GH5 to Alexa Conversion

[RCV]

2 minutes ago, Sage said:

In my case, I shoot to 2K All-I, and use the digital Olpf settings, to make the resolution organic (and upscale as needed). Paired with the DD1, I find I only need the lighter olpf settings (5.2/20) to counter sharpening, and the DD1 takes over texture from there for a solid match. The full 6/20 is too much with the DD1 (beyond a match)

Man!!!! I learn more and more with each reply. What is the digital olpf setting?

[Sage]

1 minute ago, RCV said:

Man!!!! I learn more and more with each reply. What is the digital olpf setting?

The walkthrough is detailed in the last step for the NLEs in the Pdf. It essentially spreads every point of light out, lowering micro-contrast, like an 'inverse-sharpening', by using a blur layer paired with opacity

GHa Documentation V3.pdf

[mercer]

@Sage do you have any matching, ungraded shots from the Alexa in LogC and the GH5 in vLogL?

[RCV]

Just now, Sage said:

The walkthrough is detailed in the last step for the NLEs in the Pdf. It essentially spreads every point of light out, lowering micro-contrast, like an 'inverse-sharpening', by using a blur layer paired with opacity

GHa Documentation V3.pdf

wow. thanks. U rock!!

Maybe in the future when u get a chance, check out the Schneider radiant soft filter

[Sage]

Just now, RCV said:

wow. thanks. U rock!!

Maybe in the future when u get a chance, check out the Schneider radiant soft filter

Will do!

1 minute ago, mercer said:

@Sage do you have any matching, ungraded shots from the Alexa in LogC and the GH5 in vLogL?

These are LogC + R709, converted LogC + R709, and Panasonic V35 R709 thrown in for reference:

https://flic.kr/s/aHsmzCgFFP

And these are all the raw files, LogC and VLog L:

http://www.mediafire.com/folder/x3ub82eh21u63/ALEXA vs GH5 (Side-by-Side)

[mirekti]

7 hours ago, Sage said:

The optimal stack I settled on was:

Lens > Firecrest ND (Cancels out inverse sensor reflections) > Tiffen Low Contrast 1/8 > Tiffen Digital Diffusion 1

Now this is interesting. I have a pro mist filter, and love it, but the reflection...

Would any ND any strenght work? Is it specific to Firecrest?

[Sage]

1 hour ago, mirekti said:

Now this is interesting. I have a pro mist filter, and love it, but the reflection...

Would any ND any strenght work? Is it specific to Firecrest?

Yes, that's why I didn't even consider filters for so long. Its not specific to Firecrest, those are the reference Full Spectum NDs for EC though (how the Day conversion was made). It needs a minimum of a 2 stop ND to fully cancel out the reflection; the glass also needs to be parallel to the sensor plane, as one ND I have is slightly off axis, resulting in a diverging reflection.

Interestingly, the Alexa doesn't even have this problem, despite having CMOS, as best I can tell. The falloff is silk and there are no ghost reflections, as I believe the filter is 'integrated', and not a stack (that causes 'stair-stepping' falloff):

GH5

GH5 (1/4 LC, DD1, Contrast matched)

Alexa

[TurboRat]

52 minutes ago, Sage said:

Yes, that's why I didn't even consider filters for so long. Its not specific to Firecrest, those are the reference Full Spectum NDs for EC though (how the Day conversion was made). It needs a minimum of a 2 stop ND to fully cancel out the reflection; the glass also needs to be parallel to the sensor plane, as one ND I have is slightly off axis, resulting in a diverging reflection.

Interestingly, the Alexa doesn't even have this problem, despite having CMOS, as best I can tell. The falloff is silk and there are no ghost reflections, as I believe the filter is 'integrated', and not a stack (that causes 'stair-stepping' falloff):

GH5

GH5 (1/4 LC, DD1, Contrast matched)

Alexa

Wow the Alexa one still looks amazing even with a filter. You think it can be achieved with a filter and adding a contrast on the GH5? Now I'm rethinking about purchasing a Promist. Looks like it will just look the GH5's shots muddy

[Sage]

9 minutes ago, TurboRat said:

Wow the Alexa one still looks amazing even with a filter. You think it can be achieved with a filter and adding a contrast on the GH5? Now I'm rethinking about purchasing a Promist. Looks like it will just look the GH5's shots muddy

That is, the Alexa shot has no filter - nothing can quite match the two in terms of falloff. The GH5 (and I assume most every other CMOS camera) has a reflective 'stack', with no reflection dispersion. The falloff can be smoothed, specifically with a Tiffen Low Contrast 1/8 or 1/4 (but the contrast will be lowered from reference, no LC is closest to AA falloff strength). DD1 is amazing for texture though; in that sense, they can be matched.

*Oh - and the bokeh with this filter stack + light digital Olpf is amazing. It feels like I'm using incredible glass.

[TurboRat]

1 hour ago, Sage said:

That is, the Alexa shot has no filter - nothing can quite match the two in terms of falloff. The GH5 (and I assume most every other CMOS camera) has a reflective 'stack', with no reflection dispersion. The falloff can be smoothed, specifically with a Tiffen Low Contrast 1/8 or 1/4 (but the contrast will be lowered from reference, no LC is closest to AA falloff strength). DD1 is amazing for texture though; in that sense, they can be matched.

*Oh - and the bokeh with this filter stack + light digital Olpf is amazing. It feels like I'm using incredible glass.

