GH4 Help with Vid-Atlantic Cinemorph "anamorphic" filter

J

joe12south

Veteran
flare+bokeh.jpg
Anyone have experience with this filter? Obviously, I'm not getting the expected elongated bokeh or horizontal flares.
This was with the Lumix 25mm f1.7
 
To get flares you really need a powerful point source firing down the barrel.
This looks like veiling, potentially caused by the uncoated glass on the filter.
 
You're seeing that result because the filter is designed to show streaks off the brightest lights in the frame. In this case, that's the side of your face and hair. Try pointing it at a street at night and you'll get a better feel for what it's designed to do.

Hope this helps :)

Cheers,

Paul :)
 
visceralpsyche said:
You're seeing that result because the filter is designed to show streaks off the brightest lights in the frame. In this case, that's the side of your face and hair. Try pointing it at a street at night and you'll get a better feel for what it's designed to do.
Click to expand...
I'll try with a more focused light source, but what about the bokeh, though? I'm sure it's not supposed to be round with a visible line through it.
 
Does the filter support a 25mm lens? I thought I read for optimal results it should be used on a longer lens. Plus you don't want to use too much of a step up ring to fit the filter on a tiny lens because the oval doesn't cover the lens properly and gets cropped.

I thought about getting one of these but the lens limitations seemed to be too great. There is a better DIY solution out there where you place a small cutout with fishline between the lens and sensor. This way it always covers the sensor perfectly no matter what lens you use on the camera.


edit:

Ah I found it. For m43 cameras they recommend 45mm as the widest.
 
Thomas Smet said:
Does the filter support a 25mm lens? I thought I read for optimal results it should be used on a longer lens. Plus you don't want to use too much of a step up ring to fit the filter on a tiny lens because the oval doesn't cover the lens properly and gets cropped.

I thought about getting one of these but the lens limitations seemed to be too great. There is a better DIY solution out there where you place a small cutout with fishline between the lens and sensor. This way it always covers the sensor perfectly no matter what lens you use on the camera.


edit:

Ah I found it. For m43 cameras they recommend 45mm as the widest.
Click to expand...
That's probably it. I *wanted* that to mean 45mm equivalent, but it probably doesn't. I rarely shoot anything but portraits with that long of a lens.
 
Is the Lumix actually at f 1.7? These filters work by having an oval shaped opening on the front of the lens. If the lens iris is wider than this opening, you will see the oval shaped bokeh. When you stop down, smaller than the opening, you lose the effect. It's the one limitation of using this cheat. I made an insert and put it between my speedbooster and the lens. It works even on my 16mm cine lens, but as mentioned, when you stop down enough, you lose the bokeh characteristic. You also lose light, about a stop with my insert.
 
Yeah, wide open at f1.7. I was looking for something I could use with small native glass on a gimbal. The 25mm is the longest native lens I have, so I can't confirm if 45mm and above would work correctly.

I do have cine lenses I use with a SpeedBooster. Won't help me with this specific project, but your hack could come in handy in the future. Can you explain a bit more about the insert you made? Something like black card/board and a fishing line?
 
joe12south said:
Yeah, wide open at f1.7. I was looking for something I could use with small native glass on a gimbal. The 25mm is the longest native lens I have, so I can't confirm if 45mm and above would work correctly.

I do have cine lenses I use with a SpeedBooster. Won't help me with this specific project, but your hack could come in handy in the future. Can you explain a bit more about the insert you made? Something like black card/board and a fishing line?
Click to expand...

Yes, it was black card stock, printed on my wife's silhouette crafting machine. I didn't do the fishing line. I don't like the way the line shows up in the bokeh.
 
I think I'm going to 3D print a piece to fit into my SpeedBooster. I rarely use long lenses for narrative work (which I suspect is true for most people) so putting it in front of a wide or standard lens is never going to yield the cat's eye bokeh.

I'll update here with my results. (Shooting a submission for PGL next weekend.)
 
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