What is the right focal length for video?

Hmm.. interesting observation Massimo. It hadn't occured to me that the fisheye distortion accentuates the WWL-1 diagonal FOV, but I see your point. Still, even if the horizontal field of view of the WWL-1 and 7-14 are roughly equivalent, the WWL-1 for sure produces much more usable results.

The perspective distortion with a rectilinear lens at 7-8 MM is very off-putting. 

Hmm.. interesting observation Massimo. It hadn't occured to me that the fisheye distortion accentuates the WWL-1 diagonal FOV, but I see your point. Still, even if the horizontal field of view of the WWL-1 and 7-14 are roughly equivalent, the WWL-1 for sure produces much more usable results.
 
The perspective distortion with a rectilinear lens at 7-8 MM is very off-putting. 

I haven't shot with a rectilinear lens like the 8-18 or 7-14 on the GH5, but my experiences with the 7-14 on the GH4 amounted to the pespcetive distortion being too great at the 7mm end.

On the other hand, now that I think back, I shot video with the 16-35mm on A7RII for a while with Nauticam 180mm dome and was overall fairly happy. Never experienced the severe pincushion perspective distortion you see with a 7 (14mm FF equivalent) lens. Now, if I read you article correctly Massimo, the horizontal angle of view of a 16mm (full frame) is more or less the same as the horizontal field of view of the WWL1 at the widest end, right? Maybe that suggests that this is the widest angle of view you can deploy for video before perspective distortion becomes too distracting.

I should play a bit more with my 9-18mm olympus lens with GH5 and 180mm dome. If the horizontal AoV is really quite close to the WWL-1 and the rectilinear percepective distortion is under control at 9mm, it does give some advantages over the WWL like being usable for split shots and better reach and IQ at the long end.

16-35 full frame or 8-18 is the limit for still images when it comes to distortion at least for me but is a tad narrower than the wwl-1 (94 vs 102) the frame however is taller and not distorted
The old school consensus when you shot a gates or similar was that 18 mm equivalent is the best because horizontally this is exactly 90 degrees and you never have corner distortion
If you have the 9-18mm olympus and the 180 mm dome try a shorter 50mm extension instead of the suggested 65 to avoid pull in corners


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Interceptor,

Did you ever shoot one of the PMW-EX1 or EX3  cams in a gates back in the day? Seems it wasn't that long ago that this was THE way to get the best quality underwater. Time moves on.

Interceptor,
Did you ever shoot one of the PMW-EX1 or EX3  cams in a gates back in the day? Seems it wasn't that long ago that this was THE way to get the best quality underwater. Time moves on.

Nice information there - thanks !

So what do you think about the P6K with the WACP port? Which Canon lens would be your go to in that scenario?

I know you dont like RAW but I am at the 180 degree opposite opinion to yours on this. I think RAW is the best thing sliced bread.

I've mentioned it before but I will say it again.....given all the time and cost that goes into a dive (I mean, honestly..what is the cost per dive when you add up all the gear you own and how quickly it dies and needs replacing if you dive often enough and even worse, if you dont dive much since it then cost so much more per dive if you used it little, plus the cost of travel and air fill's etc to get down to the site you are videoing ?) a bit of time correcting and tweaking images to be the best they can seems trivial to me.

To put this into perspective, I am currently building a new editing PC. Its been 10+ years since I built my last PC so its time to upgrade (yay!! i'll be able to keep 100 plus Chrome Tabs open at a time !). I am trying to get an AMD 3950X 16 core into the case I have along with a 2080Ti video card. With or without video editing this is the rig I will build. It will carry me for another 10 years (I hope). So for editing that 6K BRAW I will be in good shape. I already have a 4U SuperMicro server with 36 x 6TB HDD's in it for storing footage plus looking into getting an 48 tape LTO tape library for writing footage out to tape for long term archiving (not much difference in cost between a 48 tape library and a standalone LTO 8 tape drive, so may as well get the library machine). To give you an idea on cost of LTO 7 tapes formatted to LTO 8 the cost per TB is around $6.00. Yes, that is $6.00 per Terabyte. Not so heavy. The Tape Library is 6K so its an investment for sure but if you plan to shoot enough footage it pays over time. So the sheer amount of data generated by the P6K is not that big a deal to me.