What's AA again? And the filter stack is using Tiffen or using Digital Diffusion? lol sorry I haven't kept up

[Sage]

1 minute ago, TurboRat said:

What's AA again? And the filter stack is using Tiffen or using Digital Diffusion? lol sorry I haven't kept up

Arri Alexa ? And that's Tiffen Digital Diffusion 1. The stack I was referring to in the previous comment is the Panasonic filter stack directly on top of the sensor, as opposed to my 'olpf stack' experiment in front of the lens. AA, I think, has a unified piece of material in front of the sensor, rather than a divided stack (olpf, IR/UV cut, dispersion etc. all in one)

[kye]

Man, I read that whole thread thinking AA was an Anti-Aliasing filter, which even made sense in the context that it's in the filter stack!!

Too many acronyms! ???

[Sage]

1 hour ago, kye said:

Man, I read that whole thread thinking AA was an Anti-Aliasing filter, which even made sense in the context that it's in the filter stack!!

Too many acronyms! ???

Also - 'Always Already'

[ChristianH]

16 hours ago, Sage said:

Yes, that's why I didn't even consider filters for so long. Its not specific to Firecrest, those are the reference Full Spectum NDs for EC though (how the Day conversion was made). It needs a minimum of a 2 stop ND to fully cancel out the reflection; the glass also needs to be parallel to the sensor plane, as one ND I have is slightly off axis, resulting in a diverging reflection.

Interestingly, the Alexa doesn't even have this problem, despite having CMOS, as best I can tell. The falloff is silk and there are no ghost reflections, as I believe the filter is 'integrated', and not a stack (that causes 'stair-stepping' falloff):

I'm looking at those shots on a crappy old laptop, so take this with a grain of salt - but while the GH5 with filters shot looks great in terms of fall-off, it also looks quite soft. Won't all this manipulation make the image too soft (LC, DD1, digital olpf, 1080 upscale)?

I like a detailed, organic filmic image. Not the overly sharp digital look. But I don't want to go too far in the other direction and make it look like it was shot on Betamax with a 35mm adapter :) 

[TurboRat]

2 hours ago, ChristianH said:

I'm looking at those shots on a crappy old laptop, so take this with a grain of salt - but while the GH5 with filters shot looks great in terms of fall-off, it also looks quite soft. Won't all this manipulation make the image too soft (LC, DD1, digital olpf, 1080 upscale)?

I like a detailed, organic filmic image. Not the overly sharp digital look. But I don't want to go too far in the other direction and make it look like it was shot on Betamax with a 35mm adapter  

Not really sure about the correct workflow with the filters but I assume you can adjust the sharpness in the picture profiles, or you can add back the sharpness and contrast in post

[Sage]

9 hours ago, ChristianH said:

I'm looking at those shots on a crappy old laptop, so take this with a grain of salt - but while the GH5 with filters shot looks great in terms of fall-off, it also looks quite soft.

Its a combo of compressed contrast because of higher halation than the Alexa (distinctly higher with LC1/4), and a missing top three stops.  DD1 with light Olpf settings (5.2/20) is quite a close match (optical Olpf side-by-side coming)

I shoot to 1080p, as that's all I need (a match to the classic); if you don't mind the data rates, 4K is worthwhile (most are shooting to 3.2k with Alexa Minis today, and some high end productions to Alexa 65/LF)

[ChristianH]

3 hours ago, Sage said:

Its a combo of compressed contrast because of higher halation than the Alexa (distinctly higher with LC1/4), and a missing top three stops.  DD1 with light Olpf settings (5.2/20) is quite a close match (optical Olpf side-by-side coming)

I shoot to 1080p, as that's all I need (a match to the classic); if you don't mind the data rates, 4K is worthwhile (most are shooting to 3.2k with Alexa Minis today, and some high end productions to Alexa 65/LF)

Thanks! I'm going to buy GHa in a moment, even though I don't have a GH5 yet  Hopefully I can find some sample footage to practice on (perhaps even some G85 Cinelike D just for the fun of it!). 

I was thinking of getting two filters - one variable ND for convenience and a Black Pro-Mist. But I gather that getting a DD1 would be a better choice? 

[RCV]

15 hours ago, ChristianH said:

I'm looking at those shots on a crappy old laptop, so take this with a grain of salt - but while the GH5 with filters shot looks great in terms of fall-off, it also looks quite soft. Won't all this manipulation make the image too soft (LC, DD1, digital olpf, 1080 upscale)?

I like a detailed, organic filmic image. Not the overly sharp digital look. But I don't want to go too far in the other direction and make it look like it was shot on Betamax with a 35mm adapter  

Even with "organic filmic image" productions use a stack of filters as well

[Sage]

22 hours ago, ChristianH said:

I was thinking of getting two filters - one variable ND for convenience and a Black Pro-Mist. But I gather that getting a DD1 would be a better choice? 

The budget option would be to use the higher digital Olpf settings (6/20). The DD1 is solely a texture filter, sans halation. It optically makes detail 'thick' and 'smooth', whereas the normal digital aesthetic might best be described as 'anemic' and 'crisp'. For halation, I prefer Low Contrast over BPM, as it is optically true to the way that organic lenses diffuse light (BPM always looks like BPM). It will smooth falloff, at the cost of distinctly stronger diffusion than Alexa (often preferable on a film)

[jase]

Sincd @Sage did not cover FCPX in his manual - any FCPX users out here using GHa?