Filters for Astrophotography

[Rob52]

Was wondering if anyone has used a #12 Yellow filter to help with CA on an achromat refractor

thanking for all advise

[cometcatcher]

Yes I have. It does help some but shifts the colour balance a bit too. The Baader Semi-Apo filter helps also but none of them eliminate it. Probably the most effective is the Astronomik CLS.

Depends on the refractor's F ratio also. A fast F5 achro has worse colour fringing than an F10.

[Rob52]

thanks for that Kevin. I have a skywatcher 80/400 achro it is an F5 will have to look into the others you suggested

thanks again mate
Rob

[doppler]

Here's a comparison, I think it was with a 120mm f5 achro. As Kevin said a light pollution filter works much better, I have another pic with that filter, somewhere in my computer if I can find it I'll post it.
Here's a link http://www.iceinspace.com.au/forum/showthread.php?t=144540