. in F5/Fs7.. what I do with the F5 is if say I change from ISO 2000 to 1000.. the recording is staying 2000.. the image in my VF,(with the REC709.800 MLUT) becomes darker by 1 stop.. I open up the iris to compensate.. things look right in the VF.. in the F5 all zebra,s WFM etc are reading the LUTed image in the VF..
So in effect Im over exposing the 2000 recorded footage by 1 stop.. when corrected in grade the image will be "cleaner" and less noise .. at the expense of 1 stop in the highlights.. but with about 6 stops over grey.. usually not a big problem.. BUT I usually don't do it.. as Im not grading my own footage.. and the data is not read by post prod edit software.. if i do, do it.. I do it for every shot and notify post.. best thing with Log keep it uniform as possible .. hence the only be allowed the 3 preset WB..
The LUTS are mapped to LOG exactly so if your MLUT VF image is exposed correctly so is the Log you are recording.. draw back you are seeing a REC 709 image.. well much wider in the high end.. but not the log image obviously.. so you are not seeing the total DR in your VF.. some people don't like this and just go with the Slog image in the VF.. but personally I think that makes judging focus especially hard.. and lighting for that matter.. but no right or wrong way.. but I thing the easiest in the MLUT road.. I don't like to see zebra,s in my frame.. and certainly not a WFM taking up a big lump of the frame.. have it on an ext monitor sure.. so I base exposure by eye.. but Im an old guy and have been doing so for about 20 yrs now.. and well its worked fine so far.. if Im in doubt about a certain shot or green screen I,ll throw in the Zebra,s and WFM.. the High/low assign function is very handy for a quick check shooting Slog with an MLUT..
But each to their own.. and many people will hate this system.. But it works and its very simple and easy if you have shot a lot of REC 709 already.. and even not i think its an easy way to go.. compared to shooting with a log image in your VF.. and peaking at 101%.. and judging lighting I have no idea how..
Anyway as with anything .. try the both ways and see what works for you.. the way i do it is NOT right and the only way.. BUT it does work.. I guarantee that..

As to why your 800 Iso footage wasn't over exposed.. yes odd.. if you had adjusted your iris due to a darker picture.. if you didnt then it would have been fine.. as its recording 2000 all the time.. or you are using Sony software and its reading the metadata and correcting it for you.. the way i wish Resolve etc would do !!

Thanks for all the info! Yes I am in Cine EI mode, the custom just has to much going on with settings, and to be honest so many small things you could mess up in the settings. Only thing missing in Cine EI is noise reduction but that is on it's way in firmware 3.0 (yay!).

So one could say that if it's a really bright sunny day, one could set the camera to lets say 3200 ISO in order to save the highlights from clipping, giving me more room to raise and adjust everything in post? And the other way around, if its a darker scene and I want to make sure that I avoid any unneccesary noise in darker areas, I might go with ISO 800 and adjust the iris and/or add more light.


As for eyeballing the image, that's the way I have found to be good too, at least for me. But I like to use the zebras since that's a thing I've always been using, I found some info on an other forum about setting the zebras to 88% when monitoring with REC709 (800%). So my approach is simply to adjust the iris until all important parts of the image is free from zebras, besides glossy/swetty foreheads, and the sky/water that simply naturally too bright. Would that be the right approach if using zebras?

Really appreaciate all the help I get, thank you!

 

[Donny 123]

Thanks for all the info! Yes I am in Cine EI mode, the custom just has to much going on with settings, and to be honest so many small things you could mess up in the settings. Only thing missing in Cine EI is noise reduction but that is on it's way in firmware 3.0 (yay!).

So one could say that if it's a really bright sunny day, one could set the camera to lets say 3200 ISO in order to save the highlights from clipping, giving me more room to raise and adjust everything in post? And the other way around, if its a darker scene and I want to make sure that I avoid any unneccesary noise in darker areas, I might go with ISO 800 and adjust the iris and/or add more light.


As for eyeballing the image, that's the way I have found to be good too, at least for me. But I like to use the zebras since that's a thing I've always been using, I found some info on an other forum about setting the zebras to 88% when monitoring with REC709 (800%). So my approach is simply to adjust the iris until all important parts of the image is free from zebras, besides glossy/swetty foreheads, and the sky/water that simply naturally too bright. Would that be the right approach if using zebras?

Really appreaciate all the help I get, thank you!

