Cinevate's CF1/2/3 Imaging Screens..Exposed!

Damn.... shallower than CF3Le? Hope youre dropping that FF soon, Dennis. I'm excited to see what CF4(?) looks like as I can't quite envision the mixed properties (more shallow DOF than CF3 with "tighter" bokeh than CF1, which has the least diffusion). And same light loss as CF1? Sounds like that CF should be the new standard brevis diffuser but let's see once you post some grabs/clips.

You've definitely got my attention.
 
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What does vary is the usable aperture range and the total system loss as you stop the 35mm lens down 4 more stops to f5.6 With the 50mm lens at f5.6 (which most think would result in 5 stops of light loss) the camera still only loses ~1 stop with CF1Le, ~1.3 with CF2Le and ~2 stops with CF3Le.
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Dennis thats my biggest problem... Since we don't adjust aperture "by eye" or by waveform and we use the cinematic way, that all DoP's are using on film (photometer or lightmeter) and in cinema class cameras like Varicam, a five stop on the lens it should be five stops on the camera... and this is very crucial.

The other day I was renting for a six weeks future my Varicam with my relay lens and Brevis35 and the DoP return the package because he couldn't have an accurate aperture control on the most useful range of the lenses from 1,4 to 8 ... to all that range was just 1,5 stops light adjustment... even thought he liked the DoF of image, the color and the sharpness... with no aperture control is useless... so with great grief we put back the Canon Cinestyle Zoom... unfortunately I didn't had my fiber GG ready (since I still waiting the delivery) and I couldn't give a solution.

So thats what I define as "Brevis effect", which is OK if you thing it as a special tool for occasional use or non professionals or semi professionals use... but for real DoP's that are building their scene contrast the same way that do on film is useless...

I have to state that I don't know how other adapters are performing on this issue, and hope that the new CFl4 will address this problem... If not my fiber GG will address it. Again thats the beauty of Brevis35 with the exchangeable GG's.
 
but for real DoP's that are building their scene contrast the same way that do on film is useless...
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What are you talking about? You can still measure lighting ratios with a light meter. Setting the lens aperture in digital should ALWAYS be done with a waveform monitor. Any serious DP knows this.


Marco
 
Varicam (and Viper) since 2003 they didn't need a confidence monitor... you can shoot with just a light meter and set aperture with no monitor or waveform. The camera is rated to 640ASA at -3db's so its very simple the operation and its equivalent to film experienced DoP's. I can assure you guys, that their is no need to look a monitor when you shoot with Varicam, since it has more than 10 stops of latitude (its very hard to over expose), and with just the viewfinder for framing you can have very good results! The camera was designed to be operated like film...
In film there is no monitor to look at...

Additionally modern LCD monitors can show no more than 4-5 stops of total scene brightness, so when you set lighting and scene contrast, you can easily be mislead and constrain your image to these 5 stops... so without knowing you end up with a TV look! On the other hand DoP's that set the scene by eye and lightmeter the result is much more filmick since it doesn't constrain the image brightness to fit to the monitor.

Lastly, with mid exposure point of 31% IRE (mid gray) that Varicam has its very difficult to judge by waveform...

We do have an Astrodesign 7inch waveform/vector for DoP monitor and a Panasonic BT-LH1760 for director... DoP didn't care about that, he wanted to work with his lightmeter. He usally shoot on 35mm, so no room to convince him, he has won so many awards in his carrier...
 
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You're right, the monitor IS for confidence, it's to see exactly what you are getting. I call that precision. Who doesn't want that? If a film veteran wants to shoot digital he/she should learn to use a monitor, plain and simple. If you have a good monitor and you know how to use it you will be 100% in control of your image.

I'm not saying you can't or shouldn't use a light meter too, but in the case of 35mm adapters you should consider all the variables that lead to exposure: the camera's sensitivity, gamma setting, lens aperture, shutter speed, the adapter ground glass, and the taking lens aperture. In a film camera there are half as many variables: t-stop, shutter and film ASA. And keep in mind that still photo lenses are marked by f-stops, not t-stops, so light transmission is only approximated. Add the fact that you can't trust any adapter's ground glass to have linear one-stop increments of light transmission through the aperture range, and you've got a mess if you plan to use a light meter. The Brevis is clearly the most eccentric, but I wouldn't trust any of the others even if they appear to come close. The solution is to use a waveform monitor.


Marco
 
The good thing with Varicam is that in filmrec mode you shoot preset settings since almost everything is handled by filmrec, I always have the waveform ON on both monitors... DoP's when they shoot two to three days they immediately understand the exposure behavior and simply don't look at the waveform any more... its much faster for them the light meter... The EEs Canon screen gives a linear behavior to Brevis35 but it has to much glow so I cant use it... I will test the EEa also... but my findings with the fiber screens are much better so I will wait until the end of month...
 
