When you think of a 35mm sensor camera, what characteristics come to mind? Probably the first is shallow depth of field. It is part of what many consider the “look” of that imager size and a principle defining difference between it and other formats. But while some consider this the chief attribute of the format, others may find it to be a detriment in certain situations. For those shooting documentary, run-and-gun productions, a deeper depth of field may be preferable to maintain focus. Fortunately, there is another major facet to the latest crop of 35mm sensor cameras – a very low noise floor. This means that in a camera such as the Canon C300, a wide range of ISO settings can be applied with little objectionable artifacting to the image. Using the concept of the “variable depth of field camera,” you can adjust the available parameters of the camera to yield the depth of field desired for any given image. Watch the video to see this concept demonstrated.

I often get asked about the stuttering video motion, or judder, seen in 24p video. Even though we have all been watching or shooting 24p for years, for many of us it is new to see true 24p (or 23.98p) video displayed on a monitor.

24p is ‘jumpy’ by its nature, but the look of 24p video in a digital video camera can still come across a little more ‘jumpy’ then you’d expect. There are several reasons for this, which I explain in article for HDVideoPro magazine called “Did I Judder.” As part of the article, I put together these two videos to show the difference between native 24p video and 24p converted to 60i. I did this because much of the 24p content we see has been converted to 60i already, which has a smoothing effect that is very noticeable on television.

…continue reading 24p Judder and 60i Conversion

DVCPRO HD vs. AVC-Intra

In my last entry, I discussed the 3-way trade off between quality, size and complexity in codecs. Panasonic’s move from DVCPRO HD to AVC-Intra in their latest generation of P2 cameras provides an excellent example of a trade off between quality and complexity, as both codecs record at the same bit rate of 100mb/sec (at 30fps). How much better is AVC-Intra? To start off with, it preserves a lot more image information than DVCPRO HD. It records full raster (1920×1080, when recording 1080p) 4:2:2 at 10 bits per channel compared to 1280×1080 4:2:2 at 8 bits per channel, which means it’s starting out with almost double the data. Here’s a comparison of a frame of each (the same difference frames we looked at last time).

…continue reading Image Evaluation Series: Compression (Pt. 2)

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Setting the correct depth on the lens mount of Digital Cinema cameras is a critical and precise task. The new Red Null tool makes the process quick and easy. Everybody should have one in their kit. Watch the video to see how it works and how simple it is to use.

For more information, visit ibe-optics.com.

For pretty much any film or video project you might work on these days, you’ll spend at least part of the time dealing with compressed material. In order to decide which codec to use, you need to keep in mind what purpose you are using it for and how a particular codec fulfills that purpose. In this entry, I’ll explain some of the techniques I use for evaluating codecs. In later entries I’ll cover some more specific results.

…continue reading Image Evaluation Series: Compression (Pt. 1)

One of my tasks here at Abel is to evaluate new technologies and products so that we can better understand them and better advise our clients. This is the first entry in a series meant to give some insight into how I go about these evaluations. I’ll be concentrating on the process, not the results. Also, I am constantly improving and expanding on my testing techniques, so these will be snapshots into evolving processes. If you will be at NAB this year, feel free to stop by our booth to discuss any of this in person, or if not, make an appointment to see me some time in the office.

…continue reading Image Evaluation Series: Introduction