What is a big deal is getting out to the dive site, gearing up and diving safely to get the shots. Not to mention that over time doing many dives the cost is quite large to do those dives.

So to me the cost of the camera rig seems to be the smaller part of it all.

So with all that gibberish out of the way, what would you say is the ideal setup for the P6K? Which lens with which port. Being able to zoom through from 10mm to 25mm seems ideal with the WACP, but is there another way to do this that you deem better?

@JohnDoe who said I do not like RAW? Unlike most people here in the video section I shoot stills maybe I am even a better photographer than I am a video guy listening to the feedback. I use RAW all the times with still images however my workflow for still images is not focused on white balance. In fact as a photographer you know that if you don't the colour right in the shot at least on a good part of your subject using a strobe or ambient light when you white balance it looks weird. In fact in most cases the reason why I white balance ambient light shots is because I did not white balance at time of shooting, then the white balance is right later corrections are minimal. What RAW gives you is the ability to exploit the dynamic range of the camera much more, underwater you tend to shoot underexposed according to the camera to avoid clipping highlights as camera metering fails in many situation due to blue water scattering light. So then you push up you darks and stretch the image to bring it back to the detail that seemed to be missing in the first place. After you get this right the next steps are local adjustments like graduated filters, brushes etc etc. Usually you spend much more time on local adjustments than you do on exposure. 

For video is a bit different as you are moving around in most cases and video tools do not offer the same ability to perform local adjustments. What you are left is exposure and white balance. For white balance what I said before holds if you use lights the adjustments are minor if you don't you need to adjust in camera. The other items is the ability to bring the dynamic range back into the picture that is probably the most important part however if you lock exposure this will only work well on a static scene. It is crucial for video to get the exposure right in camera and actually I am not a believer of fixed exposures. If you set a fixed exposure and you move around you have a risk of clipping the highlights or crushing the blacks here with a RAW editor you can recover to an extent. Otherwise you set a variable exposure for example set aperture and shutter and leave ISO float this will make sure you don't have huge variations reducing the need for the raw adjustment later.

It goes by itself that unless you have backlit scenes you can nail exposure and white balance in camera and in fact many of my still images have only local adjustments for things I could not fix in camera.

Regarding your question on the WACP it vignettes until 20mm so out of 18-55 you get 20-55 x 1.4 crop x 0.36 = 10-27 mm fisheye am not sure how useful is the range between 17-27 mm for you but the alternative is to forget the WACP entirely and go on Canon EF mount for APS-C

So instead of your WACP you could get

1. Sigma 17-70 mm (as this is cropped sensor I would not get the 8.5 acrylic dome and settle for the 180mm glass dome need to work out the extensions) this gives you 24-98 mm rectilinear which for most cases this is all you need

2. Tokina zoom fisheye 10-17 mm this gives you the same of WACP if you need more zoom you put a kenko teleconverter

With the WACP you still have to cover normal angles and macro so the cost of the set up above will be significantly less as the Tokina takes a compact acrylic port

I do not own this camera nor I plan to buy it however as I said before I would not be looking at the WACP personally if I had to

Interesting thoughts Interceptor. Good read as always from you. Thanks for your input.

1 hour ago, John Doe II said:

Interesting thoughts Interceptor. Good read as always from you. Thanks for your input.

Subscribe to my blog John there is plenty more stuff http://interceptor121.com

On 11/20/2019 at 12:03 PM, Interceptor121 said:

For video is a bit different as you are moving around in most cases and video tools do not offer the same ability to perform local adjustments. What you are left is exposure and white balance. For white balance what I said before holds if you use lights the adjustments are minor if you don't you need to adjust in camera. The other items is the ability to bring the dynamic range back into the picture that is probably the most important part however if you lock exposure this will only work well on a static scene. It is crucial for video to get the exposure right in camera and actually I am not a believer of fixed exposures. If you set a fixed exposure and you move around you have a risk of clipping the highlights or crushing the blacks here with a RAW editor you can recover to an extent. Otherwise you set a variable exposure for example set aperture and shutter and leave ISO float this will make sure you don't have huge variations reducing the need for the raw adjustment later.

