We’ve had our Sony FS5 for a few weeks now and I’ve gotten a chance to do some shots to get test footage. I wanted to see how the image quality of the new Clear Image Zoom function of the camera would hold up, so I set up a target and recorded some zooms.
First I tested out the Sony 18-105mm kit lens that came with the camera. You can see the results in the video below.
As you can see, the Clear Image Zoom looks pretty good, with no noticeable artifacting or pixelation. For purposes of this test I recorded the optical and clear image zooms independently, but they do work in concert and the camera will transition seamlessly from optical to clear image when zooming in. When zooming back out there is a slight hiccup in the zoom when it transitions from clear image to optical. This will hopefully be addressed in a firmware update soon.
When playing back the zoom I did notice a weird thing happening to the chip chart early in the video. It seemed like the chip chart suddenly expands in size several times. If you didn’t see it I encourage you to watch the video again, I’ll wait.
At first I thought that maybe my editing computer, which is getting kind of long in the tooth, was struggling with the XAVC codec due to its processor intensive nature, but I was able to spot the effect on multiple computers after converting the file to ProRes. I narrowed the problem down to the cameras lens compensation algorithm, which automatically corrects for the distortion that is inherent in the kit lens (and other lenses). You can see in the video below that the effect disappears when you turn of the lens correction, though the distortion around the edges of the frame is pretty bad.
That’s just one of the trade offs you have to deal with when you use a $600 lens. I think the effect we saw in the lens compensated video would be a lot less noticeable, possible not noticeable at all, with a subject that didn’t have perfect geometric shapes, or with a subject in motion.
Just to see what kind of a difference a better lens would make I put the Sony 28-135mm zoom lens that comes with the FS7 on the FS5 and reshot the tests. I put both the lens compensated and uncompensated videos into one clip so you can watch them back to back.
Off the bat you can tell the 28-135 is a much nicer lens, and it should be, for $2500. The camera still does have to do some lens correction, but it is a lot less than with the 18-105, and I didn’t notice the strange expansion of the chip chart that we saw earlier. It was also interesting to to me that the 28-135 lens zoomed more quickly on the FS5 than it does on the FS7 and I have no idea why that would be.
That’s it for now. Hopefully I will have more footage for you soon. I really want to play around with S-Log on the FS5 with the WB Shift to make the post work go more smoothly.
-Keith M
