Rolling Shutter

For the past weeks I've been looking at the new Nikon D3100[a] DSLR as an upgrade for my Nikon D40[b]. The D40 isn't bad in any way - quite the opposite. When it was released in 2006 someone at the market segmentation department at Nikon must've been asleep, because the D40 ended up a mid-level camera sold at an entry-level price. Four years later it survived the D40x, the D60 and the D3000, all intended to replace it.

But with the D3100 Nikon seems to have sneaked one past the market segmentation department again. The big gain for me is the video ability. Lately I've been experimenting with video, and I'd love to play around with the added abilities one gets from using a video-capable DSLR.

However, if one reads the forums, the D3100 is utterly worthless, because it has a rolling shutter[c]. This causes the image to skew during panning[d].

dirkluchtman wrote:

I am also deciding between the D3100 and T2i, but early videosamples of the D3100 are putting me off somewhat. Check out some videos on vimeo.com and you will see a strong jello effect with the D3100. EG: http://www.vimeo.com/15146964[e]

As you can see, the slightest movement causes the infamous jello-effect.

Thanks for the heads up. I didn't realized the rolling shutter jello effect were this bad. My fascination for d3100 is cooling off some what.

— 007peter[f]

But how representative are those videos that show the rolling shutter? After all, it is easy to get bad footage from a camera - all you have to do is to use it wrong. If you intend to get pro-quality results, you must handle the tool like a pro. In The Great Camera Shootout 2010 - Film Vs DSLR Comparison[g], you repeatedly hear the judges comment that knowing this, you can shoot accordingly or that's what you can work around. Professionals know the limitations of the tools and know to avoid situations where they would impact the quality of the product. The difference is mostly in how much work one has to put in in order to work around the problem.​[1] Is the rolling shutter something I should worry about, or is it just the usual lamentations from people who are stuck chasing magic bullets[i]? It took some time, but I finally found a thread named D3100 and rolling shutter[j] on the Fred Miranda[k] forums, and it had a post that really put things in perspective:

It's a large CMOS sensor, so with improper technique, it WILL exhibit rolling shutter. It remains to be seen how much is present... the camera hasn't even shipped yet!

FYI, the American Society of Cinematographers recommends that for a camera with an effective 28mm angle of view on 16x9 format (i.e. 18mm on DX or Super35 film), an object should take 15 seconds to cross the frame from side to side to prevent rolling shutter or motion strobing at 24 frames per second.

— Jason Callen[l]

American Society of Cinematographers recommends (...) 15 seconds to cross the frame from side to side, huh? Look at a Youtube "test of rolling shutter" video: Nikon D3100 - cinematic video test, Full HD[m]. Fifteen seconds to cross the frame? Jason Callen goes on to note that:

Rolling shutter is an issue inherent to CMOS chips in general, not just Nikon. My $5000 dedicated video cameras at work have the same issue!

— Jason Callen[n]

CMOS chips are used in Panasonic's 3MOS cameras, for example.

So what is one to do? The video Working with 3MOS Imagers[o] by Jan Livingston has a lot of good points:

Finally, Jason Callen gives a 5 minute film school class[p], making some very good points in regards to the recommended speed of panning.

Footnotes