Yes handy to have NR in cine EI .. F5/55 got that after a while.. another good thing about cine EI is you are out of the custom REC709 color space.. I could never get a good WB in custom anyway .. so Im fine with the presets.. also from the start.. I always just used pre sets.. unless some lighting was just looking really weird .. Sodium etc.. another thing you can do is "burn in" the LUT.. usually you wouldn't .. but if its a shoot with out the grading needed for Slog.. rather than shoot custom/matrix you can actually burn in the LUT to the recording.. I do this also a lot and haven't shot in custom for ages .. except green screen .. where you might as well use all your data.. there is an extended LC709A "look" IRE 0-109 knocking around or even burn in the 709.800 .. so you are recording the LUT ..
Re a sunny day.. well you could .. it depends on your frame really.. with Log you can let highlights go a bit.. you have 6 stops over grey.. you don't have to protect all highlights.. unless the important part of your shot is in that area.. you,ll also introduce more noise this way when you correct .. it seems more people will go down ISO to 1000 or 800.. when they don't need the 6 stops over .. and go for less noise in the footage..

sorry I don't know what the 88% zebra in 709.800 is pertaining to.. maybe its white level I guess.. I don't know how that would work .. I guess it means basically you will never be over.. but Im really not the person to ask about zebra,s.. I have used them for green screen... and face levels in interviews.. I started really early days on film and the idea of these horrible lines all over the frame I really didnt like it.. I think people are worrying about zebra,s more than their camera work.. Ive also worked with guys who will do WB for just about every shot.. !.. just the way people prioritize their work mode.. you have to know whats going on technically .. but DIT and camera person are different jobs.. just my 2 cents

 

[Tass]

Yes handy to have NR in cine EI .. F5/55 got that after a while.. another good thing about cine EI is you are out of the custom REC709 color space.. I could never get a good WB in custom anyway .. so Im fine with the presets.. also from the start.. I always just used pre sets.. unless some lighting was just looking really weird .. Sodium etc.. another thing you can do is "burn in" the LUT.. usually you wouldn't .. but if its a shoot with out the grading needed for Slog.. rather than shoot custom/matrix you can actually burn in the LUT to the recording.. I do this also a lot and haven't shot in custom for ages .. except green screen .. where you might as well use all your data.. there is an extended LC709A "look" IRE 0-109 knocking around or even burn in the 709.800 .. so you are recording the LUT ..
Re a sunny day.. well you could .. it depends on your frame really.. with Log you can let highlights go a bit.. you have 6 stops over grey.. you don't have to protect all highlights.. unless the important part of your shot is in that area.. you,ll also introduce more noise this way when you correct .. it seems more people will go down ISO to 1000 or 800.. when they don't need the 6 stops over .. and go for less noise in the footage..

sorry I don't know what the 88% zebra in 709.800 is pertaining to.. maybe its white level I guess.. I don't know how that would work .. I guess it means basically you will never be over.. but Im really not the person to ask about zebra,s.. I have used them for green screen... and face levels in interviews.. I started really early days on film and the idea of these horrible lines all over the frame I really didnt like it.. I think people are worrying about zebra,s more than their camera work.. Ive also worked with guys who will do WB for just about every shot.. !.. just the way people prioritize their work mode.. you have to know whats going on technically .. but DIT and camera person are different jobs.. just my 2 cents

Well it sounds like you have a good approach, nothing to advanced but still good enough to get the job done. I have never been that much for "rating" an image and then correcting in post, since I have been shooting with DSLRS where what I see is what I get. Now all of a sudden you have so much power and freedom to adjust whatever you want however you want (almost). Only time I really can see myself shooting with custom is really dark footage where I can choose a hypergamma that's a bit nicer to the darker parts of the image since that is the majority being fed to the sensor (such as night clubs or run n gun in dark places).

As for the zebras, yes I was reffering to whites, and the info I got was from here: http://www.dvinfo.net/forum/sony-xdcam-pxw-fs7-fs5/526940-how-much-compensate-zebras-mlut.html

My only goal with the zebras is that it simply turns on when things start to clip, so that I know how far I can push it in contrasty situations before I start loosing information. At least that's my plan if I am understanding everything correct!

 

[Bern Caughey]

Tass,

In case you haven't seen this already here's Alister Chapman's approach. Not advocating it over other's, just think it's a good read.

http://www.xdcam-user.com/2014/12/ultimate-guide-for-cine-ei-on-the-sony-pxw-fs7/

 

[Tass]

Tass,

In case you haven't seen this already here's Alister Chapman's approach. Not advocating it over other's, just think it's a good read.

http://www.xdcam-user.com/2014/12/ultimate-guide-for-cine-ei-on-the-sony-pxw-fs7/

Thanks Bern!

