REVIEW: DVDO iScan VP50 Part 10

Table of contents:

Introduction
Why buy a video processor?
Scope of supply
Exterior and manufacturing quality
Connectors
Core functions
Additional features
Test setup
Scaling
Deinterlacing
Frame rate conversion
Additional functions
Conclusion

Frame rate conversion

If your own screen only allows 60Hz with pixel-precise control, you face the problem of having to convert signals with unsuitable frequencies to 60Hz. The DVDO iScan VP50 manages this very well, although of course it cannot work wonders. In order to carry out the aforementioned conversation, the user should select the "frame rate" menu option in the output options.

Subsequently, the requested output frequency for the pre-set output frequencies (24Hz, 25Hz, 50Hz, 60Hz) must be set. After conversion, 50Hz signals which are reproduced at 60Hz are comparable with the display of 24fps material that has undergone 3:2 pulldown. Micro-juddering is therefore present, but to a significantly lesser extent than with primitive conversion. Here, it depends entirely on your personal sensitivity.

Choice of output frequencies on the iScan VP50.

As well as this conversion, the iScan VP50 offers various "locked" modes where the output frequency is coupled with the input frequency. Here, additionally introduced juddering is avoided. The combinations are numerous, depend largely on the capabilities of the display used and the material being played back and can not all be covered at this point. Basic information is available in our Perfect Viewing Enjoyment article.

By way of example, we will describe the handling of 60Hz signals at this point. These can come from a film or video source. In the latter case, "60Hz lock" is the correct setting: each incoming half frame produces an outgoing full frame. If the original input as a 24fps source (film) which was converted to a 60Hz half frame signal, this setting causes visible juddering.

Although the deinterlacer wins back the original full frame sequence, the 24 frames per second must be divided by 60, which cannot be done in a linear manner. In this case, you should switch to the 24Hz, 48Hz or 72Hz output frequencies offered by the video processor, in so far as the display supports the relevant refresh rate. This functions without difficulty and is rewarded with a judder-free picture.

Now, the "Forced 3:2" setting on the iScan VP50 becomes more important. Here, you can be sure of winning back the 24fps from the 60Hz signal in an absolutely stable manner. Even a short slide back into Vireo mode would bring with it visible effects and image errors. However, in this case, the "Film Bias Mode" setting is absolutely sufficient.

Frame rate conversion for full-frame playback

Frame rate conversion not only works when half frames are being played back but also functions for full-frame-based signals. DVDO calls this "progressive cadence detection". Thus, for example, a 1080p24 output signal can be created from a 1080p60 input signal.

However, this feature cannot be switched off on the. The three frame lag caused by the analysis of the full frame sequence is a considerable setback for gamers. Here, a firmware update is urgently needed which would allow the feature to be deactivated.

As mentioned before, the output frequency for particular input frequencies can be set. A material-based selection is not possible, however. This, when changing between film and video material, this must usually be changed manually.

Additional functions

CUE correction

The CUE correction on the 24Hz DVDO iScan VP50 functions well, but cannot remove serious errors on the part of the player device. In any case, a clear improvement is made. Nonetheless, you should consider replacing your player device if it produces many Chroma Upsampling errors. It is always better to avoid errors than to correct them afterwards.

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