Sorry to disagree but I do  Pretty much all tools available for photos are available for video you just need the right software and processing power. Is it more time consuming? Yes it is but you can do it.

As for the auto stuff it works much better if you just slow down a bit, plan what your shot is going to be and fix your exposure. If you are a bit out you fix it in post. Please note the word a bit. But if you plan it it will be a bit and not blown out which is usually the problem rather than be too dark. Otherwise get a go pro and shoot from the hip  (not you Interceptor its a generic coment)

1 minute ago, Lionfi2s said:

Sorry to disagree but I do  Pretty much all tools available for photos are available for video you just need the right software and processing power. Is it more time consuming? Yes it is but you can do it.

As for the auto stuff it works much better if you just slow down a bit, plan what your shot is going to be and fix your exposure. If you are a bit out you fix it in post. Please note the word a bit. But if you plan it it will be a bit and not blown out which is usually the problem rather than be too dark. Otherwise get a go pro and shoot from the hip  (not you Interceptor its a generic coment)

Pretty much does not mean same and moving around creates complexity.

But this is all academic as I have yet to see a single impressive clip shot with a camera with CinemaRaw or Blackmagic Raw underwater that has had all the adjustments done to it that looks amazing. I think there is a significant difference between a staged shot like a commercial film on land and shooting underwater

11 minutes ago, Interceptor121 said:

Pretty much does not mean same and moving around creates complexity.

But this is all academic as I have yet to see a single impressive clip shot with a camera with CinemaRaw or Blackmagic Raw underwater that has had all the adjustments done to it that looks amazing. I think there is a significant difference between a staged shot like a commercial film on land and shooting underwater

What local adjustment you can do in a photo that you cant do in video? Agreed on the complexity.

BMPCC 4K is not the best choice IMO for UW video that is why not so many people use it at the moment and so not many clips available. Video RAW codecs to consumer market is relatively new very few cameras offer it and very few people know how to properly exploit it. As time goes by and more cameras start to offer it people will use it learn it and get the benefits.

I am not talking about staging the shot I am talking about thinking the shot which doesnt take that long. Its the same with photo, you see the subject think the settings you ll use adjust and make the shot. Why acting differently when doing video? 

Thinking the shot is key of course.

Local adjustments I use regularly are:

Brush I can brush parts of the frame as I wish and then apply the whole set of exposure white balance sharpness etc to that area. I have not see this

Graduated filter: as above on a line with a gradient

Radial filter: I have seen this but is the least useful

Control points: click on a point and perform adjstments on similar pixels I have seen this but is not really useful

So I would say the key ones are the graduated filter and the brush those I can't find anywhere the others I can but they are not useful as the previous two

2 hours ago, Interceptor121 said:

Thinking the shot is key of course.

Local adjustments I use regularly are:

Brush I can brush parts of the frame as I wish and then apply the whole set of exposure white balance sharpness etc to that area. I have not see this

Graduated filter: as above on a line with a gradient

Radial filter: I have seen this but is the least useful

Control points: click on a point and perform adjstments on similar pixels I have seen this but is not really useful

So I would say the key ones are the graduated filter and the brush those I can't find anywhere the others I can but they are not useful as the previous two

You really need to start learning and using resolve (btw the new cut page is almost the same like FCPX so the editing is the same).

Graduated filter: available in the colour page with one click

Brush: create freeform windows and do changes isolating anything outside them. You can track the windows if there is movement

Radial filter: Same as graduated filter

Control points: lots of tools to do qualifications and perform the same.

