Letus Extreme - first footage, and a problem...

lovetrumpsfear

lovetrumpsfear

Active member
Hi all!

Got my Extreme in a week ago, and to break it in I helped my roommate shoot a short film for an intro cinema class. Here it is:

http://bedouinsinternational.org/letus_test/LostCar_web.mov

Please be gentle. I'm shooting on an hv20 without a monitor, so focus is a problem, and I'm pretty sure I forgot to turn the Letus on in at least one scene. ^_^ But all in all, I was really impressed with the Letus, in construction, ease of use, and picture quality.

Now, my problem: in several scenes, but most noticeable at 1:30 and 2:10, there is a pronounced "waving" or "wobbling" in the picture, that seems to travel upward through the frame. Can anyone think of why this would be happening? I'm pretty new to this, so my best (uneducated) guess would be something to do with shutter speed..?

I'd really appreciate any input the pros on the board could throw my way.

Thanks!

Paul Bryant
 
It is the rolling shutter in your HV-20. There is nothing you can do, that's how CMOS cameras with rolling shutters resolve straight lines with motion. The Sony EX-1 and the RED do basically the same thing to varying degrees.

Buy a non-rolling shutter camera and you will not have those issues.

Dan
 
RE: rolling shutter

RE: rolling shutter

Thanks for your feedback!

I didn't know that about CMOS sensors, and now I've done a little research... I learn something every day from these boards. ^_^ From what I can tell, the artifacts usually caused by the rolling shutter are of the sort shown in the geometric distortion of the buildings during the whip pan at 2:49. It might be a different manifestation of the same problem, but what I'm referring to is the pronounced waving of the doorframe behind my actor at 1:35. There's no camera or subject movement, and it's just dancing away...

Thanks again!

Paul
 
lovetrumpsfear said:
I'm referring to is the pronounced waving of the doorframe behind my actor at 1:35. There's no camera or subject movement, and it's just dancing away...
Click to expand...

Could it be that the whole wall of glass is moving because the door is being shut?

Nice footage! I liked the laugh track at the end :)

Sami
 
lovetrumpsfear said:
Thanks for your feedback!

I didn't know that about CMOS sensors, and now I've done a little research... I learn something every day from these boards. ^_^ From what I can tell, the artifacts usually caused by the rolling shutter are of the sort shown in the geometric distortion of the buildings during the whip pan at 2:49. It might be a different manifestation of the same problem, but what I'm referring to is the pronounced waving of the doorframe behind my actor at 1:35. There's no camera or subject movement, and it's just dancing away...

Thanks again!

Paul
Click to expand...

Hi Paul:

To be clear, it's not a problem with the CMOS sensor itself, it's an issue with how the shutter is implemented with the CMOS sensor.

Now that you pointed it out, I see that bizzare rolling of the window and door. I don't think it could be the door itself bending like, I assume the frame was made out of metal? Frankly, I have no idea what could be causing that, it's very strange looking and I have never seen anything like that. From what I know, roling shutter artifacts manifest themselves when the object being photographed and or the camera itself are moving. In this shot, neither appear to be moving, except the door a little bit when it is closed. Very strange!

Yes, the pan on the building was what I was noticing right off, definite rolling shutter artifacting.

Hope you get it figured out, its a very weird effect. Just took another look, I even see it, albeit less of it, in the shot that follows. Look at the risers on the parking meters, they are doing it too, a little bit. Weird.

Best,

Dan
 
Last edited:
the 'strobing' from the shutter angle is just another bonus the hv20 gives us, added with the look of a 35mm adapter, so we really can replicatate film cameras :)
 
That door wobble is quite trippy. Definitely seems like some kind of sensor related artifact. The fact that it oscillates makes me wonder if it's the sensor artifact combined with GG vibration. Wonder what Barry has to say? Couldn't find it on any other vertical lines in static shots. Also, the door is significantly brighter. See if you can duplicate it with any hot bright verticals.
 
You must log in or register to reply here.
Back
Top