Jump to content

30sec_exposures_2021.jpg.48851b1871a4bf9500ebd53c3e790d81.jpg

 

 

Light pollution filters


Recommended Posts

Just to add a bit of info. here. I measured up the slide in filter in my 600mm Sigma Cat. lens and decided to get the 1.25" version, take it out of the metal mounting ring and stick it onto the clear glass standard "filter" that's in the lens. To save someone else the bother - it didn't seem to work well at all. The focus just wouldn't work anymore but I don't know enough about optics to say why it wouldn't.

If anybody can chip in and offer an opinion, I would be grateful for a cure for this. BTW the exposure times went up dramatically without getting all orangey so the filtering seemingly worked out. Just in case it matters I was pointing at the Andromeda galaxy at the time.

Oh and thinking about sticking the 2" version on the front of the 400 APO lens, it sent it all the way down to f/8 and I expected vignetting so I didn't go this route as my guiding system doesn't inspire confidence in exposures longer than 30 seconds ish.

Captain Chaos

Link to comment
Share on other sites

Cheers for your replies.

Just read the review & checked Stockport binocular center. They have the 1.5" @ £26

Will pop in next week and pick one up.

Havn't got any 2" eyepieces so will have a go at creating a makeshift tube to attach to camera.

On the review page I only saw the top of the two images, any chance of posting them here?

Link to comment
Share on other sites

I measured up the slide in filter in my 600mm Sigma Cat. lens and decided to get the 1.25" version, take it out of the metal mounting ring and stick it onto the clear glass standard "filter" that's in the lens. To save someone else the bother - it didn't seem to work well at all. The focus just wouldn't work anymore but I don't know enough about optics to say why it wouldn't.

If anybody can chip in and offer an opinion...

The slide-in filter of the Sigma 600mm cat' lens is not optional; it is an integral part of its optical design and the lens does not work without it (this also applies to the Tamron 500mm cat'). Fitting an alternative filter is unlikely to be successful. A front mounted filter (at that size, it would probably need to be as gel) would work.

Steve :lol:

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.