Yes I've been reading every last bit of it from time to time. But it is confusing since at one hand Allister tells that that a white or grey card can be used for correct exposure, but then on the Sony forum he told this to one guy, and let me quote:


"My prefered method is still to use the 709(800) LUT for exposure. The 709(800) LUT works because your viewfinder and monitor are almost certainly also going to be set for 709. So when you use a 709 LUT with a 709 display you should get a contrast range that more or less matches what you are seeing. You don't get crushed blacks and you don't get crushed highlights. BUT you won't be seeing your full recording range, that's where the Hi/Low key function can be a big help to allow you to peek into the highlighs and shadows to look at your total capture range. But for me one of the key things about 709(800) is that because the center range is quite narrow, if you are over exposed or under exposed, even by only a small amount, it's normally obvious.
I've run dozens and dozens of S-Log workshops all over the world. As part of the workshop I normally get someone that has never shot Log before to come and set the cameras exposure using only the 709(800) LUT and a random scene. Once the student has set the exposure I introduce a grey card and we see how he/she did. No one has ever been over 1 stop away from perfect, the majority are within 1/2 a stop and these are people that have never used the camera before. And it doesn't matter what EI is used, you don't need to remember different white or grey values for each EI or anything else, it's very simple and very effective."



So while reading how people are exposing correctly I find that no one does it the same way. Alisters mLUT method has been my main way to do it and it probably will continue being it. Some people were really harsh and calling his method "guessing" but as he sais, it's pretty obvious if your blowing out a face in bright light.

 

[Nirv]

If you have LUTCalc you can easily see where your zebras should be set for reflected 90% it's the LUTed %IRE value below 90.

I create an All File preset for each LUT which selects the appropriate zebra level for 90% reflected for the LUT. So far it's worked well.

 

[Donny 123]

Exposing by LUT is not guessing .. the LUTs are mapped precisely to the LOG.. maybe people who think its guessing don't quite understand that.. I think the compromise is that you are not seeing in the VF, highlights/shadows that the Log recording is giving you.. You can use the high/low button as assign.. (thats what I do if i want to check) .. or you can have log in the VF but have to presumably turn your peaking way up to see focus..and Zebra,s going full time.. and have another REC709 luted monitor to see lighting..
I think the grey scale in XDCAM user was to show that the exposure is the same .. when using a VF LUT or LOG .. in the VF

To me personally.. not seeing the full DR in the VF is a lesser of evils .. for others its the burning coals of hell.. see what suits you.. or Nivs method of making all files.. but you don't have to over complicate things ..

 

[starcentral]

You can very accurately expose using LUTs so long as you are aware of the mapped values for middle grey and 90% white reflectance (white card or white paper).

This is an excerpt table from my Ultimate Exposure Guide for Sony cameras:

 

[Donny 123]

Dennis.. is that LC709A for the extended 0-109 version.. or it doesn't make any difference ..

Thanks

 

[Lenilenapi]

I think it would be useful to have a # for caucasian skin also. ( I realize its just an approximation as everyone is different) since that's often all you have to look at it in a shot.

 

[Nirv]

Dennis.. is that LC709A for the extended 0-109 version.. or it doesn't make any difference ..

Thanks

Assuming you're talking about a stretched version of the LC709A LUT and not the ART Adams full range LUT that uses the Varicam Gamma.

18 at 42 and 90 at 78 (90 at 77 for ART Adams LUT)

 

[Donny 123]

Assuming you're talking about a stretched version of the LC709A LUT and not the ART Adams full range LUT that uses the Varicam Gamma.

18 at 42 and 90 at 78 (90 at 77 for ART Adams LUT)

Many thanks sir .. you rule..

 

[Nirv]

Many thanks sir .. you rule..

That's very kind of you to say but cameramanben is the ruler here, I just pulled the info out of LUTCalc.

 

[Donny 123]

That's very kind of you to say but cameramanben is the ruler here, I just pulled the info out of LUTCalc.

But you rule for taking the time and effort to reply sir .. Although Ben is indeed ..The Dear Leader ..

 

[Liam Hall]

Exposing by LUT is not guessing .. the LUTs are mapped precisely to the LOG.. maybe people who think its guessing don't quite understand that..

No. The LUTs are mapped correctly, but they are only useful if your viewfinder is correctly set-up and your viewing condition is perfect, in all other situations you are guessing.

 

[Admir]

No. The LUTs are mapped correctly, but they are only useful if your viewfinder is correctly set-up and your viewing condition is perfect, in all other situations you are guessing.

By correctly set up are you referring on using an external calibrated monitor or are you referring to zebras? Isn't the thing with log that you have a bit more headroom to guess, where a traditional camcorder or DSLR would burn in the look and all overexposed hightlist are lost the slog is more forgiving and easier to save in case you over or underexpose by a stop or two?