Video Accessories Misc
- Written by John E. Johnson, Jr.
- Published on 01 September 2008
The PMW-EX1 On the Bench
First, the lens falloff tests.
Here are the results with the lens set to wide angle and infinity focus. The maximum is 0.295 f-stops falloff, which would not be noticeable.
Here is the telephoto result, showing a maximum of 0.113 f-stop falloff, which is negligible.
Shown below is the MTF-50 sharpness test result graph. The MTF50 uncorrected (without standard amount of sharpening) is 780.4 LW/PH, which is the best test result we have yet obtained with any HD video camera. Results for the corner of the lens were slightly worse (this is expected), at 691.1 LW/PH. The MTF50 value refers to the number of adjacent black and white lines arranged vertically, and where you would see a 50% contrast between them, and represents what is felt to be the highest resolution for optimum picture quality. We can, of course, detect lines closer than that value (780.4 LW/PH), and MTF30 would be an example of that, but the MTF50 value is the standard. In this sense, it is the "Useful Resolution Value". But regardless of semantics, the PMW-EX1 MTF50 result is terrific!
Measured chromatic aberration (CA) was also very good, at 0.161 pixels near the center of the lens (0.732 pixels for the lens corner). The Fujinon is a very good lens. Now you can see why we spend so much effort with the bench tests. Many HD cameras specify 1080 resolution, but it is not just the sensor that gives you the image. The lens is extremely important, and the Fujinon lens in the PMW-EX1 is undoubtedly a significant part of the $7,000 price.
Here is a summary chart showing the MTF50 LW/PH values for all the video cameras we have tested, using the MTF50 criterion, so far. The Sony PMW-EX1 is far above the others, but the Canon HV20 does pretty well too (and is a bargain at about $1,000). The Panasonic AG-HVX200 is 720p native rather than 1080i.
The ChromaDuMonde chart (a standard color test chart in the television industry) was reproduced by the PMW-EX1 as close to the original as I have ever seen.
The gray scale results indicate that Sony does not roll off the white response just to keep the highlights from being blown out. They assume you, as a photographer, know what the heck you are doing, so the response is flat. The noise data (lower graph) show a steady rise in noise as the gray levels become darker, meaning they do not employ noise reduction processing. With some cameras, the darker grays actually have reduced noise compared to the whiter grays, suggesting strong noise reduction, and that will reduce sharpness (noise and image sharpness are intimately related; if you utilize image processing to reduce noise, you reduce sharpness as well, unfortunately).
The Q-60 Color Target appeared very natural, with all colors rendered very close to the original. Perhaps a bit of underexposure.
Below are the Gretag SG Color Chart results. Just a bit of overexposure, but overall, the colors are reproduced well.
Conclusions on the PMW-EX1
The Sony PMW-EX1 is a superb camera. It would be somewhat cumbersome to carry around on vacation, but when you returned home and put together your family vacation video, you would thank yourself for lugging its 6 pounds of weight (not including the case, which weighs 14.5 pounds by itself and has wheels) all over the place. And, Indie film producers take note. This may be just the camera you are looking for.