u/Ok_Snow3538

Okay guys I need a Octane EXPERT!!! (Octane Blender)

So I'll explain my situation in short. I am working on a lens simulation project for about 2 months. The goal is to simulate real life modern/vintage lenses in Blender, With realistic distortions, dispersion, flairs and Bokeh etc. How I did this is I copied the exact glass optical geometry from the patents of given lens I modelled, the image above shows a 16mm Olympus Zuiko Auto-Fisheye f3.5. And if you put the glass geometry in front of the camera of Blender Cycles or Octane set to Orthographic they work like sensor plate for these glass lenses to form an image on.

Now I was using Cycles (Blender's native renderer) And it isn't spectral so I wasn't getting any dispersion thus no Chromatic aberration... So I switched to Octane and after setting up Octanes glass material (Image 2 shows the glass material I used in Octane).

I obviously like how Octane can natively do light dispersion and split white light into colours giving me realistic chromatic aberration...

But the problem I facing is with "Octanes orthographic camera'', Look the the comparison of results from Cycles vs Octane in the Image 1 above: Problem is focusing, When I was using cycles it worked just like a real camera with proper background blur and lens breathing. But I don't know why Octanes camera just doesn't work how it should, look at the focus chat and the background of the Octane's example How can both be at focus at the same time??? The focus chat is like a meter away and the HDRI should be at Infinity focus????? Just look at

more Screen shots for more context if it helps

Anyway, thanks a bunch for all who read through! ^-^

Okay people! I'm back after a month of work on this project. I'm Mik, and the 2nd image shows my previous post regarding issues related to simulation dispersion/ chromatic aberration,

Before I start explaining, this can very well turn into a long rant so be patient please.

To summarizes what my project is, it's basically simulating real life camera lenses inside 'Blender' to benefit from their different characteristics and what not. The unique swerly Bokeh, chromatic aberration, barrel distortion, flairs, ghosting, curved spherical focus etc... You know what I mean right!?

This is all for a movie I am making a and I wanted to have anamorphic/ unique vintage lenses in it.

Now what I am doing is, I find the patents of lenses I want to make and those patents have precise data on what's the radius of each surface of all the optics, their IOR and Abbé.

I make the glass optics geometry in blender accurately like reallllyyy accurate with a python script, after I have the physical geometry I work on the glass shader material.

Now the problem with my previous workflow was, it was working great, just it wasn't able to simulate dispersion and TIR inside lens (basically I was only able to simulate light rays coming in twords the sensor plate but my glass material wasn't simulation some rays that glass reflect back causing some nice cool artifacts).

Look at image 6, it showed my fix for both the problems, I modified my glass shader to also account for reflected light rays although that increased my render times and samples, and to somehow simulate dispersion I separated nodes and had to render in 5 wave length passes which is good enough (though you can have as many as you like), and then combine then at last by compositor node system in image 6, but it took my 4 hours to render all the individual 5 wave length passes with their slightly different IOR... This wasn't efficient...

Then I realised how dumb I was (T - T)

The RENDER ENGINE I WAS USING AKA 'Cycles' is a non spectral renderer, the light rays it generate only consist of RGB, and you cannot have caustics with dispersion, unless you forcefully split them one by one like me and render with wave length passes... Uff

{Guys can we make this a big deal? Common, cycles should be a spectral render engine}

Anyways I switched to Octane, a render engine which is truly Spectral (you can use LuxCore as well it is even open source but eh, it's like too slow and I mean too slow)

So it was like I'm in heaven, Octane did everything right like perfect, the first image you see is a render from octane look at that Chromatic aberration and barrel distortion.

Now to the main issue at hand (yeah finally!), idk why but I'm not getting that swerly iconic bokeh of a Zeiss Biotar as you can see in the reference image 4, I don't know what's happening why it isn't looking like that?? Can someone explain or help?, also I also don't know why the background blus is so less, I mean I did something and now both the focus chat and the background environment (which should be at infinitely focus) are both in focus (no image for this problem at present), mind you I focus by moving the sensor plate back and forth rather then optics, why? Because I can and it's easier...

I think I'm soooo close to having the perfect system...

Anyways, thanks for reading all that and I'm super eager to her from everyone what they think! ^-^

So people I am facing 2 big problems:

Problem 1: when I was modeling an accurate to life lens, I wanted to not only put real Refractive Index but I also waned to simulate Abbé number so as you can see in the last image I used this node configuration to simulate R G B light rays but this was too heavy for my computer (I use GTX 1660ti), as you can see in image 1 at last I can only see a black sput even with 10,000 samples there were barely any light rays passing through. I tried everything to optimise but I couldn't do it, at last overheating my CPU...

Problem 2: for a moment I dropped the Idea of simulating Abbé number and was modeling this new lens (image 4/5), and I modeled everything perfect to the mm. But my anamorphic lens isn't focusing nicely, as it should eve patent says that it is barely focusing that to only on either X or Y axis. Image 3 is a focus char to show how bad it focuses. Image 2/6/7 should my model of optics.

I've put house making this, and all my past spherical lenses worked fine even zoom lenses. Just this doesn't for some reason?

Please help!!!