ken

My mounting way for 58mm filter thread (Canon 85mm f1.8) taking lens is here.

 
BTW, this lens is easy to add(glue a step up ring) non-rotating filter thread for CPL

Hi, I can tell you this one is exactly renamed 16D.
https://www.ebay.com/itm/Sankor-Anamorphic-35-J-Projection-Lens/223770656675

16H and D, the difference is only view angle.  the front and rear glasses size are almost same.  I never own S.  But looks it is close to D.  might be a little bit wider.

Good call! 
5D3 coupled with ML still yields one of the best looking images, IMHO. 
100% correct, these are the Holy Grails that everyone lusts for. 
These are a bit easier to get. I've seen a couple of them going for sale during the last year. 
However, they are more suited for smaller format cameras (eg. GH5) and shorter focal lengths. 
Definitely. 
If it comes to Kowas, the adapter you should be looking for is Kowa 16-H. It's sometimes called Kowa 8-Z or Elmoscope (Elmo) II. 
These are the finest anamorphic adapters and usually cost around 800 - 1000$ (adapter only). 
If you get a variable diopter (which you put in front of your anamorphic block), then every anamorphic adapter becomes single focus. 
Sorry, but this is not possible with 5D3. 
The widest you could go on a full frame camera would be ~ 80 mm if you plan on acquiring a 2x stretch factor anamorphic lens. 
You could (though I cannot guarantee that) get away with 50 mm if you bought a 1.5x anamorphic, like Aivascope II. 
This calls for either ISCO Ultra Star or Schneider Cinelux. 
I have both of them and, in my opinion, they are hugely underrated. 
They are as sharp as your taking lens and do not degrade contrast, at all. 
What's more, it's not that difficult to find one in a good condition and they usually run for ~350 $. 
Unfortunately, it doesn't go more compact than ~ 600 - 800 g and 10 - 15 cm. 
It's not that bad, but usually takes around 20 seconds to achieve perfect focus. 
The worst thing is: you cannot rack focus. 
From 550$ up to 1000$ if you want to have something you can rely on. 
There are two brands: Rapido (which offers FVD-16A) or Rectilux (and its Hardcore DNA aka HCDNA). 
 
I realize this may sound complicated at first, but if you keep on reading, you'll quickly get to know what's right. 
My interest in anamorphics started only a year ago, so it's not that difficult topic to grasp. ( :
The most important thing here is patience. 
 
If you have any questions, feel free to ask them. 

Yes.  Perfectly.

I also like to mount this anamorphic lens and take photos vertically.  So just looks as normal, not widescreen. ?
1. F1.8
2. F5.6 (to get good flare, need to use small aperture)
 

Elmo II is top notch. Elmo built some very advanced projectors and good cameras. They were and are still used by pros. Tito just had a poor example for his test. For the looke I like Moeller even more but sadly the rear is smaller. Moeller is king! Had them all and sold them. I am an idiot...

just attach it to your gopro it should fit the waterproof housing theres four screws  that secure it too the plastic housing. Or there's a clamp that will hold it onto the gopro lens if you dont want to use the housing.
I have 1. thats what i used on the front of  my $200 camera challenge. However i secured mine to the camera with about a meter of electrical tape. i have heard some people say it helps straighten the gopro's distortion. If it does its minimal or marginal perhaps. It will fit the 3, 3+ and 4 unsure of the 5 but it doesn't fit the 6 as i tried that and i presume it wouldn't fit the 7 either.  You may be able to modify it to fit later gopros or the gopro's themselves. However you'd probably kill the resale value if you did that. but thats for you to decide. maybe we should do our own little gopro challenge lol

Hey @ken! I'm pretty sure these (as most 1.33x fixed focus lenses) are two cylinders. They might be tiny and close together.
I had it for a brief while and the footage was indeed squeezed and there were flares. Saying there was oval bokeh was too much, because I don't even think GoPros can have bokeh. ?

The mighty Tito wrote in one of his comments that he is preparing an 'Anamorfake Guide'.
So, I highly recommend just waiting a little, since there is no better person that could answer your questions.
 
But, if you only want to 'enhance' your flares, then putting an UV filter (or two) between your taking lens and anamorphic adapter really works wonders.
Fishing line is also a good idea, but its distinct shape is often visible in bokeh. Not a deal breaker, but for purists - meh.
Don't know anything about being able to influence flare color by painting over it.
 
 

I did some research several years ago.  And got these combination:
1.5X:                          Sphere/Cylinder
Schneider ES front     0/-10.50
ISCO integrated rear  +7.75/-7.75
1.3X:
Moller46/2x front      0/-9 to -10 (estimated value, due to too thick, unable to measure)
ISCO integrated rear   +7.75/-7.75
The combination means using 2X lens with more powerful rear lens(or weaker front lens) can get less ratio than 2X.
For reference, original combination is:
2X:
Schneider ES front     0/-10.50
Schneider ES rear      +6.00/-6.00
2X:
ISCO integrated front  0/-13.75?
ISCO integrated rear   +7.75/-7.75
BTW, for 16H,
2X:
16H front              0/-17.00
16H rear               +9.50/-9.50
So that explain powerful lens combination(shorter distance between front and rear lenses) has wider angle.

depends on how you measure the length.   looks you measure it at the longest.  if measure in shortest, kowa's length<diameter.  But Isco Ultra Star is internal focus lens, never change in length.
 
 

I use mspaint and  working too.?

I made my own lens. ?
 

Just finished in first stage.  Prime lens: Canon EF 40mm STM, actual ratio: ~1.5x

You can refer my method. 

Your lens barrel has been cut out the distance marking part, obviously.
Mine's price?  I think it worth around $200 nowadays.  Its front lens was too bad when I bought, not usable.  So I took out rear lens for use with other front lens.   

Maybe not many people know, 16D has its twin named 35J.  

16D usually means Sankor's 16D.  And don't confuse with Kowa 16D, which is smaller lens.

similar to Proskar, Sun.  Eiki(16F, same as Senkor) is more recent lens, sharper.

Dose your lens like this lens?

Dose your lens like this lens?

Dose your lens like this lens?

Low light anamorphic test Schneider ES Cinelux 2x (custom single focus) with external IRIS 20 blades
.
Camera:
Sony a6300 (Slog2, SGamut3.cine, ISO 3200)
.
Anamorphic:
Schneider ES Cinelux 2x with custom single focus
.
Taking lenses (wide open, external iris):
Helios 44m-5 58mm F:2
PO-109-1A 50mm F:1.2 (projector lens without build-in aperture)
.