The ‘Extron EDID Method’ is a way to downscale HD content to 15kHz using a compatible Extron scaler on the Product Configuration Software (PCS) list, though this does not guarantee compatibility with this method. The PCS software communicates with the scaler to upload a custom resolution via an EDID.bin such as 240p. Downscaling to 240p is very sharp and with Accu-RATE Frame Lock (AFL), frame skipping is diminished with only 1 frame of lag for progressive input resolutions, and 2 frames when the input is interlaced. The downscaled video needs minor tweaking to have the image centred and filled to the display which should only take about 1 minute by navigating the LCD status screen with the front controls, or through the PCS. The DVS 605 is the most suitable scaler on the PCS list for downscaling as it has the necessary HDMI/VGA inputs and does not require a DAC to display RGBs/RGBHV/YPbPr.
The DVS 605 was almost an ideal downscaling solution, but was missing 480i output for downscaling 3D content, text-based media, and motion video. Through sheer luck I made a 480i EDID that the Extron DVS 605 can understand, and voila! I did not have any geometry anomalies on the Sony PVM L5-series and BVM D20F1 (subtle flex). My friend did have some minor left-sided distortion on a PVM 20M4 that somewhat improved by slightly increasing the DVS 605’s horizonal size, brightness and contrast. Changes can be made to the 1920x480i custom resolution using an EDID manager if necessary, or create an EDID from scratch.
Links to the PCS, 240p and 480i EDID’s are in the embedded video’s description and the total setup will likely take less than 10 minutes for plug and play downscaling.