Shirozina

Yes at around 5'36" he shows the effect of increasing ISO but says 'everything steps up' when he increases ISO but if you follow the scopes it's only the mid and shadows that increase and the highlights stay the same. Notice the highlights do move BUT the max IRE available at each ISO is not fixed and starts at about 80% at 100 iso (which will be normalised to 100IRE during grading) and increases up to 100% at 1000 ISO . His other tests are misleading as he's changing exposure to compensate for ISO changes which is not required as the digital ISO changes are a log curve adjustment where black and white points are fixed. This is certainly a different approach to ISO and shows the problem with the concept of ISO when applied to a LOG capture. ISO was and is a legacy from the days of film when the response curve of film was not log and the ISO was rated at a midpoint ( mid grey) along the middle flat part of the graph. With LOG the mid point is elevated and bears no relation to a mid point ISO hence why Native ISO for camera shooting LOG is always much higher than standard picture profiles.

Hum - beer......? If you need to retain highlights without clipping then first of all ETTR is naturally the best exposure method and if in addition to this you want a lot of tonal information in those highlight areas then a low ISO with it's flatter response curve allocates more data in the upper end of the response curve. DR remains the same so it's just about placing the most data where you want the most tonal detail and with the P4k once you have got an ETTR exposure just under clipping you can change the ISO and highlights will remain unclipped (as long as you use scopes and not the Zebras). On the other hand if you want to avoid clipping the clouds but want to show a lot of shadow detail then I'd be setting a high ISO that allocates more data in the lower levels and compresses the highlights into less data. With RAW it doesn't matter as long as you ETTR at native ISO but RAW is not truly RAW on the P4k as it still has a tonal response curve baked into the data so I'd still want to get this curve as close as possible in camera to the required output. Obviously for maximum DR I'd use the lower of the 2 native ISO ranges. I need to photograph a stepped density chart from black to white using the same exposure but different ISO to show the change in the response curves. Again I have to state that to do this properly you need to use scopes as ETTR with the Zebras away from 400 and 3200 doesn't appear to be very accurate.

Notice how the DR stays the same throughout the ISO ranges? This means BM is not varying the ISO like other cameras by digitally amplifying the whole signal but is altering the mid point in the response curve using a gamma like change. Cycle through the ISO at a constant exposure and see how the data moves on some scopes and you will understand. The above chart looks like they have made an exposure change for each ISO which is misleading. Look at any other camera DR vs ISO graph and the DR ramps down as ISO goes up just as in practice if you ETTR you need to change your exposure with ISO. Not so with the BM where the clipping point remains at the same exposure value throughout the ISO range.

Changing ISO on the P4K in ProRes just ramps up the log curve in the middle so midtones and shadows get boosted and the highlights get compressed. If you want lots of light tones in a high key scene and not much shadow detail drop the ISO right down and if you want lots of shadow detail and compressed highlights in a low key scene ramp the ISO up (withing the 2 ranges) Even with 10bit I wouldn't want to try to do the reverse in post for optimal results. BM say the 400/3200 are 'native' which means they are a good compromise for most scenes.

This is not true. The low ISO's compress the shadows and put more tonal data in the highlights and the higher ISO's expand the shadows and compress the highlights. This is clearly evident on the scopes of a monitor or in an NLE.

You certainly know how to teaze....... Don't regret buying the Ronin-s at it Xmas offer price and not sure how much better another gimball could be unless it had another 2 axis.

ETTR is just one among many exposure tools. It depends on the circumstances as to if it's the best tool. There are no scopes on the P4K and the zebras are not accurate and change with ISO so there is quite a bit of experience needed to get the best out of it in a contrasty lighting situation. As a result of some tests today I'd advise only using ISO 400-1000 and 3200-8000 in ProRes and be wary of what the zebras are telling you if you go off 400 or 3200 ISO.

Depends on what your subject matter is, what the contrast ratio of the scene is and what the DR and profile of your camera is. 'Middle grey' was a method for exposing for film stock.

It only describes exposure using the 'middle grey' method which may not be the best approach with this or any digital camera.

