ISO 100 on M-X

[Paul Plonka]

Hello!

I want to ask what do you think about shooting at ISO 100 on MX`ed RED ONE. Yes, i know what has been spoken in this topic, that then we lost dynamic range etc and that minimum sensitivity is 320 at MX and 250 at old sensor. But now i have a new project with my friend, his name is Andrzej Dragan, he is known photographer and he compose his image with using a hundreds of layers for making a final photo. I explain him what i know about shooting with low ISO on RED, but he is very determined to make it so mimimum as only possible. He wants to work in post with recorded texture, but in his opinion, the noticeable grain can destroy his work and make it very hard to compose movie image as he used to make with photo image. He really hates grain I want to ask you what you think about it, maybe you work in post that way as my friend want to. btw, here`s some information about a project and also some photos which can you explain his style and work: http://www.kickstarter.com/projects/932671704/hierarchy-lost

 

[Jannard]

Bad idea. Shoot ISO 250, control the latitude of the scene and shoot REDCODE 42.

If he is determined... at least do tests 1st.

Jim

Hello!

I want to ask what do you think about shooting at ISO 100 on MX`ed RED ONE. Yes, i know what has been spoken in this topic, that then we lost dynamic range etc and that minimum sensitivity is 320 at MX and 250 at old sensor. But now i have a new project with my friend, his name is Andrzej Dragan, he is known photographer and he compose his image with using a hundreds of layers for making a final photo. I explain him what i know about shooting with low ISO on RED, but he is very determined to make it so mimimum as only possible. He wants to work in post with recorded texture, but in his opinion, the noticeable grain can destroy his work and make it very hard to compose movie image as he used to make with photo image. He really hates grain I want to ask you what you think about it, maybe you work in post that way as my friend want to. btw, here`s some information about a project and also some photos which can you explain his style and work: http://www.kickstarter.com/projects/932671704/hierarchy-lost

 

[Justin McAleece]

good luck finding grain on the mx chip at even 500 iso. it's virtually noiseless. 100 would not be a very great idea.

 

[Patrick Tresch]

BTW could RED kill iso setting preset lower than 250 please.

Pat

 

[Dylan Macleod CSC]

...and start calling it EI (exposure index).

 

[Graeme Nattress]

Advice - ignore the concept of ISO and expose to the right (avoiding clipping) then adjust the ISO to get an image of visually correct brightness. Then you've got the least grainy possible image on your RED. And out of interest, after testing, tell us what the ISO you ended up with is.

Graeme

 

[Paul Plonka]

Thanks for your opinions. We had 1st test shots, but now we definitely need a second one. With light conditions close to the final (dark interiors with a minimum light, comparable to dark scenes in Fight Club by David Fincher).

 

[N_Villers]

I have very much admired Andrzej's work for a few years now since a friend showed me his work in an album. I would be very excited to see how his still images can translate into the 4th dimension. Please keep us updated. If you ever need assistance or want to shoot in Budapest let me know. We have also worked ourselves for free to support different artists and students and I personally find it the most fulfilling of the work I have done for others.

Powodzenia!

-noel

 

[Jannard]

I just do not see ISO 100 for this use under any circumstances... especially this.

Jim

Thanks for your opinions. We had 1st test shots, but now we definitely need a second one. With light conditions close to the final (dark interiors with a minimum light, comparable to dark scenes in Fight Club by David Fincher).

 

[Paul Plonka]

yes, but please remember that besides the image look, he want to work on many layers in post, especially on textures, what define his work on photography. It`ll not be just a movie, rather composition in time. Btw, two years ago i work at similar project directed by Lech Majewski, "The Mill & The Cross" with Rutger Hauer. Postproduction there was very complicated also, specialists works on tens layers, composing old painting, real shots and special "green" shots all together. The movie has been screened at Sundance f.

 

[Jannard]

Paul... you asked our opinion in your 1st post. We have given it. If you guys have done tests and the results satisfy your needs, then you don't need advice. If you haven't done tests to prove your use... I strongly suggest that you do because you are going into dangerous territory. We just don't want you to be surprised with results that are less than you hoped for.

Best on your project.

Jim

yes, but please remember that besides the image look, he want to work on many layers in post, especially on textures, what define his work on photography. It`ll not be just a movie, rather composition in time. Btw, two years ago i work at similar project directed by Lech Majewski, "The Mill & The Cross" with Rutger Hauer. Postproduction there was very complicated also, specialists works on tens layers, composing old painting, real shots and special "green" shots all together. The movie has been screened at Sundance f.

 

[Steve Sherrick]

And I would add that it can't end at ISO either. Color temperature, quality and spectrum of light sources, proper makeup for RED, and digital sensors in general(if there is any), best possible post pipeline to ensure there is no weak link in the chain, understanding how the camera's metering works and using it to best expose the M-X sensor. There's a lot that goes into getting the cleanest possible signal out of this camera. There are many examples of people who understand how to get the best from the R1 and many examples of not so good practices (I've been guilty at times too). When shot correctly, grain should be not much of an issue.

Good luck with the project, seems intriguing.

 

[Paul Plonka]

If it depends all on me, i would go 320. I`ve never do anything less on MX, so i need to ask for opinions. First shots hasn`t been too auspicious for my friend in background of post. Of course i`ll consider all your opinion it in 2nd test shots, Thanks!

 

[Raphael Varandas]

Follow the geniuses... and you won't get hurt :thumbup1:
The least that I did was to go down to ISO250.
Good Job Matte.
Looking forward to hear your tests results
cheers

 

[Rich Schaefer]

I don't get it. If its a dark movie, wont you need some speed/ISO? Say 500-800 even at T1.4?

