UV filter causes halos and disco effects at DVinfo.net

Ryan McBride · July 10th, 2004, 06:22 PM

Has anyone else had any weird results from their
Canon UV filter. It seems like everytime I use it in poorly lit situations I get some weird halos or stobe effects around headlights and other flashing lights. I was thinking that I might have my f-stop set to low. It has happened a few times when I had the camera set up to f1.6-2, 1/30th-160th on the shutter, no gain, autofocus off, preset outdoor white balance. I have cleaned the lens and filter but they really werent that dirty. I have some frame grabs but I dont have a site to post at.

Ken Tanaka · July 10th, 2004, 09:39 PM

This is common, particularly for dark scenes with bright points. Sometimes called "fireflies", it's caused by reflections bounced between the lens and the filter. Solution: take the filter off the lens.

Rob Wilson · July 10th, 2004, 10:41 PM

Ryan,

Good quality COATED filters are less likely to cause this effect. May want to try a different filter.

Bernd Binder · July 11th, 2004, 02:26 PM

I had the same problems with a cheap UV filter. Now I am using a Hoya filter - works perfect, without halos and other unwanted effects.

Ryan McBride · July 11th, 2004, 06:54 PM

Thanks a bunch for the input. I thought maybe since it was a Canon Filter it would be adequete, I recall it wasnt much money. I will try out another brand sometime soon.

July 10th, 2004, 06:22 PM	#1
Ryan McBride Regular Crew Join Date: Feb 2004 Location: Seattle WA Posts: 28	UV filter causes halos and disco effects Has anyone else had any weird results from their Canon UV filter. It seems like everytime I use it in poorly lit situations I get some weird halos or stobe effects around headlights and other flashing lights. I was thinking that I might have my f-stop set to low. It has happened a few times when I had the camera set up to f1.6-2, 1/30th-160th on the shutter, no gain, autofocus off, preset outdoor white balance. I have cleaned the lens and filter but they really werent that dirty. I have some frame grabs but I dont have a site to post at.

July 10th, 2004, 09:39 PM	#2
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	This is common, particularly for dark scenes with bright points. Sometimes called "fireflies", it's caused by reflections bounced between the lens and the filter. Solution: take the filter off the lens. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

July 11th, 2004, 02:26 PM	#4
Bernd Binder New Boot Join Date: Mar 2004 Location: Vienna, Austria Posts: 5	I had the same problems with a cheap UV filter. Now I am using a Hoya filter - works perfect, without halos and other unwanted effects. __________________ Bernd

July 10th, 2004, 10:41 PM	#3
Rob Wilson Major Player Join Date: Dec 2002 Location: Flagstaff, AZ Posts: 473	Ryan, Good quality COATED filters are less likely to cause this effect. May want to try a different filter.

July 11th, 2004, 06:54 PM	#5
Ryan McBride Regular Crew Join Date: Feb 2004 Location: Seattle WA Posts: 28	Thanks a bunch for the input. I thought maybe since it was a Canon Filter it would be adequete, I recall it wasnt much money. I will try out another brand sometime soon.