Using the scopes after a WB there is nothing to recover after ETTR. Using the onboard zebras set at 100% it’s the same but the red channel clips first so it’s best to set the zebras at 95% to give some headroom if the highlights are not WB’d. Neither the zebras on the Ninja V or the onboard ones are accurate IME (for various reasons) so unless you have a monitor with RGB parade scopes I’d suggest take care with ETTR via zebras and if in doubt under expose or set them at 95 or even 90% Seems though that once ETTR is set you could ‘ride’ the ISO 400-1000 to get the look in terms of a light or dark scene which is interesting but I need to test the noise to see if pushing 400ISO in post is the same as 1000 ISO in camera with the same scene and exposure.

There is no 'rolloff' when exposing for digital using ETTR.

The P4k does some strange things when you change ISO ( or perhaps perfectly logical things?). At 100 ISO the IRE % on my Ninja V scopes max out at 80% i.e no matter how bright the content of the frame the levels won't to push past 80%. This increases gradually up to 100% at 400 ISO. If you ETTR with the zebras anywhere between 100 and 1000 ISO the highlights remain the same and all that changes is the brightness of the shadows and midtones. If all the camera is doing is internally applying 'digital gain' when you change ISO then this is quite logical and between 400 and 1000 ISO you just use ISO like a 'brightness' adjustment which lifts the shadows and midtones but preserves the highlights.

Good advice for anyone who uses middle grey as an exposure method but using middle grey as and exposure method may not be good advice.....

I found reading the manual to be very helpful - all sorts of useful information in there.......

Looks a bit unsteady to me.

I've not noticed any issues wide open on the EF-M2 + 18-35 sigma on either my GH5 or P4k. I reckon the OP of that link had a bad sample or had not set it up correctly.

Especially if you have to rescue very underexposed footage

Both Neat image and Resolve Studio NR is very good for cleaning up high iso and slightly under exposed footage but it can't fix seriously underexposed footage which is what the OP will get with the GH5 + 12-60 in a very low light environment.

Game over BM....... Apart from the fact the P4k comes in at less than 1/2 the price of the Nikon / atomos.

The 18-35 may be a bit heavy. I do have that combo but haven't tried mounting it yet. It's not so much the total weight but the amount of mass away from the center that the motors may not be able to control as quickly as a lighter lens.

I got my Ronin-S direct from DJI for £500 when they were on offer a few weeks back. I assume these are Grey imports with no import duty or VAT to pay on the listed price?

Just a few tips - the P4k fits best on the Ronin -S without a cage and no way will the tilta's side mounted battery work unless you reverse the rig . On any gimbal the more weight and bulk you can take off the camera or keep at the center of the mass the better. Sony NP-F battery sled + dummy battery can be mounted on the Ronin grip. The P4k and Ronin-S is a great combo as the 5" screen means you don't need an ext monitor. Like I said earlier a P4k + Ronin-S still comes in cheaper than a GH5s......

I'd have to disagree Construction is fine for a camera at this price level. Absolutely love the control layout which is simply the best and most intuitive I have ever used. Form factor is great and fits on my Ronin-s without a problem and quite how you would fit a 5" screen into an XC10 style body is beyond me - really? As others have said it's form factor is decided by one of it's greatest features which is 5" screen I can see the voltage fine in my batteries both internal and external. Yes it needs batteries and a lot of batteries if you are going to drive a bright 5" screen. What do you suggest as an alternative - bigger batteries so you get an even bigger camera or a smaller screen? A hinged screen would I agree be nice but at what cost in size and price? Until someone does a teardown and we can see the cooling system which may well be for the screen this may be an impossibility without a significant cost and size increase.

Why so angry about camera you don't own and don't intend to own ?

There's not much stuff you need to buy. You don't need C-FAST as an ext 1tb drive is less than £200 and give you nearly 3 hours of 4k 24p - how much is 3 hrs of V90 cards ??? An external battery sled for a Sony NP-F is £30 and many already have these batteries. Anything else is not essential and is an optional add on for any camera. Did I not mention that you also get a free copy of Resolve studio with the P4k? :). You could add a gimbal or external recorder/monitor to a P4k and still come in cheaper than a GH5s. Now I'm not saying the Gh5s isn't a good camera and in some ways may be better for some users but it's not at all in the same price range.