FS7: What is the actual base sensitivity of the FS7

Ben Scott said:
My point was more that Cine-EI give you a number it calls EI200/ISO2000. It doesn't matter if that number is accurate because it can't be changed and one has all the tools and readings to expose accurately for that number and in addition can calibrate a light meter (shock, horror!) to be accurate to that specific camera too.
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I mean, that's true, but it's also nonsense. Yes, in CINE-EI the signal is recorded at the "native" EI2000, and you can't change the level the signal is recorded at. However, you have "all the tools and readings to expose accurately... [and] ...can calibrate a light meter (shock, horror!) to be accurate" at any CINE-EI reading the camera offers. Yes, this does mean you're asking your post software to perform a transform (shock, horror!), but we do that *all the time!*

If baking the exact image we wanted as our final output into the original recording was a paramount requirement, we would all be using custom mode color profiles, not S-Log and CINE-EI. Both you and Doug Jensen seem to propose that CINE-EI transforms are to be avoided if possible due to not making optimal use of the recorded image. But that was really a significant factor, we wouldn't be getting beautiful rich saturated images from S-Log in the first place, since that also is (shock, horror!) a transform away from the recorded S-Log curve.
 
Well exactly. For people using Cine-EI, we're all shooting at EI2000 and then grading it to taste, whether we do it in Catalyst Browse or in Resolve or in Colorista. The rest is just semantics talking around the subject. I'm saying that you're either pushing or pulling the image, just like people have been doing for an eternity.

So we/I (hopefully) shoot to give ourselves as much leeway as possible to achieve our look in post. How one does that depends on one's experience, workflow and desired results.

I am absolutely not saying everything should be WYSIWYG in-camera. I'm saying that EI/ISO2000 is the arbitrarily named and unchanging amount of gain the camera applies to the recording in Cine-EI mode. And so every trick or technique one employs, either in post or in camera, is basically a way of getting the best out of that EI2000.
 
Ben Scott said:
I'm saying that EI/ISO2000 is the arbitrarily named and unchanging amount of gain the camera applies to the recording in Cine-EI mode. And so every trick or technique one employs, either in post or in camera, is basically a way of getting the best out of that EI2000.
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Okay, put that way, you're right, and put that way, it's not misleading. Absolutely true on this.
 
The confusion is that 2000 is not an aribitary name. It implies stuff.

"Sony S Gain" would be an arbitary name.

Then this thread could have been simple..

Q: "What is ths ISO of "Sony S Gain""?
A: About 1200, go to 2000 if you are short of light or have highlights to protect!

Overall - keep that histo/WFM full. The actual ISO only seems to matter when you are pre-lighting rec-e-ing or looking to match other cameras.

When Im DPing I use my Nikon D70 as a directors finder, light meter et al. knowing the relationship between the D70 and the '2000' would be useful to me.. I should check.

S
 
Ben Scott said:
Well, it's EI - Which IS an arbitrary name as far as I'm aware.
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Well, "EI" is "exposure index" which, while I can't Google an origination date, is a concept that has roots in film photography, and is used in essentially the same way: given a film stock with a set ASA/ISO, you would use the exposure index to arbitrarily rate the film at an offset from the fixed ASA/ISO of the stock itself... ie, push or pull, under expose or overexpose. If you had only one speed of film available when you needed to shoot something that is going to be over or underexposed if you process the film for it's rated value, then you would need to push or pull using exposure index as an adjustment (this assumes you either couldn't or didn't get the exposure right using on set tools like ND, shutter, or iris).

So, it's not terribly arbitrary of Sony to use the term. Essentially, a digital image sensor is stuck at one "film speed" (or ISO/ASA), so exposure indexing makes plenty of sense.
 
To be honest I wouldn't even put it in the top 10 most counter-intuitive things Sony have done as they made the transition to large sensor motion cameras.
 
i find in general that iso ratings these days are very flexible...check dxo marks...to me the worst obvious offenders are RED, i have to set epic at iso 800 which is in reality iso 250-300 max....that is for clean shadows...dragon is a total mess in that regard with the different OLPFs....and it would not be half as bad if red would not rate their cameras at least a stop and half higher then they actually are....or i am just crazy with my perception of what is a clean shadow.....
which brings me to the FS7....i only shoot CINE-I with the switch set to L....i wish i had waveforms or histogram along with my LUTs but i don't so i have to wing it....not a problem, i have found a way that works for me....which includes getting shadows that are squeaky clean....as in zero noise....but that is such a personal preference it just makes little sense to discuss it....
i consider the FS7 to be a real iso 800 camera the way i shoot it and the way i like my files to look....when things get a little tight i have no issue whatsoever underexposing up to a stop which brings the camera closer to the 2000....i don't have any real problems with those files but i prefer them cleaner and usually i don't need to go there anyway....i find myself dialing in ND much more often then having to open up because there isn't enough light.....
again: this is completely personal and my preference and what and how i shoot....
in general i do prefer being able to crank the iso because you never know.....i really like the 2 step iso setting on the varicam....somehow they worked some magic there that i thought wasn't possible and i can't really comprehend technically....but hey, it works, so it is great....
i don't think numbers or technical explanations work in this case....the FS7 is definitely not a low light monster but it also does not need a ton either....
for my workflow, file preference i could handle and extra stop and just dial in that one extra stop of ND so i guess that means i would not agree that the FS7 is a iso 2000 camera but i can totally understand if someone would call it that and work like that and get great results with those settings....
 
