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peterbkk

Member Since 25 May 2005
Offline Last Active Yesterday, 01:25 AM
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Posts I've Made

In Topic: Panasonic GH4 might get a V-log profile?

20 February 2015 - 02:33 AM

As always it is a personal and creative choice but I never use red filters underwater.

Red filter only have any benefit in certain situations and they add a bunch of complications to an already complex process. Too shallow and they make the footage too red. Too deep and they remove too much light (remember that the filter removes blue and green but does not add red). If you leave it on in the wrong light situation, you will have some difficult footage to grade. Even if you do get the on-off timing right, the footage either side of the transition is difficult to color match. If you pan up, all the highlights will have a red tinge.

And why bother with that complication when the GH4 has a more viable solution: the 4 WB presets. Fill these up BEFORE you go diving and flip between them, depending on the ambient light color. I wrote an earlier post on how to do this. Just take a WB setting off four pieces of coloured paper in sunlight, save them in the presets and remember which preset is for which lighting condition. Save that with your other favorite settings in a Custom Setting so you can get back to them quickly if you ever decided to play with MWB while diving. I keep it simple: 1. shallow to mid tropical blue water, 2. mid to deep tropical blue water, 3. shallow to mid greenish water and 4. mid to deep greenish water. These get you very close to a good WB that can be tweaked in the edit. And it doesn't rob you of an f-stop or two.

Regards
Peter

In Topic: Panasonic GH4 might get a V-log profile?

16 February 2015 - 09:49 PM

If your white balance is a bit off, do you still use it as it, or you would attempt to color grade it?

 

I use a fairly flat profile in the GH4.

 

In FCPX, I've set up and saved a few colour grading presets:

- Increase contrast

- Reduce Green a little

- Reduce Green a lot

- Increase Blue a little

- Increase Blue a lot

- Warm up slightly

 

These seem to work on 95% of all footage.

 

Regards

Peter


In Topic: Just Keep Swimming!

09 February 2015 - 08:19 PM

Fun.


In Topic: Upcoming Panasonic GH-4K

05 February 2015 - 05:20 PM

Thanks for the info Peter, I'll certainly see if I can replicate it.  I haven't witnessed it in my own use.


If Keldan lights are used in the normal "car headlights" approach to underwater lighting or even with both lights providing front lighting from a distance, this issue will never arise. But I like playing with different lighting positions (hence my preference for locline arms). One or two of my favorite lighting positions puts one light close enough to the subject that light from the main light can bounce off the side of the close-in light unit. Painting the Keldans black solves the problem.

I suspect that there's a good explanation why Keldan uses that purple colour (daughter's favorite color, maybe) but there's a good reason why professional camera equipment is black or neutral so as to avoid the possibility of introducing stray colours.

Regards
Peter

In Topic: Upcoming Panasonic GH-4K

05 February 2015 - 07:27 AM

 
RE: purple reflections in macro video from Keldan lights, I call bs on that one.   I'm willing to be proven wrong if anyone could demonstrate the phenomenon...
 

When I first bought the Keldan lights a couple of years ago, I did some pool tests. One test was shooting a macro subject with a classic cine lighting setup - one that I like to use to separate the subject from the background. The prime light is up high and back to the left at about a 45 degree angle, mimicking a diffuse mid-morning sun angle. The secondary light comes in from close on the right and slightly behind the subject, creating a rim-light on the subject. This light is on low power, in close to the subject to minimise the light spread, with the light head just outside the frame.

In the test, I could clearly see a purplish sheen on the side of the subject as the brighter prime light from above bounced off the angled side of the rim light. I don't have the test footage but you could easily replicate the test if you do not believe me.

So I got a couple of those car "touch up" pens and painted the Keldans matt black. Problem solved.

Regards
Peter