Light Pollution Filters

I see, by searching the forum, that the topic of light pollution filters was last addressed in 2012. I know a few things have changed since then (full frame clip-in filters is one advancement) so I thought I'd enquire about current feedback.

I would like to purchase a light pollution filter. 6D and 82mm & 77mm filter thread lenses.

Should I go with a clip in or 82mm screw on filter? I can only find one 82mm screw on (Hutech 82mm LPS-D1 filter), and for clip in there are a few different Astronomic full frame clip in filters, at least one of which is a light pollution filter.

Feedback would be great. The clip in is cheaper, but I'm concerned about image quality and filter ability over price.

I've now found a Lumicon filter as well, but I think they're made in China. It seems silly to put a Chinese filter over a gorgeous Zeiss lens.

So, I think my options are as follows:

a) The Lumicon 82mm (http://www.lumicon.com …ydrogen-Alpha-Filter.aspx) Least costly, will work for both of my cameras as it is a screw-on.

b) The Hutech 82mm (http://www.sciencecent​er.net/hutech/idas/lps​.htm) Most costly, but will work for both of my cameras as it is a screw-on.

c) Or the Astronomik clip in CLS filter (http://www.astronomik.​com …fur-canon-vollformat.html). I could purchase one for my 6D and one for my 70D for a bit less than the Hutech.

Can anyone comment on how fiddly the clip-in filters are? I'm concerned about the ease of using them in the field. Is not being able to use the optical viewfinder with the clip-in a really big inconvenience?

Edit: I may be wrong. Lumicon states (on their website) that their filters are made in the US.

I've been curious about this topic but am not well versed in it. Considering these filters aren't cheap, is there a large benefit for wide-angle landscape shooting? I shoot the MW quite frequently in "dark sky" locations but I'm wondering how these would work for say my Zeiss 21mm. I'd love to utilize my 14mm but it doesn't take filters so it would have to be a clip-in. Anyone have any before and afters?

rparchen wrote in post #16747989
I've been curious about this topic but am not well versed in it. Considering these filters aren't cheap, is there a large benefit for wide-angle landscape shooting? I shoot the MW quite frequently in "dark sky" locations but I'm wondering how these would work for say my Zeiss 21mm. I'd love to utilize my 14mm but it doesn't take filters so it would have to be a clip-in. Anyone have any before and afters?

I don't know if there would be much benefit from wide angle landscape shooting during the daylight hours. It might be advantageous at dusk and dawn. I think the filters could complicate light painting: by filtering out the painted light.

I think what I would have to do would be take my landscape/foreground shot (along with any light painting) filterless, and then add the light pollution filter to get my celestial shot. This makes the screw-on filters more appealing, I think.

I'm just guessing, though.

I guess I threw in the landscape comment meaning that I have foreground in the frame that is generally light painted when I shoot at night. I wouldn't use these during the day at all but wondered how well the MW would look in wide-angle versus shooting specific celestial objects with a telephoto. Didn't really want to spend $200+ just to be a guinea pig

Heya,

Before you buy anything, research heavily into this. A lot of people don't use these filters because it depends on what you're shooting as to which filter is best, as one filter doesn't do the whole job. There's a difference when shooting objects that reflect versus emit light. Also depends where you are and what kind of light pollution there is, even though the filters cover most of the common light pollution wavelengths, it still pays to look into what is local to you or where you're shooting.

I would look into whether you need a filter, or if you can simply learn to post-process the light pollution out. I would also look into whether you are just trying to shoot from within an area that will never be good to you as it's too heavily polluted or whether this is in addition to you leaving the city and going off into a relatively dark sky area. Nothing beats having a dark sky. Maybe that's impossible for you, not sure. Filters are not benign. They block light. Hope you have a tracker!

If you do end up with one, get the largest size you can get, and use step down rings to avoid buying several filters.

They work differently on wide angle and wide aperture compared to tighter fields of view. Research this before you buy!

Very best,

This is going to be really tricky.

As it turns out, Calgary (since 2003-2005) uses high-pressure sodium (HPS) "Lumalux/Eco" lamps made by OSRAM SYLVANIA.

http://www.calgary.ca …streetlight-retrofit.aspx

http://www.calgary.ca …tlight-retrofit-FAQs.aspx

That lighting made an improvement, but it hasn't resolved the issues created by commercial and residential applications.

From what I've been able to learn, the HPS lights are really tough to block. The IDAS filter only blocks a portion of HPS band (though it blocks all of the LPS band).

The Astronomik CLS appears to block all of the high pressure sodium band (http://www.astronomik.​com …/astronomik_cls​_trans.png), while letting in Hydrogren Beta, Oxygen 3, and Cyanogen. It may let a bit of mercury in. It would do a better job than the IDAS filter for me.

The Lumicon Night Sky is a much more aggressive filter and blocks pretty much everything: including Hydrogren Beta, Oxygen 3, and Cyanogen.

I think it is in my best interests to try the Astronomik clip in CLS. The Lumicon is tempting, though.

Sorry. I was interrupted before I completed that last post.

I do have a tracking mount, which I'm just starting to learn how to use. I'm dealing with some frustrations in my backyard. I can see Polaris, but I can't see the other stars needed for correct polar alignment. My images went a very orangey-pink colour. I may be able to deal with that in PS, but polar alignment is still an issue.

Backyard EOS and drift alignment might be helpful, but having the filter might also give me a better look at the secondary alignment stars.

I'd really like to get aligning the mount (an AstroTrac) sorted out, and test image acquisition and stacking before I drag it out into the field.

I've ordered the "Astronomik CLS" for full frame Canons. I think it is the best one for my situation, even though it isn't a screw-on. I opted just to get the one for now. I do think it is going to be a pain in the arse, however.

I'll update this thread when I have anything to report.

Nice! Please post up some samples when you get it in. I have no problem heading to dark skies but I'm still curious to see the filter effect on the MW.

rparchen wrote in post #16748889
Nice! Please post up some samples when you get it in. I have no problem heading to dark skies but I'm still curious to see the filter effect on the MW.

The clip in one still lets some white light in, so it may work for light painting a foreground while clipped in. My fingers are crossed.

i had the clip in for my 600d but its not very good with wide angle lens and threw the infinity focus out quite a bit , so i sold it , the filter will not help with the polar alignment on the astrotrack , this is to do with your polar scope have a read here about polar scope setting up

http://astrograph.word​press.com …e-astrotrack-polar-scope/

freelanderuk wrote in post #16749912
i had the clip in for my 600d but its not very good with wide angle lens and threw the infinity focus out quite a bit , so i sold it , the filter will not help with the polar alignment on the astrotrack , this is to do with your polar scope have a read here about polar scope setting up

http://astrograph.word​press.com …e-astrotrack-polar-scope/

I'm thinking that the clip in should be okay with my 21mm, but I don't think it would work particularly well with a 15mm. I'll find out when it gets here. While the filter won't help directly with polar alignment, looking at images taken with it may help me identify the secondary stars used for alignment: if I can see them in the photo it might help me to see them in the sky.

I've already collimated my scope, but thanks for sharing the link. From what I've been reading, a lot of people don't realize that it needs to be done . . . which leads to frustration.

My Astonomic CLS has arrived, and I played with it a bit last night.

Here are a couple of handheld, blurry, test images:

Without the filter:

The cyan cast to the final images (it has not been corrected above) is a colossal pain in the backside to deal with. Based on my reading I suspected it would be, but it is frustrating.

I was able to remove most of the cast in this image in Photoshop: