IR blocking for Jupiter and Saturn?

Greetings all,

I notice a number of you are using your IR blocking filters for saturn and jupiter. Have you found this to be necessary?
I like to leave it on the ToUcam to keep the dust level down, but I am not sure that is needed for these planets.

thanks for your thoughts on this,
Alan

Alan,

I have removed my IR blocking filter when I image Jupiter. I will when I start imaging Saturn again as well. I haven't found anything bad about not using it and the image is brighter which gives me more latitude for brightness adjustments. Someone in one of the Yahoo groups suggested removing the filter for Jupiter and Saturn.

Paul Maxson

You need the IR blocking filter when shooting through a lens. When shooting through a mirror system all the wavelengths come to focus at the same spot. A lens isn’t corrected for the IR to come to focus at the same point as the visible spectrum and since the CCD is sensitive to IR you get a fuzzy image.

You don’t need the IR blocking filter on a Newtonian. It should have little effect on a Catadioptric. It’s necessary on a Refractor.

Here's a probably quite dumb question. What is so bad about capturing the IR component in the image anyway? Why does the IR light apparently cause such a problem in the image?

John