Home of Professional Cinematography since 1996
Filter – Centre Spot Distortion
Published : 8th September 2003
I'm shooting a spot next week where we're going to attempt to recreate the vision distortions associated with people who have an sight disorder referred to as Macular Degeneration. I'm hoping to accomplish two things in camera (though we could probably do both in post if I can't find a good solution) and was wondering if anyone has come across filters or techniques that might help me achieve these effects.
The first is to "make straight lines appear wavy." I can't think of any reason a filter to achieve this effect would exist, so I have been trying to think of some type of glass object through which I could shoot to get this look. Although with the disease, I think all straight lines are affected, in this case I would be satisfied with simply breaking up the lines on one axis.
The other effect is something that could be achieved with a filter that was the exact opposite of a heavy version of Tiffen‘s Center Spot. Here I need to recreate the vision of someone who has a very blurry spot at the centre of their field of view.
I'm guessing that Tiffen could custom make this, but the job has neither the time or money, so I'm wondering if anyone has any ideas out there. Vaseline on the lens is certainly one way to deal with it.
Any other thoughts?
Thanks in advance for your help. FYI, I've made a 2003 resolution to stop being such a lurker. But damn, some of you folks are so knowledgeable...
DP - NYC
Rob Barocci wrote:
>...was wondering if anyone has come across filters or techniques that >might help me achieve these effects…first is to "make straight lines >appear wavy.
A few years ago, for a movie titled, "Blink," Clairmont Camera in LA produced a lens attachment using heat-warped plastic in a motion control mount that created the type of distortion you are probably looking for.
For the centre diffusion with a clear edge, you can certainly use Vaseline, but clear nail polish has the advantage of being more durable in use. You might also find this method allows a simpler form of distortion as above, with some experimental texturing of the nail polish surface.
In both cases the materials applied are readily removable to re-use the filter substrate.
The Tiffen Company, LLC
Robert Barocci writes:
>I'm shooting a spot next week where we're going to attempt to recreate >the vision distortions associated with people who have an sight disorder >referred to as Macular Degeneration.
That doesn't give you a lot of time to experiment.
A number of years ago I shot a film for a Blind Association which also attempted to simulate some of the effects of various eye diseases. From what I remember there are a couple of forms of macular degeneration and various stages with very different visual symptoms.
>The first is to "make straight lines appear wavy”…
I'm pretty sure we used clear plexiglass which was heated and then bent for one type of effect and then we also used water in a sandwich of glass that could be squeezed to create another type of distortion. The two layers of glass were held together with a strip of soft rubber attached to the glass with silicone adhesive.
I can't remember which was finally used.
At the International Center for Photography (6th Ave and 43rd St.) there is an exhibit of WeeGee's Trick photography and how he did it. You can also see the Fox Talbot exhibit. I went to see the Fox Talbot exhibit and didn't have much time to spend at the WeeGee exhibit, but I know he used melted plexiglass to achieve many of his effects.
>The other effect is something that could be achieved with a filter that was >the exact opposite of a heavy version of Tiffen's Center Spot.
A small circle of Kodak Wratten ND gel stuck on an optical flat.
These filters are gelatin so a little moisture on the flat will allow the filter to glue itself to the glass, f/stop and distance of the filter from the lens will allow you to control the softness of the filter edge. Then put whatever amount of Vaseline, etc. necessary on the other side of the flat.
This way you can alter the diffusion without ruining the gel, or change the gel density without disturbing the Vaseline.
IA 600 DP
Rob Barocci wrote:
>I'm shooting a spot next week where we're going to attempt to recreate >[...] vision distortions
Rob check out making up filters from this sort of thing :
I've used 4"x4" filters cut some something similar to the design called 'Flemish' and it produced some lovely effects. The effect varies greatly depending on f-stop, focal length & the distance between subject/lens & lens/glass so it's worth playing about.
Come to think of it, the filters I used came from a rental house - it's truly amazing what wacky 'one offs' are gathering dust in these places if you bother
someone to look around for you.
