Opinion POLL: EPIC native ISO = 800 or ISO = 320?

[Graeme Nattress]

Well, that'a Flame and nothing to do with us..... 320 doesn't correspond with the RAW image - again, read the thread.

A good ISO range is 320 to 6400 on Epic and each has it's use, each is valid. It's the skill, and knowledge of a DP to pick which is most appropriate for the scene they're shooting.

Graeme

 

[Nathaniel Kramer]

Rory and Graeme - you are both correct. But, All I can say based on all my jobs with Epic, is that our best results, are shot at 320 on a light meter. If you use a light meter and dial it to 320 as your reference point then it does not matter what iso the epic is set at since thats meta data. NOw when you bring that into RCX and RED LOG it , and the iso set to 320, you will have a similar image in terms of exposure, to what you saw in the monitor if the iso on the monitor was set to 320. The image will still be very flat as its redlog, but its now a great start point to apply your curves and other stuff. From experience, with this method, i can easily push to 800 in RCX without gaining any noise in my darks. And yes, if i have very bright highlights I will let them clip. Of course if you have the ability to look at rcx while you are shooting, then even better. We always try to go to RCX on set/location so we can do qc and set a look. To Rory's point, and I totally agree, you need a reference point as if using a light meter. With out that, how is a gaffer going to light for values?

 

[Adrian Jebef]

You have to have a starting point to expose the image regardless of whatever post effects and tricks you can apply to the image after capturing it.
If the image you capture is incorrectly exposed then you're off to a bad start in the quest for making great looking images.
The camera sensor or film stock you're using has to have a base point, a "native" ISO/ASA on which you dial in your exposure settings on location by either moving the F stop or adding ND.

This thread goes around in circles because of the science behind the process but at the end of the day you're shooting with a camera sensor that has a "native" rating that needs ND to be used at lower F stops to get the properly exposed image with the desired DOF.

This thread is a clear example why people choice to shoot on a different camera that isn't lost in its own technology, running around in circles trying to explain the science behind the art.

I'm still confused as I'm sure many others are... What is this camera, which is a tool used to capture light, rated at? 320 or 800

Why make it so confusing?

+ 1

 

[Adrian Jebef]

if its so basic then why do some many people have conflicting opinions on the "native" ISO/ASA of the camera?

Wouldn't it be easier and benefit everyone to have a true reading of the sensor and know if you change the ISO/ASA then you're moving away and adding a process.

Doesn't the R3D default to 320 when you work in RedLogFilm?
Sure I can change the settings just like I can manipulate the image in post but it doesn't help much on-set in the elements judging the available light and acting accordingly.

So what is it? 320 or 800?
Judging from this poll is leaning more towards 320 yet still people are insisting on 800.

Pretty crazy that there is such a great contradiction to what effectively is the most important spec to know when you're capturing light.

+ 1

 

[Adrian Jebef]

But surely even if the camera and post software can happily work with different ISO settings the amount of light being captured by the sensor will remain the same amount of light being captured by the sensor and the only things that will effect the light captured by the sensor would be Aperture and Filters in front of the lens.

+ 1

 

[Adrian Jebef]

To a DP who wants to expose the image correctly knowing the "native" sensitivity of the sensor or film stock is crucial to either closing or opening the F stop on the lens or removing / placing ND in front of the lens.

If Red are saying to rate the sensor at 800 to force the use of ND or Stopping down when the actual raw sensor is 320 (defaulted to 320 when using RedLogFilm) isn't that just a trick to protect the highlights and get a more film like response to the bright roll off on a digital sensor.

To me this all seems gear towards protecting the highlights as the camera software in Redcode and in post debayer all work better at less noise and better shadows and its the highlights that the Red sensor has problems with.

So the sensor is really 320 but because of software advancements if you work at 800 you'll have more protection in the highlights.

+ 1

 

[Nathaniel Kramer]

you actually have 3 variables to work with 1) amount of light falling on subject or reflected back at lens/sensor 2) shutter angle/speed 3) aperture

 

[Martin Stevens]

Please......just forget about "Native" or "Fixed" ISO with RED EPIC etc. and just focus on the
virtue that it has "Variable ISO".

And if you are still confused then shoot at ISO 800 because this yields the best results
in the majority of conditions.

 

[Ian Laurie]

Got a feeling this thread is headed for closure. You have Graeme, with firsthand knowledge of both the sensor and the magic pixies telling you that, if for some reason you need a set iso, the recommendation of Red and himself is 800. The fact that he can explain more is beneficial to our understanding, but if this was any other company his response would have been 800, with no other comment. However you have pushed and pushed for a technical answer and he has stated that technically, there is no native ISO on a digital camera. Which explains why some like to expose knowing exactly where they may have problems (the 320 crowd, me included) and others prefer 800 because it allows them to worry less about clipping and work in the way they are most comfortable. you wanted an answer ( i did too) he gave it too you, and now your upset because not only was it not an answer you wanted, it wasnt even one you ( or I) expected. Accept it, if you like 800 use it. if not don't. I personally am gonna take graeme's information to try some new things outside of my comfort zone. yeesh... rant over.

 

[Adrian Jebef]

If I may, let's just all pause for a minute and have a "Come to Jesus" moment...

There are a lot of Users on this thread that are pointing out their personal opinions and techniques on how they set exposure with the EPIC. That's great! But it's not the point of this thread. The initial Poll question included some semantics that were confusing: mainly "ISO". I think we all agree that only Mr. Graeme Nattress can set the record straight. So allow me to rephrase the question:

"What is the EPIC's native sensor sensitivity for exposure purposes?"

