15 replies to this topic

[liquidguru]

Thought I share this great sequence from this week. These stunning orange nudibranchs harbor an evil secret....they eat other nudibranchs alive!!!

While most other nudis munch on algae, hydroids and other such stuff, these ones make a meal out of other nudis. They find the slime trail left by another nudi then follow it from behind, catch it's tail in their mouth then proceed to swallow it's entire prey whole.

It was quite fascinating to watch. The entire process took about 16 minutes. At the end of the video I have sped up the entire clip into 30 seconds, so you can (quickly) watch the whole process there.

[vimeohd]41670230[/vimeohd]

Edited by liquidguru, 06 May 2012 - 09:47 PM.

[ATJ]

Very cool sequence.

(Note it is no more a cannibal than a lion eating a wildebeest.)

[Pete L]

Wow, that is amazing to watch. A little sad but unbelievable.
Was it shot with natural light?
Cheers Pete.

[liquidguru]

Very cool sequence.

(Note it is no more a cannibal than a lion eating a wildebeest.)

True, though maybe more like a lion eating a house cat, as it's a Gymnodoris eating a Hypselodoris

Wow, that is amazing to watch. A little sad but unbelievable.
Was it shot with natural light?
Cheers Pete.

No, filmed with my Sola 4000s, though I've started to turn down the exposure when shooting, as it seems to make things look a lot better, helps stop the whites flaring and keeps the green Sony shadows to a minimum. It was shot at about 14m deep, shitty (normal) Lembeh vis of about 6m.

Kaj

[Pete L]

Wow Kaj, you got the lights spot on i think.
Looks great. I find it very hard to shoot white nudis with lights.
Cheers Pete.

[liquidguru]

Thanks Pete,

I have found that, for macro work, once you've setup your lights and white balanced, I then go into the camera settings, to the exposure setting, and knock it down a couple of steps. It has been making a huge difference.

Here's a clip from last week, of another nudi, this time eating a shrimp. This was taken in very tricky light conditions, about 5m, sunlight coming through the water surface, light coloured muck on the sand, but it came out very very well by knocking the exposure down. I highly recommend this when using Sony camcorders. I now need to re-film everything from the last two years!!!

These large nudibranchs are carnivorous and have a great way of feeding.
They throw their 'head', an oval veil, in front of them, and using hairs around the edge, attempt to scoop up whatever they can find, usually small Crustacea.
You can watch this Melibe moving around, searching for food. About 2/3 of the way through you can see the Melibe captures a small shrimp in it's mouth and then holds it shut until the shrimp is, presumably, devoured!

[vimeohd]41231238[/vimeohd]

[Pete L]

Another great clip Kaj, love it.
It's funny you mention the exposure settings, it's something that i learned about over the weekend. I havn't had a chance to put it into practice yet but i will try & get in the water this weekend & play with that.
Cheers Pete.

[RWBrooks]

Very nice, if somewhat gruesome!
Like Blueface said, good lighting.

[peterbkk]

Thought I share this great sequence from this week. These stunning orange nudibranchs harbor an evil secret....they eat other nudibranchs alive!!!
While most other nudis munch on algae, hydroids and other such stuff, these ones make a meal out of other nudis. They find the slime trail left by another nudi then follow it from behind, catch it's tail in their mouth then proceed to swallow it's entire prey whole.

I think that I would have been tempted to intervene and save the poor little fellow from the big fat bully...

[Steve Douglas]

What a great behavior shot from beginning to end. I wonder if using optical flow would have smoothed out the last sped up sequence. Congrats for staying with it from beginning to end and recognizing the behavior from the beginning. Many might have moved on because it took so long.
Steve

[Nick Hope]

Yum yum, I've always thought those Hypselodoris zephyra look tasty.

Interesting clips, and I agree that the lighting/exposure has improved.

[liquidguru]

Thanks for the kind words.

Nick, yes, since you pointed out of inconstancy in my lighting I've worked hard to try to work out a better system with the equipment I have Thank you for your criticism, made me get less lazy!!

Steve, how does optical flow work? I was, as ever, in a hurry to edit, but would be interested in knowing how I could make it look smoother.

Peter and RW, I did feel sorry for the little guy but also was just in awe of how the Red Bumpy could fit the entire nudi inside it's body!!

BFM, good luck!!

Kaj

Edited by liquidguru, 08 May 2012 - 03:09 PM.

[Drew]

Optical flow is just basically image stabilization in post. Only issues are that it'll crop and uprez to fit 1080, and depending on the amount of correction, the resolution can change noticeably. It also occasionally "misinterprets" water movement and irregular panning as camera movement. If you have the time to fiddle with settings and the extra rendering, you'll find it can stabilize quite a bit without too much degradation.

[liquidguru]

Thanks Drew. I'll look into when I can find more time...

[Steve Douglas]

However, Optical Flow, at least in FCP, does not uprez as Drew said, nor is it a stabilization plug in. Optical Flow smooths things out, whether for slow for fast motion, because it creates new frames in-between current ones rather than duplicating or blending them together which can cause the jerky stutter you see when you sped the sequence up.

Not every NLE has optical flow. In Final Cut Pro, I have never had the Optical Flow issues that Drew mentioned. All stabilization plug ins whether from Red Giant, CHV, Boris, Digital Anarchy or Apple work by rescaling which, as Drew mentions, and dependent upon how much stabilization is needed, works by upscaling. Upscaling more than 103% can reduce resolution. Just note that a stabilization plug in is a whole different thing from Optical Flow.

Steve

[Nick Hope]

Premiere Pro can now use optical flow technology for speed changes, as AE could before it. Other plug-ins/programs that use it are Twixtor and Speedo (which might still be in beta or not even released). I use MVtools2 in AviSynth, which does the same thing for free, but is a little more complicated because all the settings are in text scripts. A new AviSynth plugin by SVP appeared recently, taking forward what MVtools achieved, but mainly aimed for realtime interpolation of frames. These plugins are great for slomo, but I'm not sure if they would improve that degree of speed-up much. Never tried it for that personally.