Paul schefz said:
i find in general that iso ratings these days are very flexible...check dxo marks...to me the worst obvious offenders are RED, i have to set epic at iso 800 which is in reality iso 250-300 max...
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Yeah.. Well that bit in bold simply isn't true. Plenty of multi-million dollar theatrical movies have been shot at 800 ISO or higher on MX sensors. If you can't get a clean shadow I'd suggest your workflow might be the issue over the native sensitivity of the sensor.
 
I completely agree that the MX is 320 400 or so (according to my personal tests) - but of course if you 'light for digital' (a phrase I invented in the early digital days) where your shadows are always filled.. and then put a nice S Curve on in post then 800 works. In big productions shadows are mostly filled due to 'big lighting'.

The relationship between the on set and the post curve is so critical nowadays as to have almost rendered 'ISO' meaningless or at least hugely varied in interpretation

Call it 400 as Paul does or call it 800 and put in a nice S and you get.. the same thing :)

S
 
Not even in big productions. Just in productions where they know how to use the camera and footage properly.

Any time you under expose an image at a certain gain or iso you are going to run into problems the moment to try to push that image in post. I'm not sure you invented the concept of lighting the shadows and bringing them down again in post to retain detail and a cleaner negative. It's a fundamental tenant of this job and the ability to do it properly is - in my opinion - one of the things that sets apart someone who can shoot versus someone who just has a camera. It's not rocket science. Just accrued experience and knowledge about what happens in every link of the production chain and how best to serve it.

Just to add, the ISO control on a Red tends to be used in a very different way to most other camera systems I have used/owned. When shooting it's more like a guide as a highlight or shadow protector and most redusers I know would up the ISO while shooting outsdoor in bright light and lower it indoors or in low light whilst shooting. But that's another story :)
 
Ben Scott said:
Yeah.. Well that bit in bold simply isn't true. Plenty of multi-million dollar theatrical movies have been shot at 800 ISO or higher on MX sensors. If you can't get a clean shadow I'd suggest your workflow might be the issue over the native sensitivity of the sensor.
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there is very wide range of opinions of what clean shadows actually means....endless discussions over at reduser....and i always rate epic at 800 but when you have a nice full histogram and everything looks good and you then take out a light meter the reading you will get will me more like iso 300....or shoot side by side with another camera and you will find the same thing.....not a problem but i always found it annoying that the number is just so off.....
of course with red there is the issue with compression ratio as well....i really never shoot above (or below) 5:1...to me that is the cleanest file while still being able to do some off speed stuff and keep the file sizes manageable....but shoot at 8:1 and rate epic at anything over 800 and noise is just too much for me....does not mean that other people don't or should not do just that and shoot features with these settings.....
i guess what i am saying is that i don't agree with RED's stats when it comes to base iso and DR.....sony is much, much better....i would agree that the FS7 is much closer to 2000 iso then the MX sensor is to iso 800....but again, how you shoot it and what anyone's personal opinion about what noise is and how much is acceptable can be very different for everybody....
i don't have a problem at all with clipped highlights....wold much rather do that then have muddy or noisy shadows.....and i can totally understand if other people want the opposite...
 
morgan_moore said:
I invented the phrase :) not the concept. I have of course been bending raw since 2003 - kodak dcs anybody?

S
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i remember it well....my first glimpse of digital was in school, digital capture (in BW of course) with digital output (in BW of course) along with some really lame early photoshop (v1?) filters in 93....also captured and edited (premiere v1?) my first video on an apple quadra 660av (that thing had video in...on the front!) around that time....:)....not sure when i came across the first raw files?
i only know that i just had to switch from aperture to lightroom and found lots of raw files from the 90s and early 00s that current software has a hard time with:)
 
I used to be an Avid engineer on the slightly later Quadras in the Mid 90s. Horrible machines that turned me off Apple for years way past the point of it being rational and only touched one again circa 2010.

As for your experience with Reds it's hard to comment I guess as my personal experience as an owner for a few years differed greatly, and we'd probably need to be watching precisely what each other are doing to ascertain what we are each doing 'right/wrong'. But as long as I have blackshaded correctly and exposed correctly I have never ever had a problem with shadows shooting at 800iso. 6:1 was my usual cutoff point for compression, but snuck through several 8:1 shots on a BBC doc I shot as a bit of a test and edit and colour didn't flag it. But you're absolutely right about what is 'acceptable' differs for everyone. Needlessly blown highlights drive me crazy.
 
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