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Camera Tests/Prep Standards


Jacob Mitchell

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Hey all!

 

Got a shoot this weekend with some gear I am unfamiliar with, mainly a set of Kowa Anamorphics.

 

What is everyones procedure/best practices for a camera test? Additionally, we don't have access to focus charts, etc... what are some substitutes? I've heard of using a dollar bill, etc

 

Thanks!

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Hey all!

 

Got a shoot this weekend with some gear I am unfamiliar with, mainly a set of Kowa Anamorphics.

 

What is everyones procedure/best practices for a camera test? Additionally, we don't have access to focus charts, etc... what are some substitutes? I've heard of using a dollar bill, etc

 

Thanks!

 

Well, it's this weekend now... but here's a PDF of the ISO 12233 resolution chart.

 

http://www.f20c.com/stuff/canon/ISO_12233-reschart.pdf

 

The problem with printing it out, is one will also have the resolution of the printer yielding certain subsampling artifacts...

 

But if you get it big enough, you can perhaps use it to get an idea of the lens+camera quality.

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Besides checking back focus and general sharp focus, shoot something circular like a Seimens Star focus chart, a roll of gaff tape, or a lens cap to make sure the anamorphic element is aligned correctly.

 

If the alignment is off, the circle will appear distorted and the lens should be adjusted by a technician. This is important, as it is not something that can be easily fixed in post.

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I always use a crisp dollar bill. It's the best focus chart.

 

G

 

Come on now Greg. You just had a film break the all-time box office opening record. Surely you should be using Benjamins now!

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Come on now Greg. You just had a film break the all-time box office opening record. Surely you should be using Benjamins now!

 

We just broke the $1Billion barrier in 3 weeks but I'm sure my check is in the mail! :)

 

G

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With the dollar bill test chart, how big is it in the frame? Cheers

You can fill the frame with it. Just move the camera in close for wide lenses and back for longer ones.

 

G

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A camera test is dependent on the variables you are intending to use for the project. As a DP, you'll start to focus less on technical standards of testing camera/lenses and more on the artistic uses of the camera/lens. The best thing to do is get the equipment in your hands for a few hours. Have a friend help "act" and bring different colored objects to play with in camera as well.

 

Here are some things to look for:

  • Focus
    • Does the gearing of a particular lens move in/out as the lens is focused or does it stay static and move the elements inside?
    • How does the lens breathe?
    • What is the distance between the hard-stops of the lens? Does it go from CF to Infinity in a matter of 45 degrees or 270 degrees?
    • What is the close focus?
    • What is the front element? What matteboxes can be used with it?
    • Are all the focus gears the same distance from the FFD?
    • Is the aperture smooth?
    • Do the lenses all weigh the same? Same length?
  • Aperture
    • T stop? F Stop?
    • What's the "sweet spot"?
    • How many stops?
    • Geared?
    • How many blades?
    • What does the bokeh look like?
  • Sharpness
    • Charts are one thing, but what about a real human face?
    • What do the edges look like in comparison to the center?
    • Where does sharpness fall apart in relation to the aperture?
  • Color/Contrast
    • Again, charts are one thing, but what about a real human face?
    • Consistent color/contrast from lens to lens?
    • How are the colors rendered in comparison to the human eye? In comparison to a different lens brand?
    • How much does color/contrast change with the aperture?
    • Is the camera sensor favorable to a particular color temp?
  • General Camera
    • What codecs does the camera record?
    • What resolution(s)? If multiple resolutions: how does the camera down sample from 4k - 2k?
    • What's the post workflow of the files?
    • Weight of camera?
    • Balance of camera fully built?
    • Ease of use for either an one-man-band or AC?
    • Battery type? How long do batteries last?
    • "House power" options for camera?
    • Video signal outputs? What signal is sent out?
    • How quickly can playback be turned on?
    • What type of media does the camera use?
    • How far can a sensor be under/over exposed before it's "useless"?
    • What's the manufacture dynamic range? What's the dynamic range you can see?
    • How many cases does the camera system need?
    • How does it work handheld?
    • Boot time?

Some of these may seem obvious, and they with time as your experience increases. However, the goal of a camera test isn't to measure it by chart metrics; it's to understand out this specific tool works and how you can use it for your craft. One final time: charts are one thing, real world is another.

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