Menu alteration request ISO

[Antony M]

A lot of Red One users seem to get very confused as to how to use the ISO settings, or even IF we should use them.

What I would like to suggest is that the menus for Sensitivity and Color Temp should be moved from the Sensor menu, and put under Video->Video.

This would make it much clearer that you are NOT changing anything about the sensor, and that all you are affecting is the monitoring and the metadata.

 

[Stuart English]

Sensitivity and Color Temp

Sensitivity and Color Temp

If we need to do a better job explaining how adjusting ISO impacts how you approach shooting, O.K that's fair comment.

But because as an operator you will normally react to changes in ISO, at the camera SYSTEM level, its not JUST metadata.

 

[Antony M]

Well, now I am totally confused.

Does altering the Sensitivity (ISO) setting alter the way the sensor works, or not?
[...and as a side question, how does changing the ISO work on most DSLRs?]

The consensus (these days) seems to be ETTR using RAW meters.

My understanding, after reading this board, is that changing the ISO setting when shooting can only end in tears, because whatever you set it to, the sensor and the R3D file still contain the same data, which is effectively 320 ASA (although some people say it is 160 or 250 ASA).

The only use of changing the ISO setting when shooting is to be able to see in the monitor (and on the non-RAW meters) what you will end up with in post, if you use those ISO settings in post.

 

[Adrian T.]

Anthony, very good suggestion. I brought it up before and also got support from Ian Bloom - Mr. Crimson himself:

It's not the naming. It's the menu location!
Sensitivity and Color Temp don't belong in the "Sensor" menu but rather in the "Video" menu. These settings don't modify any sensor property, they're just for preview and meta data.

My 2 cents... :violin:

I've often had that thought. Also putting all Audio in one menu would be great. As has been said :beatdeadhorse:

But well frankly, all this confusion is how some of us guys get our street rates so...

IBloom

Stuart, if everything an operator reacts to needs to go to the Sensor menu, why don't you put "Look", "Color", "Gain" and "Tone" there too? :wink: These parameters are used to alter the PREVIEW image in just the same way as Sensitivity does.

I hope you can follow my arguments.

 

[Colin Sheldon]

I think what Stuart is trying to say is that when you change the ISO you begin exposing for that new ISO setting - which has implications at the system level.

Edit: And unlike Look, Color, etc, under or over exposing the image cannot be simply switched in post. If you expose everything for ISO 2000, you can't exactly switch it to 320 in post and start editing. You can, however, shoot everything at 3200 and switch to 5600 and have no problems.

 

[Stuart English]

ISO location

ISO location

... when you change the ISO you begin exposing for that new ISO setting ...

That is precisely the point. From that understanding you just need to consider why you would adjust ISO.

 

[Adrian T.]

I think what Stuart is trying to say is that when you change the ISO you begin exposing for that new ISO setting - which has implications at the system level.

And you begin changing makeup or set design when you alter the "Look" - so this has also implications at the system level. :wink:

Fact is that ISO and Color Temp are parameters for the preview video look and they don't change in any way the raw picture recorded - as far as the camera is concerned. So it has nothing to do with the sensor and therefore doesn't belong in that menu.

My 5 cents...

 

[Stuart English]

So it has nothing to do with the sensor and therefore doesn't belong in that menu.

My 5 cents...

Well that's your opinion, and fair enough. Our 95 cents will stay on the existing menu scheme...because as I explained it does.

 

[Antony M]

But because as an operator you will normally react to changes in ISO, at the camera SYSTEM level, its not JUST metadata.

On a previous shoot, it was very bright daylight.

Coming from a film background, I would use 100ASA daylight film.
So I set the Red's ISO to 100, and (as you say) reacted to that change in ISO.

Result?

Totally overexposed highlights, because even though the ISO was set to 100, the sensor was still operating at something like 320.


But, what's the point. Red seems to thrive on confusion and obfuscation. So carry on. You are obviously not interested. I will shut up for now... until I get pissed off again

:banghead:

 

[Antony M]

Having said I will shut up, I now find this explanation from Jim...

Here is our take on Build 16 ISO selection.

ISO 320, 400, 500- The Gold Standards. Extremely low noise (ISO 320) to Very low noise (ISO 500). All purpose ratings for many lighting conditions. Best of all worlds.

ISO 200, 250- wicked clean images. Need more light.

ISO 100, 125, 160- wicked clean image. Image softens as ISO goes down. Need even more light. Use with care due to resolution decrease.

...
Jim

Suggesting that it does affect the sensor.

But I'm not sure why setting the ISO to 100 should decrease resolution. I haven't noticed that. Unless he meant dynamic range, instead of resolution????

Then in the same thread, Jim says

Clipping is caused by your actual exposure, not the metadata or viewing ISO.

Suggesting that ISO *is* just for viewing and doesn't affect exposure.

Then he says

If the proper exposure for a given scene is ISO 125 @ T4, then the proper exposure for that same scene is also ISO 500 @ T8... or ISO 500 @ T4 with a .6 ND. Neither will clip.

Unless you are only shooting in bright light, ISO 125 is impractical because it is too slow (for me).

Which seems to be saying that changing the ISO *DOES* change the exposure and prevent clipping.


Then Jason Ing asked TWICE "What if you change just the ISO? "

The second time, Jim replied,

Then you are just changing the monitor path... and just metadata."

