Shutter Speed and ND Filters

[TSV]

Hi everyone, me again.

I have another question for you guys... I need your advice to better improve my videos. I have this rule of thumb on my GH4 
F 4.5 (The sharpest aperture on the Lumix X12-35), Shutter Speed 60 and ISO 200. With these settings I have, normally, the best result when shooting 4k at 29.97. Now, unfortunately when shooting outside it is really difficult to stick to these settings so I bought a pair of ND Filters from Kenko ND4/8/16 and a Zeta EX PL polarized.

So here you are my questions.

1.  Is my rule of thumb above good? I am playing depending of the lighting between the aperture 2.8 and 8 (After 8 there is too much diffraction to be used in 4K).
2. Is using an ND Filter the good solution when there is too much sun? Any other advise?
3. When there are no fast moving elements I tweak the shutter speed down to 30 or up to 500 (or more), is this advised?
4. Everything that I have read/watched on taking video with shutter speed is to go 180deg, when you shoot at 30p set your shutter speed at 60, but will setting around 120 or 240 will offer the same result?
5. Finally, I like the polarized filter, BUT it give a brownish look to my shoots, how can I overcome this on the camera? is Post prod the only way? Is there some kind of magic trick or filter I should use on FCPx?

Again, sorry for my questions, I am just looking for a way to improve my videos and become one day as good as you guys.

Cheers

[leeys]

1. Yes
2. Yes - might need to stack in your case
3. Nope
4. Nope
5. Try another CPL that doesn't give a tint, or save a custom WB when you use the CPL

[Liam]

Don't feel bad for asking questions

A lot of people, Andrew included, have had good results cheating a bit with shutter speed for exposure. Don't go crazy with it. Definitely less movement is better. faster could be better than slower, if you're breaking the 180degree rule. 120 and 240 won't look the same as 60.

I'd think you at least have iso 400 as well if you want it, which could help, especially if your nd's aren't variable (which could be a good option too, but variable nd's have issues in specific situations and get pricey) - but if you've tested and decided against iso400, you know better

[TSV]

1. Yes
2. Yes - might need to stack in your case
3. Nope
4. Nope
5. Try another CPL that doesn't give a tint, or save a custom WB when you use the CPL

​Thanks! Any ideas on brand and model another CPL? As for the WB I tried but I was not successful, ok I was in rush that day, I will give it another try and see. 

 

Don't feel bad for asking questions

A lot of people, Andrew included, have had good results cheating a bit with shutter speed for exposure. Don't go crazy with it. Definitely less movement is better. faster could be better than slower, if you're breaking the 180degree rule. 120 and 240 won't look the same as 60.

I'd think you at least have iso 400 as well if you want it, which could help, especially if your nd's aren't variable (which could be a good option too, but variable nd's have issues in specific situations and get pricey) - but if you've tested and decided against iso400, you know better

Thanks! ISO 400 is acceptable indeed, and I have room between 200 and 400 on the GH4... I really play with ISO as a last resort kind of thing...  

[leeys]

Mmm, I use Nikon CPLs in my film days (film has no WB), so you might give that a try, but try WB first.

[M Carter]

ISO is really down to the sweet-spot range of a given camera/sensor... and for more range, testing with something like Neat Video to see how far you can push things and get natural cleaned-up footage.

But you mentioned shooting at 29.97 - I've never been happy with that look, though it's a YMMV thing.

I've never seen a tint from any CPL I've owned, even Tiffens, etc - lately it's those cheap-ish Marumis, which are great. The red-brown sounds more like IR contamination, though I haven't heard of that being an issue with the GH4.

Trying to gain a half stop with shutter speed has always burned me... I really see the extra blur and would rather push ISO when needed. But I have quite a pile of lighting and haven't messed with that for years. For slowmo, increasing your shutter speed will help keep motion blur consistent. I know there are tables on line with suggested shutter speeds for various frame rates, to date I only own cameras that do 60p - on a 24p timeline, I tend to use 100th to 120th for 60p.

[Guest Ebrahim Saadawi]

I don't know why but it NEVER bothered me to change exposure with shutter speed, and clienta never ever ever noticed even filmmakers on huge productions. Really, in lowlight I ALWAYS use a 360° shutter (1/24s) to get the most light into the sensor, and in the same project in an outdoor scene 1/500s, no problem, motion is fine. I just have this weird despise for putting anything in front of my lens. 

Also worth mentioning, I have noticed that some cameras really look choppy when used at high shutter speed so you can't cheat as much as I do on the Canon/Nikon SLRs, one worthy of notion, the C100 and C300, a lower shutter angle really does affevt the image. It's really strange how different cameras can render motion differently, puzzling, it may be related to what people call 'motion cadence''. 

[Damphousse]

1. Finally, I like the polarized filter, BUT it give a brownish look to my shoots, how can I overcome this on the camera? is Post prod the only way? Is there some kind of magic trick or filter I should use on FCPx?

 

​Polarizers can do that.  Honestly the simplest thing for you to do is use 1/60th of a second shutter speed when you are using 29.97 fps.  Just set it there and leave it.  The next thing you have to do is get some good ND filters.  You can go with the variable ND like the Tiffen variable ND.  It is convenient.  Anything you put in front of your lens has the potential to affect quality.  You absolutely must read reviews and/or try before you buy or you could very well have issues.  Also I don't know how much IR pollution is a problem on the GH4.  On the BMPCC it is a big issue so in addition to an ND filter I also use a UV IR cut filter.

 

To get an idea of some issues with variable NDs check out Dave Dugdale's review.  Variable NDs are basically two polarizers stuck together so the issues you see with a polarizer you will see with a variable ND.  I am not familiar with Kenko.  For the BMPCC Hoya PRONDs are what is suggested along with a Hoya UV IR cut filter.  That is pretty much the gold standard for that camera.  Variable NDs are a step down.

[TSV]

Thank you every one!!! And thanks @Damphousse for the video I will check this now.