Page 1 of 1

Spot reflections on glasses

PostPosted: 06/13/2017, 12:41 am
by homnislash
Hi everybody,

just asking if you may know some tricks to avoid spot reflections in the studio ?

I know there's a spray, but is it more for 'black' sun-glasses type-of-thing...

Have a nice day

Re: Spot reflections on glasses

PostPosted: 06/13/2017, 1:18 pm
by Michael_Szalapski
Careful placement of lights is the best trick I know.

Re: Spot reflections on glasses

PostPosted: 06/15/2017, 3:28 am
by Farmfield
A couple of years ago I had a gig mapping some distortion and reflections onto a pair of glasses because they had such issues lighting a specific scene in a kitchen with lots of small spotlights in the ceiling, so they removed the lenses from the frames to avoid weird reflections and then I got the shot and a environment map.

Another time we did something similar using sunglasses with removed lenses on someone where we shot him close up but didn't want the cameraman reflected in the glasses. As it was a hand held walking shot and pan, we used a GoPro shooting wide angle mounted on the camera pointing backwards to capture the correct reflections which were then tracked and a stabilized version of the GoPro footage was comped onto faked lenses in the empty frames. One of those times I was very happy I wasn't the one to track, roto and comp, hehe... :D

And this approach of course needs to be planned and implemented beforehand, it's not gonna work for everything, it's not always a reasonable or even possible solution, but it's a good workaround to know of, either way. :D

Re: Spot reflections on glasses

PostPosted: 06/19/2017, 6:31 am
by [signuversum]
Michael_Szalapski wrote:Careful placement of lights is the best trick I know.



^This and if you're using greenscreen, watch out for the distorted background/problems with keying.
Try experimenting with different camera angles.

Most of the time we encourage our guests to take the glasses off, because we are lazy ;)

Re: Spot reflections on glasses

PostPosted: 07/3/2017, 9:35 am
by homnislash
Thanks for your replies,

oops, I made a mistake : I did film with HUGE reflections on glasses... I guess my lighting setup was really bad.

Any tricks to correct it a little in post-production... ? :(

All the best

Re: Spot reflections on glasses

PostPosted: 07/7/2017, 7:49 am
by Michael_Szalapski
Other than grabbing bits where the reflections aren't there and tracking them into the shot...not really.

Re: Spot reflections on glasses

PostPosted: 10/24/2017, 12:19 am
by homnislash
Just to keep you informed... Finally we'll try to film again... :(

Re: Spot reflections on glasses

PostPosted: 12/5/2017, 3:12 am
by homnislash
We had better results, here's a description of the setup:

2 spots on each side
AND 1 big hot lamp on the floor lighting a big white screen to have a diffuse "area" light on one side
AND 1 spot in the back of the character (up in the air) - to isolate the character from the green screen

It works if the character keeps looking at the camera in front of him
BUT you can still see some reflections in the glasses if the actor turns his head to face the spotlights.

Re: Spot reflections on glasses

PostPosted: 01/20/2018, 5:49 am
by homnislash
Just a quick note on what I could have done better.
I used around 1/50 for the shutter of my camera, but I regret now. I think I should have increased the number to have 1/150 or 200

So the hands of the characters would not be so blurred when moving, and keying would have been cleaner I suppose

Anyone experienced that ?

Cheers

Re: Spot reflections on glasses

PostPosted: 02/16/2018, 6:56 am
by jimmygilmore
Reflections are really all about the lighting. Basically the bigger the reflection the better. Cars, which are one big reflective surface are studio lit with a giant source overhead so the entire car is covered by one giant single reflection. Another way they do it is outside right before the sun comes out at dusk with nothing close enough to reflect off it. But there's a lot of 3-D composite happening these days too.

What I'm saying use the biggest possible light source you can and move it around and your subject until you get something acceptable. Bouncing the light off the ceiling is a trick used often by cinematographers. I used to work on the Oakley account and we spent a whole lot of time making the reflections look great in production and post.

Re: Spot reflections on glasses

PostPosted: 03/5/2018, 1:10 pm
by Bitman
You need either to remove the offending light or supply much more additional light to wash out the reflection.

Removing the light can be accomplished by shading it. In this particular situation it's possible a helper could just stand nearby to block the light source.

Another way that can work with specular reflections like this is to use a polarizing filter, because the reflection tends to have a preferred polarization. The reflection won't go entirely away but it can be much reduced.

Adding light is usually done with a flash or similar source(s). Use of a diffuser or bounce is almost required, as well as appropriate positioning to avoid or at least displace the reflections. You need to add enough light that you can stop down the original exposure enough to reduce the contribution from the ambient reflections. Because this can cause related problems exposing the background, this method is to be used after careful consideration of the effect you want in the photo.