New Canon EOS Insert Filters

Which filter is that Steve, the OIII?

Keep up Seanie - its the CLS that he mentioned a few posts back.

Keep up Seanie - its the CLS that he mentioned a few posts back.

Yes, but I thought there are different CLS filters! I guess I'm missing something from the Astronomik site.

CLS - Type II
broadband anti light pollution filter

There are many other tyes of filter available including OIII but they're not CLS.

Here's the list:

AS EOS Klar Clear glass filter. The filter permits the entire spectrum and is coated for maximum transmission.
Ideal for dust protection!
AS EOS L L-Filter (IR & UV cut)
If you remove the original IR cut filter of your camera for astro-imaging
AS EOS HAlpha 13 H-Alpha 13nm
AS EOS HAlpha 6 H-Alpha 6nm
AS EOS CLS CLS - Type II broadband anti light pollution filter
AS EOS O3 O-III
AS EOS O3 CCD O-III CCD
AS EOS HBeta H Beta
AS EOS 742 Planet IR Pro filter 742
AS EOS 807 Planet IR Pro filter 807
AS EOS UHCE UHC-E Further Info
AS EOS MEL Multi Emission Line

Ah, I get it now... thanks for the clarification John! :oops:

The only real downside of this filter is the increased exposure times necessary. So unless your mount is up to it (and mines not) expect to run longer exposures.

Exposure times increase by a factor of between 2.2 and 2.7x, background illumination is reduced by 70%.