Evangelos, what we normally recommend is to set the 35mm lens where it works best in terms of sharpness and/'or DOF, and then use the camera's aperture for a linear response. Using a light meter on a 35mm adapter is a bit dicey as once you rate a given ISO, no adapter responds the same with with respect to convention.

What does work is to rate the camera's ISO with the 35mm lens attached and wide open. Then the DP uses the camera's aperture and/or ND filters to set exposure which will behave as the light meter predicts it will.

This is a sneak peak at CF?? : http://www.cinevate.com/forum/viewtopic.php?f=2&t=2479
 
hey looks good, how would you say the granularity of the grain compares to the cf1?
How far can one stop down on a 35mm lens before you start seeing GSE?
I know you can stop down on the camera or use ND's for exposure control, but i'm more intersted in the bokeh rendition at around f/4 and beyond.


Also, will it be available in the CF line for smaller cameras, and will it work with the non-flip achromat?

thanks.
 
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Astig, the grain is tighter than CF1 or CF1Le. The grain aperture threshold is a tiny bit less than CF1 or CF1le, so panning across a bright sky for example, I'd be using an aperture no greater than f5.6, preferably f4. Indoors, under muted light, you can use tighter apertures.

Bokeh is at it's best with this imaging element at f 2.8 in the all-important specular highlights test. If you want out of focus lights at their best, f2.8 is my recommendation.

It will work with the non-flip achromat on other cameras, however with regard to the EX1 specifically, all testing is being done with the flip. In other words, if you're shooting with an EX1, we are only recomending one setup...the MP.1 flip.
 
At f4 with CF1Le, you're only losing about .8 total stops to the camera. This means if the lens is sharper at f4, then there's not much of a penalty for stopping down a bit to pick up edge sharpness with our system. We talk about it in various clips in our video university series to encourage DPs to stray from convention a bit :-)

Stopping down a lens slightly will define the bokeh areas better for a more pleasing look. Specular highlights will go from an undefined orb, to a smaller orb, but with crisper edges defined by the aperture blade configuration. It's a little adapter tip for rendering out of focus lights in a more pleasing fashion.
 
Yeah, but cf1l is also the gg with the least emphasis on bokeh rendition.

Dennis Wood said:
Stopping down a lens slightly will define the bokeh areas better for a more pleasing look. Specular highlights will go from an undefined orb, to a smaller orb, but with crisper edges defined by the aperture blade configuration.
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That is a lens function though. I thought you were saying the gg somehow reacts differently.
 
Dennis
Astig, the grain is tighter than CF1 or CF1Le. The grain aperture threshold is a tiny bit less than CF1 or CF1le, so panning across a bright sky for example, I'd be using an aperture no greater than f5.6, preferably f4. Indoors, under muted light, you can use tighter apertures.
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On the cf3, f4 is actually where things start looking really good, ofcourse it's unusable because of the grain, but if the new diffuser will get me that type of rendition between 2.8-5.6 I will definitely be happy. If you do more video samples I would love to see footage of rendition changes through the usable stops.

thanks!
 
Dennis, can you explain whether the DOF is actually shorter or the background just appears blurrier? As far as I understand it DOF is a function of the focal length and iris so I'm confused as how changing these Cinefuse elements can affect DOF.
 
It doesn't actually effect the DOF.
It is rendering the bokeh differently.

Generally speaking, less diffusion will look like it has more DOF and the bokeh will be hazy. Also, less lightlloss.
More diffusion will look like it has less DOF and bokeh will be sharper. Also, more lightlloss.
 
Matty_g said:
Generally speaking, less diffusion will look like it has more DOF and the bokeh will be hazy. Also, less lightlloss.
More diffusion will look like it has less DOF and bokeh will be sharper. Also, more lightlloss.
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Isn't it the other way around? More DOF=more defined bokeh (less blurry), less DOF=blurrier bokeh.
 
don't confuse DOF and bokeh rendition.

cf123.jpg


you can see on the left with cf1l (which has the least amount of diffusion) it appears to have more DOF when the lens is set at the same stop.
cf3l has more diffusion and appears to have less DOF, but you can see in the video when the waves are kicking up at the bottom there is more clearly defined bokeh.
 
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Astig, f4 is 100% workable with the new imaging element system, and you're still lookinging at less than 1.5 total stops loss to the camera :-) We'll post more tests at f4 to demonstrate. The 85mm portion of that test was done at f2.8
 
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