Film stock was rated at an Exposure Index that, when used, gave an equal distribution of Dynamic Range above and below 18% Grey (IE: 7 stops over and 7 stops under). A DP could adjust this EI for differing results but said DP always understood that a particular stock had only one EI that was considered "native" (many DP's endlessly tested stocks to arrive at their own EI for a particular stock, 5218 is rated at 500 by Kodak but many DP's insisted it was closer to 400) Mr. Nattress confirmed that the EPIC's DR is evenly distributed when set to 1600 ISO.

Yes ISO1600 would balance above and below stops more evenly but we feel that ISO800 is a more appropriate starting point for people shooting the camera. I guess that takes us back to the ISO recommendation....

Graeme

Yet many DP's insist on using a light meter (an isolated test instrument that measures the intensity of light falling on a subject :yesnod when setting exposure and have found 320 ISO to be their "rating" of the EPIC.

I can understand a DP conducting tests to arrive at 400 instead of 500. But the difference between 1600 and 320 ISO is over 2 full stops. That's a heck of a lot of wiggle room when a DP "needs" an absolute base-line exposure index to work from before lighting a scene.

 

[Adrian Jebef]

Got a feeling this thread is headed for closure. You have Graeme, with firsthand knowledge of both the sensor and the magic pixies telling you that, if for some reason you need a set iso, the recommendation of Red and himself is 800. The fact that he can explain more is beneficial to our understanding, but if this was any other company his response would have been 800, with no other comment. However you have pushed and pushed for a technical answer and he has stated that technically, there is no native ISO on a digital camera. Which explains why some like to expose knowing exactly where they may have problems (the 320 crowd, me included) and others prefer 800 because it allows them to worry less about clipping and work in the way they are most comfortable. you wanted an answer ( i did too) he gave it too you, and now your upset because not only was it not an answer you wanted, it wasnt even one you ( or I) expected. Accept it, if you like 800 use it. if not don't. I personally am gonna take graeme's information to try some new things outside of my comfort zone. yeesh... rant over.

A digital camera that can record a RAW image does not have an ISO because the function of ISO is technically in image processing not acquisition. This is because a RAW image is fundamentally considered to not be an image (yet). ISO is metadata when dealing with a RAW workflow. It cannot be burnt in so it cannot be considered native. Graeme is correct. Any ISO setting can be considered a valid one and they are all equal in that respect. However, that does not mean that the camera's sensor itself does not have a base exposure sensitivity index.

So semantics = confusion. Clarity = re-clarification:

"What is the EPIC's native sensor sensitivity or exposure index?"

 

[Terry VerHaar]

Jeesh - time to go home. The value of this thread has been laboriously squeezed out. If you can't (or won't) understand what Graeme has stated here and elsewhere, then what is the point of asking?

 

[Yousuf Abbasi]

Jeesh - time to go home. The value of this thread has been laboriously squeezed out. If you can't (or won't) understand what Graeme has stated here and elsewhere, then what is the point of asking?

Agreed, its going nowhere past this point. Graeme has been clear as to how there exist a range of ISO's are acceptable with same DR, with ISO800 being a good starting point.

 

[Adrian Jebef]

Jeesh - time to go home. The value of this thread has been laboriously squeezed out. If you can't (or won't) understand what Graeme has stated here and elsewhere, then what is the point of asking?

From the RED website concerning the new DRAGON sensor:

"A $6000 upgrade for a 6K sensor. Native ISO 2000. 15+ stops of Dynamic Range. 120 frames per second at full 5K. This is obsolescence obsolete"

This continues the confusion. And is exactly why I'm asking. So, no, I don't understand what Graeme has stated.

Do you?

 

[Nick Gardner]

Thank you Graeme for humoring this level of dumbassery. Thank you Red for being this open. If you don't get it after all this, you should probably apply for a job at the post office. They have really good benefits. Better than 600.

Nick

 

[Adrian Jebef]

Thank you Graeme for humoring this level of dumbassery. Thank you Red for being this open. If you don't get it after all this, you should probably apply for a job at the post office. They have really good benefits. Better than 600.

Nick

You'll never learn anything new if you don't leave your (mis)conceptions at the door.

 

[Nick Gardner]

Holy ShiT! I never thought of it like that.... Graeme! I think you fucking got it wrong! explain it again!

 

[Evin Grant]

This thread is rapidly comingto a close....

Almost final word: There is no such thing as ISO

Really close to the final word: If you must use ISO Start with 800

Final word: If you can't seem to understand that for some reason overexpose, cause clipped highlights look great:banghead:

If it helps anyone here feel better I use the exact same methodology to expose for the Alexa.

 

[Gunleik Groven]

@ Evin

So do I vs the Alexa.

They are really two of a kind in many ways...

 

[Mark Pedersen]

Exactly. It's not really a matter of opinion. The sensor sees what it sees, changing the ISO does not increase the amount of photons actually collected by the sensor. When you shoot at 800 ISO you are effectively under-rating the sensor by 1 1/3 stops and "printing up." There's nothing wrong with this, but you should be aware of what's happening. Personally, I prefer to split the difference and shoot at 500 ISO unless I'm in a really low light situation or dealing super hot highlights that I need to protect.

After several tests, that's the same conclusion we've come to. Rate it at 500 in "normal" situations.