RED DOT on Footage - HELP!!!

[Christopher Lansell]

Hi Everyone

Over the lasy two days I have been shooting for a surfing film using a 250mm with a doubler and I keep getting a larger red dot in the middle of my footage? Does anyone know what would be causing this?:emote_head_explode:

 

[A. Clint Litton]

flare? can you post a still?

 

[Martin Weiss]

Have you done black shading?

A still would really help.

 

[Christopher Lansell]

Hi

Thanks for that here is an image

 

[Christopher Lansell]

 

[MichaelHalsell]

Could you attempt to post the image again? It seems not show up.

 

[Filip Orlandic]

Could you attempt to post the image again? It seems not show up.

I can see the image.

 

[Martin Weiss]

No image here either.

 

[Christopher Lansell]

It is a 1k tiff so it might take a sec to load! I think somehow the light is reflecting off the sensor back into the lens and then back onto the sensor?

 

[Peter Matthes]

It is a 1k tiff so it might take a sec to load! I think somehow the light is reflecting off the sensor back into the lens and then back onto the sensor?

Are you using a IR Hot Mirror filter of any kind?

 

[Michael Romano]

Have you visually inspected the lens? Try another lens to see if it persists. Other than that I'd make sure about a black shade calibration.

 

[R Fogg]

Have seen this before with wider (18, 25, 35) superspeeds used with rosco ir cut filter & nd's shooting into bright backlight. Suspected it was light reflecting off of the ir sensor back out through the lens. Was able to duplicate behavior on all 3 cameras on set.

 

[Peter Strietmann]

Hi Christopher,

I'm thinking flare. Looks like you are shooting into the sun as the subject is backlit. Do you have any grabs where you have shot away from the sun?

 

[R Fogg]

This just seems to happen under certain lighting/lens/filter conditions.
http://reduser.net/forum/showthread.php?t=33153

 

[Martin Weiss]

If you can't see the image, follow this link: http://www.lansell.net/A001_C017_02048V_00241.tiff

Can you see that dot in the monitor? If so, does it move as you pan the camera?

 

[Cail Young]

From the description, it's flare. You may need to switch out to a zoom covering the 500mm range as it sounds like the extra glass in the doubler + 250mm is causing lots of reflection.

 

[Jim Hoffman]

I had this problem with one lens out of a prime set. We were trying to figure out if it was flare or reflection of the sensor or what. It had a red/purple hue. Ultimately the only solution was to use a different lens.