Grotesque Interlaced Problems

[William Urschel]

I have been using Cineform Aspect HD in all of my productions since last Summer, and I have always been very impressed with the product and its behind the scenes impeccability - so impressed, that I just purchased Prospect, in anticipation of purchasing an EX-1. I am currently shooting with three HDV cameras, including the FX-1

But I now see such horrible lack of detail and smearing in a production that I started last week, that I have gone no place. It is so bad that I thought there was something wrong with my installation, and I have completely uninstalled Premiere Pro CS3 twice, and re-installed it - and installed and uninstalled Cineform Aspect many times in the last few days. I may have experienced this issue in all my other productions, but even though I'm very attentive, I just never perceived it before. I attributed any smearing to the long GOP just running out of capacity. But seeing what I do now, I am ready to throw in the towel on this production.

To be more specific, please see the attached still exports from Premiere. As labled, the first is the original Cineform, as captured by Premiere/Cineform - and the very notable interlace artifacts are quite obvious in the fast moving train (an HO model, at a model railroad show). The second shot is with the Cineform Playback Settings set to de-interlace - if the video is exported through Cineform to 1080p video, the smearing and total loss of detail looks exactly like the still. The third shot is a 1440 x 1080 still export of an MPEG video file imported from the FX-1 by Premiere alone. This is the same kind of detail I have always seen previously in shooting train shows with Sony DV camcorders, and then editing the 720 x 480 in Premiere - until now, I had just never seen anything so bad as exhibited in that first Cineform grab.

I have been at this nightmare without a break today for almost 10 solid hours without a break (yes, that's since 5:30 this morning). And I have been running various permutations and combinations of settings and keep getting the same horrible results! The MPEG shot is what I have been accustomed to seeing with the several model rail shoots I've taken over the years, but as soon as I run that MPEG through Cineform, it turns into the same garbage as using Cineform alone.

Soooooooo, I guess I am really missing the boat somewhere - and that train show is for three (!) different customers who are waiting - they've seen some of my earlier DV rail work, and nothing smeared like this! I'd appreciate ANY suggestions about where I might be going wrong, just short of using interlaced cameras, which will be rectified shortly!

[David Newman]

Welcome to the hell that is interlaced. Firstly there is nothing wrong with all three, they are all display choices.

Image 1) A full resolution interlaced frame, showing both fields. This is the only truly correct full resolution image. As with all interlaced images you have to consider how you will be mastering it for final display. 60i "frames" look like this when frozen on display. NORMAL.

Image 2) De-interlaced by summing both fields in resolution friendly way. Provides more vertical resolution than de-interlacing a from single field, but introduced more motion blur. This is an esthetic choice. While the motion blur is obvious, notice the increased resolution (particularly on the tracks) as compared with image 3 what show stair stepping jaggies.

Image 3) De-interlaced from a single field. Only 540 lines are used, so the vertical resolution is the worst of the three (SD like.) Premieres default to this mode for frame grabs, although it is misleading as video exports will look different.

If you going out to HD 60i, then don't use 2, 1 & 3 will result in the same smooth 60i motion (if you are not de-interlacing within Premiere.) If you are going out HD 30p, you have to de-interlace somewhere. If you de-interlace on capture with CineForm, you get good resolution but more motion blur, if you de-interlace using the Premiere export option you will get image 3 (whether you are using a CineForm time for M2T timeline.) I happen to prefer the extra resolution with motion blur, than the reverse. If you are exporting to SD, I hate 60i SD, I would choice the de-interlacing style you want as SD resolution will not impacted either way.