Hallelujah. A straight answer at last.

It IS just metadata. From the horse's mouth.


Ah... but then he goes back and says,

1. Set your ISO depending on light. 320-500 for normal, higher as the light goes away. Lower if you forgot your NDs.

 

[Adrian T.]

Antony, what are you trying to prove here? ISO is and always was metadata. That's not the question. The point is that it doesn't belong in the sensor menu - because it's metadata. Native ISO never changes. :wink:

 

[Stuart English]

ISO location

ISO location

Lets go over this one more time.... Lets assume we raised the ISO.....

- If you do nothing, a higher ISO setting will also do nothing to the recorded RAW data, however the monitor path and meters will reflect that change. (ISO is just metadata argument)

- If you react to what the monitor path and meters are showing you, or consult a light meter, you likely will close the lens aperture or add an ND filter. Hence less light will now hit the sensor and therefore your RAW recording IS affected. (ISO influences exposure argument)


With this understanding ISO can be used as a tool to bias exposure and provide extra highlight protection / shadow protection if needed.

 

[Mark Pugh]

The trouble is, ISO is supposed to be a measure of the sensitivity of film stock in film cameras, and of the sensor speed in electronic cameras.
To put ISO in the sensor menu implies to many people that the sensitivity of the camera can be changed, which isn't the case.

Antony's point was that changing "ISO" in the Red One does something much more akin to changing "view mode" from RED 709 to REDSPACE- in that curve is being manipulated, but nothing changes at the sensor. It's MUCH more akin to the functions in the "Video" menu, than, say SHUTTER. It's a simple, true point, and that's all Antony was pointing out.

It's probably the very use of the term "ISO" in the camera that's causing all the confusion, (and causes people to set their lightmeters to a position they later regret) and the name of the menu function should be changed, as well as it's position. I guess "POST GAIN" doesn't seem so sexy, though...

 

[Stuart English]

ISO location

ISO location

ISO is supposed to be a measure of the sensitivity of film stock ... and of the sensor speed in electronic cameras.

I agree with you on film stock but not for digital sensors, there it's being used in a different sense.

But if you would like to suggest a different name for what is being labelled ISO, we are always open to ideas.....

 

[Adrian T.]

- If you react to what the monitor path and meters are showing you, or consult a light meter, you likely will close the lens aperture or add an ND filter. Hence less light will now hit the sensor and therefore your RAW recording IS affected. (ISO influences exposure argument)

I fully agree. But then again, when you adjust the look in the video menu (color, gain, tone) you also change the monitor path and you may react by changing aperture, filters, lighting etc. Hence the image recorded can also be affected.

I have a hard time seeing any difference between ISO, color temp and all the video look settings in this regard. They're all parameters used to build up conversion matrixes and LUTs for the video path.

Can you see where I'm coming from?

 

[Adrian T.]

But if you would like to suggest a different name for what is being labelled ISO, we are always open to ideas.....

"View as ISO" or "Interpret as ISO" or "Convert to ISO" would be a bit clearer. But again, the menu location still bugs me. :001_cool:

 

[Noah Kadner]

It's more like a LUT than an ISO if you take ISO's meaning carried over from film...

Noah

 

[Stuart English]

ISO location

ISO location

Can you see where I'm coming from?

I do hear what you are saying, but happen to disagree with your conclusion where the ISO value should be located.

It's located where it is because of it's use case.

I could happily shoot a RED ONE without ever touching the video menus, but that's not true of the ISO value.

It's more like a LUT than an ISO if you take ISO's meaning carried over from film

That's another way of thinking about it, but I prefer the highlight / shadow protection bias explanation others have offered.

 

[Antony M]

Antony, what are you trying to prove here? ISO is and always was metadata. That's not the question. The point is that it doesn't belong in the sensor menu - because it's metadata. Native ISO never changes. :wink:

I think what I was trying to prove was... that I am totally confused :blushing:

And that whilst I was fairly sure that it was just metadata, conflicting advise given made me think that maybe I was wrong.

I also don't understand why changing the ISO should decrease the resolution as Jim said. What does the resolution decrease to? And does this only get reduced if you are shooting in 4K, or also in 2K, 3K and 4.5K ????

What is needed is clear operating advice.

What we have on these boards is very well meaning advice, but so many conflicting explanations (even by the same person), that there is MUCH confusion and uncertainty as to how things should be done, and what they actually do. This can only harm Red's reputation.

I have a Red, and what I want is to be able to get the best possible image out of it.

I am not acheiving that at present. Two weeks ago I shot a side by side test of a Sony Z1, a Sony EX3 and the Red One to compare performance/price for a client. What I expected in advance would be an obvious quality increase of Z1, EX3, Red. The actual results shocked me, because the Red footage was worse than the EX3 (this is on Vimeo if anyone wants to see where I went wrong http://www.vimeo.com/6990500).

Now I'm sure this must be something that *I* am doing wrong, either with the camera or in post. But the fact that this is happening means that for this forthcoming shoot, I will be renting 7 or 8 EX3s instead of Reds. And my Red will just sit unused. Which is a shame.

 

[Cail Young]

Now I'm sure this must be something that *I* am doing wrong, either with the camera or in post.

You shot in 2K. Bad idea, unless you need high speed.