What is the cause?

teerex · 27th January 2005

Hi guys,

I shot this in the morning, can someone answer my query in the pic?

Is it because I was pointing towards the sun? It's shot with R72 at 300mm with the Sigma APO II 70mm-300mm

tomcat · 27th January 2005

Looked like a ghost image of the sun since it is exactly the same size as that of the sun in the photo. Could be due to the reflection off the surface of the R72 filter since it is not multi-coated.

tOGGY · 27th January 2005

It is a form of flare. When the taking pictures in digital, the ccd or cmos can actually reflect the light under some condition. eg bright moon in this case. This light travels out of the lens and mostly absorbed by the blackened surface inside the lens barrel. Some travel straight out of the glass. If the glass or filter is not high grade or well designed/made, it can bounce back through reflection into the ccd sensor again.

Hence a flare is observed.

Try to use a better filter eg B & W MRC type and usually it works better. Putting on the hood can help in some other form of flare.

teerex · 27th January 2005

Thanks tomcat and tOGGY for your explanations on the cause of the "ghost" in that pic.

I had a HMC UV behind the R72 and it still happens.

BTW, tOGGY that is the sun. I shot that in IR at about 8.00am. Maybe a better multi coated filter could help.

Thanks again

27th January 2005	#1
teerex Moderator Join Date: Mar 2003 Location: Singapore Posts: 4,652	What is the cause? Hi guys, I shot this in the morning, can someone answer my query in the pic? Is it because I was pointing towards the sun? It's shot with R72 at 300mm with the Sigma APO II 70mm-300mm __________________ *Before you embark on a journey of revenge, dig two graves.* teerex@myinfrared.com

27th January 2005	#2
tomcat Senior Member Join Date: Nov 2003 Posts: 3,457	Looked like a ghost image of the sun since it is exactly the same size as that of the sun in the photo. Could be due to the reflection off the surface of the R72 filter since it is not multi-coated. __________________ Fish Pics:http://www.pbase.com/pschia/oddballs IR Pics:http://www.pbase.com/pschia/infra_red

27th January 2005	#4
teerex Moderator Join Date: Mar 2003 Location: Singapore Posts: 4,652	Thanks tomcat and tOGGY for your explanations on the cause of the "ghost" in that pic. I had a HMC UV behind the R72 and it still happens. BTW, tOGGY that is the sun. I shot that in IR at about 8.00am. Maybe a better multi coated filter could help. Thanks again __________________ *Before you embark on a journey of revenge, dig two graves.* teerex@myinfrared.com

27th January 2005	#3
tOGGY Member Join Date: Oct 2004 Posts: 522	It is a form of flare. When the taking pictures in digital, the ccd or cmos can actually reflect the light under some condition. eg bright moon in this case. This light travels out of the lens and mostly absorbed by the blackened surface inside the lens barrel. Some travel straight out of the glass. If the glass or filter is not high grade or well designed/made, it can bounce back through reflection into the ccd sensor again. Hence a flare is observed. Try to use a better filter eg B & W MRC type and usually it works better. Putting on the hood can help in some other form of flare.