 

[Dylan Macleod CSC]

If you rate and light for 100 ISO (or EI as I like to call it) you are going to get very clean shadow detail - but you will have to be very careful about highlight clipping. And conversely - if you rate at - say 1000 ISO (or EI) your highlights will be much safer, but your shadows "may" be noisy.

Changing ISO doesn't change the sensitivity of the sensor - so beware!

 

[Chris Parker]

i agree with other posters. i'd think you could go as low as 160, although i'd recommend 250. the problem with 100 is not just clipping of the high end, but it also becomes an unattractive pink sort of cast. for this reason, i'd go with the advice of others here and crank it up a little. you don't need to shoot 500 or anything, but 100 will most likely result in clean images....sure....but images you are not entirely happy with.

 

[Robert Knoll]

Jim, I read a while back that 800 is the sweet spot for MX, and that 320 was the sweet for the preMX. Is this still accuarte?

 

[Jannard]

Yes.

Jim

Jim, I read a while back that 800 is the sweet spot for MX, and that 320 was the sweet for the preMX. Is this still accuarte?

 

[Dan Hudgins]

Contrast Range

Contrast Range

Forget everything you know about shooting 35mm color negative film.

Sensors hard clip unequal color balance at the top end, they do not have a built in S-curve like film is made to have, or was when there was enough silver in it to work like a filter for grains under the top layer.

Most of todays sensors clip the green pixels at about the same ISO based on the 90% White side of the Kodak Gray card, they clip at about ISO 160 to 200 for 5500K lighting. You can rate the ISO a bit lower by using some of the unclipped data from the red and blue, but there can be a color shift in the highlights, see the DRX function in RED's de-Bayer.

You cannot shoot normal subjects with the green sensors above 50% signal on the 90% White card in the frame, because you do not get any of the specular reflections that are above 90% matte white, even matteish white subjects like a whit cotton shirt would have some specular reflections above 90% white card lite at 45 degrees.

Most of the time you want the green sinsors at 25% signal, I think Panavision shoots as low as 16% signal for white in their Panalog curve, you can look that up at their site.

For higher contrast range subjects where you want to hold the highlights, you need to shoot at HIGHER ISO, that means in DAYLIGHT you need to shoot at ISO 1600 or HIGHER to get subjects in broken sunlight and not burn out reflections in the direct sunlight areas while holding the shadows as well.

Same at night where contrast ranges can be very high, you need the higher ISO to roll off the top part of the S-curve, not to clip the highlights.

To shoot in daylight where there is sun and shadow you need ND 2.1 plus IR cut in front of the camera, you cannot stop the lens down past about f/ 8 and get the full 4.5K resolution.

The only time you can shoot at about ISO 160 to 200 in on a title stand where the subject is lite with 45 degree lighting so that the subject has not specular reflections.

You can use a linear pola filter to control the highlight specular reflections, most of the time you want to dull them as much as you can optically before the light clips the sensor, and that goes for any digital camera its not a special issue for RED cameras.

So:

Measure the contrast range of the subject that is important with your light meter.

Adjust the ISO based on how many stops above 90% white some of the subject matter is.

Set your RAW histogram based on the white card,

overrange green signal, not to be used except for overexposed footage, ISO 80 - 125 (green clipped overrange, DRX used?)

90+% green signal for copy stand and test chart use only (no head room), obie lighing for people ISO 160 - 250 (11+ bits under 90% white)

50% green signal for low contrast range subjects (one stop head room), overcast ISO 320 - 500 (11 bits under 90% white)

25% green signal for normal subjects with the specular controlled with a Pola flter, studio lighting (two stop head room) ISO 640 - 1000 (10 bits under 90% white)

12.5% green signal for higher contrast subjects, people with sun from the side (three stops head room) ISO 1280 - 2000 (9 bits under 90% white)

6.25% green signal for very high contrast subjects, such as forest with broken sunlight (four stops head room) ISO 2560 - 4000 (8 bits under 90% white)

Past that the noise may be too high for full size use, but if you are going to SD or DVD you can de-noise better and shoot higher.

Once the signal go off the top of the ADC it does not come back, DRX does not replace data that is overrange, it improves the luma because the red and blue are about half a stop less exposed due to the dyes in the Bayer filter being darker and the IR cut filter in the camera cutting the red a bit, and the sensor being less blue sensitive.

Because the gamma 0.45 correction plus the "hypergamma" curve used to adjust the mid-tone for the ISO spread the darker tones the bits you end up with in the shadow in relation to histogram gaps is about two less than the bits under 90% white, so the 8 bits at ISO 2560 - 4000 ends up showing histograms more like 6 bits, but there is noise and you normally reduce the images from 4.5K to 1920x1080, so that averages the pixels together (its better in that case to de-noise the HD size so the noise is passed through the down size average) and so you get back about 2 bits with a half size reduction.

These facts are the same for all digital cameras, the difference you see is how well the de-noise and oversample are done to get an image out of ADC output that has 90% white 4 to 6 bits above the bottom.

RED does have its REDCODE issues with the way the wavelets are used with various absolute signal deltas, in MX it seems they are using some non-linear encoding to reduce the shadow noise caused by the wavelets so you get closer to the signal look if you had recorded actual ADC output.

Some cameras may have too much noise to be able to underexpose the sensor enough to hold the contrast range of the subject, so you have to re-frame and otherwise control the lighting or time of day or weather to fit the contrast range within the usable range the camera can deliver in the end use size, what looks too nosy for Blu-Ray by be able to be de-noised for DVD, so you need to learn what the limits ARE for any given camera before you find out the hard way that what you shot is not going to be usable. It better to stand back at least 5 feet from the edge of the cliff...