KipperTie Lowcon OLPFs - sharpness/aliasing opinions

[John Marchant]

As you may be aware we are in the process of producing a small range of third party filters for the swappable OLPF system on Dragon.

We have a fork in the road as far as the 'Lowcon/Halation' versions go.
The filter stack is quite complex for this version. Including a true birefringent OLPF is tricky, but not impossible.

If we omit it, there is a slim chance of real-world aliasing, but in improvement in the sharpness underlying the slight diffusion.

If we include it, we have the option to match or go beyond the softness of the standard item.

My gut feeling is to go with the omitted option, even though a focus chart may show the occasional gremlin... but I want to know how everyone else feels. Bear in mind again, this is in conjunction with filtration that bleeds the edges off highlights, adds halation and softens contrast a little.

 

[soren k jensen]

How do you think it will play with e.g. Contax lenses that are already somewhat lowcon?

 

[John Marchant]

I've been testing with old nikons, zeiss etc etc, and there's no conflict as such - the veiling flare and low-con of old lenses is broader across the frame - our option is a little more localised and targeted, so they play together well.

 

[Phil Holland]

Based on collected data from Reduser and "abroad" I'd recommend leaning towards matching the Red's OLPF or going slightly less sharp. But as close to Red's OLPF in terms of sharpness would be ideal for me.

Most who are looking for the LowCon/Halation effect are attempting to match a more film-like image and too sharp isn't exactly that look.

Aliasing can happen on CUs of eyelashes even. For a multi-purpose and useful for general shooting OLPF such as this I'd aim to match Red's. The additional advantage there is people can swap between that LowCon/Halation and the standard OLPF without a loss in resolving power (theoretical).

 

[Matt Ryan]

I agree with Phil. This is the olpf I'm looking for but if it causes aliasing, I'm out. For feature film and tv stuff, DP's will want to avoid aliasing at all costs. I'd say match Red's formula for sharpness and avoid aliasing. If you can make the tack sharp version and avoid aliasing in 99% of situations (eg. brick walls, roof tiles, fine lines like power lines, etc,) then maybe..

 

[John Marchant]

My quandry really comes down to - if I add back in the true lowpass, it means I get to tune it... and given that I can create aliasing with the standard one sometimes, it seems silly not to go a little further.

Maybe I'm answering my own question. Oh so many layers in this little piece of sparkly glass hehe

 

[David Battistella]

What phil and Matt said.

sometimes the slightest change is the best one.

battistella

 

[Jon Carr]

Another vote for a red style low con OLPF.

 

[Gavin Greenwalt]

Personally I've always felt like RED is slightly too aggressive on their OLPF. I would lean towards slightly sharper.

 

[PatrickFaith]

I'm shooting mainly 6k anamorphic FF on the dragon, so when i look at the picture in square pixels it's 12k. Problem with that is it's almost impossible for me to see if I have a production problem since it's hard enough to even find a straight 6k screen let alone 12 for production, and i don't want to get into post and realize i need to reshoot. So i clicked on "softer" since normally low con spreads things out a bit, but what I really want is I think what Phill is saying. Just gave this info as background, since I'm not familiar with the exact details of what you guys are talking about.

 

[Jake Wilganowski]

I would want same as red or sharper, not softer

 

[Abe Espinoza]

I'd prefer you go with RED's standard OLPF. Not a fan of super sharp images. No need for the possibility of introducing aliasing. Unless RED is coming out with this flavor and you want to create a variation thereof as an option...

Abe Espinoza

 

[George A.]

RED's Standard OLPF as well.




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[Adam Johnson]

What Phil said...that's what I want too

 

[Bob Gundu]

It's the same logic for what to decide when choosing standard filters... It will depend on the type of lenses you're using. With Modern lenses, you may be inclined to go softer with the OLPF. With Vintage lenses, you lean towards a sharper one.

 

[Tommaso Alvisi]

John,

I think that these OLPFs will be used mostly to take the edge off modern sharp lenses without dealing with filtration,

so I think it could be beneficial to go even a little bit softer than the standard OLPF,

like having a built in SoftFX 1/2 in addition to an HBM / Low Con 1/8 or or 1/4 or something like that...

Ah, what kind of low con/halation recipe/emulation are you aiming for??? I'm really curious!!

 

[John Marchant]

Our softening / halation / lowcon is a thing in its own right. I want to get a little glow around highlights, a little lift of shadows, but no veiling across a scene from a large bright source.

Because its rear of lens, none of the pre-existing strengths of filtration apply conceptually... and we're working to minimise the appearance of artefacts in the bokeh which show up with rear filters (ie nets can be visible in the bokeh quite clearly).

I may yet make a heavy version that uses a real net embedded in the glass for people who want that look without the pain and fiddlyness.

 

[Tommaso Alvisi]

I think these 2 OLPFs will turn out great!

I agree 100% with your approach! I love halation but I'm always sad when I see the downsides...
The speckles of BPMs and HBMs + many others in the OOF areas (bokeh)!

Probably something comparable to a 1/4 LC + 1/2 SoftFX?

Too much?

 

[Ketch Rossi]

I am a freak of sharpness, I can always get the image softer in post, but adding sharpness is always the negative thing to do vs softening...

Having said that, I must also agree with Phil that I in this case would also prefer this to be as close to RED's with a touch less sharpness.

 

[Ivan Kovax]

have a matching set. keep the actual olpf sharpness the same. just add a lowcon...