F5 & F55 Center Scan vs Full Scan

Tree FullScan

Now that firmware v3 is released for the Sony PMW-F5 and PMW-F55 I thought it would make sense to test the Center Scan mode and Full Scan mode on the F55 using the same framing from the two shots to really see what kind of image quality difference there might be between the two modes. The Center Scan mode is actually designed for use with super 16mm lenses however it can also be useful for immediately doubling the focal length of your super 35mm lenses since in essence it introduces a 2x crop factor. Basically you now have a 2x lens extender without the need of any mechanical adaptor or additional light loss.

I did not want to switch out any lenses in order to get the same framing when switching modes as I did not want any possibility of introducing other variables which could account for image quality differences so I only used one lens for this test and moved the camera positions in order to get approximately the same framing. I shot all clips at f8 -1/2 to f11 in order to get a wider depth of field and help increase the sharpness of the images fom the lens.

These video clips are straight out of the camera only transcoded through FCP X in order to create ProRes video files. It is best to download them and view them on your computer. I decided not to upload them to any video sites because the added compression and softening would take away from the differences you would see straight out of camera.

Camera settings: Standard Gamma 5, 500 ISO, 0db gain, 1/48th, 23.98p, 5600k, no ND filters.

Test 1 Clips: Frozen Bush 200MB (ProRes)
(contains 2k center scan mode and full scan mode with same framing)
DOWNLOAD

Test 2 Clips: Jingle Balls 280MB (ProRes)
(contains 2k center scan mode and full scan mode with same framing)
DOWNLOAD

Conclusions: Center Scan mode is definitely not as sharp as the Full Scan mode, but center scan mode so far does not appear to suffer from any aliasing as we have seen in full scan HFR mode. Two more interesting tests would obviously be center scan HFR mode, and also shooting in 4k full scan mode then cropping out the center in post and comparing the image to the same framing shot in 2k Center Scan mode. More testing to be done.

  1. samuel ameensamuel ameen01-04-2014

    I’ve been using an adaptor (stop loss :( - with my F55-with & my Canon HD 5.5-50mm eng zoom,
    It’s quite useful but the stop loss is killing me in low light.
    What’s the final horizontal resolution of the image when using super 16mm lenses in the crop down mode on the F55 sensor?

    • Dennis HingsbergDennis Hingsberg01-04-2014

      The pixel resolution is 2048×1080 but for actual lines of resolution the speculation is that it would be around 850lpph vs 1000lpph when using the full 4k sensor to derive a 2k image. I myself have not put it on a line chart but seen some results and the center scan (crop) mode is a hair softer but nothing significant in my opinion for most applications.

      Interestingly enough if you use B4 2/3″ ENG lens with a built-in 2x optical doubler it should be enough to yield 3000×1600 onto the 4k sensor. You could record it in full scan mode and crop in post, or shoot in center scan mode with satisfactory results. It is on my list of “things to test”.

  2. samuel ameensamuel ameen01-05-2014

    Where do you like your zebras on caucasian flesh?
    Hg7
    Hg8

    The show that I work on when shooting S-log seems to put them at 50 ire.

    • Dennis HingsbergDennis Hingsberg01-06-2014

      This depends on many things from personal preference to sometimes wanting shifting the latitude of the image for the specific gamma curve you are working in. For slog on the F3 a properly exposed middle grey card would be 38% so if you are placing it at 50% you are between 1-2 stops over middle grey. With slog2 on the Sony F5/F55 middle grey is mapped far lower around 32%. Placement also depends on where you intend to bring it back in post ie. be cautious not to bring it back further than the true mapped value or you will introduce noise to your image.

  3. Isaac AlonzoIsaac Alonzo01-15-2014

    Great info! Here you have a lot of info about the F55 which I am researching now because I am going to by 3 of those later this year.

    Thanks for sharing your knowledge with the world mate.

    Isaac

    • Dennis HingsbergDennis Hingsberg01-15-2014

      Thank you for the very kind words Isaac. The F55 is packed with features check back on my site for even more to come!

  4. ACostaACosta12-01-2014

    Hi Mr. Dennis Hingsberg!

    Can i shoot in cine mode EI / slog 2 or 3 / 23,98psf. / SSTP 4:2:2, changing ISO?
    Or the camera F55 only rec in native ISO 1250?
    Can i REC with other ISO or only monitoring with ISO select and REC only native ISO (1250)?
    Thanks!!!

    • Dennis HingsbergDennis Hingsberg12-01-2014

      Hello Andre. When you are in CineEI mode, the ISO of the camera is always locked to the native ISO. For the F55 that is 1250ISO, for the F5 that is 2000ISO.

  5. ACostaACosta12-01-2014

    Thanks Dennis!!!

    I don’t have more doubt about ISO on the cameras F5/55!!!
    You SAVE ME!!!!!!!!

    Bye

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