What your brush example does is a mask and that is not useful a freehand brush is used to correct an area and stop the brush as you describe it is also available in FCPX and is useless. The other issue is that once you brushed your object it moves in the frame 

Same issue with graduated filter if you change the angle it moves

At the end you frame the shot correctly and expose you avoid most of those. When you shoot stills instead you push the camera as you have more selective controls see above

I would like so see something done in resolve that explains me the benefits above and then understand how long it takes to achieve them

26 minutes ago, Interceptor121 said:

What your brush example does is a mask and that is not useful a freehand brush is used to correct an area and stop the brush as you describe it is also available in FCPX and is useless. The other issue is that once you brushed your object it moves in the frame 

Same issue with graduated filter if you change the angle it moves

At the end you frame the shot correctly and expose you avoid most of those. When you shoot stills instead you push the camera as you have more selective controls see above

I would like so see something done in resolve that explains me the benefits above and then understand how long it takes to achieve them

Re brush and graduated filter use tracking it will follow whatever you want to follow you can do it manually too but the its rotoscoping and we are talking vfx which you can do in fusion or after affects. You can also assign keyframes. The tools are there but it takes time to learn them I agree.

Agreed that your best strategy is to think the shot and expose it correctly.

Why so you all think the P4K is not so good for underwater? 12 Bit RAW. Whats not to love? P6K even bettter - room to reframe and stabilize shots. Whats not great about that?

I understand if you have a GH5 and sunk a ton of $$$ into that rig that you may say there is no huge LEAP above what the GH5 can do so you will pass on the p4k. I get that. But why do you say its not that great underwater? Its surely no worse than the GH5.

If only you will bite the bullet Interceptor and get into a P6K rig..........

15 minutes ago, John Doe II said:

Why so you all think the P4K is not so good for underwater? 12 Bit RAW. Whats not to love? P6K even bettter - room to reframe and stabilize shots. Whats not great about that?

I understand if you have a GH5 and sunk a ton of $$$ into that rig that you may say there is no huge LEAP above what the GH5 can do so you will pass on the p4k. I get that. But why do you say its not that great underwater? Its surely no worse than the GH5.

If only you will bite the bullet Interceptor and get into a P6K rig..........

John I take stills not just video and I think the video I shoot has margin for improvement to do with my skills. I don't feel like my clips need more technological power I just need to shoot better videos

In terms of suitability people that shoot on land (check out wolfcrow) say after using it that the BMPC4/6K are not suited for documentaries but for small commercial projects and studio work which is not the underwater environment I dive in so I think even if I had the money (and I do) I would not buy it. Right now am just starting to understand the capabilities of AVCI 400 mbps and they are significant I do not think I am missing anything for the little I do

When I compare my clips with others including pros is not the image quality that is lacking but my storytelling ability 

...and THAT is the crux of it...the story telling. Have a compelling story to tell and no cares what you shot it on. 

Having said that, nice tools do help. If we can get a bit more dynamic range, more bit depth so that we can change from one colour into another with no banding etc. A lot of this has already been achieved. It's no longer the HUGE leap forward. Now its tiny steps forward.

While I get your point entirely, wouldnt be able to reframe with oodles of room to spare help you tell a better story? Wouldn't being able to zoom in on something much tighter then you originally shot it help with accentuating a part of the story you are trying convey? (in post I mean, because you have all that extra res the 6K gives you...especially if you are delivering a 1080p deliverable)

Sure you can do all this manually by just shooting it right......while underwater you manage all the other things that your life really do depend on down there. Your workload down there is high. Years of experience helps one manage all this, but surely it is nice to be able to zoom in without losing res to get closer to that shy animal or reframe a shot (in post) because you got it ever so slightly wrong (while 40 metres down) etc.The P6K allows all this. Its no panacea to the perfect clip by any means - just more useful and nice to have tools that help out along the way. 

At the end of the day its mostly about the skill of the shooter. But those tools can help polish things even tighter. And that is my point.

I just bought a new boat and outboard and that has dented the account balance somewhat. Next problem is, on my beach it is so rocky that I cant actually pull the boat up onto my beach. So now i have to build a jetty. It never ends. I just bought a D800 rig, so going to console myself with that for a while, but I have every intention of getting into the P6k in a Naughty cam. I just dont see the value in a Red costing 10x more. Underwater we have natures thick filter holding back the best of glass. Water. 800 times denser then air. What a damm filter we have to deal with! By time I get the jetty done and I can actually use my boat and get out to my dive spots maybe the P8K will be here....who knows? But I can say BlackMagic have surely opened pandora's box to allowing the average man to access higher bit depth RAW. 

Who knows what the GH6 wil be? Its a fast moving target for sure.