Baader UHC filter or LP filter ?

[Vox45]

I'm back in Paris after having spent some time in the Alps... what a shock !

I can't take lights longer than 10sec due to LP ... I did ok on M42 but that's it.

So i would like to get some advice from experienced imagers here:

- am I fool to think that I can image something like IC434 from Paris ? I did try stacking 150x10sec lights and got a small hint of "something"...

- would an astronomik CLS filter with my modded Canon 1000D would do the trick ? or would a Baader UHC filter be better for nebulae ?

I'll do down the route of NB CCD eventually but until then I'll need to work with what I have

Cheers!

[wxsatuser]

A decent LP filter will help but you will need to try one to see by how much.

Here with no filter the sky is orange in 30seconds but with a filter like Astronomik CLS

I can easily do 5 and have done 10minutes on good nights.

Orion is hard for me as it's in the huge orange glow coming from the south coast and this

is what I get, it's not pretty as not many subs and my processing needs more effort.

This was taken with the 67mm f/3.8 Borg.

[Vox45]

Here with no filter the sky is orange in 30seconds but with a filter like Astronomik CLS

I can easily do 5 and have done 10minutes on good nights.

Ho that much ?! I can only dream of going over 20sec here ... That is a very nice image you got there, I would be quite pleased to be able to achieve this.

I am still wondering which filter I should use .... UHC or LP (Astronomik CLS)

I read this thread about filters, and although it is very informative, I still cannot decide which one would be best for my conditions (LP+Modded DSLR+DSO mostly Nebula)

According to the OP

"UHC filters can be used to reduce LP but they are really nebula filters particularly allowing passage of nebula emission lines. They may work ok on emission targets but aren’t designed as LP filters." 

This sounds good although I am not sure about the last line ''They may work ok on emission targets but aren’t designed as LP filters."

And on LP filters :

"Astronomik CLS – this is a very popular filter and works very well. I used it for a long time on it’s own believing it was IR blocking. Actually it wasn’t although I have always been very happy with it! It can be used on it’s own but you might want to add an Ir blocking filter. I believe the latest CLS filters are IR blocking"

This sounds also good, that would mean that I could remove the 2nd filter in my camera (I only removed the front one) and just buy a CLS-CCD from astronomik which would also contain the IR blocking filter (the regular astronomik CLS filters does not, only the 'CCD' type)

Very hard to decide.

[Vox45]

and just to add to my confusion there is this !

"Baader Neodymium – this is an absorption filter and is worth considering if the cost of the above 2 make your eyes water. The neodymium conveniently has light absorption properties that make it an effective LP filter. It is also touted as having an effect on reducing interference from moonlight. I have no idea how it does this or how well it works. The latest version, at least in 1.25” form, is IR blocking."

Cheaper than Astonomik CLS-CCD filters. According to FLO's website it has "enhanced 'Phantom' coatings with UV/IR cut for even better performance."

www.firstlightoptics.com/light-pollution-reduction/baader-neodymium-filter.html

[wxsatuser]

The only way to find out is to buy or borrow one and see.

[Vox45]

From all the threads I read, I think that the Baader Neodymium is the one that suits my needs...

(1) It's good on planets (jupiter/mars) and the moon

(2) it has IR-cut

(3) it's an LP filter

(4) reasonnable price as I need to save for NB filters for my future CCD setup...

My only concern now is: will a 1.25" filter on a Canon 1000D cause vignetting ?

I'd rather buy 1.25" as I plan to buy a 1.25" filter wheel for NB CCD and would like to fit that filter in the wheel for planetary targets.

Decision, decision :/

[Dave In Vermont]

David Knisely is a well-known expert of filters for astronomy, and these articles by him are very good indeed. As long as he's credited, it's fine to post these. So:

http://www.prairieastronomyclub.org/resources/by-dave-knisely/filter-performance-comparisons-for-some-common-nebulae/

And:

http://www.prairieastronomyclub.org/resources/by-dave-knisely/useful-filters-for-viewing-deep-sky-objects/

As well as:

http://www.prairieastronomyclub.org/resources/by-dave-knisely/some-available-light-pollution-and-narrow-band-filters/

The usual choice people come down to is which one first - the UHC or the OIII? Answer: Flip a coin. As for can you get good detailed images from within a brightly lit city? Yes you can - with proper filters and a knowledge of how they work. Many folks don't realize how this can be. But it's true that you can reduce the incoming light to a very narrow band of, say, Hydrogen-alpha. Within this narrow range can be the most amazing and detailed views of intricate nebulae.

I'm also a filter-nut - and have 35 of the little darlings. They are capable of amazing vistas, even immersed in city lights. But as more cities and towns switch over to LED lights, this is becoming harder to do unless the local government is approached and told that it's injurious to everything from amateur-astronomers and all the way to developing children's health and well-being - unless these lights - which emit light in all wavelengths at once - are masked and aimed only down at the roadways. Not up into the sky.

For further information on this, and how to make a difference in your location, here's a link to the International Dark-Sky Association:

http://darksky.org/

Enjoy!

Dave

[Vox45]

Very interesting read! thanks for sharing but aren't these articles geared towards visual observation ?

In my case, the goal is to image with a modded DSLR from a LP location, the end game is to go for NB CCD with Ha/OIII/SII filters, so wouldn't an UHC become useless at this point ? I feel that the neodynium would still be useful for planetary imaging (?) and would be an addition to a Ha/OIII/SII filter set.

Please correct me if I'm wrong in my thinking there ...

[Dave In Vermont]

Best way to find out is to try it. But from cities with LP-problems, narrowband filters seem to work best in imaging. Which leaves quite a lot of choices: 7nm, 6nm, SII, so on. The only problem is the high price of good narrowband filters.

Dave

[Paul73]

35 filters!!!!!!!!

And you call David Kmisely the expert?

We really need a "Show us your filters" thread. Granted, not the eye candy of the "show us your Dob" thread. But, I would be very interested to hear people's thoughts past the UHC vs OIII discussions.

Paul

[Dave In Vermont]

I do have a file showing the effects of many of the filters after I aimed them at a light with the filter held in front of a camera. It's rather interesting.

Here's 2 of them: A Baader UHC-S, and a Lumicon Swan-Filter (specific for the Cyanogen-band) -

Dave