Choosing a High Definition Image Sensor for Small Gauge Film Transfers


Rumble House Media Group Inc., May 8th, 2009

The age of small gauge film (8mm and Super 8mm) transfers to DVD using 4:3 DV (Digital Video) technology may very well be drawing to a close as a mainstream service by the latter part of 2010.  In light of the promises of what high definition (HD) technology can deliver, it’s not a stretch to make that prediction.  Just as ‘off-the-wall/VHS’ film transfer methods used not a decade ago has mercifully faded away, a much improved Standard Definition (SD) DV technology will also be giving way to the new kid on the block, High Definition Video or HD, – whether or not it’s worthwhile. It will just be the expected thing to do.

Regardless of where HD technology will lead the film transfer business, it should be noted that the standard DV resolution of 720 x 480 pixels used in film transfer is marginal at best.  This is particularly true for Super8 and 16mm film gauges, where the film images can be under sampled.  Adequate results can be had assuming the image sensors were physically big enough, that good post processing occurred, the imaging system has good horizontal resolution (better than 520 lines) and the attached optics met 1MP requirements, even though many DV based imaging sensors were sub 720 pixel rated.  Conversion often resulted in loss of detail.  Use of elegant pre and post image processing techniques within the camera or specialized software in the post production phase in an NLE did a very good job at masking many sampling based errors but at the expense of hiding the finer nature of the actual image content; -an acceptable tradeoff given the current state of SD based transfer technology.

Is high definition video with its greatly increased spatial resolution and dynamic range set to carry-on where SD left off then?  It looks like it.  The technical means to faithfully render the high resolution nature of small gauge film does now appear to exist, barring that certain caveats have been met.  The availability of larger image sensors, higher pixel densities, better noise figures and lower cost higher precision optics are certainly moving in the right direction, providing the basis for what can be impressive amateur film to digital results.

It does leave a lingering question though, why have a superior imaging system capture and process amateur film that is in many cases questionable.  In other words why bring out any ‘warts’ the film may have in finer detail?  The answer simply is that regardless of the ‘warts’ (which will be there anyway), the higher image resolution and deeper pixel depths possible that HD technology can offer, can now be used to approach the resolution and contrast ratios of film.  A notion not possible in the SD telecine model, as imaging errors were inherently masked very well……

Choosing a High Definition Image Sensor.pdf