Light pollution filter options for full frame SLRs?

[Logieberra (Logan)]

I've got some serious light pollution coming from the main road near my observatory.

I've seen the sky glow filter drop-in options for small, APSC frame sensors, but nothing for the full frame Canon SLRs. I've got a 6D.

Any suggestions? Any full frame, drop-in, clip-in filters in the works out there?

Cheers.

[pluto (Hugh)]

I used a 2" Astronomik CLS filter that screws into the camera adapter. It worked great with my 5DmkII.
I just happen to be selling it at the moment as I'm shooting narrowband with a CCD now and don't image with my 5DmkII anymore. Check out this thread if you're interested:
http://www.iceinspace.com.au/forum/s...d.php?t=108736

[Logieberra (Logan)]

Thanks Hugh. I'm dealing with 'high-pressure (HP) sodium' lighting in the streets of Canberra.

There is significant commentary on US forums regarding this filter against HP Na lighting. Here's a useful link that I came across: http://www.northsouthsky.com/astronomik-cls.php

The 2" option is ideal for my Tak extender TOA 1.6x setup, as it will not change the metal back distance of extender to the CCD chip, and they don't make a 'clip in' for the full frame chips at this stage (to my knowledge).

[alocky (Andrew lockwood)]

I also used the CLS 2" with a D800 on the back of an FSQ106. No vignetting that was not fixable using flats. However, I have never been happy with the resulting star colours.
Cheers,
Andrew.

[PRejto (Peter)]

Logan,

Have you looked at these?

http://www.sciencecenter.net/hutech/filters/ffilter.htm

I have an IDAS (not for a DSLR) and I think it works very well.

Peter

[Logieberra (Logan)]

Thanks for the info guys.

Andrew, I propose to use the 2" Astronomik with my narrow-field extender 1.6x setup. This does not fill the full frame chip of the 6D. Major vignetting but great for the 'small stuff' up there. I'll be interested to see the star colour effect that you describe. How did you go with post processing those stars, or was result direct from the camera that looked strange?

Thanks Peter, I'll give the Astronomik a go and keep Borg in mind. Is your IDAS a 2" thread in variety? Are you using that with your narrow filed barlow setup as well? I've seen your results with the 2x barlow on that galaxy. Impressive. Borg do make good stuff (I'm also considering their version of the OAG, though Phil suggests I go with the tried and tested MMOAG - as he has done).

I'll post back here in the next few weeks once I've had a play with the Astronomik 2".

[alocky (Andrew lockwood)]

Originally Posted by Logieberra

Thanks for the info guys.

Andrew, I propose to use the 2" Astronomik with my narrow-field extender 1.6x setup. This does not fill the full frame chip of the 6D. Major vignetting but great for the 'small stuff' up there. I'll be interested to see the star colour effect that you describe. How did you go with post processing those stars, or was result direct from the camera that looked strange?

The CLS filter gives the image a blue cast which is fixable in post processing, but even using LRGB filters on my QSI683 I cannot get yellow stars with the CLS in place, and the DSLR likewise.
I'd love to know if there is a fix.
Cheers,
Andrew.

[PRejto (Peter)]

Originally Posted by Logieberra

Thanks for the info guys.

Thanks Peter, I'll give the Astronomik a go and keep Borg in mind. Is your IDAS a 2" thread in variety? Are you using that with your narrow filed barlow setup as well? I've seen your results with the 2x barlow on that galaxy. Impressive. Borg do make good stuff (I'm also considering their version of the OAG, though Phil suggests I go with the tried and tested MMOAG - as he has done).
.

Hi Logan,

Yes, I'm using the 2" screw on IDAS LP Filter. There is an excellent write up on this filter in Ron Wodaski's Book "The New CCD Astronomy" see pages 300,301. Ron remarks that the IDAS has excellent colour balance compared to several different filters (though not the ones you are considering). He also says: "It slightly darkens red, but blue and green are left in very good shape."

That M83 image of mine is a hogpog of different configurations of the barlow and ONAG with and without the IDAS. Even the image scale has varied. Exposures need to be longer with the IDAS but I feel I'm miles ahead in terms of gradients and SNRs.

Peter

[g__day (Matthew)]

I researched this about two years ago and ended up going with the Hutech light pollution suppression filter. Even though other filers edited out a bit extra light pollution, the Hutech one did a much better job of preserving colours.

If you want to preserve colour fidelity - maybe read http://www.sciencecenter.net/hutech/tokai/lps.htm

[skysurfer]

Originally Posted by pluto

I used a 2" Astronomik CLS filter that screws itelescopehe camera adapter. It worked great with my 5DmkII.
I just happen to be selling it at the moment as I'm shooting narrowband with a CCD now and don't image with my 5DmkII anymore. Check out this thread if you're interested:
http://www.iceinspace.com.au/forum/s...d.php?t=108736

But then the FF camera cannot be used with its lenses, only with a telescope. And a Hutech is much better, I used to have the Astronomik, but the blue tinge is very hard to correct. The Hutech IDAS LP has only a very slight purplish tinge.

[White Rabbit]

I have the CLS CCD 2" filter, and I does give the image a very blue cast. It's totally a non issue though as you can fix it in the mix. It works very well.

Sandy

[alocky (Andrew lockwood)]

Originally Posted by White Rabbit

I have the CLS CCD 2" filter, and I does give the image a very blue cast. It's totally a non issue though as you can fix it in the mix. It works very well.

Sandy

Pretty important point here Sandy - although the blue cast is easy to remove in processing, can you post an example showing nice yellow stars and 'properly' coloured nebulae? I've honestly yet to see one using a CLS.
Cheers,
Andrew.