A geared rotating mattebox tray with 'dog-lead' /motor would add to the effect too (a la 'Blink').
All the 'inverted centre spot diffusion' ideas already proposed sound like they'd work a treat - why not jazz up the idea by renting a lightweight rain deflector (clip on style - for digi beta) and muzz up the centre of that.
If you could figure some way to slow it down (they run DC if they're battery/camera powered so dropping the supply voltage should do it) and your 'misting' was off-centre or misshapen you'd get a pulsing to the soft spot.
I think the plexiglass ideas are right on target, especially melting it with blow torches.
You may want to try shooting via acrylic mirrors that you bend or play a hairdryer over to distort the image.
Geoff Boyle FBKS
Director of Photography
>The first is to "make straight lines appear wavy."
Check out the "cyclone" filter on the Cokin web site :
I don't know much about the disease, but this will certainly give you a strange feel especially when panning. Warped plexi has also produced some interesting effects, and with a bit of skill in your workshop, you should be able to obtain a certain amount of warp.
>The other effect (...)was the exact opposite of a heavy version of Tiffen's >Center Spot.
Harrison make a complete line of spot diffusers with varying densities, shapes and sizes. Most serious rental houses should have a certain number of these available.
Groupe TSF / Paris
>I think the plexiglass ideas are right on target, especially melting it with >blow torches.
I had to make a "drunk filter". I tried about half a dozen things.
The best: Got some clear plexiglass cut in 4 x 6 inch sections.
Used a propane hobby torch and slightly melted them. Took many tries to get the hang of it (too much and you can't see through it). I wound up hand -holding the filters and moving it around very slightly in front of the lens, while doing drive-by shooting of the Vegas strip lights at night.
Worked great. Everybody loved it, although I don't think it would work in day exteriors, it was the practical lights in the scene that made it believable. The resulting show, Judgment Day, premiers on HBO's America “Undercover”.
Director of Photography
O.k. - a few of my favourites for the distorted stuff.
Shooting through glass blocks. The type they use in construction for bathroom walls, etc.
Shooting into plexi-mirror and then bending it around.
Shooting through an office supply magnifying sheet. There's a still of this on my "Whatever Happened To Alice" feature page :
I rest the magnifying sheet against the lens and then roll it around - fun stuff!
Like a diopter, it brings the focus in to almost macro which is interesting to.
Rob Barocci wrote:
>exact opposite of a heavy version of Tiffen's Center Spot...
Haven't come across this filter. Found it listed on Optex's, and Tiffen's websites but can't see any stills of it in use.
Anyone know of where I might see it online? I'd love to try it for an upcoming music video (my first in charge). Thought those defocused fringes were all done in post.
Love to try it in camera. Even though I'll shoot clean as a safety.
Saw your message regarding the Tiffen Center Spot filter, and I happened to have a frame grab from an old shoot where I used the filter to good effect.
Since we can't post "attachments" on the list, I'll send you a private email with the graphics file sample.
Jim Furrer, Director of Photography
Denver Center for the Performing Arts
Thanks to all for the filtration ideas. I'm going to try some of the plexi-melting stuff for sure, but, I also loved Tom's pilkington glass site :
as an option for the wavy lines gag.
It looks like there are a ton of fun textures to play with there. I'll let you know what ends up working for us. Though I'm certain I'll get to shoot some of this, it may be that the client will end up using our clean passes and create the effect in post. They're concerned with precisely matching what patients with this disease see (as opposed to a more dramatic interpretation) and want the option of dissolving in the effect in order to illustrate the degenerative nature of the disease.
Either way, I get to play with blow torches, so I guess we all win in the end.
Thanks again and I'll report back in a couple of weeks.
NYC - DP
>Haven't come across this filter. Found it listed on Optex's, and Tiffen's >websites but can't see any stills of it in use.
This is a bit of a late reply to Jim's request, but due to pesky work related endeavours, I got behind on my cml reading.
Tiffen actually does have an example of the WARM Center Spot on their website (which will give you and idea of the standard version, but, well, warmer).
Good luck out there...
DP - NYC