GH4 Latest Gh4 Experiments and the Myth of iDynamic

iDynamic is like a automated highlight/shadow recovery system. Nikon calls it D-lighting, and the other camera companies have their own versions. Usually it looks **** anyway so it's always off for me.
 
Nice work, your hands-on conclusions confirm my expectations of how the GH4 would perform, based on my experience with the GH2 and AF100. I'd also agree that the Natural profile looks good in well-exposed daylight scenes, while Cine-D is better for nighttime and controlled-lighting situations.
 
I agree with 2/3rds of your conclusions:

1. Natural produces better colors than Cine-D.

2. Raising ISO is better than not raising ISO and trying to boost in post.

However, i.Dynamic doesn't add noise to your picture any more than adding Shadows +5 or whatever adds noise to your picture. It just reveals the noise that is already present.

All i.Dynamic does is actually do a more linear tone curve (which exposes the GH4's noise). It is not doing any funky processing.

The trick is: if you are using i.Dynamic, don't get over-confident and underexpose. You're not going to magically gain an extra stop in the shadows.

Bruce Allen
www.boacinema.com
 
I also think "natural" profile is the best because it doesn't have as much "coloring weirdness" in the highlights.
I'm also finding the only way to get a real nice highlight rolloff on this camera is to set contrast to full +5 and boost the highlight curve +5

Now I think skin tones are looking good especially if approaching overexposure.

As a result the overall picture is too contrasty (low dr), I open up the shadows using +5 shadow curve and idynamic full and master pedestal +15 picture is looking noisy even at iso200 but I'm really liking it as a graded in-camera look.. in post do film colors only (no contrast or curves levels adjustment) and slight denoise and regrain (will try post tests soon)

So I guess it's very similar to James martins approach except instead of cine V with bad highlights rather use natural profile with full contrast.. then raise all the shadows, etc.

If a scene is flat and doesn't need boosted DR I'll take the idynamic setting off completely, infact I try not to use idynamic if possible but I like extended dr even if it means denoising a bit.
 
bruceallen said:
i.Dynamic doesn't add noise to your picture any more than adding Shadows +5 or whatever adds noise to your picture. It just reveals the noise that is already present.
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Okay. I think that's fairly equivalent. It's a given that noise is always present, and that lifting it into a more visible part of the curve will make it more visible to the eye. To me, that's the same as adding noise. But, in the interest of clarity, you are correct. :-)
 
Nicholas Christopher said:
I'm also finding the only way to get a real nice highlight rolloff on this camera is to set contrast to full +5 and boost the highlight curve +5

As a result the overall picture is too contrasty (low dr), I open up the shadows using +5 shadow curve and idynamic full and master pedestal +15 picture is looking noisy even at iso200 but I'm really liking it as a graded in-camera look.. in post do film colors only (no contrast or curves levels adjustment) and slight denoise and regrain (will try post tests soon)
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Nicholas, if you do a test with the settings you described, I encourage you to try a second test with these settings:
Profile: Natural
Contrast:0
Highlights:0
Shadows: 0
Master Ped: 0
iDynamic: off

What you'll end up with might be similar to your proposed settings, but be about 3 stops less noisy, and with way, way more dynamic range in the highlights.
Your settings are jamming the GH4 in a direction that is really noisy and low DR. By cranking the contrast to full AND lifting BOTH shadows and highlights to +5, you are basically just raising the ISO very high and lowering the dynamic range of the camera.

Let me know your results.
 
I see what you saying thanks for that.. infact I'm even liking natural with -5 contrast with no shadow boosting of any sort.
I'm still holding on to my highlight +5 curve for the rolloff tho - makes overexposure pretty like a film camera. I don't wanna be forced to shoot in flat shady scenes like the old digital camera days.. I wanna paint with light like a film camera.. which is why I won't use cine D anymore.. I've noticed a modern trend amongst images lately that have a flat image with abrupt highlight clipping it's awful. I'm finding that cine D needs lots of grading in post to correct the image that still suffers from weird highlights.
 
I agree the thing that I like least about the gh4 is the harsh highlight rolloff. And reducing the highlights curve makes the rolloff harsher. But pushing the curve reduces the dynamic range in the highlights. This camera really needs a wide-dr curve.
 
AlexLeith said:
I agree the thing that I like least about the gh4 is the harsh highlight rolloff. And reducing the highlights curve makes the rolloff harsher. But pushing the curve reduces the dynamic range in the highlights. This camera really needs a wide-dr curve.
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I own a C300 and C100 and while I admit the GH4 has slightly less DR than those cameras, I don't think its highlight rolloff is that bad. It just has less DR in the highlights overall. But it does roll to clip decently. And I'm a stickler for that.
 
SuperSet said:
dvbrother - That does look great! Are you doing any grading or was that straight out of the camera?
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Thanks. I did an old school simple grade in Premiere. I added a luma curve to add contrast. Then a few shots had to be brought up or down in exposure. And I warmed up a few shots (like the one of the juggler on the unicycle) to match the color temperature of the others. That's it. Nothing fancy.
The first version I uploaded had some sharpness added, and I added film grain. But I didn't like the result. It looked too sharp and the grain looked ugly in the shadows after Vimeo compression. So I re-uploaded it without sharpness or grain and I think it looks much better.
The film grain version, in its original Pro Res form, looks great on my monitor. But, alas, Vimeo is not kind to it.

EDIT: I forgot that I monkeyed around with the Ferris Wheel shots in Magic Bullet Looks. I added a yellow filter to that first silhouette shot of it. Then the others I isolated the sky and made it a darker shade of blue and boosted saturation.
 
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Thanks for your post prod notes, dvbro. I read your other post, the one with the sailboat, when you essentially did the same but were using CineD. They both look great.
 
Is it reasonable to hope that a futur firmware or hack would help here?

AlexLeith said:
I agree the thing that I like least about the gh4 is the harsh highlight rolloff. And reducing the highlights curve makes the rolloff harsher. But pushing the curve reduces the dynamic range in the highlights. This camera really needs a wide-dr curve.
Click to expand...
 
NeedCreative said:
I own a C300 and C100 and while I admit the GH4 has slightly less DR than those cameras, I don't think its highlight rolloff is that bad. It just has less DR in the highlights overall. But it does roll to clip decently. And I'm a stickler for that.
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I don't know... It's probably not as bad as I'm making out... It's just that the wide-DR profile on the C100/300 has SUCH a nice curve so overexposure gently fade away into clipping... In comparison the GH4 hits the clipping much more suddenly (16-235 or 0-255).

Personally I think this lack of gentle rolloff actually makes the GH4 *look* like it has far less dynamic range than it actually has. I was pretty convinced it wouldn't come ANYWHERE close to the C100/300, but actually in my non-scientific testing (shooting a variety of side-by-side shots in a dark-ish room in front of a blown-out window, wide-DR vs Natural) the range doesn't look significantly different. Sure, a little less in the GH4 - the shadows are certainly noisier and despite the bitrate, when recorded internally the noise is lumpy and not very pretty.

With the C300 I've gotten quite used to being fairly cavalier about exposing skintones and I'll frequently underexpose to protect highlights. The image from the C300 is happy to be pushed a long way before it looks bad or too noisy. That doesn't work so well on the GH4... So point of learning for me – expose for skintones on the GH4 and don't assume you can push the image too far.

I'm just hoping this gamma-log firmware update rumour turns out to be true.
 
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